# solar collectors



## mondakkid (Oct 17, 2006)

Has any one made their own air type solar collectors....if you have I need a source for supplies. I need to find the temp control switch and blowers. Must get ready for the upcoming winter...might as well take advantage of some free heat.


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## fishhead (Jul 19, 2006)

Try looking here on Gary's site.

http://www.builditsolar.com/


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## MoonRiver (Sep 2, 2007)

mondakkid said:


> Has any one made their own air type solar collectors....if you have I need a source for supplies. I need to find the temp control switch and blowers. Must get ready for the upcoming winter...might as well take advantage of some free heat.


If you figure it out, please let me know. I am trying out PC fans. I bought a couple of DC 12V fans and ran 1 yesterday off a 9 volt battery. Seems to do the job, but I have no idea how to do the sensor part.

Here's a web site that probably has the parts:  Digi-Key

I also came across a guy that makes and sells a differential temperature controller. If I can't figure out how to do it myself, I may just buy a controller from him. He has schematics on his site, so if you understand electronics, you could probably make it yourself.


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## wy_white_wolf (Oct 14, 2004)

http://www.mobilehomerepair.com/solarheatswitch.html

Google "temperature controlled fan switch" and you'll find lots of them.


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## mondakkid (Oct 17, 2006)

MoonRiver said:


> If you figure it out, please let me know. I am trying out PC fans. I bought a couple of DC 12V fans and ran 1 yesterday off a 9 volt battery. Seems to do the job, but I have no idea how to do the sensor part.
> 
> Here's a web site that probably has the parts:  Digi-Key
> 
> I also came across a guy that makes and sells a differential temperature controller. If I can't figure out how to do it myself, I may just buy a controller from him. He has schematics on his site, so if you understand electronics, you could probably make it yourself.


Thanks....I have heard of some people using fans from overhead stove vents. The problem of using PC fans is that they are too small and not enough volume of air unless you have a real small collector.


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## mondakkid (Oct 17, 2006)

wy_white_wolf said:


> http://www.mobilehomerepair.com/solarheatswitch.html
> 
> Google "temperature controlled fan switch" and you'll find lots of them.


I found the sute,,,,good info and reasonable prices.....will order one today. Excited to start the project.


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## TnAndy (Sep 15, 2005)

MoonRiver said:


> I also came across a guy that makes and sells a differential temperature controller. If I can't figure out how to do it myself, I may just buy a controller from him. He has schematics on his site, so if you understand electronics, you could probably make it yourself.


You don't really need a differential controller on a simple heater like this.....any simple thermostat switch will work. DC's are really meant for storage of heat, so you don't pump heat out of a warmer storage area to a cooler collector.....they are used mostly on water storage/collector systems.


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## SolarGary (Sep 8, 2005)

Hi,
www.PEXSupply.com carries a wide selection of the thermal snap disk switches that are commonly used for solar air heating collectors. They just turn the fan on when the collector gets up a useful temperature.
Here is one example: http://www.pexsupply.com/White-Rodg...110-Degrees-F-Cut-Out-90-Degrees-F-14691000-p
and
Adjustable: http://www.pexsupply.com/White-Rodg...-F-Includes-Tab-to-Screw-Terminals-14699000-p
they have many more models with different temperature ranges.

Be sure to get one that closes on heating, as there are also ones that close on cooling. There are some where the turn on temperature can be adjusted -- I think this is a good feature. The switches are only about $10.

The air heating collector section on BuildItSolar is here:
http://www.builditsolar.com/Projects/SpaceHeating/Space_Heating.htm#ActiveAir

On the fan, you want about 2 to 3 cfm per sqft of collector. So, a 4 by 8 collector wants about 100 cfm. Fans are often rated by their free air delivery, but, the collector and ducting will have some resistance, so a fan that is rated at 100 cfm at free air typically won't deliver anywhere near that with the collector and ducting pressure drop. Its a bit involved to figure out exactly what fan is right, but if you get one that supplies the cfm you need with about 0.2 inches of water pressure drop, that might be in the ball park.

Gary

Gary


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## Jim-mi (May 15, 2002)

Its a good idea to use the snap switch to trigger a relay . . .to keep down on arcing of the snap sw contacts............


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## MoonRiver (Sep 2, 2007)

What if I only have 12vac?


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## SolarGary (Sep 8, 2005)

MoonRiver said:


> What if I only have 12vac?


I believe that the snap switches will handle 12VAC if you stay within the current ratings.
I guess you could email the manufacturer to be sure.

Gary


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## wy_white_wolf (Oct 14, 2004)

MoonRiver said:


> What if I only have 12vac?


Are you sure you don't mean 12VDC?


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## MoonRiver (Sep 2, 2007)

wy_white_wolf said:


> Are you sure you don't mean 12VDC?


Yes, that's what I meant. 

So what switch can I use with 12vdc?


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## TnAndy (Sep 15, 2005)

Any switch. Switches aren't rated by the voltage ( except on the high end ), they are generally rated by amperage.

What Jim was saying to you is a small switch won't take much amperage, the contacts inside the switch aren't rated for it. You use the switch to control a relay and get a relay that IS rated high enough for the amperage and it does the "heavy lifting".


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## mondakkid (Oct 17, 2006)

Thanks to all of you that responded to the Solar collector question....some very good replies and info. Here is something that a lot of people can build and use to help heat our homes. Must look into the tax credits if we build something like this. 
I still need to look for a source for fans. I will check with Grainger Supply Company. 
Gary gave a very good source for the control units and at a very good price. 
Thanks Gary.


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