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Installation advice for heat pump water heater

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Ah... so ~2x more expensive than I thought after the add-ons. Even a heat pump with a COP of ~4 would be slightly more expensive if you're buying from the grid. The biggest savings is the $11.57/mo access fee. As you say, the best way to make it pencil is heat pumps + PV :). What sucks is the savings are marginal unless you can go 100% electric, just reducing gas use doesn't really save much.
Our rates are about the same. Electricity is around 9 to 10 cents per kWh. Gas is about 23 cents per therm. However, the gas base rate is over $32/month. I checked again yesterday and was overstating slightly but not much. I like the idea of no gas both from an environmental and a safety standpoint.

I have an Infinity system with a COP of about 3.8 and hspf of 11. Interestingly they boldly advertise SEER of 24 and hspf of 13. When you look through the technical data all units (2 to 5 ton) are hspf of 11 and the highest SEER is 22.5. I have been unable to get an answer on the difference. Any ideas? I doubt it is an out and out lie since competitors would probably love to catch them.

For me this is about more than $$$. The HVAC change has mode the house much more comfortable even though I have moved the set point from 72 to 77. The difference is humidity control to 46%.

The next step is to get two ERVs installed. If anyone knows a source of the new model from Panasonic let me know. All I can find is the older -1 model.

After ERVs are installed then I need to seal unused vents and get the attic foamed. Interestingly most people are suggesting much less foam than I want to do. I want the rafters covered. After the attic is foamed then I’ll spend the next couple of years working to seal where the foundation meets the framing. I know it won’t make a lot of difference but I also want to put in an insulated garage door.

If the HOA didn’t have a fear of black rectangles I would put solar on the east and west ends and get close to net zero. Last month (old 12 SEER system) I used about 980 kWh and that is without any car charging. Solar made about 1000 kWh.

The Rheem EcoNet app is abysmal. I think it is the first 1 star rating I have ever given.
 
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The Rheem EcoNet app is abysmal. I think it is the first 1 star rating I have ever given.
Sad to hear. What are you trying to do ?

I have an Infinity system with a COP of about 3.8 and hspf of 11. Interestingly they boldly advertise SEER of 24 and hspf of 13
I have seen that discrepancy also with (I think) a different manufacturer. Different testing protocol perhaps.

I should point out to people new to heat pumps that the manufacturers expect consumers to use the HSPF for the heating season. That number is divided by 3.4 to get the standardized test COP for winter. Physics pushes the summer COP higher than winter COP, but I think manufacturers also design for a cooling dominant climate.
 
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I have an Infinity system with a COP of about 3.8 and hspf of 11. Interestingly they boldly advertise SEER of 24 and hspf of 13. When you look through the technical data all units (2 to 5 ton) are hspf of 11 and the highest SEER is 22.5. I have been unable to get an answer on the difference. Any ideas? I doubt it is an out and out lie since competitors would probably love to catch them.

We have an Infinity Greenspeed system from Carrier as well. Looked into this 2-3 years ago and spoke with a couple installers about the issue back then. They claimed this is not an issue particular to Carrier. Specs will often show SEER and HPSP a bit lower than advertised. It was explained to me that the advertised SEER and HSPF has to do with matching the outdoor unit up with the optimal indoor unit for max possible efficiency.

For example, the latest central ducted INFINITY 24 Heat Pump systems boast cooling efficiency "up to 24 SEER" and heating efficiency "up to 13.0 HSPF". But as you note, when you look at the spec sheets, depending on the tonnage, SEER shows 21-22.5 and HSPF of 11.

To get the advertised 24 SEER and 13.0 HSPF you have to pair with something like this:

Series : INFINITY 24 HP with GREENSPEED INTELLIGENCE
Outdoor Unit Model Number (Condenser or Single Package) : 25VNA424A*030*
Indoor Unit Model Number (Evaporator and/or Air Handler) : FE4AN(B,F)005L+UI
(see attached file below)

The Rheem EcoNet app is abysmal. I think it is the first 1 star rating I have ever given.
Indeed, much to be desired. With each app update they seem to improve something and break something else. Many would settle for 2 steps forward, one step back, but that is probably too optimistic.

