Good article about the downsides of infrared heating. These things can be useful. They are very light, safe and easy to install, and they can really make a difference in tight spaces like a caravan. However, with 425W, of course you cannot expect this thing to heat a larger room (to be fair, the article also does not claim this). The theory that you can direct this thing at yourself so that you feel warm but the rest stays cold is nice in theory, but as the article says, this is really difficult to achieve and usually not worth the trouble. And of course, these things only make sense in your home if you happen to get electricity very cheaply (which the writer of the article apparently does).
I mean, the two main issues here seem to be : poor placement and bad thermostat control, both of which seem (?) to be fairly easy to solve (at least for manufacturers) : place one horizontally over the top of the TV, focused on the sofa (since it's basically a big lamp, would it work better with a parabolic shape and/or a reflector ?), and don't use a thermostat so dumb that it can only do on/off, but instead one that slowly modulates power output %.
(The expensive electricity point is also kind of moot in case that's your only heating option.)
I'm also wondering about the potential for hyper-localized heating. Like, could I have a family picture printed 8"x10" and place one on my desk? Could I then stay comfortable in a much colder office?
I'm only ever in one place at a time, and both my house and workspace are compact, so I'd be up for moving one around with me if it meant saving on propane for the "real" heater.
I'd also happily place one under my sink or wherever to keep my pipes warm without having to heat the rest of the room when I'm not in it.
You can find heaters using the term "parabolic infrared heater". This is what I use for my basement studio, where I frequently produce music and thus do not want a heater with a fan (like many basements, it's quite a bit chillier than the rest of the house). Something like this [1], which appears to be a differently-branded identical unit to the one I actually purchased in Canada [2]. You can point this thing directly at yourself and you'll be perfectly comfortable even in a very chilly room, and it's noiseless.
Caveat emptor: in my experience, these things only last one or two seasons. But paying $25 or $50 to be comfortable for the winter is worth it. There are more expensive, presumably more durable wall-mounted options as well. [3]
I've also tried various methods like electric blankets and pads but I find the sensation of direct heat like that kind of annoying, plus I often end up with a warm butt and cold fingers, which is not ideal for music or coding.
My basement tends to be colder than the rest of my house as well.
To solve this, I put a blower fan at the foot of the stairs blowing up. This takes the coldest air in the house and sends it to the middle of the house.
The 1 ~100 watt fan balances the heat of the basement far more than any supplemental heating systems ever would, and at 13 cents/kwh only costs me about $0.30/day to run.
Fans are very underrated. I've been heating 1700 sqft of living space using a 25k BTU mini split in Maine for 2 years now.
The hot air is moved with some repurposed computer fans up high in a few doorways, and a return cold air fan , like your case, blowing the lower colder air back to the room with the mini split.
The introduction of the fan moving the cold air into that room has a FAR larger impact on the house temp than just the fans moving the heat alone. (They obviously help as well but it's far more effective to move the cold air).
As a geek side note, I also have a few "in wall" fans that direct into 6" vent work, and come out floor registers for the second floor. There are enabled or disabled via esphome temp sensors -- when a differential greater than X is noted, the fan(s) turn on, more rapidly evening the temps upstairs and downstairs.
(To be fair, I also have an oil hot air furnace, and a wood stove, but the furnace has not been used for 2 winters, and the wood stove on the cold cold days in Jan/Feb when the heat pump isn't very happy)
Can I hire you to figure out how to cool my space? It's only 625 sqft, and it's all one room except the bathroom, which accounts for the middle third of one side of the house (kitchen is on one side of it and bed area on the other, but they're not separated from the other half of the house by anything.
The problem I have is that all my windows are narrow casement (crank out) windows, so the only AC I can use is a floor unit, with a plexi plug covering the rest of the window. They're too narrow for real window ACs. It's 14,000 BTU, ostensibly, and has a dual hose to avoid creating negative air pressure inside the house, but it can only really keep it 10-15° cooler inside than outside. That's fine until it's over 90°, which thankfully doesn't happen all that often. The AC has to be in the southeast corner, and there can only be one, because all the outlets near the windows are on the same circuit, and it's not able to power two. Oh, and the whole east wall is a giant double sliding glass door, which has a gorgeous view of the river, but gets hot first thing in the morning.
