pex pipe btu rating

Nick Mason

Hello, my name is Nick Mason. I work for a Plumbing & Heating wholesaler in New Brunswick, Canada. I was asked a simple question the other day and could not really give a definite answer. What is the Btu rating per linear foot of 1/2" oxyguard pex pipe? I realize there are some variables that have to be taken into consideration, such as type of liquid, temperature of liquid, spacing of pipe and location of pipe. Is there a chart available that would give this information? My customer wants to be able to work out the heat loss of a room and then determine how much pipe is required for that room. I usually use a factor of 1.3 x sqft for in concrete and a factor of 1.7 x sqft for in joists to give approximately 30 btu/sqft, but he wants something a little more accurate. Lets say we are using water @ 120 F @ 9" spacing in between joists with 4" foil back insulation. Looking forward to your reply, Thank You ,Nick.