Heating room with infrared bulb

[Dimm]

Hi guys,

I'm working on a small solar project to power my room in my apartment. The lights and phone chargers are no problem but the issue of heating has been tricky. At minimum 700W the average space heater is a monstrous load on my battery.

Recently while studying under a bright 200W lamp I noticed that the temperature of the room would increase significantly when the lamp was on. By a couple of degrees. Which gave me the idea to heat with infrared lights. My room is tiny (like 8 feet by 9 feet) So I'm wondering if one 250 incandescent infrared bulb would be enough. I could simply point it towards my bed from accross the room while I sleep. At 8$ and 250W this would be a great find... if it works.

 So do you think it would?

Google searching revealed surprisingly little except people using infrared bulbs to heat sore muscles and garages. Searching this forum I only found passing references on how people used to heat their bathroom with an Infrared bulb at some point in time.

In general there seems to be little information.

Is there a reason people don't just have infrared bulbs in all their rooms?

[DamonHD]

It's still resistive heating, which turns high-exergy electricity into low-grade heat, though it does have the advantage that radiative heat does *feel* pleasant.  It's still not going to keep the whole room any warmer than the same fraction of a space heater.

Better, if you could do it, would be to have more clothing, some of it with embedded heating elements, ie heat just you the most, with the rest of the room rather less!

Otherwise a little heat pump will give you more than one unit of heat for each unit of electricity (CoP>1): our portable dehumidifier is under 200W, has a CoP>1, and has a pleasant breeze out the back too, for example.

Rgds

Damon

[birdhouse]

i use those same type of bulbs to keep 8" dry type sprinkler (fire suppression) risers from freezing in the winter, and it works.  but thats a far cry from home heating...

adam

[richhagen]

I have a small room about 88 square feet, it is insulated with r25 on the walls and ceiling, heated above and to one side, and it has a small 32 by 32 inch double pane window in it.  one side faces the outside and one an unheated back porch.  This room has a 250 Watt heat lamp in it.   Because it is so well insulated I believe you could just about keep it warm enough most of the time with just that lamp with the exception of the coldest months when the outside temperature can dip to below zero degrees Fahrenheit where I am at.  I don't actually heat this room except when it is in use though, and when the temperature is extremely cold and I worry about freezing - as it has a drain line along the outside facing wall - I open the door and let warmer air in from the adjacent room which has forced air gas heating.  This room is actually a bit too well sealed as when closed up for a bit it is actually a bit stuffy.

Most rooms of similar size however will have much more heat and air transfer and would require at least a minimum of double that amount of heat and probably a bit more in cold weather I would think.  The nice thing about the infrared is that it disperses the heat and feels warmer on your skin instantly.  The bulbs do burn out though, especially when accidentally knocked,  and the long term costs of heating this way are therefore likely a bit more than resistance heating.

Heat is transferred by convection, conduction, and radiation only, so eliminating any air leaks, adding insulation and curtains can reduce the heating requirements dramatically, and this is the place to start regardless of what type of heat source you ultimately use.

[ghurd]

I could simply point it towards my bed from accross the room while I sleep.

Might look into heating pads and what they would draw from a battery on low voltage DC.
All the heat would be under the blankets with you, as opposed to up near the ceiling.
G-

[dnix71]

I second GHurd. I live in a 14 by 15 foot room with block walls and little roof insulation. For those rare times it gets 'cold' by south Florida standards, a heated blanket is the only thing that works aside from expensive resistive space heating. There were times I would preheat the bathroom with a hair dryer and take cold sponge baths because I also had no hot water for 2 years. There is a gas water heater in the next apartment and it's shared. No occupant in #2 meant no hot water in #3.

The biggest drain on my batteries is the fridge in the summer, second is a 12v fan that blows on me at night to keep me cool.

The low setting on my heated blanket is 175 watts and that's plenty if there is a heavy blanket over that. Putting the heated blanket under me didn't work well because there are safeties built-in now that shut them off if there is a pinched cord or resistive element or one spot gets too hot. They also shut off after x hours and the only reset it to unplug and replug.

[ghurd]

The low setting on my heated blanket is 175 watts and that's plenty if there is a heavy blanket over that.

Agreed.

I use a heating pad instead of a blanket.  Wiki says typical watts is 65W on high.
I can't leave mine on low for long, and the blankets are not heavy by Ohio standards.

Math math math R-values cube-square radiation covection conduction reflection etc.
5W under the blanket is better than 250W from the other side of the room on the wrong side of the blankets.

G-

[Dimm]

Thanks for the ideas guys! They're all interesting. I'll look into them. I actually just got an Infrared Bulb and its not what I thought it would be at all. For starters, it makes a lot of visible light! I mean at 175W it makes about as much light as a 60W incandescent bulb. So my idea of sleeping with that over the bed is quite futile. But it does make quite a lot of heat.