I'm mostly kidding, but man, any suggestions for how to improve this would be great!
I had a similar issue in my old apartment. You might consider the use of a thermal battery.
Cool the space at night (when it's cooler already) as much as possible. Then during the heat of the day, use thermal curtains to both block the heat out and to trap the cool in.
On days where that is simply not enough, cross breeze is underrated.
Get one of those magnetic mosquito door net things and set it up on your front door. Open the windows and the doors when it's too hot for the AC to help and get some air movement with a fan if necessary to push air from the shady side to the hot side.
Get a heated mouse (those exist), heated mouse/desk pad (those exist), heated chair(pad), heated footpad (often bought for animals), some IR thingy for the head and you're covered. Any mask over your nose/mouth will retain a lot of warmth and humidity.
This is the same logic for electric cars where heat is expensive: conduction>>> convention. Heat the occupant(s) and not the air with heated steering wheels & heated seats. Some ICE gear shifter knobs would get warm from transmission conduction!
At one point in life, I had a heated mattress pad so I could turn the heat off a lot. I just ran it before I went to bed so it wouldn't be frigid when I got in. In the morning I'd just run into the shower and leave for the day. My place was western facing (in northern hemisphere) so I got a lot of afternoon sun and would return to a warm place in the afternoon.
I'm not going to go through the list individually, but I can't use a mouse for ergonomic reasons (literally have bones where I shouldn't, so these are fairly unique ergonomic problems), and my laptop already doesn't ventilate very well, so I'm still a lot more interested in something very subtle, like a picture frame on my desk, that wouldn't make me look as weird as I'd look with half a dozen wired things in different places.
It's not freezing in my workspace, just a few degrees cooler than I would like, and something inconspicuous like this seems like a great idea!
You could try putting a ceramic terrarium heater into metal desk lamps (I assume metal reflects far IR too) and use them to irradiate whichever body parts feel cold. They operate on the same principle as the panels but at lower power.
425w is about as much as having two 50 inch plasma tvs on. So it might ever so slightly increase the temp in the room but not if it is cold outside at all really.
For anyone else for whom the term is new - it's not "an infrared heater that can heat you from far away", it's "heating that uses far infrared radiation".
I think this overall makes a good point that any type of directly heating people is much more efficient than heating an entire building. I hope electrically heated clothing catches on soon... as it already exists and works pretty well. For example, you can get lightweight vests for fairly cheap that will keep you warm all day long from a USB battery in your pocket. Heated blankets and mattress pads of course have also been around a while and work great.
I'm not sure if this makes sense - even if you had very efficient personal heating, you'd probably still want to maintain your house at a certain temperature(for times when you're not wearing your personal heating, or for pets, or visitors, so your pipes don't burst, etc), meaning you should be investing in good insulation/air gap sealing, etc. Once you pay that cost, the cost of heating the house a few extra degrees isn't that big.
I am not suggesting that people in extreme cold climates not heat their house at all and burst pipes, etc. but you could, for example heat your house to 65F instead of 72F and use about 25-30% less heating energy, and still keep family members that like it warmer comfortable. If you drop it to 60F that uses close to half the heating energy on average that heating to 72F.
Personally, I live in a mild climate where it rarely gets below 50F or over 85F outside, and I just leave the windows open year round and let the house fluctuate between about 60F and 80F, and find it very comfortable without using anything but different clothing. It is interesting that even with all of the windows open the house averages out the evening lows very well, and stays about 10F warmer.
For a not so small minority, it's more of a if you can afford that cost (ironically, probably more of an issue in places without pipe-freeze-busting temperatures).
(And they probably cannot afford redoing insulation of where they live either, assuming they even own rather than rent.)
P.S.: The hot water bottle is pretty great, in particular when sick.
