- cross-posted to:
- climate@slrpnk.net
- cross-posted to:
- climate@slrpnk.net
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Things to note about these:
- Most models are 220V 30A. If you have an electrical already, you likely have everything you need here. If you have gas, you will need to run 10 AWG or 8 AWG wiring and install a new breaker. Depending on where you live, you’ll likely need a permit and have your handy work inspected before putting the water heater to service. If you aren’t sure when you’ll need 10 AWG over 8 AWG, hire a professional.
- The 120V 15A models are slower at heating water and do so for a smaller volume. These models you can plug right into the wall, but they are usually a bit slower at coming to temperature for the water and for smaller volume. There’s a Rheem version that’s plug-in and has something like a 80 gallon store. However, it is highly recommended for use only in warm climates and installed outside in a small enclosure. Basically if you don’t live in Southern California, Texas, Florida and all the states that touch those states in between them, you shouldn’t try using this.
- Like all heat pumps, there is an air filter that you need to replace. Usually these devices have apps that will notify you when a filter is needing to be cleaned or replaced.
- Also like all heat pumps, there’s a fan motor that will make sound. Luckily, most heat pump water heaters attempt to minimize the sound. That said, it’s not zero sound and nobody should be recommending that one of these things be installed in a room adjacent to a bedroom. I mean, this is one of those things that really depends on “how well do you tolerate noise?” But these things will produce a pretty consistent hum.
- The act of cooling the air from these reduces the humidity in the air. So you must drain that water that is produced. I think this is one thing that catches most people off-guard about these. Most water heaters don’t have a method for draining water because water around a water heater is usually a bad sign. So you do need to drain off the condensate. You can take a big bucket and collect the water to bail later, but how much water it’ll produce is dependent on what the humidity is in your area. If you’re in like Florida except something like a hint over a gallon of water per day. But most professional installations will install a drain line for you that leads to the outside, unless you’re putting this thing like smack dab in the dead middle of your house and you’re on a slab. That would obviously present a slightly higher challenge for that drain line installation.
But all that said, these things are super neato. It’s just really important for people to have realistic expectations before installing one.
A lot of these depend on the model and where it’s installed (geographically and within the house). In many areas of the US, there is a drain in the floor near all water heaters as a matter of code, you can drain condensate directly to that (and unlike gas appliances, the condensate is clean and does not need treated to go in household drains). I honestly think the noise concern is hugely overblown and used as an excuse for people that don’t like change. Sure it exists, but if your water heater is in the basement or garage like the majority are at least in my areas of the US, you’ll never notice it. I also look at the cooling air as a benefit for at least half the year, I can close all the vents in our basement for the whole spring/summer and it’s super comfortable. In the winter it’s a tad chilly, but not uncomfortable. Drying the air is also great for our basement, it’s literally a dehumidifier in what’s usually a pretty damp location for many people. Ours (a rheem unit) has a flimsy plastic air filter you vaccuum off once a year as well so not really a huge deal. I think most are like this.
I agree that folks should do their homework and understand what they are getting. Heat pump water heaters are great, but are overpriced at the moment. Even with electric company rebates and a tax credit it cost more than a decent gas replacement would for us. It’s likely to only pay off because we have solar and so don’t really pay for electricity for a large chunk of the year. But I expect costs to come down over the next 5-10 years as these become the go to for most electric installs (and with fewer new gas hookups in new and renovated buildings that’s like to be most installs). Once these hit that $700-$1000 price point there’s really no good reason most people shouldn’t default to installing one.
