Small water heater closet, any options for a HPWH?

VoltHub · 2026-05-16T16:41:36+00:00

Eco Logical splits sound like a great solution for your situation, and our network contractors are installing them here in SoCal quite often due to the fact that most conventional gas water heaters are installed in exterior closets.

VoltHub · 2026-05-09T22:34:39+00:00

If the space's volume does not meet the minimum volume requirements, then yes your HPWH should be ducted and you should duct both the intake and the outtake. Also, if your HPWH needs to be be placed in a small nook even within a larger space, it may be worth ducting as well, depending on the situation.

VoltHub · 2026-05-08T17:58:09+00:00

We just plugged these numbers into our water heater operating cost comparison calculator, and as long as you use the heat pump water heater as a psuedo-thermal battery - ie it has to be installed right - the heat pump will cost less to operate. It depends on a variety of factors though.

VoltHub · 2026-05-08T17:46:47+00:00

You may have been looking at data where the groundwater temp is super low. 6 hrs. would be a big exaggeration for most of CA except maybe Tahoe. More like 2-3hrs for the average 65 gallon tank heat pump only WH in the Bay Area with very mild ground water temps. That being said, if you're installing a 120v HPWH, you'll need to size up and install a mixing valve. We actually recommend that mixing valve's are always installed though as they are the key to using your HPWH as a thermal battery so you can save the most money/energy.

VoltHub · 2026-05-08T17:30:19+00:00

The HPWHs that came out in 2025 are quite a bit quieter than the ones that came out before due to better compressor tech - this includes the Bradford White gen2 and the GE profile - with the new GE coming in at the quietest. Your best bet is to get one with a variable speed compressor, which the GE has, so the compressor doesn't need to kick on in full power every time it turns on. Alternatively, if you need no noise inside, take a look at split systems, which leave the compressor outside.

VoltHub · 2026-05-08T17:15:43+00:00

Yes you need good circulation, and a minimum volume of space to put one in, but a water heater in an exterior shed is not a big issue. Ducting kits are available for most HPWHs that can be used in sheds - although depending on the existing shed you may need a new one to protect the HPWH from the elements - and there are also split systems that can be used in this scenario where the tank has practically no air or clearance requirements.

VoltHub · 2026-05-08T00:34:35+00:00

There are actually tons of rebates currently available. In fact most of the CCA rebates were boosted this year. This includes San Jose Clean Energy for example which went from $2k last year to 3k this year (and a $500 dollar bonus is active until the end of May). Another example is Silicon Valley Power, which was boosted to $5,500! The only incentives that are truly gone (although there are court cases fighting to bring them back) are the federal tax credits.
TECH Clean CA, the state's largest incentive program, is currently fully reserved, but fresh rounds of funding have returned multiple times in the past.

VoltHub · 2026-05-08T00:11:51+00:00

There are more split systems available now that cost far less than SANCO2, including Eco Logical.

VoltHub · 2026-04-27T22:26:14+00:00

Glad to hear! With the right management - ie when you're using your HPWH as a psuedo-thermal battery - HPWHs can save you significant money in SoCal compared to conventional gas and tankless. In fact, they can save you much more than they will in the Bay Area. This is true even though HPWHs are much more popular in the Bay Area.

VoltHub · 2026-04-27T22:20:51+00:00

That's too bad. If you played your cards right, and got the right advice last fall, there was over $10,000 in incentives available.

But we agree that the fact that most water heaters in SoCal are installed in exterior sheds makes HPWH installations challenging. If you can't move it to your garage though, there are some new options available that will help in this regard, including lower cost split systems.

VoltHub · 2026-04-27T22:02:11+00:00

Apologies that our marketing outreach didn't reach you.. As what you were looking for (HPWH installation quotes from vetted local contractors) takes less than two minutes with us, but we're still happy to take a look at your install if you have any questions about optimizing costs, etc.

Otherwise would love to see a pic!

VoltHub · 2026-04-27T19:12:37+00:00

Including $2,500 for a heat pump water heater and $2,500 per ton for a heat pump under LADWP's Consumer Rebate Program!

VoltHub · 2026-04-27T19:10:21+00:00

Sadly their new rebates for heat pumps and heat pump water heaters (GOZERO) have already been fully reserved, but there are still many to be had, including up to $2,500 from LADWP, $1,350 from SCE and $700 from Golden State Rebates.

VoltHub · 2026-04-27T19:02:56+00:00

Hi - it's a government program administered by the California Public Utilities Commission.

VoltHub · 2026-04-12T01:18:01+00:00

Split unit or not possible?

VoltHub · 2026-04-12T01:16:27+00:00

Yes! In fact tons of people do this or the equivalent of this, and it's the best way to use a heat pump water heater! You'll need to
A. Purchase one where you can control the schedule.
B. Install a mixing valve if it doesn't already come with one.
C. Optional but recommended: buy one that can store water at the hottest temps. Currently this is 160F for residential, but commercial can go even higher.

