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Hey Everyone...Im Looking For Any Advice On Solar Power Heater For My Bedroom Answered

Hey Everyone Im Looking For Any Advice On Solar Powered Heater...

So Heres My Problem I Just Moved Into My Friends House And Its Big And Cold All Day long...And Since I Work From Home...I Just Cant
Afford To Be Running An Electric Heater All Day...So Im Curious If It Is Possible To Have An Electric Heater A Cheap One I Bought From Wallgreens Of Off Solar Power...So I Can Heat My BedRoom...

I Can Afford About 150$ Total For The Project...

Any Advice Comments Or Help Is Very Much Appreciated...I Love Instructables...Haha...

Thanks To Anyone Who Can Help...


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9 years ago

Most of the time when i am at home, i am sitting in one spot (watching tv or searching the internet). Since the human body puts out about 300 btu's per hour, why not use that heat to keep yourself warm? Here's what i have done and it works GREAT: I got myself a sleeping bag (used for camping), and place it in the chair where i am sitting. I zipper it up about half way to keep my legs warm. Then place a soft blanket over me... wrapped around me to keep my upper-half warm. My arms and head are the only thing exposed to the cold room air. If i need to get up, it is easy to get in and out of the sleeping bag because it only covers my legs. My house stays at about 60 to 65 degrees (f) most days WITHOUT RUNNING THE FURNACE AT ALL. I am toasty warm and comfortable without running any heater. If you don't have a sleeping bag, you could use a large blanket folded over on itself and hand-sew it like a big "bag". Using this method, I am able to leave my furnace almost totally OFF during the months of OCT, NOV, and DECEMBER. Then january/febuary it is REAL COLD so we turn the furnace on for those months. Soon it is MARCH, APRIL, and MAY... we turn the furnace OFF again. Last year, the wife and I just used blankets, but this "sleeping-bag" idea works LOTS BETTER. I live in the middle of the USA, so it does get pretty cold here in Jan and Feb. I don't like giving my money to the gas company. It's not that i am too poor to afford the bill, I just get a kick out of keeping my money for other things.

Jack A Lopez
Jack A Lopez

9 years ago

They always say that, I mean the people who post questions to this forum often say that "any advice" is appreciated.

But are you really going to appreciate it when I tell you how naive this solar-powered-electric-heater idea is?

I love questions like this... Ha Ha...

The technology involved in turning sunlight into electricity, typically involves photovoltaic modules,
and these are costly and inefficient when applied to the task of simply heating something.

In contrast, turning sunlight directly into heat is simple and cheap.  Just painting something black, and leaving it out in the sun, will cause that object to get warm.  If you've got some glass too, that's even better.  Put a black object behind glass, and the sunlight moves through the glass (with little loss), heats the black object, and then the glass keeps the warm inside air,near the black object, from mixing with the colder outside air, in the outside part of the world, where the sunlight is coming from.

Now at first this is going to seem unbelievable, because I suspect you are someone with a great deal of admiration for modern technology,and naturally you'll suspect that the more "modern", and expensive solution is the "better" solution. Just painting something black and leaving it in the sun, that's far too simple. Right?

But if you look up the cost of photovoltaic panels, at the time of this writing, you'll find that about the best deal on PV you can find is about 5USD per watt.  So essentially that means you take that 150 USD, you can afford, and buy one 30-watt PV module, this will, as the specification implies, give you about 30 watts of electric power, while the sun is shining on it. 

As you can already see from looking at the label on your electric heater, 30 watts is not going to make your room significantly warmer.  Or that is to say, a typical electrical heater is rated at around a KW (1000 watts) or so. To make the room warmer you probably want a few KW, of heat

Back to what I was saying about painting things black, the amount of raw power (energy per unit time) in a square meter of sunlight is also about 1 KW. Seriously. It's really that much!
So if you have a south facing window, a few square meters in area, and the sunlight is shining straight through it, you really are getting kilowatts of power flowing into the room.  Typically the sunlight is not shining straight through it, so you know, you multiply by the cosine of the angle the sunlight makes with the normal of the window (where cos(0)=1 )

Of course one drawback is that the heat appears where black absorber is, and then after that it may be difficult to move the heat to the place where you want it. For this reason it helps if the place in the sun is also the place where you want to get warm. 

If you could just move your daytime activity to the south side of the house, where the sun is, and maybe put up some black curtains to absorb the sunlight and re-emit it as heat, then that would be the easy way to do things.

If you want to move heat from one side of the house to the other, or store heat, then that's going to involve mass flow, you know: plumbing, moving air or water from here to there, and that might sound troublesome, but ultimately that will be cheaper than photovoltaics.  

Also thermal insulation might be part of the part of the equation.  If you make the room better insulated, then the heat in the room will leak out more slowly. 

Again I apologize for bringing up topics like plumbing, and thermal insulation, because those are a lot less sexy than photovoltaic modules, and wires, and power convertors, but plumbing and insulation are truly what is involved for transporting raw heat.

Alternatively you could use a system of mirrors, to pipe the energy from one place to another as sunlight... There are such things as skylights and shiny reflective light pipes, for bringing sunlight down from the roof of a building. Something like that would also probably more expensive than 150 USD.

In the related panel, on the right there,
it looks like there are some ideas of the black-painted-plumbing variety, and that stuff really works. You know, you put stuff that's black in sun, and it gets warm, or even hot, depending on how you do it. 

Anyway, I hope this advice is appreciated.


9 years ago

....add insulation to the room and/or you.

Typical electric heaters are around 1000W - that's a couple of thousand dollars of panels, and we're in WINTER and there isn't a lot of sunshine at this time of year. To get 1000W in winter you'd probably need a 10,000 W installation.

Winterise your windows with secondary double glazing - polythene sheet taped over the window frames will make a BIG difference cheaply.



9 years ago

Sorry, it ain't practical on several levels.
  1. Cost too much.
  2. IF you could afford IT would weigh too much.
  3. SF is cloudy too much.
You have other ways to go :
  • Wear a ski suit
  • Convert a South Wall, Door or Window to Catch some rays to heat air in one room.
  • Get an office job.