As for the blanket heaters I'm not quite sure I see the logic. If all you're heating is your blanket and not the room why not just get a whole bunch of thick blankets and just use zero electricity? I mean I've slept outside at -20C (Which must be about -10F or something) with a winter sleeping bag. It wasn't an amazing experience but its definitely possible. It seems like heating a blanket is just making up for a blanket that's too thin.

And having another body under the blankets also helps heat things up

[Dimm]

And I'm not implying anything! A person at rest produces about 100W Of heat. So cuddling up with someone is definitely energy efficient.

[ghurd]

As for the blanket heaters I'm not quite sure I see the logic. If all you're heating is your blanket and not the room why not just get a whole bunch of thick blankets and just use zero electricity?

The logic, to me, is it makes the cold blankets warm faster than my skinny shivering butt does in 45 minutes, so I can get comfortable and fall asleep faster.

http://en.wikipedia.org/wiki/Bed_warmer

Notice they also mention your other idea.   
G-

[XeonPony]

I have 4 mobile biochemicle heating systems, they use no electricity at all! down side is at times they can be noisy.

4 dogs in bed with ya keep ya toasty! but not all ways asleep as the runt likes to snore right next to my head!

[Bruce S]

I have 4 mobile biochemicle heating systems, they use no electricity at all! down side is at times they can be noisy.

4 dogs in bed with ya keep ya toasty! but not all ways asleep as the runt likes to snore right next to my head!

Ours would be a 2-dog night cause the 3 cats don't equal one thick-furred mutt and a fuzzy Lab/mix.

[spottrouble]

I live in a little 40'x30' room, concrete floor/walls/ceiling, no way to insulate, with the fireplace blazing away room stays somewhere in the 60's depending on how cold it is outside (sometimes as low as -20F). The only way I stay warm at night is an electric blanket + 2 dogs and a cat

Kristi

[stag]

I know an old guy who lives in a wooden shack who built himself a box from foam slab to house his sleeping bunk and sleeps cosy and warm . Insulation and body heat are all you need. Also, when I worked on a fishing boat in the arctic, our bunks were like a cupboard with about 3ft headroom and sliding doors so you could shut yourself in, leaving open a bit for ventilation. again ,warm and protected from draughts. Pete.

[Mary B]

Several ways to insulate, furring strips on the walls/ceiling with foam board, directly spray foam on and plaster over it, False ceiling with lots of insulation above it...

I live in a little 40'x30' room, concrete floor/walls/ceiling, no way to insulate, with the fireplace blazing away room stays somewhere in the 60's depending on how cold it is outside (sometimes as low as -20F). The only way I stay warm at night is an electric blanket + 2 dogs and a cat

Kristi

[bob golding]

And I'm not implying anything! A person at rest produces about 100W Of heat. So cuddling up with someone is definitely energy efficient.

if you cant find another person large dogs are good. only problem is you have to take them out for a walk in the cold.  i use a dehumidifier. about 250 watts. you need the desiccant type, not the compressor ones. the rooms in our granite walled cottage are like fridges in the winter. 2 hours with the dehumidifier warms them up nicely.

[hiker]

110 v ac blankets put out rf waves--not really vary healthy to sleep under !!  they have 12v dc blankets that are much safer !     ???

[bob golding]

110 v ac blankets put out rf waves--not really vary healthy to sleep under !!  they have 12v dc blankets that are much safer !     

where does the RF come from? do they use switch mode power supplies?

[dnix71]

Mine does. The control unit has three settings and an auto timer shutoff with hotspot detection/auto-shutoff. It's too light weight not to be some kind of pwm control.

[spottrouble]

Several ways to insulate, furring strips on the walls/ceiling with foam board, directly spray foam on and plaster over it, False ceiling with lots of insulation above it...

Yes but all that would muddle with the architecture , I did put down a bunch of oriental rugs this year, if nothing else it helps when walking barefooted. Someday when I get to the floor above me I hope to lift the wood floor 6" and insulate area between the wood floor and concrete that makes ceiling in room below. Planning to try that new ceramic additive for paints too, it supposedly reflects heat, not sure if it works though.

Kristi

[ghurd]

110 v ac blankets put out rf waves--not really vary healthy to sleep under !!  they have 12v dc blankets that are much safer !     

where does the RF come from? do they use switch mode power supplies?

The only type I ever saw (pads or blankets) had 3 heat settings in an empty-feeling many-many contact switch.
2 elements in series, plus a diode.
2 elements in series.
2 elements in parallel.

G-