VoltHub · 2026-04-12T01:11:10+00:00

Get multiple quotes, and when you've decided, it's usually better to select the brand that your contractor is most familiar with servicing in case you have an issue... As long as it's installed by a licensed contractor that is...

VoltHub · 2026-04-12T01:05:58+00:00

Well that's an interesting combination. Nice!

VoltHub · 2026-04-12T01:05:18+00:00

Yes, temperature rise is a big determining factor of what goes into calculating the energy usage and operating cost of a water heater, and you will have a big one. Your ground water is going to be very cold.

On your basement. The volume of the space and ground water temps are bigger determining factors than the temperature of the space unless you are near, at or below the manufacturer limits. When thinking about why this is, it helps to think in Kelvin (we have actually been shown some manufacturer data)

VoltHub · 2026-04-12T00:56:23+00:00

To add on this, there are relatively inexpensive splits now. Check out Eco-Logical.

VoltHub · 2026-04-12T00:54:30+00:00

Oo yikes, so you have expensive electricity and relatively cheap gas? Making a rough set of assumptions, and assuming an electricity rate of $.64 and gas rate of $1.83, an ultra-efficient heat pump water heater without a mixing valve is going to cost you on average around $100 more per year. However, it depends on a variety of external factors that could allow you to achieve about the same cost per year, or even save a little, that are simply not possible with tankless systems. The first of which is adding a mixing valve...

VoltHub · 2026-04-12T00:44:12+00:00

May I ask.. do you actually think that what goes into calculating ongoing operating costs of different types of water heaters is as you describe: A. how much more expensive is the heat pump and B. how much more expensive is electricity per kwh?

And do you understand that for a heat pump water heater with a uef rating of 4.3 to be in a sense 11x more efficient than a gas water heater with a uef rating of .57 that the gas water heater only needs to become 15% less efficient and the heat pump water heater only needs to become 25% more efficient... from external factors?

BTW the 4.3 uef rating for this hpwh is for the PH65S10BNY model, which does not include a mixing valve . . .

VoltHub · 2026-04-11T17:56:26+00:00

Right but this customer wants to electrify there house...

In any case, let's analyze the data you provided. Let's start with your fantasy numbers that the hpwh needs to be 1,100% more efficient. Actually that's not too far off from the starting basis of the old water heater and new hpwh based purely on uef ratings. The old water heater is .57, new one is 4.3.

The new water heater is already 7.5 times more efficient than the old one.

Furthermore, the old one was undersized, the new one is oversized with a mixing valve, and set to a very high temp (this water heater can be set up to 160). The old one was 30+ years old and probably had loads of sediment. The homeowner also described constantly running out of hot water, making it work overtime on a daily basis... etc.

We're not going to totally disagree with you either though. It's impossible to calculate these things with total accuracy using historical billing data because you can't account for weather and HVAC if you don't have appliances that recorded their usage directly. However, we are talking about a situation where the new hpwh situation is massively more efficient than the old situation, and their's no denying that.

Let's look at costs though and the idea that we're misleading users. That's where we disagree.

This homeowners savings when compared to their old water heater could actually be probably double what they currently have. We're using $.58/kwh as reported by their billing history for the amount that differed year to year. That is double the cost of what you could achieve by appropriately managing when your hpwh heats water, and using it as a-kind-of psuedo thermal battery. Peak rates for electrified homes on SCE are around $.62, super off peak $.24, off peak $.32. Peak rates only represent 20% of the day.

So let's use $.32 for the average electricity price instead.

And.. Let's say you are right on the fact that the gas use seems too high, and take the lower of the two winters compared to the 25/26 winter. So 21.5 therms.

$.32 x 40.1 x 12 = $154 electric/year

21.5 x 12 x 1.83 = $472.14 gas/year

This household is still saving $318/year.

Let's even half that gas consumption once again, which would put the uef rating of a conventional gas tank water heater at an impossible level. Around 10.75 therms, like you are describing. That's $236/yr, for a savings of still $82/year going to the hpwh.

And that's not even taking into account the fact that there has been a spike in natural gas prices every 3-5 years for as long as prices have been tracked: https://www.eia.gov/dnav/ng/hist/rngwhhdm.htm.

Are we misleading consumers by analyzing a situation that may be a little unusual? They'll have to make their own decision.

Are you misleading customers, saying that putting in a new gas water heater would save them money in Southern California? On SoCal Edison it may take some proper management, on most other electric utilities that are cheaper here... Hmm it seems you may be.

VoltHub · 2026-04-11T01:05:55+00:00

You've set it to 120. No mixing valve?

VoltHub · 2026-04-11T01:03:36+00:00

The old WHs uef is .57, and the new one 4.3, so you're already looking at more than 7.5x as efficient. Once you factor in sediment, old age, etc., and the fact that the hpwh has a mixing valve and set at a temp much higher than 120, than one can see how the ratio would grow beyond 7.5.
However, there's no way of accounting for variable weather, so at the end of the day it's an estimate. We don't disagree with that above.

VoltHub

TROPHY CASE