Solar Air Heaters - Has anyone built one for their home?

[GumboYaYa]

I have the perfect house for solar air heat. The back of the house faces almost due South. The yard has giant trees that shade it in the summer but allow bright sun through in the winter.

We are going to start small with a window sized solar air heater and if it works well we may build a much bigger unit.

Who has experience with these? I'm interested in seeing designs and hearing succes or failures.

[htuttle]

1. Here's a diagram of one similar to one I'd built

I described this in another thread:



Warm air flows out of the top hole in back. Cool air is drawn into the bottom hole.

I don't know anything about this company, but a cursory examination finds all the usual passive solar heat equipment:
http://www.solar-components.com/default.htm

You'd probably want to shop around for prices (a lot of this stuff is probably cheaper at your local hardware store).

[GumboYaYa]

3. My basement has three very large windows that get tons of sun.

Do you think that I could use that as the face and build the box with the aluminum sheet and insulation behind the existing windows?

If I can, it would be easy for me to install a small duct with a vent into the first floor and use a small fan with attached thermostat to push warm air up there.

[htuttle]

4. Sure, I've seen plenty of designs like that

In fact, that would probably be better than having a pane of glass on the collector set behind the glass of the window (for a number of reasons).

You may or may not need a fan. One thing to consider is that the faster the air circulates through the unit, the shorter amount of time it has to get warmed by the metal collector.

You might also want to consider a different design entirely. If you have three huge windows that receive a lot of sun, what is the floor made of in that room? If it's something like concrete or adobe, the floor itself can act as an efficient solar heat sink (if it's dark colored and not shiny), and you might not want to block the windows at that point (you could hang the collectors outside and use ducting and a fan in that case). The floor will be heated during the day, and radiate the heat throughout the night if it's the right material.

When I've seen houses designed for passive solar from the start, most of them have an arrangement like that -- thick floor as heat sink by south-facing windows -- in addition to solar air or water heaters.

[GumboYaYa]

5. The windows are in the basement so they would not radiate heat

to the living area. That is why I am thinking of installing a small fan. The surface area of window I have to work with is about 6 feet by 14 feet, so I will be generating a good amount of heat on sunny days.

We also are installing a solar water heater and solar attic fans, but there are lots of sources for those at relatively low prices.

The more I research the air heaters, the more convinced I become that I can build one for pennies on the dollar compared to purchasing a system.

[CabalPowered]

2. Why not heat water?

Heating water with solar is much more efficient than heating air. The efficiency is obviously lower in the winter but would probably provide greater energy savings than air.

If you stick with air, you might try these guys..

http://www.gaiam.com/retail/gai_shophome.asp?&lid=gateway_page&lpos=shop

[happyslug]

6. Here is some web sites for makers of Solar Water heaters

I did some reserch on this in the late 1970s and even than was viewed not only as pracical but would save money:

A web site for Solar WateR heater:
http://www.realgoods.com/renew/shop/product.cfm?dp=2202&ts=1045508&kw=Solar%20Water

Here is a "Solar Energy Calculator":
http://www.focus-solar.com/energy_calculator.htm