Infrared heat

[SailinAway]

Q: Do infrared space heaters actually save money as claimed?

I don't understand infrared heat. Supposedly, a unit like the Dr. Infrared Heater---

https://www.amazon.com/Dr-Infrared-H...s%2C344&sr=8-5

---heats up the objects in a room rather than heating the air. Why would I care if the books in my bookcase are warm? Also, these units have a fan, implying that they're heating the air?

They use 1500 watts, same as other electric heaters, so I don't see any savings, unless they use electricity so efficiently that they don't run as often as other types of room heaters.

I'm looking for the cheapest way to heat my office, given that a 1500-watt space heater costs about as much to run per month as an air conditioner.

[John Mercier]

Because the ''books'' will radiate the heat back.

[ApS]

We have two antique infrared heaters. The newest is probably 60 years old, whose simple design is seen in this modern version.

At only 800 watts, the newer heater not only warms everyone in our Wolfeboro "Great Room", it'll continue to keep this "Open Design" toasty all night if I forget to unplug it. (Neither heater has a fan). The heat is adjusted by moving to a different chair!

A suggestion: Don't aim it at a refrigerator, or everything in it will be frozen...

A second infrared heater has its reflector made of handmade decorative polished copper from the 1920s, and I don't dare use it!

Less convenient is our third infrared heater that is fitted to a propane tank.

Propane versions to heat people outdoors are everywhere on the Internet.

Indoors, your best bet is a modern 800-watt electric infrared heater:
https://5.imimg.com/data5/AX/CV/QT/S...er-500x500.jpg

[Woody38]

I recall sometime in the past reading about probably infrared heaters in picture frames, crown moldings and other accessories. These heaters are used in commercial warehouses and auto repair facilities and others where they are often open to the outside.

_________________________________

I am a retired workaholic and continuing aquaholic

[John Mercier]

The radiant (infrared) works more like your wood stove.
While the conventional element heater works on convection.

A convection heater really needs a fan to be effective in any real manner... while the radiant might have it as an additional transference for the heated air around the unit - sort of like adding one of those little fans to the wood stove.

I think the most efficient is wearing either thermals or sweat pants and shirt, with wool socks and slippers... then adding a throw to cover your lap... and either a chair that has heaters built in... or an electric heating pad.

That way, you only add the heat you need, and it is so close to your person that it becomes the most effective in getting the job done without heating the ''books''

[SailinAway]

Originally Posted by ApS

We have two antique infrared heaters. The newest is probably 60 years old, whose simple design is seen in this modern version.

That link isn't working. I'm curious to see it.

[ApS]

I forgot that a small 750 watt convection heater is adequate for a medium-sized closed room.

Here's a modern radiant heater (at 800 watts) at Amazon that will warm up an entire living room:
https://images-na.ssl-images-amazon...._QL70_ML2_.jpg

I've mounted mine about 7½ feet above the floor, and removed the wire guard for more heat transmission.

To double your heating capacity, aim it at your wood stove. It will re-radiate heat long after youve turned the radiant heater OFF!

Even in Florida, I'll have chilly days at the computer. Try a small heating pad under your feet, but wear shoes or slippers, as it'll be HOT.

Everybody's different, but if my feet are warm, I'm a happy camper!

Originally Posted by John Mercier

Because the ''books'' will radiate the heat back.

It's not legal to "cook the books".

[SailinAway]

ApS, the link to the actual Amazon page, not the image, would be helpful.

This is interesting: "To double your heating capacity, aim it at your wood stove. It will re-radiate heat long after you've turned the radiant heater OFF!" Can you explain how this works? Do you mean the wood stove absorbs and holds the energy from the heater, and releases it later? Does this really make a significant difference? It seems odd to put an electric heater in the room with the wood stove, since that space is usually overheated.

[ITD]

No, they aren't any more efficient than any other resistive electric heater. What you do get is increased perceptive and real warmth as the infrared energy warms your skin and clothes. But at the end of the day, it doesn't make the room any warmer than another 800 watt electric heater.

[LikeLakes]

I've used infrared, really good for making a person or area warm that it is pointed at. I personally don't like the "cooking me" feeling of an infrared pointed toward me. What I prefer are oil filled space heaters. They heat up, nearly all have 3 heat settings where low is around 400 watts, medium 800, and high closer to 1500 IIRC. They don't project the heat like a resistance heater with a fan but the key is to turn it on before you are using the room and leave it on if you are only going out of the room for a few hours. They are completely safe while other space heaters are not.

[ApS]

Originally Posted by ITD

No, they aren't any more efficient than any other resistive electric heater. What you do get is increased perceptive and real warmth as the infrared energy warms your skin and clothes. But at the end of the day, it doesn't make the room any warmer than another 800 watt electric heater.

I'll disagree. Radiant heaters project heat at everything within the area of its reflector. In my case, even the wood floor is warmer!

Presently typing in a warm bedroom, I have a 1500w convection heater running. When I stand up, i find most of the heated air was warming the ceiling! Opening the door to the "Great Room" (no ceiling), i walk into a nice warm moderate environment. Putting a hand on the wood of the sofa nearest my antique radiant heater I find that it has warmed up--so much so, I worry about preserving the finish!

The iron wood stove--starting empty and cold--can be heated by any heater, and continue to re-radiate heat after the electric heater is turned off. Of course, it's hardly efficient to use elecricity in that manner! Density is key. Placing the largest dense material item (iron anvil or granite boulder) in front of your radiant heater will soak up heat and re-radiate for a short time. That's also the principle that drives soapstone wood stove manufacturing.

Back in the 50s, I lived in a house that had "radical" radiant heat embedded in the floor. Even with a foot of snow outside, you could walk around barefoot, T-shirt and shorts. (And cool ears).

Here's Amazon's radiant heaters from $17 to $3000:

https://www.amazon.com/s?k=electric+..._ts-doa-p_1_16

[8gv]

For operating cost my vote is for a mini split.

This assumes that it was given to you as a gift.

[ITD]

Originally Posted by ApS

I forgot that a small 750 watt convection heater is adequate for a medium-sized closed room.

Here's a modern radiant heater (at 800 watts) at Amazon that will warm up an entire living room:
https://images-na.ssl-images-amazon...._QL70_ML2_.jpg

I've mounted mine about 7½ feet above the floor, and removed the wire guard for more heat transmission.

To double your heating capacity, aim it at your wood stove. It will re-radiate heat long after youve turned the radiant heater OFF!

Even in Florida, I'll have chilly days at the computer. Try a small heating pad under your feet, but wear shoes or slippers, as it'll be HOT.

Everybody's different, but if my feet are warm, I'm a happy camper!



It's not legal to "cook the books".

You can disagree all you want, but 800 watts is 800 watts. You'll be warmer if you move your resistive heater closer to you. They are not efficient ways to heat your home.

[jeffk]

I think the key is personal perception of being warm. The "house" and furnishings don't care if they are at 70 or 65 degrees where YOU do. So, if your heating system targets YOU like infrared heat, that seems like an efficient use of the power required. If you have to bring the whole room up to 70 degrees before you feel comfortable, you are going to spend a lot more money to accomplish that. Of course if you get up and move out of the infrared target zone, you will immediately feel colder since the rest of the house is not as warm. There may also be a real consideration to the feeling of being "cooked". Some may find it uncomfortable others may not care.

All in all, it seems like a personal preference. Maybe you can save a few bucks with infrared while you are sitting in the living room reading a book for a couple hours. If you tend to be moving about a lot, it won't work as well.

I am considering radiant floor heat for an addition. Because you are standing on the source of heat, evenly distributed across the whole floor, you feel it more directly compared to many spot sources of heat. Further, since it is a broadly distributed heat, there are no hot spots near a source. I'm still checking into it.

[ITD]

Originally Posted by jeffk

I think the key is personal perception of being warm. The "house" and furnishings don't care if they are at 70 or 65 degrees where YOU do. So, if your heating system targets YOU like infrared heat, that seems like an efficient use of the power required. If you have to bring the whole room up to 70 degrees before you feel comfortable, you are going to spend a lot more money to accomplish that. Of course if you get up and move out of the infrared target zone, you will immediately feel colder since the rest of the house is not as warm. There may also be a real consideration to the feeling of being "cooked". Some may find it uncomfortable others may not care.

All in all, it seems like a personal preference. Maybe you can save a few bucks with infrared while you are sitting in the living room reading a book for a couple hours. If you tend to be moving about a lot, it won't work as well.

I am considering radiant floor heat for an addition. Because you are standing on the source of heat, evenly distributed across the whole floor, you feel it more directly compared to many spot sources of heat. Further, since it is a broadly distributed heat, there are no hot spots near a source. I'm still checking into it.