Not great for your health, long-term - as you'd be breathing in unheated, cold air for excessive periods -
"Cold air inflames lungs and inhibits circulation, increasing the risk of respiratory conditions, such as asthma attacks or symptoms, worsening of chronic obstructive pulmonary disease (COPD), and infection. Cold also induces vasoconstriction, which causes stress to the circulatory system (198) that can lead to cardiovascular effects, including ischaemic heart disease (IHD), coronary heart disease, strokes, subarachnoid haemorrhage and death (198–206). Most of the evidence for the impact of cold on health comes from studies connecting outdoor temperatures to health outcomes. For example, cold spells are associated with increased mortality and respiratory and cardiovascular morbidity (207), and mortality and morbidity rates in countries with cold and temperate climates are higher in winter than in summer (208)."
I’m pretty skeptical of this because it seems to conflict with common sense and personal experience but I’ll look a bit more. I wonder to what degree they controlled for health effects of short days, less sunlight, more time indoors, increased infectious disease in cold months, poverty, etc.
I doubt they are finding people that do a lot of outdoor winter sports for example have increased health problems vs people that just sit inside.
I've read about saunas, and studies were saying people who spent 19 minutes, 4-7 days a week in a 174F sauna had a 66% less chance of dying from all causes.
And then marketing people tried conflating IR saunas with conventional saunas, which nobody has studied and might not have the same efficacy.
I don't know either but I suspect hot air, especially in the lungs is a big part of the mechanism.
We need to do more research into this, honestly. The biggest factor - time - isn't accounted for (I.E., do you eventually acclimate to colder temperatures, nullifying all of the bad effects these studies find in the aggregate).
The other thing that keeps me nice and warm is the stationary bike under my standing desk. I never managed the coordination to walk at my desk, but sitting and riding is easy.
Oh there's more than one of us! I also have a stationary bike under my standing desk. It's a cheap recumbent. It's not amazing in terms of ergonomics, so I use it for about 20-30 mins at a time, a few times a day. I used to walk on a treadmill but I found that my head moved enough that focusing on text could be quite annoying. Also, I'd rather get my steps outside.
My head still moves on the bike, but it's much less. Also, this way I can just raise my desk and slide the bike under, whereas with the treadmill I was unplugging and going to another room which was less convenient. I have a TV dinner tray thing with a secondary wireless keyboard and trackball that sits just above my knees so I can work while I pedal.
And yes it's great for warming up and staying warm all day!
Mine's only semi-recumbent, so I can ride it for hours. I think it was maybe $120 on Amazon. My knees only come up high enough for my thighs to be parallel to the ground, so I can keep the keyboard position nice and low for typing.
I've supposedly pedaled over 10,000 miles this year, and I've lost over 40 lbs in the process! Never mind keeping warm in New England!
One of the best purchases I've made in a long time!
Or even good woolen jumper can make a big difference. Something light so you don’t notice your wearing it but with good insulating properties and you retain a lot more of your own body heat than a cotton or synthetic top.
> I think this overall makes a good point that any type of directly heating people is much more efficient than heating an entire building.
It is, but if a building cools down below the dew point (and it will, unless you're somewhere near the equator), any humidity e.g. from the air you breathe out or from plants will just crash out and condense on the walls, resulting in mold.
Because of the effect you’re talking about, the outdoor dew point is never above the outdoor temperature- so the air even indoors gets really dry when it’s cold outside, and you only need to keep the inside slightly warmer to keep this from happening.
I am into sailing and often sail in cold climates without cabin heat- and find that my body heat alone is enough to prevent this from happening in a small sailboat cabin.
Yep, the 0/100 duty cycle of FIR panels is not ideal. Buying a panel at a lower power rating and running it at 100% is more comfortable. At high power it will also lead to dry skin/eyes if it's in your field of vision, another reason to use a lower-powered one. IME mounting it behind a mesh backrest works best.
I don't understand the assumption that the heat output is going to be directly out of the poster, only orthogonal to it, like a columnated beam of heat. Clearly, like any black body source, it's going to radiate in all directions.
In this particular case, he could just get some extra fans, mount them under radiators and achieve much better heating for a lot less money.
