# turning sunporch into a solar collecter?



## weemntfolk (Dec 27, 2005)

We have a 3 season (uninsulated) sunporch covering half of the front of our house. (south west facing)
Windows with tight, sliding storms cover both exterior walls.

The kids and I had planned on attempting to making the box collecters (that fit into a slightly opened window), but I'm wondering if it would be possible to convert this entire space into a passive solar collecter.

Do you think any effort toward this goal could be cost effective?
I thank you in advance!


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## greg273 (Aug 5, 2003)

What is the floor made of?


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## MELOC (Sep 26, 2005)

there was a post with a link onetime about a guy who didn't by fuel oil for like nearly 20 years or so. he had a sunroom that he used in this way. he had alot of other stuff going on though.


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## weemntfolk (Dec 27, 2005)

The floor is (probably) press board with heavy duty 1940's linoleum.
Underneath the floor is a stone lined crawlspace that connects to the very warm basement.


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## greg273 (Aug 5, 2003)

If the floor will support it, you could add barrels of water to soak up thermal energy, which will moderate the heat in the day and release that energy when the sun isnt shining. I am planning on such a setup for the south side of my house, using recycled patio doors and corrugated fiberglass panels.


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## blue gecko (Jun 14, 2006)

Is there a vent to the space from the basement? If so you can put a fan blowing inward in a window during the day with the inside basement door ajar for return air flow. This would create a closed loop air circuit with warm air coming into the house. I have a geenhouse used in this way with a periferal air intake running underground and entering into the back of the basement. Fans in the windows going into the greenhouse from the house are used to control the air flow.


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## SolarGary (Sep 8, 2005)

Hi,

Glazed sun porches can be very good solar collectors. 200 sqft of sunporch glazing will capture about 320,000 BTU on a sunny winter day. You might be able to transfer about half that into the house depending on the outside temperature and how tightly sealed the sunspace is -- thats equivalent to a couple gallons of propane burned in an efficient furnace.

The solar gain you get is pretty much proportional to the area of the collector, so you will get a good deal more gain from glazing in the whole porch than from doing the small window collectors you mention.

There are two approachs to using and getting heat from a sunroom:
Maximum heat to house:
For this scheme, you 1) glaze the sun porch (to collect heat), 2) minimize the thermal mass in the sunporch itself (ie no water barrels), 3) have a way to move heat from the sun porch to the house when the sun is out, and 4) have a way to shut off the sun porch from the house when the sun is not out. This approach avoids heating the sun porch itself, and transfers a maximum amount of collected heat to the house.
With this approach, the sunroom temperature will drop like a rock once the sun goes down, but you get max heat to the house.
Here is an example of that approah:
http://www.builditsolar.com/Experimental/ShurcliffPart1/PolySpace.htm

Maximum Sunroom Comfort with some house heating: In this scheme, you add more thermal mass to the sunroom itself (like water containers, masonary, ...). The extra thermal mass collects some heat during the day (which does not go to the house). After sunset, the thermal mass gives back the heat, and keeps the temperature up in the sunroom. You get a sunroom that is more comfortable, but you lose some house heating.

Tons of sunromm plans and guides:
http://www.builditsolar.com/Projects/Sunspace/sunspaces.htm

If you want to see how well this might work out without going to a lot of trouble, take a look at the "Instant Sunspace" article by Laren Corie at the link above. For $20 and an hour of work you can see how well it will work -- I am guessing you will be pleasantly surprised. 


This is a really good book on designing sunrooms and attached greenhouses:
The Homeowner's Complete Handbook For Add- On Solar Greenhouses and Sunspaces, Andrew Shapiro
Its out of print, but you can get it on Amazon.com used books for next to nothing.

Gary


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