Solar Porch Air Flow

Foxtatic

New Member
Joined
Nov 23, 2021
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2
Hi! Starting my solar journey with this passive system build. I've installed greenhouse panels on 3 sides of my south facing porch. 16mm triple wall with a 2.5R value. Next will be insulating floor and ceiling, then connecting it to the house. That’s where I’m stuck.

The idea is to connect an air inlet from the basement window so that air will be heated and enter the house through the house window (open at the top) and convect in a loop down the basement steps. But where should that basement air enter the porch floor?

Basement window is right below the house widow and I fear that air entering right below the house window will just “path of least resistance” straight up and into the house without picking up much heat. On the flip side, if I make the air path too convoluted (like running a duct from basement window out to the front of the porch/glazing) it would cause too much resistance via 90 degree bends. Any thoughts appreciated.
 

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circus

Solar Addict
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Jul 8, 2021
Messages
271
No need for ducting, natural convection will take care of it. Do you plan any flap valving to stop reverse convection?
 
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Foxtatic

New Member
Joined
Nov 23, 2021
Messages
2
No need for ducting, natural convention will take care of it. Do you plan any flap valving to stop nightly reverse convection?
Are you thinking that air entering directly below the window is good enough then? I guess the circulation won't be so strong that it will "suck" the basement air up, so maybe it will just spread out across the floor of the porch and rise as it warms.
Not sure if I'll do flaps or just plan on closing windows at night.
 

circus

Solar Addict
Joined
Jul 8, 2021
Messages
271
A valve made of a plastic shopping bag covering a screen would suffice. Automatically prevents cold drafts whenever the porch is cooler than the house. Day or night. The lower one is the most important. Close the window if you want.
 
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