The Zen of Passive Solar Heating Panel Design (2010)
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Re: The Zen of Passive Solar Heating Panel Design (2010)
#2That's pretty amazing! Clearly a lot of thought and effort went into getting the design nailed down.
Re: The Zen of Passive Solar Heating Panel Design (2010)
#3Here's the payout:
> This installation was completed in 2007 - and has been adequate to maintain the indoor temperature above 65°F/18°C since that time – even though outdoor temperatures in winter dropped below -20°F/-29°C and even though the nine-foot by nine-foot overhead door has been opened every morning and every evening.
> Before the end of 2009 the panels had saved more than their purchase price in fuel costs and the owner expects that the future savings will exceed the original cost of the entire structure. He told me he really likes starting every day (checking his livestock) in a nice warm truck.
Re: The Zen of Passive Solar Heating Panel Design (2010)
#4I actually built a similar system as an experiment, basically a 1 x 2 x ¼ meters (multi-layered) cardboard box painted all black inside and covered with a sheet of transparent plastic on one of the larger sides. It was really cheap, around $10-15 in materials. Then I added two holes (in and out), and put some cheap flexible air duct hoses with some old CPU fan, which was another $8. On a sunny day it heats up the air incredibly well, where it actually could be beneficial during the winter season.
Unfortunately there are big problems that I encountered that I couldn't solve cheaply.
1) Mounted on the roof, it has to be sturdy enough to resist heavy rains and strong winds. We get winter windstorms, and one winter it got up to 55 knots with 70 knot gusts. I have no idea how to cheaply mount this box on the roof so it doesn't fly off and kill someone.
2) Intake and exhaust hoses would have to go either through the walls or through the windows. And since I don't own the house, my only real option would be to cut circular holes in the windows, and then replace the glass when we move out. Again, not cheap.
3) For the winter months I would have to also insulate these hoses, or they would lose most of the heat on the way to the house.
EDIT:
I also think if you don't care about what your house looks like, you can either paint it black or wrap it in black plastic.
Re: The Zen of Passive Solar Heating Panel Design (2010)
#5Curious if anyone sells such panels
Re: The Zen of Passive Solar Heating Panel Design (2010)
#6I actually built a similar system as an experiment, basically a 1 x 2 x ¼ meters (multi-layered) cardboard box painted all black inside and covered with a sheet of transparent plastic on one of the larger sides. It was really cheap, around $10-15 in materials. Then I added two holes (in and out), and put some cheap flexible air duct hoses with some old CPU fan, which was another $8. On a sunny day it heats up the air…
> I also think if you don't care about what your house looks like, you can either paint it black or wrap it in black plastic.
Such heating will work during the day but transporting the energy from the heated plastic into the house is another matter. The hot surface also would radiate a lot of heat immediately away. And when the night comes you heat the sky with what you have stored up.
The article is fascinating as it shows what can be achieved on a system engineering level. As an engineer however I would also like to see some performance measurements like air flow and temperature deltas going beyond the anecdotal story keeping the build warm in the northern US. Did not see anything on his homepage.
There have been related posts on HN that showed advances on material science level where the absorption and radiation wavelengths of surfaces have been optimized.
> Unfortunately there are big problems that I encountered that I couldn't solve cheaply.
PV system cost these days is dominated by other costs than the solar cells. Engineering something that can withstand weather for a sustained period is both non-trival and not cheap. There may be some overlap in what PV systems require and what a passive heating system requires. Maybe the massive investments in the PV space make passive heating systems these days more practical?
Re: The Zen of Passive Solar Heating Panel Design (2010)
#7[deleted]
Re: The Zen of Passive Solar Heating Panel Design (2010)
#8I actually built a similar system as an experiment, basically a 1 x 2 x ¼ meters (multi-layered) cardboard box painted all black inside and covered with a sheet of transparent plastic on one of the larger sides. It was really cheap, around $10-15 in materials. Then I added two holes (in and out), and put some cheap flexible air duct hoses with some old CPU fan, which was another $8. On a sunny day it heats up the air…
maybe you can build a "plug" for the half-open window?
Re: The Zen of Passive Solar Heating Panel Design (2010)
#9Very interesting. I live in a place where we have significant issues with ice build up on roof surfaces, gutters, etc. One way to deal with this is to electrically heat the roof and gutters. This of course is expensive (very!). So I had the ideal that one could use the available solar energy (it is reasonably sunny in winter here) to melt the ice. My idea is not to use PV panels and restive electrical heating but to directly transfer the solar energy as heat to the ice. This would be done with some sort of heating panel, coupled to the metalic gutters with a heat pipe. Sometime I need to do some analysis to see if it is a viable idea. How to ensure snow does not cover the panel/solar heat collector is also a potential problem.
Re: The Zen of Passive Solar Heating Panel Design (2010)
#10See also http://www.builditsolar.com for more recent improvements and ideas for simple passive solar.