reducing space heating by instead wearing heated apparel

Hello Permies community :)

I am an avid fan of electric blankets, and more so, electric mattress pads, because I think heating up close to your body makes much more sense than heating the air.  I hope to get this same comfort while out of bed and up and about. So, finally, this year I am going to spend on a technology that must not have much backing, since it's still quite expensive. I'm going for the Tesla of winter apparel--an electric heated jacket. I hope it works, and I'll be reporting back on this as I hope innovation in "heated wearables" brings a new wave in world beating--haha!

Please, do you have any experience with direct heated (not microwaved) wearables? Sadly, a pair of battery operated socks I mail ordered years ago never functioned, so I gave up then.

They are a lifesaver for those of us crazy enough to ride a motorcycle in the winter.  The key is they have to be close to the skin and SNUG, so like a middle layer instead of outer-same as the blanket/mattress pad difference.  Mine plugged in to a cigarette lighter, but I would buy the USB powered ones today.

R Scott wrote:The key is they have to be close to the skin and SNUG, so like a middle layer instead of outer-same as the blanket/mattress pad difference.  

Excellent point!
I was thinking I should order something that will fit snug, and have a hood to keep as much warmth in.

The other factor is washings. I wish to wear my heated jacket above a thin layer (washed often,) and below an outer jacket (protecting it from the world.)

My electric blankets failed or degraded with washings, so the mattress pad was superior in that I didn't wash it as much, plus the pad was more efficient due to minimal material/wiring, and no bunching. I'm shopping for similar things with the apparel.

I would look for something marketed to commercial users, figuring that it will be a lot more robust. That, or motorcycle gear..

I know Milwaukee makes some heated gear, given that their powertools have outperformed every other brand I have tried, I'd probably start there.


This makes a lot of sense from an energy efficiency perspective; the thing that keeps me from trying it, is moisture. Between lots of wet outdoor clothes, breathing, cooking.. humidity in my tinyhouse must be managed, and that really means heating the space. I can't run a dehumidifer off-grid in this cloudy climate without a huge additional investment to power it...


My scenario is nearly worst case for humidity between location and small space, but it is something to keep in mind in many locations..

Managing humidity without buying a special system for it is the sad reality with small spaces that are well insulated against the cold.

My question is a challenge...if your place was easily ventilated, by opening a window, could you still be comfortable without space heating? It's sort of like living in a space suit, in space, except you are living in a warm bubble, in freezing cold. Your life line is an electromagnetic source.

Oops, or an electric source.

I have tried on a Milwaukee hunting jacket. It heats up very quickly. I was looking at it as a sleeping device. A way to warm up the bed quickly, when I sleep in unheated buildings. I move from job to job getting houses ready to move and tearing them down partially or completely. The only time I imagine using something like this, is for 10 or 15 minutes at  bedtime. Then I would probably take it off. My smallest Milwaukee batteries are good for 2 hours in such a jacket. Instead of wearing it, it could be used just like a blanket. That way there's no hassle when taking it off.

This hasn't been an issue for me since I'm quite accustomed to to living in comfort, while cold-weather camping. My wife, from the Philippines has never experienced outdoor temperatures below 70 Fahrenheit or 20 Celsius. About 80 is her comfort zone. So I will get her a jacket and probably an electric blanket that can be run on 110 and on 12 volt. If Milwaukee comes up with a blanket, I will buy it, since I already have lots of batteries and chargers.

It would be nice to have something that would run on 12 volt vehicle power, 18-volt Milwaukee power and regular household power. But probably cheaper to just buy one of each.

D Nikolls wrote:
Between lots of wet outdoor clothes, breathing, cooking.. humidity in my tinyhouse must be managed, and that really means heating the space. I can't run a dehumidifer off-grid in this cloudy climate without a huge additional investment to power it...


My scenario is nearly worst case for humidity between location and small space, but it is something to keep in mind in many locations..