Thanks for this, I live in Florida and have a conventional resistance electric heater in my garage so I’m looking pretty hard at this. Why can’t the condensate be drained into the water tank to be used in the house? Is it unsafe?
i mean technically, you could use it but it sounds gross to do without a filtration of some sort before it goes to whatever storage you’re referring to.
another thing to note is that most baseboard heaters are OK to use on 12/2 AWG. If you’re tight on space in your panel, you’ll likely free up 2 spaces in your box eliminating the heater but still will need to run whatever gauge wire is suggested in the installation manual. (if i’m understanding your intention of removing the resistance heater)
We’re doing a major bathroom remodel at the moment and as part of the project are planning to replace the 15 year old electric water heater that came with the house when we bought it. Heat pumps work by exchanging heat from the air around to the water in the tank, which means that in addition to reducing humidity they also put out cool air. Usually they are installed in a garage or basement where that doesn’t matter as much, but we don’t have a basement and putting it in the garage would require a lot more work in terms of plumbing and electrical work, so we’re going to keep it where it is in the house but install vents that exchange air from the attic in the winter, then in the summer we can flip open the vents and cool/dehumidify our house.
They’re expensive up front but there are federal tax credits through 2032 (I think) of up to 30% of the project cost ($2000 max) and on top of that our local electric company is offering rebates of $800 to replace an electric or gas heater with an air pump. So that will reduce the upfront cost by a pretty good amount.
The only thing I’m at all concerned about is the noise of the motor, but the heater won’t be adjacent to any bedrooms so I don’t think it’ll be a big problem in any case.
Not all heat pumps have an air filter. Those operated outdoors usually don‘t have any.
Do they get the water as hot as traditional tank water heaters?
So you do need to drain off the condensate. You can take a big bucket and collect the water to bail later
Do y’all not have condensate pumps?
What crazy ass compressor needs 220V 30A? Here in Netherlands heat pump is standard as new gas connections are banned for environmental reason, and most homes heat water and the whole house on 7 kW heat, 1.5 kW electric, or about 7A on 240V.
The backup element which only runs at extreme cold outside is a few kW yes but for hot water we just let it run dry and the tap gets colder, no big deal.
Dedicated hot water only boilers have a 300-700W compressor and sometimes a 1.5 kW backup coil. If electrical connection is an issue, just look for a pure compressor driven boiler.
They almost always have two high wattage resistive elements installed like a traditional electric water heater which require the 220v/30a circuit. The compressor runs on 220v but sips almost no real current while running.
We have two main models here, one with a sizable compressor enough to heat a whole home (7-20 kW heat) and a water tank on the side which doesn’t need resistive backup, or smaller, hybrid models that have a few hundred W compressor and maybe 1-3 kW heat output. The latter are almost all backed up by a gas boiler in a hybrid setup, usually uses zero gas until you run it dry - then the 25ish kW gas powered furnace can provide enough power to quickly fill a bath or send tons of hot water to a rain shower.
I have a Sanco2 heat pump water heater. The heat pump is located outside the house, with the tank in the basement (so no noise!). It is so absurdly efficient that I thought I was measuring the power draw wrong. Its expensive up front, but a big fat govt tax credit sure helped and the monthly power cost is about the same as my coffee maker.
The tank inside is 83 gallons. I can run the dishwasher, two showers, and anything else I can imagine and it handles it like a champ. The heat pump heats the water so fast that it refills it in minutes, not hours.
And since there’s no element or anything in the tank, there’s virtually nothing to break or fix in it. Nothing to rust, no joints to go bad. The tank is constructed solely for water in and out via pump and that’s it. It looks like a military designed tank because there’s no reason not to fortify it to last forever. So they did.
Between that and my induction range and heat pump AC/furnance, we turned off our natural gas connection. I love love love all of them.
Oh, you Americans with your hot-water dishwashers! ❤️
Wait, are hot water dish washers not a thing outside the US?
I think it’s everywhere but in the US the water comes already hot, in Europe the dishwasher heats it up from the regular cold water.
Yeah the hot water way seems better.
It’s because our dishwashers are massively more efficient and environmentally friendly.
They use very little water, which they heat up themselves to save energy
The only drawback is they take longer to clean the dishes, up to three hours
But nobody would be so selfish as to demand their dishes be done quickly over preserving our environment, would they?
