New shop build radiant floor heating sizing heat source.

[miscjames]

I have posted a few questions about my shop build and you guys have been really helpful!

So my next question i have a 28x40 slab with 5 250’ runs of half inch pex. Is there a calc out there to figure out what size heating unit to put on it? I am think some form of water heater.

If i am calcing correctly there should be about 12 gallons in the lines.

The building will be the typical metal building with 12’ walls. Insulation will probably be 1.5 inch eps with reflective side facing wall with what ever air gap i can get ~1” (any advice here is helpful as well).

I live in East Tennessee Knoxville/ Pigeon Forge area.

My main goal is to keep the shop above freezing. But I dont think an ok working temperature should not be to hard to achieve.

So again Is there a calc out there to figure out what size heating unit to put on it? or a sizing guide?

Thanks in advance!

 

[ericm979]

HVAC Load Calculation - Maunualj - Whole House Loadcalc has a simplified manual J and S which is what (some) HVAC contractors use to calculate heat gain/loss and size equipment.

It's kind of tricky in that there are some innocuous looking fields that are really required and can change the output significantly.

 

[dadster4]

You can get by with a basic system with a water heater as the source, I installed many this way with no issues. OR... you can get elaborate like the system I built for a special barn/office of about 15,000 sq. ft.