Hybrid (Electric) Water Heater

jazz4cash

Give me a museum and I'll fill it. (Picasso) Give me a forum ...
Joined
Aug 27, 2004
Messages
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Location
Laurel, MD
These units (aka Heat Pump Water Heater) including the GE Geospring model are relatively new, but the technology is not ground breaking. I am DESPERATE to reduce utility costs. We made the major mistake of letting builder persuade us to use a standard electric water heater 10 yrs ago. This model seems to be a good compromise vs. switching to a gas HWH. I've done a fair bit of research and know most of the pros and cons, but I was hoping someone here has 1st hand experience. Here is a summary of various models featuring this technology, but I am leaning towards GE because Lowe's has 18 month financing @ 0%.

ENERGY STAR
 
So, it heats water with a heat pump. That means it will be cooling off the surrounding air (in your basement or wherever your WH is located.)

It costs about $1600.

When the heat pump can't keep up with demand, it goes into "regular" resistance-element electric heating mode. Cha-ching!

I wonder how well the heat-pump function works when temps are cool (say, in a 55 degree basement or a 40 degree garage in the winter?)

I guess it might make sense if you have to cool your home most of the year anyway, but if you are heating the area where the water heater is located, it won't save much at all. It will be a net negative (by far) if this space heating is done with expensive sources (electric resistance, propane, etc.)

You'd have to run the numbers for your particular situation (especially the price of NG, the amount of hot water you use, your electric rates, your heating and cooling degree days, etc), but I think most folks with moderately-priced NG available will find it cheaper to use that. Plus, the technology of modern NG high-efficiency water heaters are well developed, this is generation one for the GE unit.

If you've got NG available, maybe consider a modern high-efficiency NG unit. Because they use a fan to expel the relatively cool exhaust gases, they can be located in areas that would be a problem for a conventional NG water heater. If you've got an exterior wall nearby, the PVC intake and exhaust pipes can go right through it to the outside. No need for a roof penetration or other hassles.
 
Have you done all the energy reduction things one normally does with electric water heaters? Do you have a thermal blanket surounding the tank? Insulating foam on the exposed pipes? Have you installed a timer so as to only run the heater at necessary times? Do you drain a couple gallons out of the bottom every year so deposits don't build up on the heating elements? Try these ideas before changing out the unit. Have you gone to 100% CFL's in the house? Have you had an energy audit?
 
Have you done all the energy reduction things one normally does with electric water heaters? Do you have a thermal blanket surrounding the tank? Insulating foam on the exposed pipes? Have you installed a timer so as to only run the heater at necessary times? Do you drain a couple gallons out of the bottom every year so deposits don't build up on the heating elements? Try these ideas before changing out the unit. Have you gone to 100% CFL's in the house? Have you had an energy audit?

Good points. Also there are some good water saving shower heads on the market. I've been washing my clothes in cold water for 30 years. No, not the SAME clothes.

Some utilities let you heat water during off times or on an interruptable meter to save on the per kilowatt charge.
 
Good points. Also there are some good water saving shower heads on the market. I've been washing my clothes in cold water for 30 years. No, not the SAME clothes.

Some utilities let you heat water during off times or on an interruptable meter to save on the per kilowatt charge.

That timer or interruptable meter lets you set the time of day for the water heater to come on and off. Ex: Off at 10PM and on again at 5 or 6 AM. Why should it cycle on and off all night. Additional trippers can be added for during the day cycling.
 
It seems that a $1600 water heater, even if it's the EnergyStar rating from hell, would have a much longer payback than a $200 gas water heater. Especially if your house already has the natural-gas piping.

I lived in 1980s Charleston with a heat pump, and in the winter I quickly learned to avoid using it because the resistive elements would kick in and really drive up the electrical bill.

As others have mentioned, you could improve an electric water heater with a lower thermostat setting, an insulation blanket, insulated hot-water piping, checking for hot water leaks, heat-trapping nipples (on the water heater, not the residents), and a "Little Gray Box" timer that'll shut off the electricity during your selected non-peak hours (like the midwatch and 9 AM-3 PM).

What's your location's insolation rating for a solar water heater?
 
Consumer Reports just this month (October, that is) had a report on hybrid hot water heaters. It was generally favorable with reported payback time in the 5 to 7 year range.

Coach
 
Lots of good solid points all around. I generally agree with all the comments, but I won't go through them point by point. These units are supposed to work efficiently down to about 50 degrees and mine would be located in a basement area that stays above that. Rebates and credits bring the cost down to about $1150. Let's just say this unit seems to fit my situation pretty well, so I'm primarily looking for 1st (or 2nd) hand experiences.
 
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