Why would that save energy? It’s going to be resistive heat, which at best matches the water heater. Some models in the US include a heating element, but it’s more of a convenience. The vast majority are simply connected to the hot water line, since that’s why it’s there.
Also, let’s talk numbers. From what I could Google, EU dishwashers use 1-1.5KWh/load, while US dishwashers use an average of 1.15KWh/load. Certainly there are more efficient models, but this shows that there isn’t a significant difference in energy usage between them.
your energy calculations are forgetting the energy cost of the pre-heated water, it’s the appliance equivalent of an offshore tax haven!
Your system - Add cold water to water heater and heat (using energy). Keep at required heat until needed, could be a whole day or more (using energy). Pump hot water through cold pipes to dishwasher, losing energy. Reheat (using energy)
Our system - add cold water to device directly. Heat (using energy)
I couldn’t explain it any clearer so I’ll fuck off now
I’m confused, our as in European dishwashers are more efficient and environmentally friendly?
But wouldn’t it be even more so if the hot water that was stored and not being used was the feed instead of cold water? That was the temperature increase is minimal and a lot more efficient.
The eco wash is the best wash on my dishwasher.
It has nothing to do with energy efficiency, and everything to do with UK plumbing. A building’s hot water system is presumed to be subject to environmental contamination, and not considered potable. Only the cold water supply is considered potable.
It’s the same reason why they have separate taps for hot and cold water, while the US uses mixing taps almost everywhere.
The majority of our hot water is on-demand so no. Also, is it more efficient to heat the water, pump it through a potentially cold pipe, only to have to reheat it again? Nope,just heat it where you need it, and with a lower wattage heater
No.
The reason your dishwashers use cold water is because your hot water supply is not presumed to be potable water.
EU regulations allows for gravity-fed hot water tanks in certain jurisdictions, open to atmospheric pressure, and thus possible contamination. They did this to prevent the possibility of exploding boilers.
Since the building’s hot water supply is presumed unsafe, dishwashers are required to use the safe, cold water supply to generate their own safe, hot water.
US regulations do not allow hot water to be held at atmospheric pressure. We use T&P valves to limit boiler pressures and prevent explosions. Our hot water is not exposed to environmental contaminants, and is presumed potable.
Ha ha ha that’s about 50 years out of date bud 😂
I’m so confused. Whose dishwashers are you talking about? I’m in the US, you’re describing every dishwasher I’ve ever had, except that we always hook it up to the hot water line. Our unit takes very little water, it takes hours to run a load due to efficiency features. It has a heating element inside to take whatever water it gets and keep it hot for the cycle.
I don’t really see why it’s any less efficient to use the hot water we are already heating with our water heater (which heats much more efficiently than a small electric heater would). The water originally arrives to my house cold, it has to be heated one way or another. My dishwasher is less than 10 feet away from my water heater, water is not losing appreciable heat on the way to the dishwasher.
It depends. Spraying your dishes with water that is prone to legionella doesn’t seem super safe to me. But even assuming that, I have dishwasher programs than run at 70C, which is above what my hot water tank produces.
Besides, isn’t there a heating element in a US dishwasher regardless? Otherwise, it feels like it has got to continually add more hot water to keep the temperature up…
It depends. Spraying your dishes with water that is prone to legionella doesn’t seem super safe to me.
That is the real reason why UK / EU dishwashers use the cold water supply. They don’t consider a building’s hot water supply to be potable water. Their hot water was once held in atmospheric pressure, gravity-fed tanks, exposed to environmental contamination. Brits treated central hot water as unclean. This is also why they often used separate taps for hot and cold water. If they need clean, hot water, they heat cold water at the point of use.
The US never allowed atmospheric pressure hot water tanks. Our hot water is not exposed to environmental contaminants, and is presumed potable.
As a Dane living in the U.K., I agree. I’d never seen an atmospheric pressure water system growing up but coming here, that seemed the norm. Now, 20 years after, the norm in U.K. new installation is high pressure water systems (so called “system boilers”) so it is changing slowly. But in the U.K. they have an almost mortal fear for high pressure systems, thinking they’ll explode at any moment.
