I want to go solar, need some advice!

YerDugliness · 01-19-2010, 10:09 PM

Last summer I scored 8 free passive solar panels, each with a 1/4" thick single pane glass that is about 7' X 3'. I don't anticipate using these as-is, rather I anticipate using only the glass and the black aluminum sheet metal that the sun's rays heated up.

I know I will need to build frames, and b/c I plan on "ganging" multiple glass panels together I wonder if I could use some metallic house studs to build the framework....don't they come in a lightweight version? I so, it would be even better if they could have holes already cut into them so that I could run the tubing easily. I would most likely use the glass for the outer panels and place some clear greenhouse polycarbonate panels below them to provide an insulated cover.

The home is approximately 30' X 30' and has a "flat roof".....although, obviously, it is gently sloped downward towards the only drain. There is one large elm tree that is on the southwestern corner of the house, but I think I'll leave it there b/c during the summer it might just provide some extra shade to keep the water from getting too hot and during the winter it will be bare of leaves and shouldn't shade the collectors too much. I would like to use the panels to provide solar heated water for a large tank in my basement, which in turn would be used to "pre-heat" the water for my home's electric HWOD unit during the times when I am at the home (it is a vacation/project home), plus I would like to be able to manage some sort of manifold that will allow me to use the tank of hot water for a radiant underfloor heating system during the winter when I am seldom there. I would simply use a recirculating pump and keep the water flowing at all times, as there would be no issue of comfort with nobody in the home. If I can find a 12-V PV cell/battery that will allow for solar power of the recirculating pump, so much the better, I could even shut the electricity off to the home while I'm gone (probably Dec. 1 through March 31).

If I were to use all 8 of the panels, that would give approximately 168 square feet of collector surface......I have no idea how much heat to expect that to produce, so you can see that I'm at the very early stages of developing the project at this time.

Any comments/suggestions/recommendations would be sincerely welcomed!

Thanks in advance!

Dugly

Mr Chips · 01-20-2010, 10:13 AM

http://www.backwoodshome.com/articles/hackleman65.html

http://www.energysavers.gov/your_hom.../mytopic=12850

pyper · 01-20-2010, 11:24 AM

You can find tables that will tell you how many BTU's fall on your location in each month. You can probably find them online, but you can also find them in library books.

If you're heating water in tubes, then you need to have two safety features. You need a pressure relief valve, in case they get too hot, and you need a way to drain the water if it's going to freeze. If you're putting panels on the roof and heating water in the basement, then you need a pump, and control circuitry.

I was interested in solar for a while, but decided a wood burning stove was probably cheaper and more reliable.

One solar use that really makes sense for a lot of people is a "batch" solar water heater. If only they weren't ugly...

YerDugliness · 01-20-2010, 06:21 PM

Thanks for the links and suggestions, guys! All the information you have provided so far has been read and I find it very interesting.

I've already investigated a batch solar heater made from the tank of a gas-fired water heater. It might become the "preheater" for my electric whole-house HWOD unit during the winter, I think I can manage to "freezeproof" it with a little ingenuity. That removes one task from the rooftop solar system under consideration.....good news, no?

The home under consideration will have some heating assist from a very small wood-burning stove and also from a passive solar heat source, a "solarium" on the south side of the house that will not be adversely affected by the elm tree. It is my hopes that the solar panel can be engineered to provide enough "assist" as necessary so that the home can be kept "freeze-free" during my winter absences, that's all I really care about at this point. Current plans for the underfloor radiant system involve using a small 240V electric HWOD unit to heat the water, I could foresee that the HWOD unit could be energized/de-energized by some sort of thermostat and relay. That way the HWOD would function in flow-through mode until its assistance is needed, then it would kick in to ensure that gloomy days do not leave the home unheated--the only issue I foresee with that is that I would really like to be able to turn the electricity off at the meter box panel when I leave. Perhaps a large enough water storage tank in the basement mechanical room is the key to allowing for that. The home is located in extreme SW Kansas, which the government's charts describe as one of the best areas to use solar.

More ideas/comments/suggestions, please!

Dugly