System fluid capacity calculation?

CarGuy

<span>Hello, we will be filling our garage floor heating system soon (it is a closed system dedicated to a 40x40 detached garage). </span><span>Could anyone provide some insight as to how to determine the fluid capacity of a system with approaximately 1700 feet of 1/2" pex?  I ask as we will be using </span><span>the appropriate antifreeze at 50% (a product such as DOWTHERM) and I need to determine how much to buy for the mixing. </span><span> We are trying to find a supplier for the product in our area and I'd like to go in with some idea of quantity needed.</span> <span>Thanks</span> <span>Chris</span>

cattledog

.92G/100'

Wirsbo specifications indicate that 1/2" nominal inside diameter tubing contains .92 gallons per 100 feet of tubing.

meplumber

50% is a little much.

Unless you are in northern Alaska or Northern Canada, 50% might be too much.



A 30% mix is sufficient for our climate here in Maine and keeps from putting too much strain on the circulator.



Cattledog's information is dead on.

CarGuy

Thanks!

I'm in Southern Ontario Canada, similar climate to most northern states.



Chris