I believe it’s mostly due to not having always hot water hookups available where laundry would be or not consistently having hot water always available. (as in on demand, from a large boiler that wouldn’t impact the remain of the hot water uses)
Yes in many places, hot water is produced on demand in smaller residences. This means your dishwasher relying on hot water would kill your shower.
I know this seems odd probably to Americans … but many houses in the U.K. doesn’t have the space for a hot water tank.
I’m intrigued- does that mean the UK uses “tankless” water heaters, at least in smaller residences? Are they underspecced that they can’t handle a shower at the same time as a (typically) 3.5 gallon dishwasher?
That seems way less efficient and more prone to issue than just having a central appliance that’s responsible for making hot water.
It is, but the dishwasher has to have a water heater in it. It has to heat water to a temp that you shouldn’t keep you got water tank at and heats throughout the cycle.
Your clothes washer (generally) also has a built in water heater.
My tank is 60° and my washing machine is 40° and dishwasher is 70° at a maximum. A lot more efficient to have a hot water feed to these that have them increase the temperature 30-50°.
In most places in Europe, hot water that’s been stored is treated with some suspicion. Besides, having a heating element is probably the least error prone thing you could make.
That probably means that the hot water tank needs to be larger though. Guess it depends on the heating source though
Do they not have mixing valves where you are?
A lot more efficient
Hundreds of engineers and scientists who designed modern dishwashers disagree with you
Dump a kettle of boiling water in the dishwasher before you start the cycle.
That wouldn’t work with every dishwasher I’ve ever had. They all start the cycle by draining any liquid in the dishwasher before they fill to run the first pre-wash cycle.
Oh. Admitably I’m not an expert, I’m still ony first ever dishwasher. I did that when our water heater died and it seemed to help.
This is crazy to me. How do the dishwashers in US heat the water up hot enough to clean effectively? Our dishwashers heat the water up past scolding, really helps cleaning.
Every dishwasher I’ve used in the United States has a built-in heating element. Mine has a steam sanitize function and gets quite hot.
However, it is conventional here to plumb the dishwasher to the hot water line, and it is my understanding that the dishwasher is designed to assume the water is hot and doesn’t try to heat it from cold during the first rinse.
I’ve found that running some water from my kitchen sink to prime the hot line with hot water makes the dishwasher more effective. I use that water for plants, or I keep it in a jug and pour it into a load of laundry in the winter.
Interesting, thanks for info!
There’s a heating coil in the bottom of the unit. Water floods in and sits for a short while while reaching temperature.
They really help conserve water compared to hand-washing. Important with the many relatively dry arid places in the south and west of the US.
Oh yeah, I’m with you that dishwashers conserve water. I was making a playful remark that in Europe, the dishwasher takes cold water and heats it up itself, not arguing for or against dishwashers as a concept.
Awesome. I so wanted the Sanco2 but the price put it out of reach, and we don’t use enough hot water toake the payback remotely reasonable. For anyone else reading, it’s an R744 (CO2) refrigerant system that’s massively better for the environment than HFCs (and HFOs) as well.
I’ve never heard of this brand before but I love that the heat pump is on the outside of the house.
They forgot the best part. That model uses CO2 (it’s in the name), instead of older HFC (or very ancient CFC) based refrigerants.
I’ve been considering replacing the central a/c in my house with a heat pump to handle home heating as well, but never thought about heating water that way also. That’s interesting. Can you get a single heat pump system that does both?
Where water heating is concerned, I do know a guy who set up a solar water heater, and he made some compelling arguments for it. Like he considered rooftop solar panels initially to generate electricity, but opted for water heating instead. He pointed out that while electric panels are maybe 20% efficient, water heating is nearly 100% efficient, and his system works so well that it even needs to shut off every now and then to prevent overheating. Anyway, I’m not vouching for this personally since I have no experience with it, but I’m just throwing it out there another possible approach?
