Heat Absorber

[conscious]

My solar heating system is designed very similar to Norm Saunders' Cliff house with vents in the sunspace ceiling for hot air intake up to the attic where the mass is. According to Saunders, an absorber is essential for the proper function of the sunspace. He used black vertical blinds as an absorber.

Can I get some opinions on whether hanging black plastic sheeting underneath these vents will function as an absorber. During my tests, the plastic got very hot to the touch when the sun was shining so I assumed it was working as I expected.

Any insight is appreciated.

[wy_white_wolf]

While Norm called them absorbers, I think of them more as a transfer agent. Sun generates radiant energy that you need to convert to a convection energy to heat the thermal mass above. Just about anything that was dark (to keep it from reflecting the radiant energy), has low density (so it doesn't hold all the energy itself), and can withstand the heat would work. It might look tacky but I see no reason on couldn't hang strips of thin black plastic much like Norm did. I do think you need to mount them 1 to 2 foot away to stimulate the covection loop between the "absorber" and the windows. Any closer and you might loose most of the heat out the window.

How about getting or using some dark colored mini-blinds? or at least dark on one side and reflective on the other for summertime?

[conscious]

Originally Posted by wy_white_wolf

While Norm called them absorbers, I think of them more as a transfer agent. Sun generates radiant energy that you need to convert to a convection energy to heat the thermal mass above. Just about anything that was dark (to keep it from reflecting the radiant energy), has low density (so it doesn't hold all the energy itself), and can withstand the heat would work. It might look tacky but I see no reason on couldn't hang strips of thin black plastic much like Norm did. I do think you need to mount them 1 to 2 foot away to stimulate the covection loop between the "absorber" and the windows. Any closer and you might loose most of the heat out the window.

How about getting or using some dark colored mini-blinds? or at least dark on one side and reflective on the other for summertime?

Thanks, Whitewolf. One question: Why the need for strips? Why couldn't the plastic be one continuous sheet?

[wy_white_wolf]

one solid sheet would create 2 convection cells. One on each side of the sheet. It would be harder to incorperate both cells into the attic for heat storage without overheating the room.

Strips or mini blinds could include the heat rising on both sides into 1 convection cell. Encouraging only the one cell would also help keep the temperature lower in the rest of the room.