Separate heat pump unit to use with an indirect water heater?

RunsAmok

We live in the Pacific NW, in a house that derives both heat and domestic hot water from our natural gas-powered furnace, with the water provided via an 80 gallon Veissman indirect water heater.  This equipment is in a room in our basement that tends to get rather ridiculously hot, year-round.  We had the indirect water heater installed when our prior traditional water heater croaked about 5 years back, and were attracted to the longevity of the indirect tanks. So we went with that  rather than a heat pump water heater. But every time I go in the mechanical room I'm reminded how incredibly inefficient our system is, as we needlessly spill a lot of heat into the mechanical room.   So I imagined trying to use a heat pump to capture some of that excess ambient heat and channel it into hot water, feeding it into the indirect water heater.  
Scouring the internet I ran across several mentions of the Nyle Geyser RO unit, which would seem to be a good solution, though it appears it has not been sold by Nyle for several years now.   (See This Old House clip on YouTube, here: https://www.youtube.com/watch?v=u4hQVr5qYZo )  Are any of you aware of something similar to this that might still be on the market?  Would this  "juice be worth the squeeze"?
Thanks for your thoughts.

hot_rod

You want to look at the square footage, or volume of the room for a HPWH to pull the heat energy from. If the boiler never runs in the summer, will there be enough heat in the space to "pump" into the DHW tank?

I think some of the early manufacturers suggestions for required space may have been a bit too small. I see more and more HPWH being ducted outside. I recall one Polish manufacturer that suggested the HPWH is a corner, intake air in one side, discharge out the adjacent wall.

So you need to be aware of where the exchange comes from and goes to.

Is Nyles still in the game? Tom from Maine hangs around here, he would know.

Additional reading here.

https://www.caleffi.com/en-us/magazine/33-heat-pump-water-heater-fundamentals

ethicalpaul

Yeah you won't have so much heat when the boiler is on, but when the boiler is not on it will be summer, so you will have plenty of heat.

You have discovered that keeping a boiler on in the summer to heat a few gallons of water per day is ridiculously wasteful. Plumbers love indirects because they love to pipe things together and charge people to pipe things together. The cost is astronomical. Turn off your boiler in the summer and a heat pump water heater will serve you well.

Jamie Hall

I think our original poster was contemplating a heat pump — in fact, an air to water heat pump — to power the indirect water heater in the summer.

It would be as expensive, if not more so, than a straight heat pump water heater, and even more complicated to run and maintain. Not, it seems to me, a very good idea…

ethicalpaul

I think you're right Jamie, thank you. My advice is the same. Look into the Rheem heat pump water heaters and abandon the indirect. It's pennies per day and doesn't heat up your basement in the summer.

Larry Weingarten

Hi, You might find this useful. https://www.heatinghelp.com/systems-help-center/air-source-heat-pump-water-heaters/ 😎

Yours, Larry