Something like https://www.speedcomfort.com/en - just attach the fans and the thermal sensor to your radiator and plug it in. From then on, anytime the radiator gets warm, fans start and circulate hot air everywhere in the room.
Hmm, you're right. While there are multiple options available in Europe, I was only able to find "ecoCalm Radiator Fan Booster with Smart Heat Sensor and 5 Upgraded Fans" on amazon.com (this one https://www.amazon.com/ecoCalm-Radiator-Upgraded-Ventilator-... ) and it's sold out.
Seems that any space that's a candidate for this is an even better candidate for a heat pump, which can exceed 100% efficiency if judged in the same terms as a resistive heating element.
Good article about the downsides of infrared heating. These things can be useful. They are very light, safe and easy to install, and they can really make a difference in tight spaces like a caravan. However, with 425W, of course you cannot expect this thing to heat a larger room (to be fair, the article also does not claim this). The theory that you can direct this thing at yourself so that you feel warm but the rest stays cold is nice in theory, but as the article says, this is really difficult to achieve and usually not worth the trouble. And of course, these things only make sense in your home if you happen to get electricity very cheaply (which the writer of the article apparently does).
I mean, the two main issues here seem to be : poor placement and bad thermostat control, both of which seem (?) to be fairly easy to solve (at least for manufacturers) : place one horizontally over the top of the TV, focused on the sofa (since it's basically a big lamp, would it work better with a parabolic shape and/or a reflector ?), and don't use a thermostat so dumb that it can only do on/off, but instead one that slowly modulates power output %.
(The expensive electricity point is also kind of moot in case that's your only heating option.)
I'm also wondering about the potential for hyper-localized heating. Like, could I have a family picture printed 8"x10" and place one on my desk? Could I then stay comfortable in a much colder office?
I'm only ever in one place at a time, and both my house and workspace are compact, so I'd be up for moving one around with me if it meant saving on propane for the "real" heater.
I'd also happily place one under my sink or wherever to keep my pipes warm without having to heat the rest of the room when I'm not in it.
You can find heaters using the term "parabolic infrared heater". This is what I use for my basement studio, where I frequently produce music and thus do not want a heater with a fan (like many basements, it's quite a bit chillier than the rest of the house). Something like this [1], which appears to be a differently-branded identical unit to the one I actually purchased in Canada [2]. You can point this thing directly at yourself and you'll be perfectly comfortable even in a very chilly room, and it's noiseless.
Caveat emptor: in my experience, these things only last one or two seasons. But paying $25 or $50 to be comfortable for the winter is worth it. There are more expensive, presumably more durable wall-mounted options as well. [3]
I've also tried various methods like electric blankets and pads but I find the sensation of direct heat like that kind of annoying, plus I often end up with a warm butt and cold fingers, which is not ideal for music or coding.
1: https://www.homedepot.com/p/PROAIRA-700-Watt-1000-Watt-in-Bl...
2: https://www.homedepot.ca/product/living-zone-oscillating-rad...
3: https://www.homedepot.com/p/Dr-Infrared-Heater-1500-Watt-Ele...
My basement tends to be colder than the rest of my house as well.
To solve this, I put a blower fan at the foot of the stairs blowing up. This takes the coldest air in the house and sends it to the middle of the house.
The 1 ~100 watt fan balances the heat of the basement far more than any supplemental heating systems ever would, and at 13 cents/kwh only costs me about $0.30/day to run.
Fans are very underrated. I've been heating 1700 sqft of living space using a 25k BTU mini split in Maine for 2 years now.
The hot air is moved with some repurposed computer fans up high in a few doorways, and a return cold air fan , like your case, blowing the lower colder air back to the room with the mini split.
The introduction of the fan moving the cold air into that room has a FAR larger impact on the house temp than just the fans moving the heat alone. (They obviously help as well but it's far more effective to move the cold air).
As a geek side note, I also have a few "in wall" fans that direct into 6" vent work, and come out floor registers for the second floor. There are enabled or disabled via esphome temp sensors -- when a differential greater than X is noted, the fan(s) turn on, more rapidly evening the temps upstairs and downstairs.
