Looking for an Improved Over Window Collector

There is a lot of interest in solar air heating collectors that work with an existing window.  One of the more popular ones has been the Mother Earth News Heat Grabber.  These collectors don't require punching new holes in your wall, are simple to build, and they can be seasonally installed.

This work is an attempt to go a step further with collectors that work in conjunction with an existing window.  The hope is to both improve the aesthetics and to include more collector area.

Clearly there is plenty of room for improvement, so lets hear your ideas.

One think I want to make clear up front is that solar collectors that just fit over or in an existing window without increasing the collection area of the window do not work -- they do not end up collecting any more heat than the window alone.  There are kits out there for collectors that fit in the window -- they are ineffective.

Collector on left window -- regular window on right

This first cut prototype sits over the window and extends out to both sides and on the top and bottom.  It increases the collection area from 12 sf for the window alone up to 45 sf -- a pretty good increase in heat gathering area.

Outlet manifold on top supports screen absorber and pulls in
the hot air across the collector width, and sends it
down the vertical pipe and into the room
The room air inlets are on the right and left at the
bottom of the window.

Inside view -- inlets on right and left -- outlet with fan in middle.

Some of the outstanding questions...

• How to make it look nicer and how to better integrate the collector with the house design
• How to improve the efficiency of the collector.
• How to get even more collector area.
• How to make it easy to install.

For more details and to contribute suggestions ...


Gary