As long as we can keep ours to stick to the programmed TOU settings, will live with it. Like Tesla service it's a pain, but competition is greatly lacking.
 

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  • AHRICertificate-3.pdf
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Our rates are about the same. Electricity is around 9 to 10 cents per kWh. Gas is about 23 cents per therm. However, the gas base rate is over $32/month. I checked again yesterday and was overstating slightly but not much. I like the idea of no gas both from an environmental and a safety standpoint.

I have an Infinity system with a COP of about 3.8 and hspf of 11. Interestingly they boldly advertise SEER of 24 and hspf of 13. When you look through the technical data all units (2 to 5 ton) are hspf of 11 and the highest SEER is 22.5. I have been unable to get an answer on the difference. Any ideas? I doubt it is an out and out lie since competitors would probably love to catch them.

For me this is about more than $$$. The HVAC change has mode the house much more comfortable even though I have moved the set point from 72 to 77. The difference is humidity control to 46%.

The next step is to get two ERVs installed. If anyone knows a source of the new model from Panasonic let me know. All I can find is the older -1 model.

After ERVs are installed then I need to seal unused vents and get the attic foamed. Interestingly most people are suggesting much less foam than I want to do. I want the rafters covered. After the attic is foamed then I’ll spend the next couple of years working to seal where the foundation meets the framing. I know it won’t make a lot of difference but I also want to put in an insulated garage door.

If the HOA didn’t have a fear of black rectangles I would put solar on the east and west ends and get close to net zero. Last month (old 12 SEER system) I used about 980 kWh and that is without any car charging. Solar made about 1000 kWh.

The Rheem EcoNet app is abysmal. I think it is the first 1 star rating I have ever given.
Totally agree the Rheem Econet app is awful, the wi-fi on the Rheem HPWH unit is also flaky, it will drop offline and never recover, while dozens of other devices work perfectly. I have a rental unit that goes several weeks at a time without anyone there, so I had a zwave 40amp switch installed so I can toggle the power which brings it back online.
 
oh that reminds me, my plumber told me my gas shutoff valve is frozen. He was going to a pressure test after capping the now unused feed to the water heater. I need to call PG&E. Who remembers to exercise their valve? I have an earthquake valve installed that can be manually actuated so I'm not completely reliant on the utility shutoff.
 
I should point out to people new to heat pumps that the manufacturers expect consumers to use the HSPF for the heating season. That number is divided by 3.4 to get the standardized test COP for winter. Physics pushes the summer COP higher than winter COP, but I think manufacturers also design for a cooling dominant climate.

I bought the Richmond (not installed yet due to personal injury )with expectation the published energy numbers need be taken with a grain of salt.
It will save me a buck, current electric is from 1996 and sounds like popcorn. As I type I have a standalone dehumidifier running which I will be able to stop using, savings will happen right there. Mini-splits are our primary heating and cooling and I plan to duct this to move some air around the house, which will actually help move the minisplits conditioned air around since there are compromises in our system.

I really only have excess heat maybe 4 months of the year, after that I might experiment with letting the home air source heat pumps supply the warm air or I might just switch it to resistance mode, will play with it.

Even if I only see savings 4 months of the year, with a 24yo water heater.........buying this was cheaper than what happens when the current one fails.

I ordered in May, promptly injured myself and needed surgery, in the meantime it came in. Going to be probably a couple months before I install, on a 20lbs weight restriction yet. Last I checked water heaters weigh a bit more than that.
 
We have an Infinity Greenspeed system from Carrier as well. Looked into this 2-3 years ago and spoke with a couple installers about the issue back then. They claimed this is not an issue particular to Carrier. Specs will often show SEER and HPSP a bit lower than advertised. It was explained to me that the advertised SEER and HSPF has to do with matching the outdoor unit up with the optimal indoor unit for max possible efficiency.

For example, the latest central ducted INFINITY 24 Heat Pump systems boast cooling efficiency "up to 24 SEER" and heating efficiency "up to 13.0 HSPF". But as you note, when you look at the spec sheets, depending on the tonnage, SEER shows 21-22.5 and HSPF of 11.