I just put electric radiant heat in a new bathroom. Seems to work well, has a programmable thermostat so we can have it pre warm the floor before we wake up, then off for the rest of the day. (We have forced hot water heat, but keep the bedroom cool (and bathroom).

[LikeLakes]

Radiant floor heat is awesome. Not fast response like forced hot air or hydronic baseboards, but nice level heat.

One misunderstood thing about heating and efficiency is that each time you go to heat a room, after letting it cool down, you are heating all the furnishings in that room. So if you turn down heat (or turn it off) at night and it drops to say 58 degrees, when you go to heat it in the morning the furniture, desks, everything has cooled off and you spend the first part of the heating cycle re-heating all those furnishings. In commercial office property we get tenants that think they are helping by turning down heat at night, we politely ask them to leave the heat where they want it, or click it down 2-3 degrees at most (some like that burst of heat when they arrive in the morning and turn it up), to turn it down more than that is actually less efficient. This assumes decently insulated, reasonably efficient heating systems.

That doesn't apply to space heaters so sorry if I'm off topic. Can we agree that an electric resistance element, whether in a fan driven space heater, oil filled radiant space heater, or infrared space heater, are the least efficient ways to heat a space?

[thinkxingu]

Originally Posted by LikeLakes

Radiant floor heat is awesome. Not fast response like forced hot air or hydronic baseboards, but nice level heat.

One misunderstood thing about heating and efficiency is that each time you go to heat a room, after letting it cool down, you are heating all the furnishings in that room. So if you turn down heat (or turn it off) at night and it drops to say 58 degrees, when you go to heat it in the morning the furniture, desks, everything has cooled off and you spend the first part of the heating cycle re-heating all those furnishings. In commercial office property we get tenants that think they are helping by turning down heat at night, we politely ask them to leave the heat where they want it, or click it down 2-3 degrees at most (some like that burst of heat when they arrive in the morning and turn it up), to turn it down more than that is actually less efficient. This assumes decently insulated, reasonably efficient heating systems.

That doesn't apply to space heaters so sorry if I'm off topic. Can we agree that an electric resistance element, whether in a fan driven space heater, oil filled radiant space heater, or infrared space heater, are the least efficient ways to heat a space?

As I understand it, electrical resistance heaters are actually the most efficient as 100% of the energy becomes heat. The issue is cost of energy vs. other sources, right, making it a question of economical vs. efficient?

We have a 100% electric house—electric stove, water heater, dryer, and all electric baseboard heat (other than wood stoves up and down). The ONLY reason I'm investigating heating alternatives is that electricity costs have increased beyond other energy sources.

Sent from my SM-G990U1 using Tapatalk

[ITD]

Originally Posted by thinkxingu

As I understand it, electrical resistance heaters are actually the most efficient as 100% of the energy becomes heat. The issue is cost of energy vs. other sources, right, making it a question of economical vs. efficient?

We have a 100% electric house—electric stove, water heater, dryer, and all electric baseboard heat (other than wood stoves up and down). The ONLY reason I'm investigating heating alternatives is that electricity costs have increased beyond other energy sources.

Sent from my SM-G990U1 using Tapatalk

You are correct from a physics perspective, but from a cost perspective, electric resistive heating is the least efficient use of your money. Which is what most discussions about heat refer to , at least from my view.

Some people are fine with this. Also, I'm not saying people shouldn't use these devices, they can make a cold house more comfortable. But you have to be careful that you don't freeze pipes by going to extremes.

[thinkxingu]

Originally Posted by ITD

You are correct from a physics perspective, but from a cost perspective, electric resistive heating is the least efficient use of your money. Which is what most discussions about heat refer to , at least from my view.

Some people are fine with this. Also, I'm not saying people shouldn't use these devices, they can make a cold house more comfortable. But you have to be careful that you don't freeze pipes by going to extremes.

Agreed—I was addressing the semantics given the discussion about infrared vs. radiant, etc. above, and also because even the discussion of economy isn't simple.

For example, my electric heat is controlled by individual thermostats in each room. This allows me to heat the rooms I want to while also not messing up the balance with the wood stove.

Also, electric baseboards are maintenance free, user-replaceable, and last virtually forever as opposed to furnaces, handlers, etc. needing to be replaced every 10-20 years or so and maintained annually/semi-annually.

The calculations can be complex, especially in years that oil and NG/LP prices are high.

Added: there was recently a discussion about gas prices on my town's forum and how people were driving to another town to save $.30/gallon without realizing that the savings (and free time!) were wiped out by the extra driving.

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[LikeLakes]

The "drive 15 miles to save $1.73 on filling the car" phenomenon is as old as gas stations. I'd say a few generations ago it was even more prevalent. More of a psychological study since it never actually saves money.

Thinkxingu, great point by you on my post, when I said least efficient I should have clarified, thanks for doing so.

It really is an interesting subject, and a variety of factors enter in. Is someone looking for the lowest environmental footprint? The lowest cost? The answer varies of course based on the goal.

In my experience it is more cost efficient to heat a space with a central heating system, if you want to supplement with a space heater for a few hours now and then go for it. Where I think people end up kidding themselves is when they keep the central heat at 50 and use a few space heaters for 5-6 hours a day or more, they think they are saving but actually would be better off just heating the house to 64 or 66 degrees and occasionally using a space heater. Spend the money on more insulation rather than electricity for space heaters.

Pellet stoves change the equation and can be a great source of comfortable heat where you want it, wood stoves too. I'm less familiar with the economics of those.

[brk-lnt]

Originally Posted by thinkxingu

As I understand it, electrical resistance heaters are actually the most efficient as 100% of the energy becomes heat. The issue is cost of energy vs. other sources, right, making it a question of economical vs. efficient?

Correct, electric heat of any kind (eg: radiant, infrared, convection, whatever) is the most efficient use of the energy/fuel to heat conversion. But that ignores the unit cost of the energy itself.

To make an analogy, you can burn a $1 bill, and a $100 bill. Both with have the same *efficiency* in terms of turned the paper into heat via flame, but the $100 bill will be 100x as costly as the $1 bill to produce the same amount of heat.

Oil or natural gas heaters are generally less efficient than electric, but the reduced cost per BTU is so much lower that you make up the efficiency difference with reduced fuel/energy cost.

There are many products they try to claim they can reduce your heating costs, particularly if you are doing electric heat, but in the end they all rely on heating a smaller volume of area.

Anything that plugs into the wall and creates heat is going to be equally expensive to run in terms of adding heat to an area. Doesn't really matter what kind of heat it claims to create.

A mini split is going to be the most cost effective way to heat with electricity because it is *moving* heat from the outside to the inside, instead of creating it with resistance. However the upfront cost of an installed mini split can make it take a season or two to recoup the investment.

Even when it seems cold outside there is still heat in the air, just not very much. Mini split heat pumps move this heat from outside to inside, but they all have a minimum viable outdoor temperature before they can no longer move heat. In some cases that means you need a backup or alternative heat option for when it is very cold out, or when you want to heat the indoor areas more quickly.

[SailinAway]

Originally Posted by brk-lnt

There are many products they try to claim they can reduce your heating costs, particularly if you are doing electric heat, but in the end they all rely on heating a smaller volume of area. Anything that plugs into the wall and creates heat is going to be equally expensive to run in terms of adding heat to an area. Doesn't really matter what kind of heat it claims to create.

Wouldn't an exception be if a device also requires a fan to move the heated air?

Also, are you saying that all types of space heaters work equally well? E.g., oil-filled radiator vs infrared. Or are you just saying that two devices with the same amps or watts are going to cost the same to run, regardless of how well they heat?

[SailinAway]

Originally Posted by LikeLakes

What I prefer are oil filled space heaters. They heat up, nearly all have 3 heat settings where low is around 400 watts, medium 800, and high closer to 1500 IIRC. They don't project the heat like a resistance heater with a fan but the key is to turn it on before you are using the room and leave it on if you are only going out of the room for a few hours. They are completely safe while other space heaters are not.

I have to caution you against getting nonchalant about oil-filled space heaters (the upright radiator type). I had three of these. Over time, two of them began to split at the seams and leaked oil, ruining a wood floor. The third one almost burned down my house. I left it turned off but plugged in. It caused a short circuit at the wall outlet. Sparks were shooting out of the wall. Fortunately I was in the room when it happened. I believe these were De Longhis.

I really liked these heaters at first, but they all gave out after a couple of years. I found many complaints online about the safety of these units. Info found online:

"Fires occur when the oil leaks or is accidentally spilled from the crack into the floor. This oil can not only ruin porous surfaces, it can also catch fire if it’s close to heating element, resulting in dangerous fire."

