Garage Build #13 In-Slab-Pex Radiant Floor Heat Layout

We laid out our pex for our concrete in-floor heat. We ran 3 zones or loops 200' long. I'll show you our layout and some important tips to help you have the best experience installing your own pex in floor radiant heat.
My Tools:
Klein Pliers: amzn.to/3IKdV8T
Milwaukee Pliers: amzn.to/3Ysmon7
Rebar Tie Wire: amzn.to/41zQszN
Oxygen Barrier PEX: amzn.to/3y415gL
iCRIMP Ratchet PEX Cinch Tool: amzn.to/3KQEWdy

[@BS25999]

Not sure you are right with one of your comments about return flow temp. The cooler the return is the more efficient your water heater runs. This is because the cooler the water is, the more energy/heat it will absorb as it flows through the heater for a given time. The bigger the temperature difference - the more heat is extracted/transferred from the heater to the water. You then use flow rate to manage the heated water temperature instead of the heater coming on and off all the time, if you are using a heat pump you absolutely want to keep the temperature gradient as large as possible with cooler return flows. Long pipe runs can however be a problem because of the reduced flow rate and reduced heat radiation as the water cools past a useful point on long runs - nothing to do with boiler efficiency.

[@ezdeezytube]

Nice overview, and awesome your wife helped! Any reason you with that that pex-b instead of pex-a? I heard that oxygen barrier is important for the slab but not sure if thats specific to pex b

[@appalachiandiy2415]

Thanks, yea she's amazing! No idea if it's specific to a or b. I just wanted oxygen barrier.

[@jeremykillebrew5232]

Could I run 5/8" tubing at 500 ft circuits?

[@jonvenusti]

5/8″ Tube loops should not be over 400′