diy solar

diy solar

Heat Pump water Heaters

My opinion, HPWH is a great concept, however so far, the physical executions are short of wonderful. I will wait for the equipment designs to mature and prices to drop before purchasing.
HPWH have been around for some time, it is mature. More than 10 years.

As for prices, until the 30% tax credit for energy efficiency is done, you won't see much price drop. With inflation, the same water heater might cost 150% of today's prices 2 years from now. Take a look at what just an electric hot water heater costs today compared to 2, 5 and 10 years ago.

I found my heat pump water heater to be one of the best additions to my solar system along with the mini split heat pumps for heating and cooling.
 
I just have a hard time spending 3x as much for something much more complicated, that has no guarantee of lasting any longer than the very simple tank.
 
Because I'm still curious lol
I debated for some time about just installing an element unit for a dump load or the heat pump unit. I decided with the hybrid I could choose whatever way I wanted. I have yet to use the element, the unit is just that efficient. Come next winter, I might use the element more as I will want to dump power on nice days.

The heat pump units are so much more efficient compared to an element heater. Conservation always pays, using more efficient appliances not only reduces system size but allows for a smaller battery bank or adopting more energy efficient appliances to use the power saved. No different than changing from a resistive heater for heating a home compared to using a heat pump. My goal for my home is 100% off grid. I'm close at less than 3% from grid in the last year while increasing yearly Kwh by moving towards more electric from gas.
 
I promise I don't get any kickbacks lol, but here is the deal I got again - it is now on sale for the next 3 days! If you are in California it is a crazy deal, hard to pass up, especially with natural gas rates on the rise and if you've got surplus solar:

$1,929.00 - $389.01 off on sale = $1,539.99
$900 instant rebate through Golden State Rebates = $639.99
Tax at 8.75% = $56
Total = $695.99
30% federal tax credit = $208.79
New total = $487.20!!!

That is less than what I initially calculated!!! (I remember, I added the $75 for the additional 5-year warranty). Will pay for itself in no time!

 
I promise I don't get any kickbacks lol, but here is the deal I got again - it is now on sale for the next 3 days! If you are in California it is a crazy deal, hard to pass up, especially with natural gas rates on the rise and if you've got surplus solar:

$1,929.00 - $389.01 off on sale = $1,539.99
$900 instant rebate through Golden State Rebates = $639.99
Tax at 8.75% = $56
Total = $695.99
30% federal tax credit = $208.79
New total = $487.20!!!

That is less than what I initially calculated!!! (I remember, I added the $75 for the additional 5-year warranty). Will pay for itself in no time!

And a 9 year heating element 50 gallon water heater costs $639 plus tax. https://www.homedepot.com/p/Rheem-P...ED-Indicator-240-Volt-XE50M09EL45U1/326433976
 
Anyone using something like


for hot tubs/soaking tanks? Capacity-wise, don't seem to cost a LOT more than than the air to air minisplits, and have pumps (I think) built in. Seems plug and play.
 
Yes I'm aware they cool the space which does me zero good-If I could fit inside our small house I would but alas that not happening space wise .
I'll gather my 12 months of gas bills annd see what gives vs buying 4 months worth of power on the non solar months midwinter.

I should I add I am a potter past 50 years and also have a separate mondo large gas meter for that business as its a semi industrial flate rate -but this water heater is on our house meter and the rates are not as good
i just bought a new water heater convectional neighborhood of 400 40 gal, the one your talking is hybrids since it has heat pump with element backup abbot 1700 for 50 gal. according to energy label's roughly 4 yrs they equal the break Evan afterword's hot waters free . they do push cold air out and i would have bought but i plan on moving in a yr since sw fl perfect temps and heaters often in garages which get hot
i have read people have seasonally made ducts to bring outside air into the unit . one defiant thing older units were trouble but tech is proven now like heat pump air/heat which were costly when a new tech . main thing you need to know electric use if your use 10-2 where the unit could heat and store might work great, if your handy check out 4 ft vacuum tube solar tubes i seen people using them for even heating in Canada in winter you will need a thermal control to prevent water too hot go through system i mixes cold water some places have them on showers . solar in cal seems to be good i read in south electric van be 36 kw . i dont like grid tied in many areas i rather buy batteries and cut cord completely
 
I bought the 65 gallon Rheem heat pump model from home depot to replace a traditional unit. Along with the fed tax credit our local utility was giving a $650 rebate when you installed one.
To me now was the time to get one so we could get the tx credit and the rebate.
This new HP water heater is using about 100kwh a month.
Ive seen reviews saying they are noisy. That is incorrect. You can stand beside mine and barely hear it running.
 
