My Pellet Stove - Heat Pump Water Heater Experiment

We have been working to reduce our energy usage using reasonable means that don't overly inconvenience us for the past few years, with an energy audit and air sealing, insulation and new exterior doors 5 years ago, the pellet stoves replacing almost all of our heat pump HVAC use in winter, insulating shades in some rooms, and a switch to LED lighting throughout most of the house. One item that I've been waiting to replace is the hot water heater, but at almost 14 years old and almost two years out of warranty, I decided it was a good time to switch it out as I've seen enough of them fail by flooding the basement. The current unit is an 80 gallon electric (4500 watts) that sits in the utility room and is much too large for a home with only two people in it, with good air circulation between the utility room and the finished basement office where the Whitfield Quest sits (have a Quad MVAE on floor above).

My theory is that I have excess heat potential in this room from the Quest that can be used by the new heat pump water heater, that it will help cool and dehumidify the basement in the summer, and a worst case scenario is that the new water heater can always just operate as a regular water heater if necessary (has the same heating elements as a regular heater, in addition to the heat pump, but uses them only if needed). The amount of heat absorbed is apparently not noticeable in most situations, so I don't expect we will even notice a change in air temps. Will likely install it on Friday after this storm passes tomorrow (will be busy running the snow thrower) and we get done hosting dinner on Thanksgiving day for a house full of people. Also, my wife has threatened my life if I endanger the house hot water supply the day before Thanksgiving!

Will keep everyone posted on how this works out, and plan to update this thread over time.

Bought the 10 year warranty for just that reason (only $99 total). I never buy those, bit for this, oh yeah...

railfanron said:

I'd like to know what one costs to run a month or year. I've been contemplating one for year or so. I have an old propane unit that the cost of operation is negligible.
Ron

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based on the yellow sticker, about $220 per year, or $352 less than a normal electric HW w
Heater of the same size. A calculator could be used to compare to propane.

Update: I installed the Geospring this weekend, and am very pleased thus far. Very easy installation with very good instructions. Ran it the first day in hybrid mode just to see what happened, and it made enough hot water for a nice shower within just a few minutes (exactly like a regular HW tank). Been in heat pump only mode since Sunday and with just two of us here it hardly breaks a sweat. My wife reports that after one load of laundry on sanitize setting, a long shower each, and running the dishwasher on "turbo" mode, the sink water was less hot than normal but usable, so that's a pretty good test for heat pump only, and close to our max use in a day. We'll switch to hybrid mode when guests arrive over Christmas for a few days, and see if that's sufficient (65 gallons first hour recovery). If I had a larger family (especially teens) I would consider an 80 gallon, which I think they make.

No louder than a typical small dehumidifier, and the exhaust air is not very cold (feels like a small fan moving room temp air) nor coming out at anything more than velocity of a small fan running on low-med. I cannot hear the unit from around the corner in the basement, and my wife's desk is on the opposite wall from the unit, with a ventilation grid in the wall. No complaints! Cannot imagine there is any appreciable loss of heat from this in the room, and certainly not enough to be noticeable to a pellet stove user. Basement room temp exactly as before, and no change in pellet stove settings, so just too little loss to notice.

No idea as to energy savings yet but will report back as bills come in. Went from 80 gallon tank previous owners had to a 50, so immediate savings there. But expect this little jewel to pay for itself in under two years, easily. Surprisingly, GE based their stated figures based on running in hybrid mode with a 135F setting. We are running at 120F (the default setting from factory, and plenty hot) and heat pump only, so should save even more than the projected $352/year. If getting hot water from natural gas may not be as efficient, but from any other source (except solar, also) I think these units are a great idea.

Re: post above about condensation fitting: They must have updated this, as mine is a separate, 1/2" NPT tee fitting that screws into the unit, not one that is built into the tray. The tee is a 3/8" barb fitting, for typical 3/8" tubing. Alows it to point down easier regardless of where the fitting stops when you screw it in. Also, unit is made in Louisville, KY as noted above, per info in my box. Suspect you gave an older model.

chken said:

Depends upon your electricity rates, I believe the Geospring's rating is based upon 10cents/kwh, so you have to extrapolate.

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Manual says calculated at 12.5 cents per kwh.

Just checked US average rate because I track our electric use and compare pricing to US and PA avg rates. Most recent data is Sep, and US avg was 13.9 cents, while PA was (from memory) about a penny lower.