Non Barrier Pex in Driveway, what to do.

John Starcher_4

...is they used Aquapex to save some $$. Since the snowmelt needs to by isolated from the rest of the system and glycolled anyway, I don't see an issue, as long as all of your components are non-ferrous. It should work just fine.

Starch

Rob Blair

Non Barrier Pex in Driveway, what to do.

I was called in to hook up the driveway snowmelt to an existing system. The system has a pump, heat exchanger and all the parts needed to separate the systems. I built the snowmelt panel and when I went to hook up the tubing to the manifold I realized it was AquaPex by Wirsbo. What is weird is that all the other heating in the house uses Hepex. Other than the cast iron pump he supplied for the snowmelt side, every other part is copper or brass. Is there something special I need to do?

Thanks,

Rob

To add on, the homeowner supplied all the materials, I built the panel in my garage, and the supplied pump was already mounted. I figure that when the pump quits, I sell him a bronze WILO Pump.

Lil-Roc

Just use bronze or stainless steel pumps. Taco and Grundfos will be coming out with stainless steel versions of their 3 speed pumps shortly.

ALH_4

Oxygen Diffusion

The only thing you might do is use a bronze or stainless circ. The low temperature and the fact that the tubing is embedded in concrete will help reduce oxygen diffusion. The cast circ may last quite a while. If the owner is willing to risk replacing the circ in the future if it fails, he or she might just replace it with a bronze or stainless circ when that happens. Compared to the cost of fuel to melt snow, the cost of the proper circ is probably small anyway.

hot_rod

and a DHW type expansion tank

adjust pressure accordingly.

hr

John Starcher_4

OOOOOOOOHHHH!

Good point!

GLENN_14

Remember that any pex for snowmwelt may also need expansion loops before it connects to the manifold especially on long runs in snowmelt due to the expansion of the pex material on the runs. I have seen jobs where the manifolds have been bent and broken by the force of the pex on long snowmelt applications. The moral of the story is to ensure you have a place for the expansion to take place