Supplemental Energy Source

Solar air heating works on a principle similar to that of how your car heats up when left out in the sun with the windows closed.  So you may be able to use that as a relative comparison.  "Recirculating" air heaters take the air from inside your house and then heat it up in the collector before venting back into the house.  These collectors can often raise the temperature of the indoor air by an additional 50 degrees.  If you have a well insulated house, it will help retain the heat throughout the day.  It sounds like you have a sunny location, and that is what is most important.  Both the Cansolair Solarmax 240 and the Solarsheat 1500G from Your Solar Home are manufactured in Canada - where they know cold!

So to answer your question, "Is this a viable alternative?" I would say it could well be.  For under $2000 you would have a supplemental heating source that would allow you to utilize your main heating system less often during the day.    Additionally, there are some product reviews on the Alt-E website, so there is real feedback about these systems in place. 
 http://store.altenergystore.com/Solar-Air-Heating/Cansolair-Recirculating-Solar-Air-Heater/Ra240-Solarmax-Solar-Air-Heater/p297/
http://store.altenergystore.com/Solar-Air-Heating/Your-Solar-Home-Solarsheat-Products/Solarsheat-Recirculating-Air-Heating-Sys/Your-Solar-Home-Inc-Solarsheat-1500G-Glazed-Solar-Air-Heater/p2282/

Good luck and send some of that chilly weather to us in New England!  Kristen

Solar heating will work just about anywhere, but whether it is the most viable solution to your problem is a more difficult question to answer. This depends on many factors, such has how many cloudy days you have in the winter, the cost of your current heat source and what other alternatives may be available to you.

If you answer/research some of these details, along with details of your current insulation, we can get closer to a sound answer. Meanwhile, I'll bet dollars to donuts that conservation measures like better insulation, better weatherstripping and better window coverings will be a more viable investment.

For more details on possible energy investments, see my blog.

Energy Guru
www.energy-guru.blogspot.com