If you want a house thermal, you want a refinery. Chicago glider club has two of them within 5 miles, and there are a lot of days in fall when cross country soaring involves a "refinery tour." Also some 7 knot thermals when nothing else is going up more than 3. Of course, if you arrive low and counting on it, you will meet the bubble theory of thermal formation first hand. It was interesting when it was shut down for a few months. You'd think sun hitting the concrete was most of it, and there was a thermal there, but the operation of the refinery made a big difference. Point your wing at the flame in the smokestack...

John Cochrane.