I believe that if I could wear a body suit that worked like my electric bedding, on 65 watts giving me toasty Bahamas on demand, then the only issue would be keeping my exposed skin from dehydrating (!) and my breathing air warm enough without condensation. AFCI / GFCI needed ?!

When managing moisture, I've found that ventilation is much more important than heating. I usually don't heat my spaces but I always ventilate. A friend was living in his van with a propane heater, which made it very moist. I was in mine with no heat. I was always comfortable and he complained constantly.

Regarding moisture problems versus heating needs...if our bodies could live in a warmth bubble, I wonder what the minimum living space temperature to allow for adequate ventilation while still avoiding problems with plumbing and other low temperature issues would be.

I have read that outdoor temperatures of twenty F or below are concerning for plumbing freezing. I would think that the indoor temperature would need to be at least ten degrees higher, unless heat tape was used.

Could the indoors be kept at forty five degrees--without holding too much moisture in the air, and keeping the risk of thirty two degrees inside the pipes away--be an acceptable starting temperature for this challenge?

Dale Hodgins wrote:I have tried on a Milwaukee hunting jacket. It heats up very quickly.

I was looking at it as a sleeping device. A way to warm up the bed quickly, when I sleep in unheated buildings. I move from job to job getting houses ready to move and tearing them down partially or completely. The only time I imagine using something like this, is for 10 or 15 minutes at  bedtime. Then I would probably take it off. My smallest Milwaukee batteries are good for 2 hours in such a jacket.

Instead of wearing it, it could be used just like a blanket. That way there's no hassle when taking it off.

This hasn't been an issue for me since I'm quite accustomed to to living in comfort, while cold-weather camping. My wife, from the Philippines has never experienced outdoor temperatures below 70 Fahrenheit or 20 Celsius. About 80 is her comfort zone. So I will get her a jacket and probably an electric blanket that can be run on 110 and on 12 volt. If Milwaukee comes up with a blanket, I will buy it, since I already have lots of batteries and chargers.

It would be nice to have something that would run on 12 volt vehicle power, 18-volt Milwaukee power and regular household power. But probably cheaper to just buy one of each.

I like it these ideas! My blankets and pads can take fifteen minutes or so to get warm. I think it would be fine to use your jacket as a blanket, as long as lying on it doesn't bend the wires. This kind of damage may really be the major question mark.

I'm glad that you have thought of these options for your wife from the Philippines, because going from only seventy and above to the cold seems like cruel and unusual punishment ;)

I received a 12 volt electric blanket as a gift, but of course the cheap converter I bought online didn't work.

The USB powered jackets can be powered by 12v, 110, or any power tool battery with that brands usb adapter.  But they are pretty light on power, limited to 10 watts where the 12v motorcycle versions are as much as 100 watts.

I used to deal with this before electrics when hunting, sitting still in 10 degree weather made you get cold easy.  I used to use Zippo hand warmers, little lighter fluid powered heaters about the size of a deck of cards.  If you put it over your kidneys or liver it would keep all of you warmer.

R Scott wrote:The USB powered jackets can be powered by 12v, 110, or any power tool battery with that brands usb adapter.  But they are pretty light on power, limited to 10 watts where the 12v motorcycle versions are as much as 100 watts.

I used to deal with this before electrics when hunting, sitting still in 10 degree weather made you get cold easy.  I used to use Zippo hand warmers, little lighter fluid powered heaters about the size of a deck of cards.  If you put it over your kidneys or liver it would keep all of you warmer.

Good information. Thank you! Does the maker still exist? I'm thinking something in between those watts would work best, but 10 watts would only work if I ran a few on different body areas.

I'm concerned about the imbalance between upper and lower body, but this is my starting point. You bring up a great thought, which is to be strategic about placement of individual heating elements. So yeah, the kidneys get a full one quarter of blood flow from the heart. The liver is a huge organ with a lot of blood in it too. I'm also thinking that going near the heart may work. So maybe I could get the kidneys in the back, and the heart/liver in the front with individual elements, and something for the feet.

