GE Geospring heat pump water heater - Should I?

[begreen]

There is pretty good info here on the Geospring based on lab testing: (broken link removed to http://www.bpa.gov/energy/n/emerging_technology/pdf/GE_Prelim_HPWH_report_rev2a.pdf)
It looks like the unit normally draws about 300-700 watts in the "eheat" mode (HP only). However, if temps at the evaporator get too low, which may allow icing to occur, a resistance element may kick in and raise usage to 4500 watts.

Thanks for that link semipro! That's helpful info. I'm considering one of these but 55db running noise is a bit of a deterrent. That's about as loud as our genset on idle.

 

[begreen]

I would put a meter on it before I tried it....transformers are pretty simple dumb things....I would figure it is ~2X. And would smooth out the high freq glitches.

A transformer is not going to bypass the power requirement. 4500w @240v = 9000w@120v.

 

[woodgeek]

A transformer is not going to bypass the power requirement. 4500w @240v = 9000w@120v.

Um, I think we have our wires crossed. I think I can put a geospring needing 500W at 240V, call it 2A, on a >500W rated step up transformer (cost ~$30) plugged into a 120V genny, and it will only pull 4A. Heck, I could run my 80 gallon AO Smith HPWH monster (aka 'optimus prime') on my Harbor Fright genny!

 

[begreen]

How do you stop it from going into defrost mode and drawing full 4500 watts?

 

[woodgeek]

HPWHs don't have defrost cycles. The compressor shuts down below about 45°F, so no frost ever forms. Above that temp, in pure HP mode the element would never be energized.

Sadly, it looks like my HPWH wants up to 900W, so the HF genny would be a little taxed.

 

[semipro]

The link posted above mentioned additional current loading when temps at the evaporator fell too low. Whether this occurs because the compressor shuts down and one of the elements lights off or for some other reason I don't recall. That info may be covered in the lab report at that link.
I guess one could install an override switch that would prevent the resistance elements from engaging while on the generator. If the evaporator ices the HWH would just stop heating but wouldn't overtax the generator.

 

[woodgeek]

I've read those ecotope reports too....great for tech minded users of HPWHs....I and seem to recall reading there that NONE of the HPWHs have defrost cycles/controls. That is why they all just shut down the compressor at low temps. For the GE, I thought it was 50°F. For my AO Smith, its 45°F. The report also said that the AOS had a much higher fan CFM per compressor ton that the GE. This makes it noisier, v slightly more eff, reduces dehumidifcation, and allows it to run to lower temps without coil icing (explaining the lower lockout temp). This all jibes with my experience of the AOS unit.

 

[legrandice]

My heater arrived!


I am putting this where the 120 gal storage tank for my solar hot water was. That tank is heavy!





Running a new circuit for this as well.

Had company tonight and I have to work tomorrow so it will be a few days.

 

[DBoon]

Congratulations! I took an old (probably 25+ years old) 80 gallon tank out a few years back and I couldn't believe how heavy that thing was.

 

[legrandice]

Installed and running! I kept the oil system hooked up so I can open a few valves and use it as a backup.

Only negative so far is the cooler temps in the basement. This is due to not having the hot boiler all the time, and the cooling from the ge.

Currently running in heat pump only mode.

This summer I need to remove the three 150 lb solar panels from the roof. That should be fun.

 

[begreen]

Looks good. How much of a temp drop are you noticing? How is the noise level?

 

[Highbeam]

I like pex and I use pex but is it code compliant and safe to run the pex right onto the water heater? I thought it had to be metal pipes for a certain distance.

 

[legrandice]

I like pex and I use pex but is it code compliant and safe to run the pex right onto the water heater? I thought it had to be metal pipes for a certain distance.

Good question. I am basing this install on 3 water heaters that were permit installed by a plumber at properties that I own. They were all done the same way. Would be real easy to change if necessary.

 

[legrandice]

Looks good. How much of a temp drop are you noticing? How is the noise level?

Noise is not a problem, sure is much quieter than the oil burner.

Not enough time yet to have an accurate number for the temp drop. The output of the heater seems to be about 10 degrees less than room temp. It ran about 10 hours on heat pump only mode to come to temp the first time.

 

[brogsie]

Looks good legrandice. Are those Shark Bites for the joints?
I have used them with no problem but sparingly. My plumber doesn't like them but he uses the caps for temp disconnects.
I think you will like the water heater especially in the summer. My basement gets pretty cold. I have a ductless split for heating so the oil boiler is sitting cold and not warming the basement.

 

[jharkin]

A transformer is not going to bypass the power requirement. 4500w @240v = 9000w@120v.

BeGreen I think you have you watts and amps mixed up. 4500 watts is 4500 watts. If you double the voltage the amps get cut in half but watts are unchanged.

P = I*V

 

[begreen]

Ah you're right, the amperage will double.

 

[woodgeek]

So running a geospring HPWH on even a small genny is possible with a $30 transformer.

 

[jeffesonm]

I've been loving the GE Geospring... it's in my unheated, unfinished basement and as best I can tell it stays in heat pump mode. Granted it's just me and the Ms., so our usage is pretty low. Hardly noticed anything on the electric bill. I live out in the sticks and it's pretty quiet out here, and you can just barely hear the fan run. The 1957 oil boiler you can hear from down the street....

 

[jdp1152]

We installed a GE Geospring last year and have been very happy with the water heater. The unit is in an unheated/unfinished basement (wood insert/electric heat upstairs) here in western CT; probably similar to your conditions. Our unit runs in heat pump mode most of the winter but switches to resistance electric during very cold spells (typically when the basement temperature is below 45F). It is also great in summer, keeping the basement a bit cooler and almost completely eliminates the previous need to run a dehumidifier (was able to plumb the condensate drain to the washer drain so no pump was required) I think you will be appy with the wataer heater - I was also glad to see that these are now made in the US, a few years ago I had looked at their previous model and was sad to see that GE chosen to manufacture their new "high tech water heater" in China. Understand they have constructed a new plant here to build them.

45 is about my cutoff as well. I just kick it over to hybrid mode when I see a cold spell coming. No complaints after a full year with it thus far. It makes some noise, but mines in my basement so I never hear it. It drains to a washtub down there so no need for condensate pump. Can't say I've noticed too much difference in humidity level down there though, but it's 3200 sq ft of unfinished basement and we don't use too much hot water.

 

[HybridFyre]

45 is about my cutoff as well. I just kick it over to hybrid mode when I see a cold spell coming. No complaints after a full year with it thus far. It makes some noise, but mines in my basement so I never hear it. It drains to a washtub down there so no need for condensate pump. Can't say I've noticed too much difference in humidity level down there though, but it's 3200 sq ft of unfinished basement and we don't use too much hot water.

Holy crap you have a 3,200 sq ft basement??!

 

[tom dee]

My heater arrived!
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I am putting this where the 120 gal storage tank for my solar hot water was. That tank is heavy!
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Running a new circuit for this as well.

Had company tonight and I have to work tomorrow so it will be a few days.

what happened to solar system?? To cold in Hadley Mass for solar?

 

[jdp1152]

Holy crap you have a 3,200 sq ft basement??!

Forgot to deduct the garage, so more like 2800-2900.

 

[legrandice]

what happened to solar system?? To cold in Hadley Mass for solar?

The Solar system was installed in 1986. I purchased the house in 2005 and the system worked very well until the tank started leaking. A new tank was too expensive and the panels don't have much life in them. We had free hot water about 5 months of the year with five people living in the house. Just needed to plan out hot water usage a bit.