I built a garage (detached) last yr & put in infloor heat. Garage is 26' widex38' longx10' ceiling ;2"x6" walls & ceiling insulated, under concrete 2" insulation & insulation along outside of foundation has 2" of insulation down 2 ft.. Also 2- 8x 10 insulated overhead garage doors & 3 -3x3 windows and 1 steel insulated service door. I ran 4-250' runs of 1/2"pex tubing I just bought($250) a 2003 Lochinvar 45000 btu boiler 82% eff. which is 36900 btu output. The previous owner said he only put about 15 days use on the boiler because it was too small for what he was using it for. A couple plumbers said that this boiler would work fine for my use. I plan on setting the temp @ 55 -60degrees and leaving it. Ithougt about buying a new boiler but for the price of the used boiler vs. the better eff. of a new one it does not seem cost eff.( Approx. 10% savings a year) figuring to spend approx.$50 per month x 6 months=$300yr for a total of $30 a year savings. I will not be able to hook up my heat until spring because i need to bury a gas line from my house (about 100 ft) to my detached garage Any positive or negative feedback greatly appreciated!