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Heat pump water heater update
Posted: Fri. Mar. 01, 2024 2:23 pm
by BigBarney
I am using my heat pump water heater now for several months..
And it is a real savings... 1.78 Kwhr per day in February...
When I get the off peak rate I will have a cost for the month...
Bigbarney
Re: Heat pump water heater update
Posted: Fri. Mar. 01, 2024 3:02 pm
by mozz
So in dollar amounts, what are you saving and how long will it take for any payback?
Re: Heat pump water heater update
Posted: Fri. Mar. 01, 2024 3:06 pm
by Lightning
1.78 kw per day would cost me about $13 per month, which might buy me lunch one day.
Re: Heat pump water heater update
Posted: Sat. Mar. 02, 2024 9:08 pm
by waytomany?s
mozz wrote: ↑Fri. Mar. 01, 2024 3:02 pm
So in dollar amounts, what are you saving and how long will it take for any payback?
Longer than the heater lasts considering their cost.
Re: Heat pump water heater update
Posted: Sat. Mar. 02, 2024 9:21 pm
by nut
waytomany?s wrote: ↑Sat. Mar. 02, 2024 9:08 pm
Longer than the heater lasts considering their cost.
I know someone that recently installed one in Ma. and expect it to pay for itself in 5 or 6 years. That's a plumber installed unit because Ma. requires that. Here in Pa. you could save a lot installing it yourself.
Re: Heat pump water heater update
Posted: Sat. Mar. 02, 2024 11:13 pm
by anthony7812
Looking into a larger 80 gallon unit for family of 4. Not sold on them entirely due to longevity concerns. Might save me some dehumidifier run time and add cool air into my duct in the summer and maybe assist the central unit. Not to mention potential water savings. We use alot of hot water with 3 ladies in the house
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 12:18 am
by Richard S.
Have you considered a mixing valve? Smaller tank and set it on high, think most of them go into the 150 degree range. I have it precisely set to where I like the hot water for shower. No fiddling with the cold valve. Yea, I'm that lazy.
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 7:13 am
by nut
anthony7812 wrote: ↑Sat. Mar. 02, 2024 11:13 pm
Looking into a larger 80 gallon unit for family of 4. Not sold on them entirely due to longevity concerns. Might save me some dehumidifier run time and add cool air into my duct in the summer and maybe assist the central unit. Not to mention potential water savings. We use alot of hot water with 3 ladies in the house
I know the Rheem has a ten year warranty. It sure drops the basement temperature.
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 7:50 am
by nut
Richard S. wrote: ↑Sun. Mar. 03, 2024 12:18 am
Have you considered a mixing valve? Smaller tank and set it on high, think most of them go into the 150 degree range. I have it precisely set to where I like the hot water for shower. No fiddling with the cold valve. Yea, I'm that lazy.
Does the mixing valve give you the same capacity as a 80 gallon tank you think? Does running at 150 increase your electric bill to what a 80 gal. at 120 would be?
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 8:00 am
by waytomany?s
nut wrote: ↑Sat. Mar. 02, 2024 9:21 pm
I know someone that recently installed one in Ma. and expect it to pay for itself in 5 or 6 years. That's a plumber installed unit because Ma. requires that. Here in Pa. you could save a lot installing it yourself.
They cost 3-4 times as much and the recommendation is to put in the next largest size for hybrid units and 2 sizes larger for the hp only. Mixing valves as well to extend usage. Maybe Lee can run the numbers. I'm not against them, I just struggle with the upfront cost. And I have hard water, so tanks only last 7-8 years.
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 8:09 am
by Rob R.
Generally a mixing valve can give you about 30% more capacity. You would need to verify that the HP water heater can be set above 120F. I think any impact on energy consumption would be too small to measure, the tanks are insulated like a thermos.
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 8:17 am
by waytomany?s
Rob R. wrote: ↑Sun. Mar. 03, 2024 8:09 am
Generally a mixing valve can give you about 30% more capacity. You would need to verify that the HP water heater can be set above 120F. I think any impact on energy consumption would be too small to measure, the tanks are insulated like a thermos.
Good point on the insulation. Question. On any setup, HP or otherwise, if well insulated, how much more benefit to insulate pipes?
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 8:20 am
by nut
I ran into this valve while looking into them. Looks promising. I currently have an 80 gal conventional electric WH. I think I'd rather go with a another conventional 50 gallon tank with a mixing valve rather than plumb in a condensation drain and worry about all the associated moving parts of a hybrid WH that can fail.
https://www.homedepot.com/p/Cash-Acme-Water-Heate ... 29#overlay
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 8:25 am
by nut
The hybrid WH I know about in Ma. already had a thermistor go bad under warranty. Not a biggy. Rheem diagnosed it over the phone and sent a new one. Just a lot of parts that can go bad though.
Re: Heat pump water heater update
Posted: Sun. Mar. 03, 2024 9:33 am
by Richard S.
nut wrote: ↑Sun. Mar. 03, 2024 7:50 am
Does the mixing valve give you the same capacity as a 80 gallon tank you think? Does running at 150 increase your electric bill to what a 80 gal. at 120 would be?
I have no idea what it increases it to but it's 40 gallon tank so I would guess it's close to the equivalent of a 60 gallon tank. It's going to eventually serve 3 households so I'll probably have to get larger tank. Valve is in place though.
It's gas and I haven't had a chance to see what kind of increase there will be since it was installed in the late October and a tenant moved in.