Last edited:
If ours was so frugal, I would ignore it.
The big one indoors (80G) uses 12.6 kWh a day and the small one (20G) uses 4.3 kWh a day (down from 6.5 since I added insulation)

It's about 500kWh a month between these two. Both are 30 years old.
You would save a ton with one them if yours is using that much power.
Ours is low consumption right now because we have no dishwasher, we dont run washing machine on hot, just warm water setting if needed, and we have a RV style shower with a shut off valve on the shower head so we arent running a constant water flow when showering.
 
Picked up an 80L wall hung unit last month for my 1 bed off-grid property:


Not cheap (£1600 ish with tax) but I needed it.
 
If ours was so frugal, I would ignore it.
The big one indoors (80G) uses 12.6 kWh a day and the small one (20G) uses 4.3 kWh a day (down from 6.5 since I added insulation)

It's about 500kWh a month between these two. Both are 30 years old.
I think you got your money's worth. :)

I wanted a dump load so I put the heat pump water heater ahead of the propane water heater. It works so well and doesn't use much electricity it isn't a dump load. I'm in search of another dump load.

The bonus is dehumidification, my basement is dry.

Customer was by the other day and told me he put a heat pump water heater in his shop. Keeps the shop temp at 68F thru the summer if you don't open large doors. Plus, takes the humidity out.
 
Customer was by the other day and told me he put a heat pump water heater in his shop. Keeps the shop temp at 68F thru the summer if you don't open large doors. Plus, takes the humidity out.
In a previous house we installed a HPWH right beside a dehumidifer, in the basement. Fed both into same condensate pump. Before the HPWH, dehumidifier ran often. After installing HPWH, the dehumidifier almost never ran unless it was a really muggy day or we were away and not using hot water. When running, power consumption of each was about the same. So, hot water was almost free during summer.
 
Last edited:
  • Like
Reactions: Zwy
My 1979 AO Smith Propane water heater is still working….🤷‍♂️
My 4 year old propane still works too. But with the addition of the heat pump water heater, it never runs. I put the 2 in series with the thermostat on the propane set slightly lower. Come winter, maybe it will run during cloudy weather. I now have 100 gallons of stored hot water so I can probably weather a few days of cloudy weather.

They say it takes about 250 to 300 gallons of propane to run a propane water heater for a year. I believe that number is probably pretty close to being correct. At prices of bulk propane here running $1.30 to $1.50/gallon, it doesn't take long for a heat pump water heater to pay back after getting federal tax credit. $1600 x 30%= $480 tax credit. Net price $1120. 250 gallons propane x $1.40=$350. About 3 years.

I think one advantage of running the pair in series is the anode will last longer in the propane water heater.
 
I like the idea of the series water heaters though as it is a very easy way to basically "dual fuel" your water heating. I think it is brilliant.
 
My laundry room gets pretty warm, so I'm considering a HPWH, but what I really want is a heat pump clothes dryer that cools the room. All I can find is ventless ones that heat up the room, which wouldn't help...
 
I’m planning on doing a series when my dual 10k Quattro system is online. Undecided if I will do Heat pump or regular resistance style. Long term I’d also like to do evacuated solar heater in the series as well as a wood fired. Options 😁
 
All I can find is ventless ones that heat up the room, which wouldn't help...
That is how they work. They cool down the air inside the dryer to "condense" the water in the air. That requires heating up the air outside the dryer. It blows that dry hot air into the dryer to evaporate more water. And the cycle repeats. If you vent the hot-air outside, it reduces the efficiency of the dryer.
 

diy solar

diy solar
Back
Top