I think if I were to design a jumpsuit, the elements would trace like the seams in pants in the lower body. Please, someone try this

I think 45 degrees is a fine target temperature when trying to save energy. But much more important, is limiting the size of the space you are heating. Suppose you like to stay 20° above the exterior temperature. There's going to be a certain energy need to keep 1000 square feet at that temperature. But if you are just sleeping, a small area of say 30 or 40 square feet could be kept pretty much as warm as you like, and it would still use far less energy than heating up the whole house. The ceiling doesn't need to be 8 feet over your head when you are sleeping. A sleeping enclosure with some sort of roof, would allow you to breathe warm air, within the enclosure. 30 inch or so above the sleeper, is enough room so that heads don't get banged and it wouldn't be claustrophobic for most people.

Heat will leak away from a nice warm sleeping area, but it's not gone, it just heats the rest of the house enough that the pipes don't freeze.

Modern heating systems generally keep all of the space in a house at the same temperature. I actually like the extreme heat gradient that happens when there's a wood stove. When you first come in from outside, stand near the stove. If you're too hot, move away from the stove and make room for Grandma. She's always cold. We used to visit our relatives Earl and June, who had a really nice kitchen wood stove. Old ladies and little kids were usually closest to the stove. Well-dressed mature adults didn't seem to need so much heat. So there would have been no advantage to keeping the whole place the same temperature, and it was also not possible with the radiant set up they had. The heat gradient allowed everyone to find their comfort zone.

With all that 5G coming up I am getting more aware of electrical pollution. I would not use an electric blanket while i am in the bed. More info at the environmental health trust. This is more about EMF's and pulsed radiation but wearing anything electrical is maybe not very good for your health.

It's 4 degrees Celsius in Victoria. I am in a 120 square foot bedroom with 9-foot ceilings. I will run a heater on the 500w setting for about 6 hours tonight. So I will consume 3 kilowatt hours or about $0.30 worth of power.

I'm heating the room to about 16 degrees Celsius.

I don't need all of this space, it's just what this house has as its smallest room. If there were a sleeping area only 1/4 this size, with a 6 foot roof , I could achieve the same temperature with one sixth of the amount of power. So it would cost $0.05 to stay warm for the night.

My bed is 6ft by 3ft. So, I could get by with heating only a 20 square foot area. If it were 6 feet tall, that would be 120 cubic feet. So it would be still quite a bit more than heating clothing, but with the advantage of having warm air. This level of heating might be achieved for 2 or 3 cents a night.

I once had a commercial building where the rooms were far too large to heat with my little electric heater. I built a blanket tent, and was able to stay quite comfortable with it on the lowest setting. It was actually very large curtains hung over top of those cheap metal stacking chairs with the plywood seat and back. Maybe 3 ft feet high. Probably 100 cubic feet or so of total air space. You don't have to worry about suffocating in a spot like this , you'd really have to work at it, to make it airtight.

Kids love blanket tents. If we all had some version of them, everyone could be comfortable at night, with houses kept just a few degrees above freezing. I imagine trips to the bathroom would be quick, and you wouldn't have daughters occupying it for 45 minutes in the morning.

Angelika Maier wrote:With all that 5G coming up I am getting more aware of electrical pollution. I would not use an electric blanket while i am in the bed. More info at the environmental health trust. This is more about EMF's and pulsed radiation but wearing anything electrical is maybe not very good for your health.

I agree. I would be concerned to have any type of electrical appliance so close to my body for any length of time.

I've never seen anything on these proximity issues, that I would call evidence. The real risk is fire if you get a really cheap one.

Last night I found some 12 volt electric blankets for as little as $12. I'm tempted to go that route, but I would much prefer to find something that runs off an 18 volt Milwaukee battery. I don't want another charger and battery system.

https://www.dirtyelectricity.ca/ might have some links to studies.  It's interesting stuff.  There's now a .org version too which has a different point of view.

