In my opinion and from my vast experience with the Apollo heating systems they STINK! They are very, very inefficient and very uneconomical. They run forever to raise the ambient temperature 2 degrees. I am heating about 1700 sq. ft to 65degrees and it costs me an bundle to heat during our mild winters. I purchased the home new and have been greatly disappointed with the system from the first winter. Gas packs seem the way to go.