(To be fair, I also have an oil hot air furnace, and a wood stove, but the furnace has not been used for 2 winters, and the wood stove on the cold cold days in Jan/Feb when the heat pump isn't very happy)
Can I hire you to figure out how to cool my space? It's only 625 sqft, and it's all one room except the bathroom, which accounts for the middle third of one side of the house (kitchen is on one side of it and bed area on the other, but they're not separated from the other half of the house by anything.
The problem I have is that all my windows are narrow casement (crank out) windows, so the only AC I can use is a floor unit, with a plexi plug covering the rest of the window. They're too narrow for real window ACs. It's 14,000 BTU, ostensibly, and has a dual hose to avoid creating negative air pressure inside the house, but it can only really keep it 10-15° cooler inside than outside. That's fine until it's over 90°, which thankfully doesn't happen all that often. The AC has to be in the southeast corner, and there can only be one, because all the outlets near the windows are on the same circuit, and it's not able to power two. Oh, and the whole east wall is a giant double sliding glass door, which has a gorgeous view of the river, but gets hot first thing in the morning.
I'm mostly kidding, but man, any suggestions for how to improve this would be great!
I had a similar issue in my old apartment. You might consider the use of a thermal battery.
Cool the space at night (when it's cooler already) as much as possible. Then during the heat of the day, use thermal curtains to both block the heat out and to trap the cool in.
On days where that is simply not enough, cross breeze is underrated.
Get one of those magnetic mosquito door net things and set it up on your front door. Open the windows and the doors when it's too hot for the AC to help and get some air movement with a fan if necessary to push air from the shady side to the hot side.
Get a heated mouse (those exist), heated mouse/desk pad (those exist), heated chair(pad), heated footpad (often bought for animals), some IR thingy for the head and you're covered. Any mask over your nose/mouth will retain a lot of warmth and humidity.
This is the same logic for electric cars where heat is expensive: conduction>>> convention. Heat the occupant(s) and not the air with heated steering wheels & heated seats. Some ICE gear shifter knobs would get warm from transmission conduction!
At one point in life, I had a heated mattress pad so I could turn the heat off a lot. I just ran it before I went to bed so it wouldn't be frigid when I got in. In the morning I'd just run into the shower and leave for the day. My place was western facing (in northern hemisphere) so I got a lot of afternoon sun and would return to a warm place in the afternoon.
I'm not going to go through the list individually, but I can't use a mouse for ergonomic reasons (literally have bones where I shouldn't, so these are fairly unique ergonomic problems), and my laptop already doesn't ventilate very well, so I'm still a lot more interested in something very subtle, like a picture frame on my desk, that wouldn't make me look as weird as I'd look with half a dozen wired things in different places.
It's not freezing in my workspace, just a few degrees cooler than I would like, and something inconspicuous like this seems like a great idea!
You could try putting a ceramic terrarium heater into metal desk lamps (I assume metal reflects far IR too) and use them to irradiate whichever body parts feel cold. They operate on the same principle as the panels but at lower power.
If you find this small device for purchase, please let me know. I would like one as well!
The poster could be placed on the floor...
$68 FIR Heater - Infrared Wall Eco Portable Heating Electric Panel 3000 BTU w/ High Quality Picture "Flowers" Folded Efficient Indoor 41''x 24''
https://www.etsy.com/uk/listing/1104443023/heater-infrared-w...
425w is about as much as having two 50 inch plasma tvs on. So it might ever so slightly increase the temp in the room but not if it is cold outside at all really.
At a previous employer, we did in fact use a large plasma TV as a space heater on chilly mornings.
For anyone else for whom the term is new - it's not "an infrared heater that can heat you from far away", it's "heating that uses far infrared radiation".
https://en.wikipedia.org/wiki/Far_infrared
I'm still a little worried about the toxicity of graphene-based products that they might turn out to be another "asbestos".
Asbestos is entirely safe as long as it is non-friable. If graphene has similar risks it should also have similar safeties. Don't huff graphene dusts.
is there any reason to be concerned about graphene that wouldn't apply to common pencil lead (graphite)?