Re recall of Sunbeam heaters from the Consumer Product Safety Commission: "The firm has received approximately 40 reports of units that unexpectedly sprayed heated oil, resulting in reports of property damage involving damaged carpet and fabrics."

"Underwriters Laboratories (UL) found that oil heaters filled with unsuitable oil, such as oil with a low flash point, can present a risk of fire."

"King of Fans Inc. has received 81 reports of incidents involving leaking oil. Two minor burns were reported, along with two reports of falls in the oil."

Holmes recall: "A poor electrical connection within the heater can lead to overheating. This poses fire and thermal burn hazards."

Etc. Please be careful. I wouldn't sleep with these running at night.

[LikeLakes]

Thank you, I wasn't aware of those problems, will do some reading. I've used them for many years with zero issues, which doesn't mean I won't take your comments seriously and look into it.

I do think that if you looked at fires caused by space heaters, open element fan driven space heaters would be the #1 cause, either too close to curtains or furniture or something falling on one that catches on fire. I don't have research to prove the above, however it's my impression.

[John Mercier]

Originally Posted by SailinAway

Wouldn't an exception be if a device also requires a fan to move the heated air?

Also, are you saying that all types of space heaters work equally well? E.g., oil-filled radiator vs infrared. Or are you just saying that two devices with the same amps or watts are going to cost the same to run, regardless of how well they heat?

With the same amps and wattage... they should cost the same to run.
The difference is the conversion of that electricity to BTUs.

Think of it like a light bulb... all bulbs produce light... but some produce more heat than others. Since the purpose - generally - is to produce light; the heat is electricity being wasted.

The fan doesn't produce heat, but it does consume electricity.

The radiant heater allows you to feel warmer because the infrared radiation is projected directly at you, rather than heating the air and blowing it at you. Because of that, you may find yourself running the radiant heater on a lower wattage... thus consuming less electricity to get the same feeling of warmth.

[ApS]

Originally Posted by SailinAway

I have to caution you against getting nonchalant about oil-filled space heaters (the upright radiator type). I had three of these. Over time, two of them began to split at the seams and leaked oil, ruining a wood floor. The third one almost burned down my house. I left it turned off but plugged in. It caused a short circuit at the wall outlet. Sparks were shooting out of the wall. Fortunately I was in the room when it happened. I believe these were De Longhis.

I really liked these heaters at first, but they all gave out after a couple of years. I found many complaints online about the safety of these units. Info found online:

"Fires occur when the oil leaks or is accidentally spilled from the crack into the floor. This oil can not only ruin porous surfaces, it can also catch fire if it’s close to heating element, resulting in dangerous fire."

Re recall of Sunbeam heaters from the Consumer Product Safety Commission: "The firm has received approximately 40 reports of units that unexpectedly sprayed heated oil, resulting in reports of property damage involving damaged carpet and fabrics."

"Underwriters Laboratories (UL) found that oil heaters filled with unsuitable oil, such as oil with a low flash point, can present a risk of fire."

"King of Fans Inc. has received 81 reports of incidents involving leaking oil. Two minor burns were reported, along with two reports of falls in the oil."

Holmes recall: "A poor electrical connection within the heater can lead to overheating. This poses fire and thermal burn hazards."

Etc. Please be careful. I wouldn't sleep with these running at night.

An engineer friend has several De Longhis. He says the originals from Italy were quality-made; however, they've since been "outsourced".

BTW: I'd conflated two heating terms:
https://householdair.com/infrared-vs-radiant-heat/

[brk-lnt]

Originally Posted by SailinAway

Wouldn't an exception be if a device also requires a fan to move the heated air?

Also, are you saying that all types of space heaters work equally well? E.g., oil-filled radiator vs infrared. Or are you just saying that two devices with the same amps or watts are going to cost the same to run, regardless of how well they heat?

Not quite.

What I was trying to say is that every electric heater will produce the same net amount of heat for a given amount of power consumption. An oil-filled 800W heater will produce as much heat as an 800W ceramic heater in 1 hour of operation, and will cost the same amount to run. If one has a fan, and the other does not, the one with the fan might distribute the heat more evenly, but their operational cost and net output will be the same (within a very small margin that is insignificant).

[brk-lnt]

Originally Posted by John Mercier

The radiant heater allows you to feel warmer because the infrared radiation is projected directly at you, rather than heating the air and blowing it at you. Because of that, you may find yourself running the radiant heater on a lower wattage... thus consuming less electricity to get the same feeling of warmth.

Many of these "reduced cost heating" scenarios all presume the person is basically sitting still in a single room. The IR heating might be able to direct the heat in a more concentrated area, but then if you move to another area, it's going to be colder.

A more practical scenario might be to have a general heat source that heats the entire to room to something like 60 degrees, and then a secondary heat source, like an IR unit, an electric blanket, etc. that heats the person to 70 (or whatever).

[fatlazyless]

Do these 1500-watt, three setting, oil filled heaters that run on 500w-1000w-1500w have the Underwriter's Lab safety test, seal of approval for electric home appliance safety?

Same question for any portable, electric heater ...... does it have that U.L. listed, safety stamp?

[SailinAway]

Originally Posted by brk-lnt

Not quite.

What I was trying to say is that every electric heater will produce the same net amount of heat for a given amount of power consumption. An oil-filled 800W heater will produce as much heat as an 800W ceramic heater in 1 hour of operation, and will cost the same amount to run. If one has a fan, and the other does not, the one with the fan might distribute the heat more evenly, but their operational cost and net output will be the same (within a very small margin that is insignificant).

If this is true, then the various types of electric heaters are all about the same in the end.

[John Mercier]

Originally Posted by brk-lnt

Many of these "reduced cost heating" scenarios all presume the person is basically sitting still in a single room. The IR heating might be able to direct the heat in a more concentrated area, but then if you move to another area, it's going to be colder.

A more practical scenario might be to have a general heat source that heats the entire to room to something like 60 degrees, and then a secondary heat source, like an IR unit, an electric blanket, etc. that heats the person to 70 (or whatever).

Unless you move the IR.
But since for other reasons that an occupied home would need to maintain at least some basis of heat (plumbing et al), we should presume the heater would be used to increase the sensation of heat within a small area.

As long as that area did not affect the thermostat, the remainder of the house should hold that basic temperature - presumably.

[brk-lnt]

Originally Posted by SailinAway

If this is true, then the various types of electric heaters are all about the same in the end.

Correct. Converting electricity to heat is pretty straight forward, it involves a big resistor at the core of it. You can do various things to move the heat (fan), or create things to help store and radiate the heat more slowly (oil-filled), but at the end of the day, the power usage, operational cost, and total amount of heat created will be the same for any given wattage.

Also, all electric heaters will be equally efficient, a 100W heater costs 1/10th as much to run as a 1000W heater, and it will heat the area 10 times slower. But they will both use the same amount of electricity in the end to raise the room temp by 3 degrees, for example.

[brk-lnt]

Originally Posted by John Mercier

Unless you move the IR.

Sure, but that isn't really a thing the typical homeowner is going to be doing. I was trying to keep it a little more high-level and relatable to common home heating scenarios so it didn't become an ad-hoc physics course

[John Mercier]

The common homeowner isn't likely to be concerned enough with the cost of heating to do so.
But one that is... is likely to do so.

It is like the high price of gasoline. It is relative.
People might not like the cost, but does it really deter them from using it in a manner that is wasteful (wasteful being a variable of perception).
I didn't notice a severe drop in boating, out-of-state license plates, or trucks on the road... so I am going to guess in most cases it was actually more an emotional than financial reaction.

Should prices really become the issue, we would see more homeowners begin to conserve through more extreme means... but I don't see it as of yet other than discussions.

[ApS]

Originally Posted by brk-lnt

Correct. Converting electricity to heat is pretty straight forward, it involves a big resistor at the core of it. You can do various things to move the heat (fan), or create things to help store and radiate the heat more slowly (oil-filled), but at the end of the day, the power usage, operational cost, and total amount of heat created will be the same for any given wattage.

Also, all electric heaters will be equally efficient, a 100W heater costs 1/10th as much to run as a 1000W heater, and it will heat the area 10 times slower. But they will both use the same amount of electricity in the end to raise the room temp by 3 degrees, for example.

IR isn't intended to raise a room's temperature: IR is designed to warm one's body. (Or many more bodies).

This is especially important when a cold north wind blasts our one-season cottage.

