Made for homes with less than 3,000 square feet of floor area, the Warmsource Total Warmth System stuffs all the manifolds and controls into a little tank on top of the main storage tank. Cost: about $9 per square foot of floor area (includes hydronic unit, tubing, and manufacturer’s radiant panel underlayment). The system’s X10 thermostats eliminate the need for low-voltage wiring. WarmBoard, 877.338.5493, warmboard.com