Just wondering if anyone has any recommendation on using a 2ton Waterfurnace water to water to heat a pool vs. a Waterfurnace pool heater? I am using the water to water geo unit for radiant heat in the winter and initially thought it would be a good idea to use it to heat a pool (especially during the shoulder months) in the summer. My geo contractor is now recommending a Waterfurnace pool heater. He thinks it will be as efficient and leave the "loop" uninterupted. Any thoughts/comments would be greatly appreciated.

Calculate your pool heat load. Most commercially available dedicated heat pump pool heaters are 5-13 tons.Gas-fired units are commonly 200,000+ btuh. If you desire to heat the pool only in fairly mild weather (60 deg F +) you'll probably be happier with an air source unit. They are said to run at a COP of 4+ in mild weather. I'm not sure how the WF unit stacks up against other brands. There are forums etc dedicated to heat pump water heaters. Beware dodgy COP claims, though. Florida has a code requirement of 4+ COP at certain outdoor temps. A brand / model independently certified to meet Florida's energy code may be a good bet.

There are circumstances where pool heating may complement a geo loop - if you foresee heating the pool and cooling the home at the same time, the loop could greatly benefit. OTOH if you found yourself trying to heat both a pool and a home at the same time, you'd need a huge and expensive loop field

What engineer said

We have a 4 ton water to water heating our indoor pool and some radiant indoor heating in our home as well. I am assuming this is for an outdoor pool and you would heat it in spring, summer and fall. In the spring basically you will just cool the field down a bit more which will help with AC in summer. If the unit has a priority of the house you might not get enough pool heating time, but some it better than none. Also it could potentially be plumbed to cool the house while heating the pool. In our case the heat pump is always heating the pool and then either dumping the cold to a coil in our furnace or to the field. The switch happens by an AC call from the thermostat.

Honestly if I had to do it again I would have gotten a 2 ton for the house and a 2 ton for the pool and shared our 5 ton field. Then the pool could call for heat anytime and the house could call for heating or cooling as needed.

Efficiency wise the water to water would be the best but the system gets a bit more complicated control and plumbing wise, which is why I am guessing he wants to keep them separate. For pool heating I would choose an air source heat pump over gas, propane or electric. But solar hot water would be my first choice.

dolphin,

We have read your comments regarding using a WaterFurnace water to water heat pump to heat a pool. We spoke with our technical service staff, and they say it is possible to use your water to water to heat a pool, if you have the right capacity. They suggested having your contractor add a heat exchanger between the heat pump and pool. If your contractor has further questions, please have them contact our technical service staff.

WaterFurnace International, Inc.

Yes, use a heat exchanger between the pool water and heat pump. We ended up adding a second heat exchanger so we could keep the temps down on the geo unit when heating the hot tub. With a single heat exchanger we were running 125F in and 115F out when the hot tub was at 100F and pool water moving at 25 gpm. With two heat exchangers (in series) we now run about 115F and 105F back to the geo unit with the pool water at 100F. Using two exchangers moved us further from the 130F lockout temp and got us in to a better efficiency as well.