The cottage wasn't built (or insulated) to be heated. This isn't a "tight" dwelling. (Which has its own sets of problems). With wind, even the ample heat from our wood stove doesn't stay around for very long. An increase of only 20° above the outside temperature can be expected from wood stove heat under windy conditions. Although well-built, focused IR heat extends this dwelling's useful season into October.

Maintaining dense tree growth along the shoreline would help, but would defeat our terrific view of the Ossipee Mountains! The dense tree growth elsewhere keeps A/C use down (this summer) to only 10 minutes one night--and winter's windfalls serve to feed the wood stove. (And don't bother to split the wood).

One drawback to IR is some aging of exposed skin may be experienced:

https://www.sciencedirect.com/scienc...87002415305049

[John Mercier]

Why would it ''age'' your skin?

[ApS]

Originally Posted by ITD

You can disagree all you want, but 800 watts is 800 watts. You'll be warmer if you move your resistive heater closer to you. They are not efficient ways to heat your home.

The infrared heater is not designed to heat one's home. It's designed to efficiently heat one or more individuals. (And any local errant objects that can retain IR heat).

You leave the comfort of your infrared heater and hurry to put another log on the fire.

Originally Posted by John Mercier

Why would it ''age'' your skin?

At the bottom of the supplied link, this conclusion:

Heat induces oxidative DNA damage in human skin in vivo

UV radiation is absorbed directly by DNA and leads to the formation of pyrimidine dimers, of which more than 75% are thymine dimers (Patrick, 1977). UV radiation produces ROS. DNA is also susceptible to oxidative damage, and 8-oxo-dG is a useful biomarker of oxidative damage in DNA (Pelle et al., 2003). As heat shock in human skin can produce ROS, we investigated the effects of heat shock on DNA damage in human skin in vivo.

Interestingly, heat shock at 43°C for 90 minutes, like UV irradiation, increased the 8-oxo-dG in the epidermis and dermis of human skin in vivo maximally at 24 hours post-heat (Figure 1a). However, heat shock, unlike UV, did not produce thymidine dimer formation (Figure 1b).
Therefore, heat-induced ROS induce cumulative DNA damage through oxidative damage.

Like UV radiation, IR-radiated heat induces aging of exposed skin. (According to this study).

(ROS=reactive oxygen species).

Like most papers at Elsevier, the link is "heavy reading"--and IR skin damage is still being studied.

[ApS]

Originally Posted by ApS

Here's Amazon's radiant heaters from $17 to $3000:

https://www.amazon.com/s?k=electric+..._ts-doa-p_1_16

Today's NY Post has selected three radiant heaters that got wide approval--even listing the number of favorable Amazon ratings:

https://nypost.com/article/best-spac...tomer-reviews/

I'd pick the cheapest one for a bedroom...

[Woody38]

We had a ceramic heater umpteen years ago living on Cape Cod. Worked just fine, no information on cost to operate. We have a Dyson "heat+cool" at the lake which is a beast. Last week set at 71 it kept the area at 71, 72. I think the night temps this week were in the 40's and 50's. This is an area approximately 800/900 square feet. We have 3 of them: at the lake, in Massachusetts and in California. I do not tkink the electric statement in huge.

______________________________________

I am a retired workaholic and continuing aquaholic

[ishoot308]

The best space heater I ever had was the "ORIGINAL" Pelonis Saf-T-Furnace" from the late 70's and early 80's. It was a ceramic heater. I still have one from back then and its still going strong! It looks like this....

[TheProfessor]

Originally Posted by SailinAway

Q: Do infrared space heaters actually save money as claimed?

No.

Again, 1500 watts is 1500 watts.

Have had professional cold weather training. Always best to huddle together with another person.

Am sure there are multiple persons right here on this forum that would love to huddle with you. To keep you warm.

[John Mercier]

The amount of electricity the appliance uses is the same... the results are different.

[ITD]

Originally Posted by TheProfessor

No.

Again, 1500 watts is 1500 watts.

Have had professional cold weather training. Always best to huddle together with another person.

Am sure there are multiple persons right here on this forum that would love to huddle with you. To keep you warm.

That cracked me up.

[SailinAway]

Originally Posted by TheProfessor

No.

Again, 1500 watts is 1500 watts. Have had professional cold weather training. Always best to huddle together with another person. Am sure there are multiple persons right here on this forum that would love to huddle with you. To keep you warm.

You sure you were paying attention during this "professional training"?

[John Mercier]

Back to the question at hand...
Did you make a choice?

[SailinAway]

Originally Posted by John Mercier

Back to the question at hand...
Did you make a choice?

I spent a lot of time studying this today and didn't come to a conclusion. There are a lot of claims about the Dr998 infrared heater heating 1000 sq ft with the same 1500 watts that a ceramic heater uses to heat 300 sq ft---But also many reviews that say that claim is exaggerated. Reviewers who dismantled the DR998 found that it consists of 1 small quartz tube and 1 PTC element, whereas other brands have 4 to 6 quartz tubes. They report early failure of the quartz tube. Another concern is the long time it takes infrared to heat a room---45 minutes to raise the temperature 5 degrees.

I did finally come across an explanation that helped me understand infrared heat: you can feel the warmth of the sun on your face in the winter, above the air temperature. That's after the sun's infrared rays traverse 93 million miles of space at minus 454 degrees.

I did buy a full tank of oil last week for $4.29 a gallon. Very glad I did that, as the price rose immediately afterward. Still trying to get my wood split to save the oil for December through February.

[John Mercier]

I figured the space heater was more about heating just you than a room or the whole house... which is what I presumed the oil boiler would do.

The wood stove, which also works by radiant heating, generally does well with a room... but it does take some time to get the room up to temperature.

[SailinAway]

Originally Posted by John Mercier

I figured the space heater was more about heating just you than a room or the whole house... which is what I presumed the oil boiler would do.

The wood stove, which also works by radiant heating, generally does well with a room... but it does take some time to get the room up to temperature.

I spend most of the day in my 12 x 12 office. I use a space heater for the between seasons---Sept, October, March-May.

[brk-lnt]

Originally Posted by SailinAway

I spent a lot of time studying this today and didn't come to a conclusion. There are a lot of claims about the Dr998 infrared heater heating 1000 sq ft with the same 1500 watts that a ceramic heater uses to heat 300 sq ft

Every heater that plugs into a wall outlet will produce the same amount of heat for a given amount of electricity (cost). Some, like an infrared heater, can help you direct the heat to a certain area. Others, like oil-filled heaters or oscillating fan type heaters help distribute the heat more evenly around the room. But they all work on exactly the same principle.

You have to decide if your goal is to heat an area, or a person (you).

[John Mercier]

Radiant and convection move heat in different ways.

Convection heats the air; While radiant heats the objects.

Some radiation will be absorbed by air molecules... but generally not all.

[DickR]

Originally Posted by John Mercier

...
The wood stove, which also works by radiant heating, generally does well with a room... but it does take some time to get the room up to temperature.

A wood stove disperses heat by both modes, by direct radiation to surfaces facing the hot surfaces of the stove and by convective air currents, heating up air flowing in from near floor level, passing over the hot stove surfaces, and continuing on up to ceiling level and outward toward other parts of the room or up a stairwell. Both modes distribute a significant amount of heat, but convective distribution does more of the total heat load. Still, distribution by air flow induced by density differences in general is slower than when a force air heating system's blower is moving it, as you point out.

For those interested, any surface radiates heat outward at a rate proportional to the fourth power of its absolute temperature (Rankine or Kelvin). The nature of the surface (dull black vs light shiny) determines its emissivity.

[John Mercier]

The electric radiant heater, and the electric convection, will also do both.

It is the dominate function that they are pushing.
Neither is operating in a vacuum like the Sun... and air molecules do absorb radiation.

[ApS]

Originally Posted by John Mercier

Radiant and convection move heat in different ways.

Convection heats the air; While radiant heats the objects.

Some radiation will be absorbed by air molecules... but generally not all.

A hair dryer--or "a heat gun"-- is a convection heater.

[John Mercier]

Correct. They also give off a percentage of the heat as radiant.

Sort of like a light bulb is about lumens, but also gives off heat. But given the same amount of electricity, some will provide more lumens... others more heat.

[Woodsy]

Its pretty funny reading some of these...

For power calcs use Ohm's law. 800W is 800W! The reason most hair dryers are limited to less than 1800W is because 120V/1800W = 15A. Most household 120V circuits are limited to 15A, and will nuisance trip at 13.5-14A depending on circuit load. You can have a dedicated 120V/20A circuit but they are pretty rare in a home and will nuisance trip at anything over 18A.

A 120V/1200W heater of any kind will pull 10A.

All of the electric heaters discussed here are convection heaters. They use electricity to heat air, and they will all heat a room slowly. The marketing geniuses just push "how" the devices use the electricity to heat the air.