I don’t think there’s much for consumer single heat pump systems that do both. I’ve seen a few, especially with geothermal systems, but mostly it’s just a tiny heat pump built into the cap of a traditional water heater.
Worth pointing out that the nature of a heat pump is that the housewide heat pump is first pumping warm air into the house to make it available for the water heater, which then pumps that warm air into the water. So it is just one big machine, fundamentally. Or, if your air conditioner is running, the water heater heat pump is adding some cooling to the space.
The criticism of the heat pump water heater: they’re loud. A high frequency compressor buzz while operating. If you are switching to one, make sure it is located somewhere where the noise won’t bother you. Mine is in a mechanical room in the middle of my house and it is annoying when operating – I program it to run at night and close doors when going to bed. If I could do it over again, I’d put in in the (insulated) attic in spite of all the risks involved in that. More hot air available for it to use up there anyway.
at my parents house the is a 14kw heat pump that does heating and water and it’s not an industrial heat pump. you can get them from daikin, but they need three phase ac.
I would call anything that needs 3-phase to be “industrial”. The number of residences with 3-phase would be in the low hundredths of a percent of homes.
3-phase 230V 16A is standard here. but you can get up to 30A if the wiring allows it. I’ve never seen a house with only 1 or 2-phase.
https://www.worldstandards.eu/electricity/three-phase-electric-power/
German 3-phase is at 400V, there is no such thing as 2-phase (you’re probably thinking of split phase 110+110 as in NA). So I’d be practically certain your parents have single phase 230V.
between neutral it’s 230V.Between two phases it’s 400V.
That’s a lot of good info. Thanks!
I hadn’t considered the noise issue. I often wear noise-cancelling ear cans while I’m working. I wonder if they might help?
Can confirm the solar water heating works great, if it’s sunny you get 60°c water by noon.
My concern is legionella. If you don’t get enough sun and the water temperature stay at ~45°C for extended amount of time, isn’t the water tank became an ideal breeding ground for legionella?
Powered solar heat pumps sanitize themselves once a week if temperature doesn’t reach 70C at least once. Same for heat pump boilers, they are usually set to 50C but goes up to 70C weekly.
On solar, there is always a downstream heater that can heat cold water to 60C+ and must be set at least that high for legionella. My setup is like that, unpowered solar tank for free heat if available, and gas boosts it up to safe temperature and does all the work in the winter.
Chlorine is also pretty effective at killing Legionella.
It is helpful to have backup heat when using solar is sunny days are not plentiful.
https://en.m.wikipedia.org/wiki/Legionella
At 50 °C (122 °F) – 90% die in 80–124 minutes, depending on strain (D = 80–124 minutes)
48 to 50 °C (118 to 122 °F) – can survive but do not multiply
The tanks can be set to bring the temp up to 60° specifically to prevent this.
That’s great! Good to know. I remember staying at a hotel in rural Mexico where they had a cistern on the roof. Basically just a big metal tank, and even that thing heated enough that it was comfortable to shower when I’d come back from the beach in the afternoon. So it doesn’t surprise me that a purpose-built water heater could do quite well.
Can you get a single heat pump system that does both?
We have a geothermal heat pump that we put in when we built our house. It uses water (closed loops) to exchange heat/cold instead of air. But that unit also has a desuperheater that does supplement hot water. The ideal setup is to have a non-powered water heater that is warmed by the output of the desuperheater, that feeds a powered water heater. This creates a situation where the water entering the powered water heater is already pretty warm requiring less work for it.
unfortunately, my knowledge at the time wasn’t where it is today, and our installer was also not well versed. So we just have a single water heater, but it is plumbed into the desuperheater at least. Ours just cycles water through the desuperheater into the powered tank. Probably still helps some but I suspect not as much.
Unfortunately in most countries in Europe the incentives for PV are much higher than solar water, which means we spend an awful lot of money supporting the least efficient of the two.
