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The Zen of Passive Solar Heating Panel Design (2010)

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Re: The Zen of Passive Solar Heating Panel Design (2010)

#11

Post by rzzzt »

imaginenore wrote: post #4

I 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…

Some people build these with painted beer can columns on the inside serving as air ducts, see this video for an example: https://youtu.be/nuxanLdtwZQ

They also tend to install it on the side wall; it doesn't get that much sunshine in the summer, but it becomes more efficient in the winter when the Sun stays at lower angles. External circulation of air is still required and is usually done by using an electric fan.

Re: The Zen of Passive Solar Heating Panel Design (2010)

#14

Post by themartorana »

samcheng wrote: post #3

Here'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…

So what's stopping a setup like this becoming standard? It's obviously generally superior, at least for new construction that's well-insulated. Right?

Re: The Zen of Passive Solar Heating Panel Design (2010)

#15

Post by swampthinker »

themartorana wrote: post #14
samcheng wrote: post #3

Here'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…

So what's stopping a setup like this becoming standard? It's obviously generally superior, at least for new construction that's well-insulated. Right?

Because this is better than building code, and builders really don't have a huge incentive to go beyond code.

Re: The Zen of Passive Solar Heating Panel Design (2010)

#16

Post by maxerickson »

themartorana wrote: post #14
samcheng wrote: post #3

Here'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…

So what's stopping a setup like this becoming standard? It's obviously generally superior, at least for new construction that's well-insulated. Right?

They won't work very well when they don't have good southern exposure, they won't circulate a lot of heat if you have rooms and doors.

Meanwhile, the direct operating costs for natural gas heat aren't all that high.

Re: The Zen of Passive Solar Heating Panel Design (2010)

#18

Post by devenson »

If he just made large windows out of the same double walled polycarbonate panels, wouldn't they collect just as much heat from the sun during the day? The problem with windows however is they don't insulate as well. Perhaps just doubling up or tripling their thickness would achieve the same result in the end, and be much simpler. What am I failing to understand?

Re: The Zen of Passive Solar Heating Panel Design (2010)

#20

Post by nkurz »

devenson wrote: post #18

If he just made large windows out of the same double walled polycarbonate panels, wouldn't they collect just as much heat from the sun during the day? The problem with windows however is they don't insulate as well. Perhaps just doubling up or tripling their thickness would achieve the same result in the end, and be much simpler. What am I failing to understand?

What am I failing to understand?

You might be missing that maximizing heat collection while the sun is shining is not the goal, that too hot in the day can be just as bad as too cold at night, that each layer of "clear" polycarbonate (ie, 2 for twinwall) blocks about 10% of the light, and that gaping curtainless windows are not always a desirable architectural feature.

How many buildings have you been in that have expansive south facing windows? How many of them have been comfortable day-and-night year-round in a harsh climate without mechanical heating and cooling? Very few buildings achieve this, and I'd guess that none of them have large windows.

The Introduction to to the article is a good "introduction" to the issues. The rest of the article explains the introduction. If you are interested in the issues, it's a good article, worth reading in depth. But as the author says in the preface, "I’d suggest reading this when you’re in a “learn” mode – because if you’re in “skim” mode, you’ll just be wasting your time."

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