Woodsy

[SailinAway]

After reading more about heaters, it seems to me that the question is, How much heat will I get with a certain type of heater? I think that should be measured not just in the obvious "1500 watts is 1500 watts," but in the perception of comfort.

I just spent a couple of days sitting next to a small ceramic heater in a 144 sq ft office. It took hours for the room to warm up to just barely tolerable rather than freezing. Touching my clothing and objects near the heater, they are cool to the touch. If I get up and move to the other side of the room or leave the room, I am immediately cold. If I open the room door, all of the accumulated heat is lost within 30 seconds. This indicates that the heat is not being stored in objects.

On the other hand, when I get up from a warm bed in the morning, I notice that I carry the stored heat in my body and clothing for quite some time, even when it's 52 degrees in the house. If I exercise outdoors on a cold day, I will warm up and stay warm for at least 30 minutes after I get back to my cold house.

So it seems that there is quite a bit of value in this stored heat, making me lean toward getting an infrared heater.

Also, reviews indicate that the perceived amount of heat emanating from different types of heaters varies a lot, even when they are all 1500 watts. There is quite a bit of agreement that the Dr-968 can warm a larger room than my small Lasko heater. I conclude that this is due to the value of the heat stored in objects, the body, and clothing from infrared heat, which lasts for awhile after the heater is turned of or as you move around the house.

Unfortunately manufacturers don't usually justify their claims about heat ouput. DR Heater says, "Wattage indicates the amount of electricity needed to power the heater--not the amount of heat it can deliver. Dr. Infrared Heater’s advanced heating system enables greater heat production without using any more power with a high-efficiency blower that delivers an average of 250°F at 3.5m/s to your room versus competing heaters that can do only 155°F at 2.2m/s." That makes me wonder if some of the wattage is going to the blower rather than producing heat.

[John Mercier]

https://www.thespruce.com/best-radia...eaters-4078803

[brk-lnt]

Originally Posted by SailinAway

So it seems that there is quite a bit of value in this stored heat, making me lean toward getting an infrared heater.

You're still going to have the problem of the general space being too cold, so when you get up to move, you'll likely feel cold fairly quickly.

Heat is a "thing" (vs. cold, which is not a physical thing, it is just the absence of heat). Objects can store heat, much like wet clothing stores water. You can think of objects storing heat similar to a sponge absorbing water, the outer layer will heat up first, and then the heat will be coducted further into the object and stored. Depending on what the object is made of, it will affect how long it takes that object to absorb heat all the way through, and how long it takes to release it.

If you want to eliminate the cold drafty feeling of a house or room, you need to heat the entire room, and you need to hold that temperature long enough for the objects in the room to stabilize at that temperature. If you blow a little bit of warm air into a room, it will quickly go back to feeling cold, because that little bit of heat ultimately gets evenly distributed to ALL the objects in the room. Again, think of it like water, you're not going to fill a room, or make all the objects in a room wet, with an insufficient quantity of water. Ceramic vs. infrared heaters is like comparing different kinds of buckets, it really doesn't matter much if you don't have enough water to begin with.

[ITD]

Also keep in mind that heat is constantly exiting a structure. The rate at which it happens is dependent on the type of structure, insulation and how tightly it is sealed. Also important is the difference in temperature between the area you want to heat compared to outside temperature. The colder it is outside, the more heat it will take to keep the space inside warm.

And it is also very important to remember that you need to keep a house heated or your pipes will freeze. Keeping an electric heater going in one room while not heating or keeping the rest of your home too cold will turn into a disaster for you.

[John Mercier]

She is looking for the sensation of heat.

The sun on your face.

[Woodsy]

SailinAway....

BRK-Int has it explained perfectly.

Nothing is better than a temp stabilized room/dwelling... I doubt any 120V electric heater will do the job efficiently.

All of the heaters mentioned here are convective (even the infrared ones). They heat the air and in turn the air heats the objects (mass) in the room. I might also argue the amount of energy needed by the smaller heater may not save you any $$. But it will keep your work area warmer.

If you want some serious heat, but are OK with some hazard, look into the propane heaters for bobhouses etc.

Woodsy

[John Mercier]

You mean the Little Buddy Radiant Heaters?

We sell those. We even sell the propane cylinders.

[SailinAway]

Conclusion after reading all of the above: No, infrared heaters don't save money as claimed compared to other types of heaters and they don't heat a room or a person any better than other types of space heaters. Is that the consensus?

[John Mercier]

I don't know.
Woodsy just suggested a radiant heater... that is what the Little Buddy heaters used to keep the bobhouses warm are.

We sell electric convection heaters. Both the fan types (fans use some of the electricity) and the large surface type.

I find the radiant give a near instant sensation of warmth even when not sitting too close, while the convection ones - unless we trap the heated air under a desk or something - require more time for me to get the same sensation.

When I shut down the radiant, I still to feel cooler almost immediately; when I do the same with the convection there is a slight cooling (I think mostly due to the lack of the fan), but the room overall seems to stay warmer for a while.

The Little Buddy has a new smaller version that at least seem to make it more bearable to be in front of for a longer period of time. I found the original to seem to make it too hot and would move from in front of it to the side, and then move back to the front as I felt cold.

[ITD]

I have a little buddy heater, and it is great, outdoors. I wouldn't use it indoors. You have a fire hazard plus a carbon monoxide potential hazard.

Sailin' I think if you want to have a supplemental source of heat, an infrared heater is fine. I would suggest a tower type or a floor model that focuses on you. A 1500 watt model with 3 heat settings and a remote control would probably work well for you. That way you can adjust to the conditions of the day. This would allow you to lower the heat in most of your house, while keeping the area you sit in comfortable.

Just keep in mind that there are at least a few people a year who lose their homes to fire started by small electric heaters each year. Usually by using them too close to combustible materials.

There seems to be and endless choice of heaters out there. Pick something that floats your boat, just make sure it has overheat protection for added safety.

[John Mercier]

The new ones are designed indoor safe with special features.
They could start a fire the same as other heat sources, and they would add humidity to the house.

Propane not exactly being cheap either.

[pondguy]

Todays 10 day Kero price is $6.399 per gallon time to lower the thermostat.

[SailinAway]

Well, after 6 weeks of being cold, I checked the chimney for storks' nests and started up the woodstove. Ahh . . . bliss . . . except for the thought of all the remaining cutting, splitting, stacking, hauling, restacking, feeding, and sweeping ahead.

[TheProfessor]

Originally Posted by TheProfessor

No.

Again, 1500 watts is 1500 watts.

You are right. 1500 watts is 1500 watts.

https://www.youtube.com/watch?v=V-jmSjy2ArM

Above utube video explains all.

[John Mercier]

You just quoted yourself.

And the question is not whether 1500w equals 1500w... it is the conversion to heat, and the focus of that heat.

If we used that wattage to create light... the LED would create more lumens than an incandescent bulb... but the 1500w would still equal the 1500w.

[LikeLakes]

So say I have a 400 watt radiant heater, and an 1100 watt infrared heater, how much wattage would that be???

Just kidding. One thing I think worth mentioning, given that a lot of this answer, as I think John has been trying to explain, is a "feel" decision, not related to the relative wattage ... is that maybe buy/borrow one of each type of heater and give them a whirl. Once the heat from various types is experienced the answer of what feels best, what seems to do the job best, will be answered.

[John Mercier]

Sort of.

If you boil water in a convection oven, and you boil water in a microwave... when you open the door to the microwave, you generally will not feel a rush of hot air. But the convection will have that effect.

The microwave is directly heating the water, and anything with more density... while the convection oven is heating the air and slowly transferring the energy to the water.

A true radiant heater should allow for the individual to ''turn down'' the heat, thus using less energy to create the same sensation.

The glow of elements giving off visible light, actually produces less heat. The perfect radiant heater (and there are none on the market that I know of) would only produce electromagnetic waves in a range that is invisible to the eye. The same way a perfect tanning bed would only produce waves on the other side of the spectrum.
Since we don't have perfect... the degree that an appliance produces EM waves in the defined range that we want... is more efficient.

The LED is more efficient because it produces the more EM in the visible light spectrum than the incandescent.
Of course, if we put an LED in an EasyBake oven... the cake never cooks.

[LikeLakes]

All true!

But in the end, I think it's a personal "feel" decision. Personally, I don't necessarily like infrared heat and how it feels. I'd rather heat the space, but that's not an evaluation of efficiency, it's just how I prefer my environment to feel.

[John Mercier]

Radiant heaters will heat a space... they will heat whatever they are directed at , so surface get warm, and then transfer that heat to the surrounding air.