[citation required]
Unsubsidized PV is around €1 to €1.5 per Wp, IKEA offers 4200 Wp for €4321 right now. That saves at least €800 off my power bill.
A solar boiler starts at €2500 at minimum and easily goes up to €4000. It saves me €250 per year in gas. Or I could get a heat pump boiler for €1500 and save 80% of the €250.
Thermal solar was a thing when PV was stupid expensive but it makes no sense in ROI now, with PV you can power your hot water, home heat and everything else for about the same price as 2-3 solar heat collectors and a boiler.
You’re talking ROI. I’m talking efficiency. SHW is about 65%-70% efficient. PV is about 20% efficient.
Efficient with money means you get more of that world and environment as savings per dollar.
Would you choose paying €4000 to replace 600 kWh of heat pump boiler hot water with solar boiler, or 4000 kWh of basically a whole home’s energy usage including hot water?
The solar boiler doesn’t even heat well during all seasons, mine still uses gas to back it up at least half the days.
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For me it means I don’t need any propane deliveries in the summer, and it helps dehumidify a damp corner of the basement. I’m not sure if it actually saves me any money though.
Depends entirely on where in the world you live, which is the primary influencing factor for the price of gas.
In Midwest USA gas is so ridiculously cheap that it still beats total cost of ownership. Plus the new electric to install. Even central heat pump is hard to justify (on price alone I mean).
This is true in central Canada too. Heat pumps get pushed saying they put out 3 times as much heat as the energy they use, but electricity is 7x the cost of natural gas.
Right, they make absolute sense if you don’t have access to cheap natural gas. I’m worried for the day NG prices rise though. It’ll be a double whammy for those of us in SK with the vast majority of the heating in the populated south provided by NG and a grid that has a significant portion produced by NG. You’ll see the increase even if you aren’t heating with gas.
Governments need to punish carbon emitting fuel sources more. People are going to use the cheaper option, not the one that will benefit the planet. It needs to be cheaper to use renewable energy, or at the very least energy efficient options need incentives.
No, they most definitely should not! Implementing such a measure unnecessarily increases the difficulty for low-income families. Instead, there should be support for the installation or a tax reduction for those who have one. Let’s focus on making it easier for people to adopt environmentally friendly practices without making things more expensive.
tax reduction only really works to incentivize people that aren’t poor
A better option would be a discount on the electrical bill for having green tech installed. If you want to help poor families, help their month to month costs.
This is still blind to the fact that those families could be in much much worse condition in 50 years if we don’t drastically change our carbon emissions. The increasingly frequent and more dangerous natural disasters could very easily leave them without a home at all. Low income families will also be the ones to suffer the most when it comes to the worsening climate disaster
I don’t deny that. However, forcing people to change by making things more expensive only harms these families. Of course, the ongoing climate situation is concerning, but in the short term, we also need to take care of those who are financially vulnerable. We can’t just let them go under.
Well, they have took off in Europe due to the cost of natural gas and … the source being a evil dictator who uses his control over natural gas to control other countries foreign policy.
Maybe my gas is more expensive than other parts of the Midwest. But my old gas water heater just died about 6 weeks ago. I swapped in a 55 gallon hybrid / electric heat pump model. I did the re-wire and install myself (which I acknowledge not everyone is comfortable doing).
My most recent gas and electric bills were compelling. I’ve been using my gas furnace already, and my gas bill is the lowest it’s ever been since I bought this house 5 years ago (including summer, non-heating months). And my electric bill increase was negligible.
Sure, my old unit was not running as efficiently as it could bave. And newer gas models probably have improved efficiency. But I can’t deny the savings in my bills. Between the tax rebate and the savings, I’ll make back my extra investment and then some before this thing dies.
If I’m getting a new water heater, I’d rather get a tankless honestly. I figure by the time I’m ready for a new water heater, the tankless technology will be even better and will be perfectly ready for me to use it.
