They look like traditional window treatments, but these blinds are actually SolarChoice Heaters – a passive solar heating system developed by Minnesotan Keith McKenzie.

Currently the University of Minnesota Duluth is testing the product to see if they can replicate the 35% savings in heating costs that McKenzie has experienced.

 

Writing about these panels, Bobvila.com explains,

Each plastic vane has a hollow channel running its length. Cold air enters the channel at the bottom of the blind, warms up through passive solar heating, and exits out the top of the vane — at temperatures as high as 140 degrees.[...] Thousands of BTU’s of heat are exhaled into the room with zero emissions, zero operating cost and zero maintenance needs.

SolarChoice Heaters are available at the Green Products Company.