The air rises, cooler air takes its place, and a standard convection loop is established.

The nature of them is really that whatever is directly in front of them feels warmer more quickly than with the standard convection loop.

[John Mercier]

The technology is changing, but I notice it most in windows rather than heaters.

[TheProfessor]

Originally Posted by John Mercier

You just quoted yourself.

Interesting. Of course if the post information is correct.

Originally Posted by LikeLakes

All true!

But in the end, I think it's a personal "feel" decision.

Correct. Does one want blowing hot air. Radiant air. Or whatever. It is still 1500 watts. Although my little under desk inexpensive fan/blower heater has 2 settings. 750 and 1500. My replacement heater. And not a milkhouse heater. As the milkhouse heater almost burned the place down.

If I can find the picture of the burned black wall outlet that the milkhouse heater caused I will post it. As some of the cheap stranded copper wire in some of these cheap Chinese heaters is not up to snuff.

[John Mercier]

1500w is the measure of the electricity used... not the heat produced.

I think I explained that pretty simply with the light bulb example.

[ishoot308]

Originally Posted by John Mercier

1500w is the measure of the electricity used... not the heat produced.

I think I explained that pretty simply with the light bulb example.

Shamelessly cut and pasted from "take control and save coop"...

"Electric plug-in space heaters are not more efficient than other electric heating sources. and Another thing to note is that all electric space heaters are equally efficient. An electric space heater rated at 1,500 watts will use the same amount of power (1,500 watts), producing the same amount of heat regardless of what you pay for it.

In addition, electric plug-in space heaters are not more efficient than other electric heating sources, and all electric space heaters are equally efficient. An electric space heater rated at 1,500 watts will put out the same amount of heat regardless what you pay for it.

You would be better off to take the money you would spend on a space heater and put it toward weatherization improvements to your home, such as adding insulation and caulking."

Dan

[John Mercier]

But it is not the same...
https://www.electricradiatorsdirect....me-efficiency/

Which I explained with the microwave to the convection oven.

The loss of heat within a space is general from convection. You pressurize the air increasing the loss.

This is a common mistake from people looking at windows and doors.

[brk-lnt]

Originally Posted by John Mercier

1500w is the measure of the electricity used... not the heat produced.

For the purposes of these discussions, it's exactly the same. All plug-in electric heaters will produce the same amount of heat for a given amount of power consumption.

The primary difference between an infrared heater and a "regular" electric heater is going to be how the heat is focused or directed. The infrared heater will let you direct the heat output more on a specific object, such as on yourself, instead of blowing it around the entire room.

An infrared heater might help you go from feeling a little chilly to feeling warm, without having to heat the entire room to do so. But, if you're looking for something that is going to work as a heat source that keeps your overall house warm, neither one is going to offer any cost savings advantages. And, if you're using the infrared heater to heat yourself, and you move away from it, you'll likely feel chilly again pretty quickly.

Originally Posted by John Mercier

I think I explained that pretty simply with the light bulb example.

Well, not really. LEDs and filament bulbs produce light in two very different ways. It's about the same as comparing gas and electric heaters. While we have a handful of different ways to produce light with electricity, with varying degrees of efficiency, when it comes to producing heat with electricity, we have been at essentially 100% efficiency for quite some time already.

Heat is a natural by product of any electrical circuit, in most cases we take great pains to try and reduce the amount of heat generated by an electrical circuit, it's just waste in that scenario. But if heat is the actual thing we want from the electric circuit, that has been a solved problem with nearly perfect efficiency for over a century. You can take your pick of what electric heater form factor you prefer, but they're all going to produce the same amount of output for a given wattage.

[SailinAway]

My conclusion about space heaters after experimenting with a ceramic heater: they are expensive to run, inefficient, and ineffective. My downstairs air conditioner uses 540 watts. It cools the entire downstairs (600 sq ft?) pretty well even in a heat wave, lowering the temperature from 95 exterior to 65 interior. The space heater uses 1200 watts, and it did a poor job of heating even my small office (120 sq ft) in September and October. When the outside temperature was 65 during the day and 40 at night, the temperature in the house was between 55 and 59 all day on most days. The space heater raised the temperature in my office perhaps 5 degrees. So it uses 3 times more electricity than the air conditioner, but the AC is effective for 6 times more space and the AC's impact on the temperature is 6 times greater.

The wood stove solved the whole problem within one hour. So perhaps my original question was moot. I abandoned the idea of getting a large infrared space heater.

[SailinAway]

Originally Posted by brk-lnt

All plug-in heaters will produce the same amount of heat for a given amount of power consumption.

If this is true, then wouldn't it also be true regardless of the number and size of the heating elements? In other words, a 1500 watt heater with one small element puts out as much heat as a 1500 watt heater with 4 large elements? That's hard to understand intuitively.

I noticed that the "perceived" heat from my previous larger infrared heater with two elements about 24" high was greater than the perceived heat from my current small Lasko ceramic heater. https://www.amazon.com/dp/B000TKDQ5C...x=lasko+heater

I also think that a fan would use part of the 1500 watts to push the heat outward rather than to create heat. There would then be less heat, but the heat would reach a person sitting within a few feet better than with no fan.

[John Mercier]

It is because their minds are failing to grasp a concept.

Stating that the LED and incandescent produce light in two different ways is correct... but then not equating that a convection heater and radiant heater produce heat in two different ways is failing to grasp the concept.

If you place the two types of heaters on a desk just a few feet away from you.
The radiant will give you the sensation of warmth. For the convection to do the same, it must use some of that 1500w to run a fan; and the fan has to be large enough to move the air the distance to you without too much vector loss to the ambient air.

Now, if you use a non-fan convection and the radiant, though both will put similar wattage toward producing heat, the sensation of warmth for the radiant will be best felt sitting a few feet from you on the desk... the convection will be best felt by moving yourself over the top of the heater (warm air rises).

Warm air is also pressurized... so it will seek out the best means to escape the room. The same way the warm air in the convection oven rushes out when you open the door as compared to the feeling of when you open a microwave that uses radiant.

But rather than purchase a bunch of heaters, you can feel the sensation of each in trial at any retailer that has an active display.

Of course, there will not be savings over using the wood stove...

I use a convection kerosene space heater in the shop to bring the temperature up to a reasonable level while we wait for the fire in the stove to place enough BTUs in the firebox for the stove to begin radiating it to the room. I have even place an aluminum diamond plate reflector behind the stove to focus more of the radiant heat into the space and away from the wall behind the stove.

I could also use pea coal; but have more wood biomass production on the property than I use every year in the shop to make that purchase necessary or worthwhile.

If your waiting for the firebox of the stove to come up to temp, a simple heat pad should provide enough comfort. Trapped between you and the chair, even on a lower setting it should suffice.

[ITD]

Originally Posted by SailinAway

If this is true, then wouldn't it also be true regardless of the number and size of the heating elements? In other words, a 1500 watt heater with one small element puts out as much heat as a 1500 watt heater with 4 large elements? That's hard to understand intuitively.

I noticed that the "perceived" heat from my previous larger infrared heater with two elements about 24" high was greater than the perceived heat from my current small Lasko ceramic heater. https://www.amazon.com/dp/B000TKDQ5C...x=lasko+heater

I also think that a fan would use part of the 1500 watts to push the heat outward rather than to create heat. There would then be less heat, but the heat would reach a person sitting within a few feet better than with no fan.

An airconditioner (or heat pump) is different from a resistive heater. The airconditioner will be more efficient at using energy than a resistive heater because it essentially captures heat from one area and moves it to another, basically via a pump. So you aren't comparing apples to apples between the two.

The 1500 watt resistive heater is 100% efficient, but it just converts electricity into heat, it is not transporting heat from one area to another. There are no other efficiencies to be gained.

The conversation about radiant heat versus convection is pretty much moot for trying to heat a room. At the end of the day you are putting 1,500 watts of energy into the room via heat. It doesn't matter if you are using an infrared heater or an old coil heater, one element or 10 elements. It's 1,500 watts.

The problem is that on a colder night the amount of heat exiting the room is greater than 1,500 watts, so the room cools, or reaches a lower temperature of equilibrium and stays there as long as it doesn't get colder outside.

The fan in a portable heater produces heat. So if the fan is using 30 watts to spin, and the element or light bulb or whatever uses 1,470 watts of power, the net result is 1,500 watts of energy being delivered to the space.

Using one of the heaters, such as an infrared heater, pointed at you, might allow you to turn the main heat down in a room or house. But unless it's a very small room, the room temperature will likely get pretty cold. So you stay warm if you stay in front of the heater, if you move away from the heater, you'll get cold quickly. If someone turns off the main heat and just sits in front of the infrared electric heater, they may not notice the room getting too cold and end up with frozen pipes.