EM pollution a great topic for the cider press, but probably a bit off-topic for this conversation.  Feel free to start a new thread about it in The Cider Press and link to it here.

Dale Hodgins wrote:It's 4 degrees Celsius in Victoria. I am in a 120 square foot bedroom with 9-foot ceilings. I will run a heater on the 500w setting for about 6 hours tonight. So I will consume 3 kilowatt hours or about $0.30 worth of power.

Thanks for this data! I am going to use it as a jumping point.

I pay approximately $0.16 per kilowatt hour, a bit more than your $0.10. When it’s colder than 40 outside, lets say 20 (-7C), I run my 1,500 watt space heater on maximum for eight hours at night in a similar size room. Given that 1,000 watts for one our equals one kilowatt hour, I will pay
1.5 x 8 x 0.16 = $1.92, and for 30 days = $57.60

If I was retired and wanted it on all day for the month, it would be
1.5 x 24 x 30 x 0.16 = $173

Let’s say I had a typical four room, one bedroom apartment, and I ran a space heater on max in all rooms for heating. This would be
x4 = $692

It would be useful to know what this felt like. Sorry, I don’t have that, but the person I know reported it was “okay,” while a boiler was getting replaced. I calculated the BTU to replace one of the typical radiators in the apartment. It took approximately 4.5 space heaters on max 1,500 watts to replace one radiator running for the same time frame. Of course this is not how boilers work, they cycle, but you get a sense.

Circling back, space heating a small volume is reasonable, for one room. However, I’ve got a more efficient way of heating while I’m asleep these days, and it feels better than a room heated to 70 degrees. In the past, I’ve lived with someone very environmentally conscious, so the heat was set to 52 degrees. While in bed, no problem. I have a heated mattress pad just the size of what my body occupies and max is 65 watts. Now the calculation becomes
0.065 x 8 x 0.16 = $0.04 per night, or for the month x30 = $1.20

While acknowledging there are a lot of temperature values missing with this scenario, this is great! Except you might point out, until you want to get out of bed. In my scenario, you would want to space heat that bathroom with all the plumbing, and for changing clothes and other bathroom stuff, but you wouldn’t wish to sleep there. Without making a sleeping tent, you could save one penny per night with the arrangement where you sleep, and also keep the bathroom heated all night long...

If a 581 cubic foot (10 long x 7 deep x 8.3 high = 581) space, like a bathroom, is heated during this time at 500 watts…
0.5 x 8 x 0.16 = $0.64, for a month x30 days = $19.20

So the total for a month of heated bed, and heated bathroom = $19.20 + $1.20 = $20.40
Looking back, if we had a 1,500 watt heater in the bedroom eight hours a night, and the bathroom heated with 500 watts, the total would be $57.60 + $19.20 = $76.80

The savings in both cost AND energy is about 75%. You may or may not be impressed, but I am, because I’m a thin person prone to being cold. This is a triple benefit, because I enjoy being toasted by the mattress pad over being kept adequately satisfied with ambient temperature. Now, next step is to try this out of bed.

Angelika Maier wrote:With all that 5G coming up I am getting more aware of electrical pollution. I would not use an electric blanket while i am in the bed. More info at the environmental health trust. This is more about EMF's and pulsed radiation but wearing anything electrical is maybe not very good for your health.

Risk of ionizing potential isn't something I considered great enough to investigate, so I am going to have to think about this, and read up on it. I don't know what the Cider Press forum is for exactly, but I'll try to come back with some data at some point.

Dale Hodgins wrote:I've never seen anything on these proximity issues, that I would call evidence. The real risk is fire if you get a really cheap one.

Last night I found some 12 volt electric blankets for as little as $12. I'm tempted to go that route, but I would much prefer to find something that runs off an 18 volt Milwaukee battery. I don't want another charger and battery system.

