Rheem ProTerra Electric Hybrid Hot Water deals

[gene]

Is 45 gallons big enough for 3 people? How often does it go into resistance mode?

We never run out of hot water. Not even with three showers at the same time. We are in California so we try to keep our shower time down a bit. I have the temp set at 111 degrees so we can just turn on the hot water valve and the temp is perfect. If I was to turn up the temp to 120 then we would definitely never run out of hot water but we'd have the inconvenience of using the hot and cold shower valves to get our preferred temp.

I am not sure how often, if ever, that it goes into resistance mode. It can be set for heat pump only, resistance only, or hybrid resistance/heat pump. The manual states, and the phone app states as well, that the hybrid mode is the most efficient. So, that it where I have set it.

 

[gene]

I would like to do this but wonder about the noise, how often does it make noise. My hot water heater is inside in a closet with insulated doors so wondering how loud it would be.

It runs a few hours a day. Sound level is like a very small window AC. Your bigger problem is going to be what to do with all the free cold air. In the summer it would be great. In the winter it will make your house too cold. You might consider mounting the heater outside or in your garage. While you are at it, consider the Watts recirculating hot water pump. Made in the USA, only $200. It works really well for saving water. It is silent. I have had these on my home and all my rentals for years of trouble free service: Watts Hot Water Recirculating System with Built-In Timer-0955800 - The Home Depot

The fact that your water heater is inside the house makes it all the more important that you get that cancer causing particulate factory out of your home! After we switched to induction cooking and electric water heat, I can tell you, the inside air feels and smells so much cleaner.

 

[nwdiver]

I have the temp set at 111 degrees so we can just turn on the hot water valve and the temp is perfect.

I do the same thing! I love it! PLUS the heat pump works more efficiently when the water is closer to ambient so the COP is higher heating water to 111 than from 111 => 120.

 

[iPlug]

65G HPWH here installed in 2017 (replaced 50G NG unit in the garage). HPWH demands: We have a family of 4, each takes two showers daily, we probably do more laundry than average, run dishwasher every night. Monthly average since install is 125 kWh. We use heat pump only mode.

Have experimented with different modes in the beginning and compared energy use. My initial thought was to set the temp as low as possible to maximize COP, but found would run out of hot water then need to use a resistance/hybrid mode that was a lot less efficient than running the HPWH at a higher temp in heat pump only mode.

What we settled at is as low as 120ºF for summer and 136ºF for peak winter to avoid cold showers and maximize energy efficiency.

Recommendations: buy a HPWH at least one size bigger than the NG or propane it replaces (eg 50G->65G or 65G>80G), run it in heat pump only mode except in rare circumstances (lots of stay over guests then run in hybrid mode), and set it at the lowest temp to avoid cold showers.

 

[nwdiver]

My initial thought was to set the temp as low as possible to maximize COP, but found would run out of hot water then need to use a resistance/hybrid mode that was a lot less efficient than running the HPWH at a higher temp in heat pump only mode.

I have some friends that are building a house. I recommended the 80G for that reason. But they also don't have NEM so they're gonna try to not do any water heating when the PV isn't producing too. Use it as a kind of thermal battery.

 

[Merrill]

I have my current electric hot water heater on a timer, comes on in the early morning for around 3 hours. Is this something I could do with the heat pump hot water heater and have it come on before we get up in the morning so we would not have to hear it.

 

[iPlug]

I have my current electric hot water heater on a timer, comes on in the early morning for around 3 hours. Is this something I could do with the heat pump hot water heater and have it come on before we get up in the morning so we would not have to hear it.

Yes, these days heat pump water heaters are programmable and you can use the app on your smart phone.

We run the heat pump water heater all year round to only run during off-peak time of use rate time.