The portable electric heater is a great example of something being 100% efficient that will cost you much more to heat your house than a well designed gas or oil system. Caveat emptor.

[John Mercier]

You shouldn't be trying to ''heat the room''... you should be focused on the lone occupant.

The convection heater is going to heat the ceiling... the radiant heater is going to heat the person a few feet in front of them.

If I add a fan to the convection heater to force the warm air toward the person, I lose some of that 1500w into the fan motor.
I also pressurize the room.

[Seaplane Pilot]

There’s so much hot air in this thread that I’m sweating to death! Who needs heaters?

Just kidding, carry on….

[ITD]

I have no use for a room heater personally, but there are several conversations going on here. Some are talking about using these heaters to heat a room, you are focused on using one of these heaters to warm the occupant.

Using these heaters to heat a room is probably one of the most expensive ways to heat a room and one of the least efficient ways to use electricity for heat.

If I were to use one of these heaters it would be to warm me while sitting in a chair. I would probably opt for an infrared heater. But for me, if I'm chilled, a blanket works great, sometimes too well as I'll fall asleep. If a blanket weren't enough, I'd get a heated throw blanket. They use much less electricity and focus the heat much better.

An electric fan is a heat source. It also imparts mechanical energy to the air it moves, that energy is converted to heat eventually and it all happens in the room for a small heater like we are talking about. In reality most of the 1500 watt heaters that use a fan have a small induction motor that probably uses a few watts of electricity. But that is still a source of heat to a room.

Thermodynamics, not just a good idea, it's the law.

[TheProfessor]

Originally Posted by SailinAway

The wood stove solved the whole problem within one hour. So perhaps my original question was moot. I abandoned the idea of getting a large infrared space heater.

The wood stove possibly does not use any watts.

A portable wood stove may require a chimney though. Could be a smoke issue without such.

[LikeLakes]

Originally Posted by Seaplane Pilot

There’s so much hot air in this thread that I’m sweating to death! Who needs heaters?

Just kidding, carry on….

I can't believe nobody has brought up a nuclear fusion heater being the answer to all of this.

Sailin, seems like you did some great analysis and came up with the best solution for your situation. As I think I said in one of the other threads, in my experience heating the room with a proper heat source is a better solution than little space heaters, and glad you came to that conclusion.

[SailinAway]

Originally Posted by TheProfessor

The wood stove possibly does not use any watts. A portable wood stove may require a chimney though. Could be a smoke issue without such.

Here's my favorite: https://www.youtube.com/watch?v=3YB7A_C_ZUo

[SailinAway]

Originally Posted by LikeLakes

I can't believe nobody has brought up a nuclear fusion heater being the answer to all of this. Sailin, seems like you did some great analysis and came up with the best solution for your situation. As I think I said in one of the other threads, in my experience heating the room with a proper heat source is a better solution than little space heaters, and glad you came to that conclusion.

Well, Mr. Mercier suggested wool socks, so nuclear fusion would be the logical counterbalance at the other end of the spectrum.

I was hesitating to light the wood stove because I didn't have enough wood for the winter. Now that Poor Richard has split my maple or oak tree (we weren't sure what it was), I'm heating with wood. My plan is to delay using oil as long as possible. I have one tank and hope to not have to buy a second tank this year.

[John Mercier]

Originally Posted by ITD

I have no use for a room heater personally, but there are several conversations going on here. Some are talking about using these heaters to heat a room, you are focused on using one of these heaters to warm the occupant.

Using these heaters to heat a room is probably one of the most expensive ways to heat a room and one of the least efficient ways to use electricity for heat.

If I were to use one of these heaters it would be to warm me while sitting in a chair. I would probably opt for an infrared heater. But for me, if I'm chilled, a blanket works great, sometimes too well as I'll fall asleep. If a blanket weren't enough, I'd get a heated throw blanket. They use much less electricity and focus the heat much better.

An electric fan is a heat source. It also imparts mechanical energy to the air it moves, that energy is converted to heat eventually and it all happens in the room for a small heater like we are talking about. In reality most of the 1500 watt heaters that use a fan have a small induction motor that probably uses a few watts of electricity. But that is still a source of heat to a room.

Thermodynamics, not just a good idea, it's the law.

But the law does not state that it will be focused heat.
A warm ceiling is nice... but not really what anyone is looking for.

[ApS]

A cold-wave came through Central Florida last night. Perhaps the windows should have been closed last evening!

At 7-AM--and 60°--the little convection space heater got switched "on" in the bedroom. After 20 minutes, the bedroom got toasty at 80°, so it got turned down. One minute later, the whole neighborhood lost power!

Fortunately, there's a radiant 1873 "parlor stove" in the living room that takes wood or coal. (Coal--hard to start--burns too hot).

Originally Posted by SailinAway

I spent a lot of time studying this today and didn't come to a conclusion. There are a lot of claims about the Dr998 infrared heater heating 1000 sq ft with the same 1500 watts that a ceramic heater uses to heat 300 sq ft---But also many reviews that say that claim is exaggerated. Reviewers who dismantled the DR998 found that it consists of 1 small quartz tube and 1 PTC element, whereas other brands have 4 to 6 quartz tubes. They report early failure of the quartz tube. Another concern is the long time it takes infrared to heat a room---45 minutes to raise the temperature 5 degrees.

I did finally come across an explanation that helped me understand infrared heat: you can feel the warmth of the sun on your face in the winter, above the air temperature. That's after the sun's infrared rays traverse 93 million miles of space at minus 454 degrees.

I did buy a full tank of oil last week for $4.29 a gallon. Very glad I did that, as the price rose immediately afterward. Still trying to get my wood split to save the oil for December through February.

Humanity can't rely on the sun for radiant heat--look at Greenland!

This reminded me that I may have owned every form of plug-in space heater ever made! (Plus one Kerosene radiant heater, and one propane radiant heater).

I may have donated my ceramic heater--a very disappointing manner of heat--IMHO.

The stand-up quartz radiant heater is too hot to be near and has only one setting. When the thermostat kicks in, it makes a startling sound like a welder sparking.
The corded baseboard heater is OK. It does take up a lot of floor space, but you can sit right next to it and be comfy.

The trouble with convection heaters is that any heat they produce rises to the ceiling and is eventually lost. Our industries have crafted an expensive way to move about rooms heated to a comfortable "thermocline".

My 1950s 800-watt radiant heater "dish" at our Wolfeboro cottage is the clear winner. Instead of mounting it at 8 feet above the floor, I should have had it professionally wired and bolted at the peak of the ceiling (at 16-feet). Left "on" while sleeping, the largest room in the cottage gets warmed with only 800 watts. Everything affected within the arc of the reflector is warmed.

A warm floor is a nice way to greet an Autumn morning.

[brk-lnt]

Originally Posted by John Mercier

It is because their minds are failing to grasp a concept.

Stating that the LED and incandescent produce light in two different ways is correct... but then not equating that a convection heater and radiant heater produce heat in two different ways is failing to grasp the concept.

Then please explain your "concept" in more detail so we can understand better.

My "flawed" understanding is that an LED light produces light by passing DC current through a semiconductor junction, which releases photons as a reaction of this DC current flow. Additional circuitry exists in the bulb itself, or an outboard power supply that rectifies the AC current we get from a power outlet, and steps it down to a lower voltage, as one of the many characteristics of the typical semiconductor junction is that they are generally limited to a forward supply voltage of a few volts at most.

An incandescent bulb utilizes AC current directly, with no additional rectification or step-down, to heat a filament to the point that it glows white-hot, emitting light. For most practical purposes, the 120V light bulb is really a heater that has a convenient side effect of producing light.

We won't get into gas-based bulbs here, but we can also use electricity to produce light by ioinizing gasses like neon, argon, etc. to produce light in various colors.

All of these various methods of producing light use very different principles at their core to produce light, and thus will have very different efficiency ratings in terms of how many lumens of output are created for a given power consumption (wattage).

Unlike the light bulbs, all of the electric heaters being discussed in this thread are producing heat by using resistance. Unlike the various methods we have to product light from an electrical current flow, we do not have many options when it comes to producing heat from electrical current flow, they pretty much all come down to resistance (again, to be clear, I'm talking about creating heat here, not moving it, as in a heat pump).

By selecting different materials for the resistors that comprise a plug-in electrical heater, we can create our heat output in different parts of the electromagnetic spectrum, such as in the infrared part of the spectrum, but for the purposes of discussion here, they are all the same efficiency (~100%), since they are all using the same basic principles of heat as a by product of electrical resistance, and we have had ~100% efficient electric heaters for over a century, and in this form of a system we cannot get more than 100% efficient without violating the laws of physics, so our only practical options for bringing new forms of electric heaters to market would be to make one that was LESS efficient than the ones we developed a century ago.

