Have read some of the responses to other guys problem and thought this would be a good place to get some advice. i got in way over my head on the radiant heat install. i have 9 loops of 1/2" pex the 261',3 at 254', and 5 at 250'. some under carpet and some under hardwood. the lay out i have for this is in 8" spacing and some 10" spacing. also was running it all as one zone for a 70 degree time thru out the house. i have no idea how to figure the heat load. is there an easier way to figure what pump i need. i read one post were a i guy said that max. of .6 gpm per loop for 1/2 pex. he then multipled that by the number of loops and got a gmp and feet of head. can someone throw me a life jacket Please!