Hydro Air Coil Pex sizing

[santanaf]

I am installing a hydro air coil in my attic and am running Pex up. The coil has 3/4 stubs for in/out. I have 1/2" pex I will be using for my radiant flooring application, and a Taco 007 IFC circulator. Will this be sufficient for my 36,000 BTU needed or should I run a larger diameter PEX. Boiler is 50' run from the air handler's hydro coil. I am insulating the PEX very well, esp in the attic.