Ergo, all heaters that are rated for a given wattage will produce the same amount of heat over a given time period (unless of course someone has decided to bring to market a less efficient heater in some way).

All of these perfectly equal heaters may utilize different methods to conduct the heat into the room, and these various methods may make them more or less optimal for certain use cases, but in the end, if you have a room that is at 65 degrees and you want to heat that room to 70 degrees, it will cost you the same amount of electricity/money to do so with any electric heater on the market today.

All of this of course is stated in the context that these discussions were born out of, which is saving significant heating costs over the course of a month, or a heating season.

If a user merely wishes to warm up briefly, such as in coming in from the cold outdoors, then I would agree that an infrared heater would be a better choice of the many equally efficient electric heaters available, as it would allow the user to better direct that heat output specifically on themselves for a brief period to warm up quickly. But if the user is talking about heating a space over a long period of time, like a month, no one form of electric heater is going to offer them measurable savings in operating costs over another

Please let me know where the grievous error is in my comments above, rather than just dismissing it as a general failure with no specifics.

[John Mercier]

brk-Int,

The relative concept working in my head is that the incandescent bulb and the convection heater use the same basic technology.

The IC being tweeked to produce more light (smaller element and a vacuum), while the heater tweeked to produce more infrared (heat)... neither being perfectly efficient due as noted by a mixture of the IC getting hot, and the heater elements giving off a visible light red glow.

The original diodes (mixing of elements) produced infrared. They were tweeked to get red visible light, then green, and finally blue. The efficiency of the process allows for a narrow EM signature, and thus less loss.

The modern IR heater is also a tweek. The tweek being to produce less light and more IR... first ceramic... and now quartz (with less loss, but still not perfect).

This improves IR (heat transfer) without the pressurization of the space.
Basically, it doesn't heat the air near the elements... have the air carry the heat to the ceiling and look for the nearest exit through air leakage.

Most loss of heat is through air leakage.

Electric doesn't have a flue... so no flue losses.

But it can not escape entropy.

And the Laws of Thermodynamics would not allow for a heat pump to be more than 100% efficient... but we compare the transferred BTUs to the produced BTUs of a conventional heater and that is what provides the greater than 100% efficiency rating.

The relation is built on the traditional technology; and is considered apparent efficiency.

[ITD]

Nothing, or maybe more accurately very few things escape the laws of thermodynamics, properly considered. Heat pump hvac units use electricity to heat a space. The amount of heat generated, or perhaps more accurately transferred by a heat pump is many times that which would produced if the same amount of electricity were used in a resistive heater to heat the same space. And it all obeys the laws of thermodynamics.

This is why using terms like "efficiency" can be confusing when considering how to heat a space. Resistive electric heat sources are 100% efficient when you consider that all the energy consumed is changed into heat.

But electric resistive electric heat sources are one of the most expensive ways to heat a space.

[John Mercier]

It is quite cost effective as compared to heating the building or a room that is not easy to heat by other means.

The reason that you see so many camps/cottages/condos in NH with electric space heating *usually not the small space heaters* is the cost to install was so much lower, and the maintenance nearly none existent.

When the structure was to be used late in the season or annually, the electric heaters would only be used as a backup to the primary (usually a wood stove).

I know several homes in the area that have that, and before being changed out... all three of our family cottages worked that way.

Each room could be turned on or off, and plumbing was highly centralized with interior ''wet walls''.

While temperature control was very precise... it was a lot of thermostats... and since once the cottages got used for more than the summer, the electric became a secondary.

I ripped some of the radiant out of the ceilings, but left it in the bathroom floor and walls.

[brk-lnt]

Originally Posted by John Mercier

brk-Int,

The relative concept working in my head is that the incandescent bulb and the convection heater use the same basic technology.

The incandescent bulb, convection heater, and IR heater all use the same core principle - resistance of current flow. All 3 of those (and while we're at it, every other form of electric heater) produce the desired output (heat, or light) by exploiting the basic rules of physics and electricity as needed to produce what is really just a convenient side effect (heat or light) of electron flow through various materials.

In the context of these threads, SailinAway appears to be concerned not just about feeling warm, but about ensuring her house is sufficiently warm enough to prevent damage from things like frozen pipes. So, we need to advise in the context of heating a room or dwelling, not just creating a perception of increased comfort.

As I mention in another thread, and I think you are aware, heat is a physical object. For these conversations we can draw a lot of analogies using water instead. People can see water, whereas they can't see heat, so it's sometimes easier to understand.

Instead of heating a room, imagine filling a swimming pool with water.

Let's say we have a 15,000 gallon swimming pool (room) and two hoses with nozzles (heaters) that we can choose from to fill the pool. Both hose/nozzle combos have an output flow rate of 1500 gallons per hour (watts). One nozzle has a large spray pattern, and one has more of a concentrated stream output, but it is important to note, they both deliver the same amount of water over a given time period. If it's not clear, the spray nozzle is the convection heater, and the stream nozzle is the IR heater.

If we want to take our swimming pool from empty to full, and the pool is 15,000 gallons, and either nozzle option delivers 1,500 gallons per hour, we can see that it's going to take us 10 hours to fill the pool either way.

Now, if we don't want to go swimming (heat the entire room) and we just want to cool off (warm up) quickly, using the nozzle with the stream output to hose yourself down will cool you down pretty quickly because you can direct all of the output just where you want it, instead of in a large spray pattern. This is the primary benefit of the IR heater, it is producing the exact same amount of output, but directing it in a smaller area. It won't heat the room/fill the pool any better, faster, or cheaper overall, but it can give a perceived level of working better via the directed output.

If we have another source of water/heat, like a wood burning stove, then an IR heater might be a better choice for auxiliary heat than a convection heater because it would let us focus the additional heat just on ourselves, instead of spraying it around the entire room, with only a little bit directed to us.

However, if we are filling a pool/heating a room, both are going to take the same amount of time, and have the same operating costs, for a given output rating.

If you are heating with electricity, the only way to save money is to use less heat. You can make the room temperature lower, or you can heat less area (eg: close doors to unused areas), but until our laws of physics change, all your options or form factors are exactly the same.

The above examples are based on using electric heaters, essentially creating heat from "nothing". This is in contrast to a heat pump, which moves heat instead of creating it.

We can belabor our swimming pool example by envisioning that we have access to a large body of clean water someplace, and we have a giant sponge. You can use the sponge to soak up this "free" clean water, and then squeeze it out into the pool, repeating the process until the pool is full. This is the basic principle of a heat pump.

If we have plenty of free water available, this process works well and it will use less energy (water) than buying water from a supplier via a hose (buying power from the electric company). We can automate this sponge squeezing with a couple of motors, and while the motors cost money/electricity to operate, 1500W of motors might be able to squeeze sponges equivalent to 5000W of the direct method. (I know, it's getting weird with motors squeezing sponges, I said it was going to be a bit of a belabored example).

As our free water supply diminishes, it becomes harder to fully saturate the sponge, and it takes more work to squeeze all the water out and into the pool. We might got from using 1500 watts of motors to get 5000 watts of equivalent output to only getting 3000 watts, and then 1500 watts, and then even potentially only 500 watts, making the sponge/free water example MORE costly to operate when the water supply is down to the last few drops.

Similarly, with a heat pump, as the outside temperature drops, there is less "free" heat in the air, and the equipment has to work harder and longer to extract it. At some point it becomes impractical to move this free heat/water effectively and we have to resort to hoses/resistive heaters. This is why your cold weather climate heat pump will often have an emergency/aux heating option to resort to heat creation instead of heat movement when it is too cold outside and/or the demand for heat inside is greater than what the pump system can provide.

Apologies for the long response, hopefully it helps clarify some of the concepts.

[John Mercier]

She isn't going to protect the pipes in her house with a space heater of any format.

The analogy you are using doesn't work.
She wished to heat only herself.

The larger spray pattern of the nozzle would mean the heat is wasted into the surrounding...

And once vaporized it would escape the area as humidity.

The loss of water can range compared to the total... but the loss is an inefficiency.

So while you are spraying the same amount of water (1500w in our example), you are not getting the full effect of the water toward the purpose (<1500w worth of real world results).

The narrow spray pattern... with less dribble at the nozzle... will be more effective in the process being attempted. It is for all intensive purposes more efficient in the real world application.

[granitebox]

Dear God let this thread die. At this point its a personal preference, there is no right or wrong -