Usage duration and frequency?
Only on HN are graphite pencils used less frequently than graphene tech.
Well most people use pens instead of pencils.
I think this overall makes a good point that any type of directly heating people is much more efficient than heating an entire building. I hope electrically heated clothing catches on soon... as it already exists and works pretty well. For example, you can get lightweight vests for fairly cheap that will keep you warm all day long from a USB battery in your pocket. Heated blankets and mattress pads of course have also been around a while and work great.
I'm not sure if this makes sense - even if you had very efficient personal heating, you'd probably still want to maintain your house at a certain temperature(for times when you're not wearing your personal heating, or for pets, or visitors, so your pipes don't burst, etc), meaning you should be investing in good insulation/air gap sealing, etc. Once you pay that cost, the cost of heating the house a few extra degrees isn't that big.
I am not suggesting that people in extreme cold climates not heat their house at all and burst pipes, etc. but you could, for example heat your house to 65F instead of 72F and use about 25-30% less heating energy, and still keep family members that like it warmer comfortable. If you drop it to 60F that uses close to half the heating energy on average that heating to 72F.
Personally, I live in a mild climate where it rarely gets below 50F or over 85F outside, and I just leave the windows open year round and let the house fluctuate between about 60F and 80F, and find it very comfortable without using anything but different clothing. It is interesting that even with all of the windows open the house averages out the evening lows very well, and stays about 10F warmer.
For a not so small minority, it's more of a if you can afford that cost (ironically, probably more of an issue in places without pipe-freeze-busting temperatures).
(And they probably cannot afford redoing insulation of where they live either, assuming they even own rather than rent.)
P.S.: The hot water bottle is pretty great, in particular when sick.
Not great for your health, long-term - as you'd be breathing in unheated, cold air for excessive periods -
"Cold air inflames lungs and inhibits circulation, increasing the risk of respiratory conditions, such as asthma attacks or symptoms, worsening of chronic obstructive pulmonary disease (COPD), and infection. Cold also induces vasoconstriction, which causes stress to the circulatory system (198) that can lead to cardiovascular effects, including ischaemic heart disease (IHD), coronary heart disease, strokes, subarachnoid haemorrhage and death (198–206). Most of the evidence for the impact of cold on health comes from studies connecting outdoor temperatures to health outcomes. For example, cold spells are associated with increased mortality and respiratory and cardiovascular morbidity (207), and mortality and morbidity rates in countries with cold and temperate climates are higher in winter than in summer (208)."
https://www.ncbi.nlm.nih.gov/books/NBK535294/
I’m pretty skeptical of this because it seems to conflict with common sense and personal experience but I’ll look a bit more. I wonder to what degree they controlled for health effects of short days, less sunlight, more time indoors, increased infectious disease in cold months, poverty, etc.
I doubt they are finding people that do a lot of outdoor winter sports for example have increased health problems vs people that just sit inside.
I've read about saunas, and studies were saying people who spent 19 minutes, 4-7 days a week in a 174F sauna had a 66% less chance of dying from all causes.
And then marketing people tried conflating IR saunas with conventional saunas, which nobody has studied and might not have the same efficacy.
I don't know either but I suspect hot air, especially in the lungs is a big part of the mechanism.
We need to do more research into this, honestly. The biggest factor - time - isn't accounted for (I.E., do you eventually acclimate to colder temperatures, nullifying all of the bad effects these studies find in the aggregate).
Just think Inuit or Aboriginal - both living in environments of opposing extremes, surviving just fine for many, many years...
this 1 study says so? I bet you can find a study claiming the exact opposite.
Go on then
We got a "tall" dining table height Kotatsu with heater and blanket. It's incredibly warm and comfortable in deep winter.
The pets love it too!
Main issue is that because it's dining table height, all the standard blankets and futons are too short/small.
Highly recommend it though, it's great. It just needed a voltage converter.
The other thing that keeps me nice and warm is the stationary bike under my standing desk. I never managed the coordination to walk at my desk, but sitting and riding is easy.