Please clarify, risk of fire from electrical inside the wall or the vehicle, or inside the wires in the blanket?

Does getting a converter make sense?

Sorry if this is nonsense questions. I am not experienced with 12V or 18V systems.

Sarah Albright wrote:

Dale Hodgins wrote:I've never seen anything on these proximity issues, that I would call evidence. The real risk is fire if you get a really cheap one.

Last night I found some 12 volt electric blankets for as little as $12. I'm tempted to go that route, but I would much prefer to find something that runs off an 18 volt Milwaukee battery. I don't want another charger and battery system.

Please clarify, risk of fire from electrical inside the wall or the vehicle, or inside the wires in the blanket?

Does getting a converter make sense?

Sorry if this is nonsense questions. I am not experienced with 12V or 18V systems.

Electrical in the wall is much more likely to have a fire with a 1500w spaceheater than a 65w electric blanket. A low wattage heating device is no more likely to cause a fire in house wiring than any other small load, and it's quite unlikely.


Fire from the blanket/pad itself seems like a real risk, but I have no data to quantify. I can think of a couple ways it could in theory happen... and I have certainly heard of them catching fire, but never have I seen the exact mechanism explained! I am betting on option 1.

1) The heating elements in these are just wires carrying current. Physical wear or damage can lead to a short, leading to a spark, leading to a fire.

2) The unit could be sufficiently insulated that it gets hot enough to ignite something.

Hm, this somewhat alarming page on this subject confirms these are risks, and mentions that other stuff could also overheat. I read that as faulty design or poor workmanship/shit components could lead to the wiring/plug/power supply burning up.

https://www.electricblanketfires.com/causes-of-electric-blanket-fires/


I sure wouldn't sleep with a $12 one plugged in!

Dale Hodgins wrote:I've never seen anything on these proximity issues, that I would call evidence. The real risk is fire if you get a really cheap one.

Last night I found some 12 volt electric blankets for as little as $12. I'm tempted to go that route, but I would much prefer to find something that runs off an 18 volt Milwaukee battery. I don't want another charger and battery system.

Very annoying that the only option right now for M18 is a USB power output gizmo. And it's only a single 2.1A port, so about 10W. Just silly.

You could chop up an old m18 tool and wire it to a 24V elec blanket with about a 25% loss of output...

Short and spark are probably the most likely way that a blanket could ignite. But you might also have a situation where most of the blanket is nestled within other blankets, while the thermostat is in the cold air and not insulated. I think that could allow the unit to just keep adding more and more heat, since the thermostat would not sense that heat buildup. I haven't had one apart. I'm guessing a unit with multiple thermostats would be safer, if it shuts down whenever the first one reaches a certain threshold.

When things burn , it's always difficult to figure out exactly what happened.

I'm going to check out the statistics on this. If it's one in a million , I'm okay with that. I've laid in front of a fire, while wrapped in blankets. I'm pretty sure my chances of being set ablaze, were considerably more than one in a million.
.......
Here is a very safe alternative. I have had a miniature oil-filled radiator. The type that look like an old hot-water radiator but they plug in and are filled with oil. If one of these is preheated, and then shut off, it can be placed along the side of the bed with one blanket going to either side of it, so that heat rises up between the two blankets. Not a perfect system. It is just about a perfect system for heating a very small enclosed space like I described earlier. A blanket tent or other enclosed sleeping area would be heated with one of those, quite safely. And you don't have to listen to fans or something that buzzes all night.

Dale Hodgins wrote:Short and spark are probably the most likely way that a blanket could ignite. But you might also have a situation where most of the blanket is nestled within other blankets, while the thermostat is in the cold air and not insulated.

Yes, though I'm going to wonder how this would apply with apparel, especially at joints, like elbows and knees, over time. With my mattress pad, it doesn't get bunched, and the wires don't get bent, just impacted.