To get the advertised 24 SEER and 13.0 HSPF you have to pair with something like this:

Series : INFINITY 24 HP with GREENSPEED INTELLIGENCE
Outdoor Unit Model Number (Condenser or Single Package) : 25VNA424A*030*
Indoor Unit Model Number (Evaporator and/or Air Handler) : FE4AN(B,F)005L+UI
(see attached file below)


Indeed, much to be desired. With each app update they seem to improve something and break something else. Many would settle for 2 steps forward, one step back, but that is probably too optimistic.

As long as we can keep ours to stick to the programmed TOU settings, will live with it. Like Tesla service it's a pain, but competition is greatly lacking.
Thanks for posting the certificate. At no time did the company say that if I paired this with that I would gain efficiency. I will say that the new system easily handles my house and never struggles. This is the hottest time of the year and it will only get easier once the attic is foamed.

if anyone has a connection for getting the Panasonic FV-10VEC2 please let me know. They are in stock in Canada but they won’t ship to US. I can only find the older model in the US. I want to get it installed before I spray foam. I am actually looking for two units. It will be overkill but every floor will get a little fresh filtered air.

so far the Rheem is working well. Turned on eco mode it heated enough for a warm but not hot shower the first night. The next day water was very hot and I have turned it down from 125 to 120. At that setting it is still much hotter than the old gas unit. I like that it helps with basement humidity. I have the adapter for the intake and will eventually put a register high on the wall into the adjacent room for the intake. That should help efficiency. The exhaust goes into the HVAC room which has some computer equipment (file servers) so I don’t mind the room getting cool.

as for the app, I am slowly figuring things out. I’ll play with scheduling this weekend. I wish it would show current water temperatures, instantaneous power draw, and estimated time to be fully heated. I find the explanations for the different modes minimal at best. For example, I was surprised that heat pump mode appears to also use the heating elements. Call it auto or hybrid but not heat pump. Nowhere does it give an estimate of differences in recovery times other than saying fast vs. slow.
 
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'Fast' and 'Heat Pump' do not go together in the same sentence.
Just remember that it also has large conventional heating elements. I was surprised to see them turn on in heat pump mode. You have to go to eco mode to make sure they don’t turn on. After two people taking showers last night it is fully recovered 7 hours later which is good enough for me. That’s on eco mode. No idea exactly how long it took. Looking at the energy use chart I would guess 2 hours.
 
Just remember that it also has large conventional heating elements. I was surprised to see them turn on in heat pump mode. You have to go to eco mode to make sure they don’t turn on...
Should not be doing that in "heat pump only" mode. Mine stays in "heat pump only" mode and have never seen resistive elements on during that time when checking on the main unit status menu. In energy saver mode (if that is what you mean by "eco"), it should have a preference for heat pump and only use resistive heating if demand is too high. That said, would not be surprised to see Rheem goof that up on some units or updates.

Others here with Rheem units who can comment?
 
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Should not be doing that in "heat pump only" mode. Mine stays in "heat pump only" mode and have never seen resistive elements on during that time when checking on the main unit status menu. In energy saver mode (if that is what you mean by "eco"), it should have a preference for heat pump and only use resistive heating if demand is too high. That said, would not be surprised to see Rheem goof that up on some units or updates.

Others here with Rheem units who can comment?
Yep, that's my experience as well. Here's what I've believe the different modes do in my experience:
Energy Saving - Attempts to minimize energy usage by prioritizing heat pump usage, but will turn the resistance heating elements on if the temperatures drop too far below set point.
Heat Pump Only - Like it says - heat pump only, never turns on resistance heating.
High Demand - Tolerates less temperature drop before turning on resistance heating. Still uses heat pump to augment.
Electric Mode - Never uses the heat pump.

90% of the time heat pump only mode is sufficient for my house, sometimes it fails to keep up if too many consecutive showers are taken. This is mainly a problem in the evenings when the temperature set point is set to 115F due to peak electricity rates. 120F gets you a bit more hot water before it starts feeling cold.

In Energy Saving mode, I've never seen it run out of hot water in our usage. The resistance heating elements do a fabulous job of rapidly heating up the tank, you can watch the temperature climb on the control screen.

Energy Saving mode does use about 50% more energy than Heat Pump Only mode for me. In my opinion, the heating elements are used too aggressively even in this mode. It would be nice to be able to set the control points. I wouldn't mind if the resistance elements came on below 105F, for example, but then shut off more quickly to let the heat pump do most of the work.
 