Oh there's more than one of us! I also have a stationary bike under my standing desk. It's a cheap recumbent. It's not amazing in terms of ergonomics, so I use it for about 20-30 mins at a time, a few times a day. I used to walk on a treadmill but I found that my head moved enough that focusing on text could be quite annoying. Also, I'd rather get my steps outside.
My head still moves on the bike, but it's much less. Also, this way I can just raise my desk and slide the bike under, whereas with the treadmill I was unplugging and going to another room which was less convenient. I have a TV dinner tray thing with a secondary wireless keyboard and trackball that sits just above my knees so I can work while I pedal.
And yes it's great for warming up and staying warm all day!
Mine's only semi-recumbent, so I can ride it for hours. I think it was maybe $120 on Amazon. My knees only come up high enough for my thighs to be parallel to the ground, so I can keep the keyboard position nice and low for typing.
I've supposedly pedaled over 10,000 miles this year, and I've lost over 40 lbs in the process! Never mind keeping warm in New England!
One of the best purchases I've made in a long time!
Or even good woolen jumper can make a big difference. Something light so you don’t notice your wearing it but with good insulating properties and you retain a lot more of your own body heat than a cotton or synthetic top.
> I think this overall makes a good point that any type of directly heating people is much more efficient than heating an entire building.
It is, but if a building cools down below the dew point (and it will, unless you're somewhere near the equator), any humidity e.g. from the air you breathe out or from plants will just crash out and condense on the walls, resulting in mold.
Because of the effect you’re talking about, the outdoor dew point is never above the outdoor temperature- so the air even indoors gets really dry when it’s cold outside, and you only need to keep the inside slightly warmer to keep this from happening.
I am into sailing and often sail in cold climates without cabin heat- and find that my body heat alone is enough to prevent this from happening in a small sailboat cabin.
"Build a man a fire, and he'll be warm for the night. Set a man on fire, and he'll be warm for the rest of his life!"
Yep, the 0/100 duty cycle of FIR panels is not ideal. Buying a panel at a lower power rating and running it at 100% is more comfortable. At high power it will also lead to dry skin/eyes if it's in your field of vision, another reason to use a lower-powered one. IME mounting it behind a mesh backrest works best.
They can be dimmed with a rheostat or any incandescent light dimmer.
Isn’t 75 C already way too hot for any surface that you could accidentally bump into?
Which suggests the ‘poster’ should be a lot bigger too.
Afaik they're closer to black-body radiators than some narrow band emitter like LEDs, so they have to operate significantly above room temperature.
Hmmm, that seems like a significant disadvantage compared to fan heaters then. Where at least the fancier ones have a ‘cool touch’ design.
Pretty good discussion of why something that sounds useful ultimately is much less so than you'd think.
I don't understand the assumption that the heat output is going to be directly out of the poster, only orthogonal to it, like a columnated beam of heat. Clearly, like any black body source, it's going to radiate in all directions.
Or am I mistaken somehow?
Chicago train stations have overhead heaters, you press button the heat you up with infrared, but they look more like 10KW devices.
Does the heater only project the heat forward? Or is it also projecting heat back into the wall that it's lying up against?
mostly forward
In this particular case, he could just get some extra fans, mount them under radiators and achieve much better heating for a lot less money.
Something like https://www.speedcomfort.com/en - just attach the fans and the thermal sensor to your radiator and plug it in. From then on, anytime the radiator gets warm, fans start and circulate hot air everywhere in the room.
It does not appear that they sell those devices in the US?
I did find them on ebay:
https://www.ebay.com/itm/405285386735?_trksid=p2332490.c1018...
Hmm, you're right. While there are multiple options available in Europe, I was only able to find "ecoCalm Radiator Fan Booster with Smart Heat Sensor and 5 Upgraded Fans" on amazon.com (this one https://www.amazon.com/ecoCalm-Radiator-Upgraded-Ventilator-... ) and it's sold out.
Seems that any space that's a candidate for this is an even better candidate for a heat pump, which can exceed 100% efficiency if judged in the same terms as a resistive heating element.
[dead]