Maybe the wires for wearing would need to be prohibitively thick/insulative to be safe. Hmm. There could be an AFCI, arc fault circuit interrupter, but I don't know how large or expensive that would be.

Your article you provided a link to refers to a "safety circuit." Maybe this is an AFCI?

Surprise! I didn’t buy a heated jacket!

Buying the whole heated jacket? What if I don’t like the jacket? I wanted a hood, but not many I liked had hoods. I like washing my clothes, and doing so without worry.

Instead, I bought heating elements designed to be placed in a jacket, to separate the two. I will probably do something else with my unit, like put it on belts or sew a pocket into a vest. I preferred buying this unit because it allows for a lot more control. I can put the heat very close to my skin, with just an undershirt, and try maximum, or add padding and use the low setting for just a bit of heat. I can try moving the three different heating areas to see what works best for me. It allows for a lot more control.

The downside is that this product seems to have less heating time than other products on the market. I can't wait until I am able to try it.

I have been loving electric mattress pads since I moved off off-grid last year. I have one lower wattage one, maybe 100W, which is only lukewarm so I leave it on for most of the night when the bedroom is really cold. Another one, maybe 140W, gets hot enough I can preheat the bed for half an hour and then turn it off and get inside. Mmmm!

The instructions say to put it under the bottom sheet so that it doesn't get bunched up or crinkled or twisted.

This is an interesting topic, one I've been experimenting with the last few years. I prefer to heat as small of a footprint as possible, while still being comfortable. I've found in ideal conditions, I can heat just my immediate self while sleeping, but the big issue is during the day while engaged in leisure activities (writing, reading, watching tv, etc). When active, of course, I'm plenty warm with the right layers.

Sleeping warmth is achieved through layers. I sleep in a hammock full time (got rid of my bed 3 years ago, which immediately fixed chronic neck and back pain), so I've found adequate under and over layers, as well as sleep clothing layers works well and I sleep toasty warm. I'll be adding a full length hammock sleeping bag (that wraps around the entire outside of the hammock and zips up like a mummy bag) for sleeping at the lake property.  

During the day, I have found I am quite comfortable at 65 degrees F. This is while wearing some combination of thermals, double socks, sweatpants, sweatshirt, neck gator, etc. I add and remove throughout the day as my body temperature adjusts (which, surprisingly, has wild, although somewhat predictable, swings).  

Of course, this would all be fine and I hope to accomplish the heating with a wood stove out on the lake property in the shelter, BUT, there will be no running water, no plumbing, no pipes, etc. At my house in town, I have all this, and I've found I cannot heat just one part of the house (such as a single room), as there is risk of pipes freezing in the cold parts of winter (though these are rare).

This is why I'm wanting to move away from such supposed luxuries, that tend to demand from their occupants more than is often expected. Having to heat most of the house, even at a lower temp demands more money through the winter months, which require I trade my finite time to afford the increase. I would prefer (as Thoreau suggested) to learn how to live without the luxury in order to spare having to trade my time for the required expenditure. Otherwise, do I really own my house, or does it own me?

With the shelter on the lake, I don't plan to have much of any heating during the night while sleeping. I will stay warm (fingers crossed) by layers and immediate covers on my hammock (this has been tested down to 25 degrees F and it works rather well, needing still a few adjustments). During the day, when idle, I plan to heat with the wood stove in a footprint shelter of 8x10. Just me, a hammock, a recliner and a small wood stove. What else does one really, truly need?

This does not factor in electronics, which I've learned do not take kindly to cold temperatures for any duration. My cell phone stays on my person most of the time and is kept warm enough just by its proximity to my body heat. The laptop, when not in use, I keep bundled up in my sleeping blankets in my hammock, and at night, I slip it in between my hammock and the underquilt. This seems to work rather well, though more testing will be needed. Thankfully, the majority of the year, ambient temps stick close to 65-75 degrees F, so nothing is needed but shorts and T-shirt.  

It's quite lovely living in paradise.

Isaac