 

[CrazyRabbit]

My 80 gallon HW heater came in, I reinforced and extended the pedestal 5.5 inches to handle the larger unit. 921lbs with water in in it, 250lbs empty. Extended plumbing as shown, used a lot of “street” 45 degree elbows and uni strut. also added the expansion tank.
Not plugged in when photo was taken. Had to go back up to Home Depot to get plastic 3/4 elbow and clear tubing for condensate and a flex coupling for safety valve.
works as advertised. removes a lot of condensate from air and drops garage temperature.

put a temporary block to hold pan in place. used 3/8 diameter rope under bottom of water heater with two deep sockets as handles and a ratcheting strap around bottom to make sure the rope didn't slide off. was a easy two person job to lift up.

 

[Merrill]

How noisy is it.

 

[CrazyRabbit]

it is quite, but i can hear it inside the kitchen if everything else is off. rh wall is adjoining the kitchen. about as loud as a refrigerator from inside the kitchen...

 

[dhrivnak]

not the 50% off i wish it was... anyone install one of these yet? I would think that the compressor would easily start with a powerwall.

We have one and it is crazy efficient and I found out it qualified for a $200 home energy tax credit. Ours has been running about 9 months now and doing even better than advertised. And at 16 amps I am sure a PowerWall will run it.

 

[nwdiver]

And at 16 amps I am sure a PowerWall will run it.

And it pulls ~3A in heat pump mode.

 

[SageBrush]

I do the same thing! I love it! PLUS the heat pump works more efficiently when the water is closer to ambient so the COP is higher heating water to 111 than from 111 => 120.

I'll keep that in mind, but it does have the trade-off of storing less energy as a demand shift device. Perhaps oversizing the tank volume would work well with a lower temp setting.

 

[SageBrush]

And it pulls ~3A in heat pump mode.

Awesome !

I bought a 200 Amp load center and 150 Amp main breaker to service my EVs, upcoming PV and eventual three heat pumps (one water and two AC.) It is irony that the actual loads on the buss, let alone through the main breaker, are going to be a very small fraction. Perhaps needed for now for the start-up loads but that sounds like a problem that is going away ... and needs to go away for all those people unable to install monster load centers.

 

[SageBrush]

And at 16 amps I am sure a PowerWall will run it.

I looked at the 50 Gallon version specs and read up to 4500 watts, so 4500/240 = 18.75 Amps. Am I correct this device requires a 30 Amp breaker ?

 

[miimura]

I looked at the 50 Gallon version specs and read up to 4500 watts, so 4500/240 = 18.75 Amps. Am I correct this device requires a 30 Amp breaker ?

That HD page has links to the manufacturer specs here: https://images.thdstatic.com/catalog/pdfImages/26/267e05d3-c08f-45aa-81b2-44c87bd49953.pdf
That says 30 amp breaker for all gallon sizes.

 

[dhrivnak]

I looked at the 50 Gallon version specs and read up to 4500 watts, so 4500/240 = 18.75 Amps. Am I correct this device requires a 30 Amp breaker ?

Yes but if you lock out the backup resistance heating it pulls less than 10 amps.

 

[MontyFloyd]

removes a lot of condensate from air and drops garage temperature.

That is what I wondering about these heat-pump water heaters.

They basically are miniature AC units, simply dumping heat into water instead of air. Why not duct the chilled air into house instead of dump cold in attic?
In your case it goes to garage, so you have that benefit without the ductwork (but could duct into house).

Did not even need to see video from Technology Connections to know this (and I do patreon him).

My gas heater is 19 years old and soon to replace. Now what to replace with...

 

[miimura]

In most places, there are times of the year that you would not want cold air dumped in your living space.

 

[SageBrush]

Why not duct the chilled air into house

You can. I've thought about it on and off for years but after you tally up the trade-offs it's not an obvious choice. To wit:

• You end up with a large penetration into the home envelope that may leak inside conditioned air
• The cost of the ducting and installation is better spent on other energy savings, or clean energy generation
• It restricts where you place the heat pump, and may add to home noise
• You have to maintain the duct and redirect it each season

As @nwdiver likes to remind me, it is hard to compete with PV
If a home was designed for energy scavenging I'd probably feel differently, but hacks do not pencil out.