Snowmelt in Summer

PhillipJones

We are doing a large snowmelt system this fall that will be about 20,000 SF with 3/4" tubing on 6" spacing, and (6) 399,000 btu boilers. The homeowner is also interested in harvesting heat out of the driveway in the summer for pool heating and domestic pre-heating. Any control strategies are welcome. There will be (5) remote manifolds fed by 2" dual-insulated pex, each with a Grundfos UPS 32-160 circulator. I'm thinking a pair of closely spaced tees somewhere on the system side to add a summer heating zone that would not affect the boiler side. The circulators will be on high in the winter, but could be switched to low for summer. A flat-plate HX would be needed, but don't want it sitting on the main system due to flow restriction.

hot_rod

if you size the HX correctly it should not add but a few ft head

You could add a couple manual valves and tees into the SIM supply return lines, direct to the hx, piped just before it goes into the boilers

PhillipJones

20260727_112704.pdf

Ok. I've sketched where I might add a HX for summer auxiliary usage. The system will use a Tekmar 671 for control in the winter. I was planning to power the 5 system pumps through 5 of the 6 boilers, to balance the electrical load. However, if we opt to use the system in summer, should I think about a separate switching relay that could turn on just 1 or more circulators in summer? I doubt we'd need them all for summer auxiliary.

hot_rod

where is this located? How large of a pool?

In sunny warm climates pools can too warm in the summer.

The driveway is basically a large un-insulated collector, efficiency can be quite high, but when ambient is near pool temperature.

So how many days is the driveway surface warmer than the pool? And the pool actually needing heat? Will it be worth the $$ to try and capture this "free" energy.

A handful of pool specific solar collectors may be a lot less $$, if you have a place to mount them. Typically the pool pump circulates through pool collectors. So no HX additional piping, controls. Or tying into those 4" lines near the sep!

More ideas here.

https://www.pmmag.com/articles/94473-pavement-to-pool

PhillipJones

Good point, HR- I may just try to steer this back to basics. Adding a bunch of tech to save a few bucks is not always worth the squeeze. The project is in Ohio, and I doubt the pool or domestic heat load would be sufficient to merit the additional cost. Just because you can does not always mean you should. Thanks!