Tapping 1/2" PVC Into Existing 1-1/2" PVC Pool Return

[garybtru]

Hi all, currently we have a 1hp hayward pump and 1-1/2" PVC coming out of the filter and into the ground (eventually into the pool, lol) as pictured on the left:



On the right, as you can see I want to hook up a 1/2" PVC pipe supplying hot water that uses a separate 1/25hp (8 GPM) pump. I know the bare minimum on head loss/gain and all that. I read the "Hydraulics 101" post here which was helpful! But does this setup seem feasible? My hope is that since the water is already flowing down toward the ground, in addition to the check valve, this should work.

Thanks!

 

[duraleigh]

The flow will work but I question that a 1/2" supply will do much to heat your pool. Where are you getting the water from?

 

[garybtru]

The flow will work but I question that a 1/2" supply will do much to heat your pool. Where are you getting the water from?

Cool, thanks! It's honestly less about heating the pool and more about cooling down some crypto miners! But even if they heat up the pool a couple degrees, that's better than nothing I guess!

 

[trivetman]

It sounds like the hot line does not have a lot of force on it with your pump being only 1/25 hp. When the pool pump is in operation the check valve will prevent backflow but there will be force against the check valve. Will your little 1/25 pump be enough to generate flow against the pressure generated by the pool pump?

 

[garybtru]

It sounds like the hot line does not have a lot of force on it with your pump being only 1/25 hp. When the pool pump is in operation the check valve will prevent backflow but there will be force against the check valve. Will your little 1/25 pump be enough to generate flow against the pressure generated by the pool pump?

I guess that was my main question! Thanks for phrasing it better than I could, lol. I'm hoping the answer is "yes" since the flow of both is aimed downward... total newb to plumbing and the like. Another issue I think I'm going to run into is the brazed plate heat exchanger is stainless steel with 99.9% copper brazing... and chlorine and copper aren't really friends are they? So I wonder what kind of life expectancy I can... expect... for the heat exchanger. If I end up having to replace it in a few years at least, I think that'd be worth it. I read somewhere it's possible that it turns the pool water green.

 

[trivetman]

My gut tells me that gravity won’t help you much against the pool pump. But if it doesn’t work turning the pool pump off for a bit to allow the hot line to flow might be an option. Will the small pump even generate enough force to open the check valve?

Yes…the folks who know more than me on this forum definitely don’t like copper in the water. It can be an ingredient in some non-recommended sanitizing products. No idea the degree to which your copper brazing will leech into the water but one of the chemistry gurus might chime ln on that.