Yep, that's my experience as well. Here's what I've believe the different modes do in my experience:
Energy Saving - Attempts to minimize energy usage by prioritizing heat pump usage, but will turn the resistance heating elements on if the temperatures drop too far below set point.
Heat Pump Only - Like it says - heat pump only, never turns on resistance heating.
High Demand - Tolerates less temperature drop before turning on resistance heating. Still uses heat pump to augment.
Electric Mode - Never uses the heat pump.

90% of the time heat pump only mode is sufficient for my house, sometimes it fails to keep up if too many consecutive showers are taken. This is mainly a problem in the evenings when the temperature set point is set to 115F due to peak electricity rates. 120F gets you a bit more hot water before it starts feeling cold.

In Energy Saving mode, I've never seen it run out of hot water in our usage. The resistance heating elements do a fabulous job of rapidly heating up the tank, you can watch the temperature climb on the control screen.

Energy Saving mode does use about 50% more energy than Heat Pump Only mode for me. In my opinion, the heating elements are used too aggressively even in this mode. It would be nice to be able to set the control points. I wouldn't mind if the resistance elements came on below 105F, for example, but then shut off more quickly to let the heat pump do most of the work.
When I saw the heating elements go on was when it was first turned on. Changing to energy saver (checked wording) turned them off. I don’t see a temperature readout other than the set point. I haven’t turned on scheduling yet. Does that make much difference?
 
Scheduling is mostly used by folks like us who are on a time of use (TOU) solar PV electricity rate schedule. That way you can heat the HPWH only during off-peak cheapest electricity rate hours.

Interesting. I would have guessed that you have some excess PV production during hours when the NEM rate is low* that would be best shunted to the heat pump. This is where a smart control device would come in handy, but it is probably not needed during the summer.

*A brief glance suggests that you are paid ~ 3.5 cents a kWh for generation sent to the utility. Is that right ?
 
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Interesting. I would have guessed that you have some excess PV production during hours when the NEM rate is low* that would be best shunted to the heat pump. This is where a smart control device would come in handy, but it is probably not needed during the summer.
We are grandfathered into the old PG&E E-6 rate plan. This plan is currently overly generous but done for early adopters. Summer off-peak rates are 9pm to 10am, peak rates are 1pm to 7pm, and partial peak rates are in-between those. Starting next year we are being forced off this grandfathered plan in a 2 years phased approach.

So right now in the summer rate months, we only allow the HPWH to run off-peak from 9pm to 10am. When we are ultimately forced onto a more grid-friendly and home solar consumption oriented plan, we will adjust the schedule to accommodate that. Were it not for our E-6 rate plan, it would certainly make more sense for us to heat the HPWH in the early to late afternoon when the garage is plenty toasty and solar PV is near peak output.

In the winter rate months, there is no peak rate, just partial and off-peak. Even then, partial peak is only weekdays from 5-8pm, so easy to schedule the HPWH to stop heating then. There is little or no sunlight then anyway.

*A brief glance suggests that you are paid ~ 3.5 cents a kWh for generation sent to the utility. Is that right ?
That’s right - once beyond net zero consumption. Prior to the net zero mark, PG&E credits us full peak rates which are as high as $0.491/kWh

We typically generate >1MWh surplus a year and run everything we can during off-peak (both BEVs, HPWH, pool pump, whole house fan, hot tub, laundry, clothes dryer, dishwasher, etc.) so end up with an imaginary huge credit before the rule is applied that everything returned to the grid as surplus beyond net of zero is only credited $0.035/kWh.
 
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When I saw the heating elements go on was when it was first turned on. Changing to energy saver (checked wording) turned them off. I don’t see a temperature readout other than the set point. I haven’t turned on scheduling yet. Does that make much difference?
I have noticed that if you switch to a mode that engages resistance heating, they don't necessarily turn off immediately when you switch to heat pump mode. So could be related to what you noticed.

You will see a difference in energy consumption using heat-pump-only mode compared to energy saver, the question is whether or not heat-pump-only mode is enough to keep water temperatures hot enough for you. For me, it is nearly all the time. When it isn't, I usually just wait 30 minutes to an hour.