Tankless still uses gas and it won’t make the water coming out of your faucet instantly hot. If that’s what you are looking for you want a recirculating pump or two.
Can’t you do electric tankless?
You can, but not as a heat pump so you wouldn’t get all the efficiency gains and it will very often end up being more expensive to run than gas tankless in the near term.
My coworker bought one and had to buy a new electrical panel because it required 45A of electricity to run it meaning 3 dedicated circuits at 120V (5400 watts!). IMO an electric tankless is the worst of both worlds.
The more and more hot water spouts you have the more expensive the tankless design is, especially for running costs and short life span. The recirculating with a water tank will last longer, cheaper running costs, and can be fitted in already existing infrastructure of water tank designed homes. In building a new home, it is possible to have tankless water heaters be better than water tanks. especially if you can use Solar Panels to make the running costs near 0.
You absolutely can… And for smaller homes they’re great.
Gas is fairly cheap where I live so that should be okay I think. Don’t tankless water heaters generally come with recirculating pumps?
If methane gas is cheap because you’re in the US, don’t count on it staying that way; there are a ton of export terminals under construction, and when completed, they’ll raise domestic prices in the US to match those on the world market, which are 2-3x higher.
I’m not in the US, and tbh I don’t really use a ton of hot water. I think a tankless would still be a good investment for me. I’ll also end up getting an air-to-air heat pump probably with a gas furnace as a backup for the really really cold winter days.
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Electric tankless tends to be quite rare due to needing a lot more wattage than most household circuits can provide
Depends on the size of the house and the water needs.
I installed a totally electric tankless water heater made by a reputable manufacturer in my home on my own 11 years ago and just wired in a new 40 amp 220V breaker into the panel to support it.
It was actually very easy and plenty adequate for the water usage in a 2 bed / 1 bath home (including kitchen usage) for a 2 adult and 2 child household.
For more bathrooms or occupants it might be more difficult, expensive, or rare but in my case I did the whole job myself for under $350 including everything… But again, it was 11 years ago so I’d expect prices to be a bit higher
FYI that’s almost 9000 watts of power to supply that thing, which is about 9 microwaves or 3 electric ovens worth.
That’s not constant throughput though. That’s absolute peak possibilities.
Editing to add:. FWIW, it also didn’t increase the monthly average electrical usage at all… In fact, I believe I had a small reduction in the average… It was replacing a significantly older traditional 30 gallon electric water heater.
Thankless really never appealed to me, unless you have massive space restrictions. Water tanks are amazingly insulated so the loss is basically nothing and you’ll almost never run out of hot water. Thankless always claim infinite hot water but it almost never works and it’s way more complicated for what it’s doing. Anyway just my 2c.
Tankless only shines if you have a large household where you need an endless supply of hot water. For everything else, they’re going to operate the same or worse than a tank heater and also come with more maintenance.
I figure by the time I get tankless in probably another 10 years the tech will likely be more stable so it won’t have nearly as many problems as they do now which is already less than they had before.
I love my geothermal water heater! With a family of 5 and 3 full bathrooms we never run out of hot water. We planned to go tankless until we went geothermal.
Do you have a geothermal heat pump too for AC/Heat? What was the cost on that? And how much land does the geothermal system take up nowadays?
There are multiple ways to do geothermal. We have 2 I believe 150ft closed loops that live around 6’ under the yard. They also have vertical bore loops that go straight down which require way less land. Lastly is open loop, which would be a set of lines that run to a pond, or i guess any body of water to do that heat exchanging.
It does both heat and ac. We went with a horizontal system that takes about 1/2 acers since we have plenty of land. The system installed was less than 15k with the tax credits, but that was a few years ago.
If only we all had a few hundred square yards for a geothermal system.
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We had a GE that had the heat pump die after a couple years. Now our AO Smith will randomly not have hot water some mornings with no error codes. I am all for heat pumps, I am just not enjoying being a beta tester. I’d like to replace my gas furnace with a heat pump but my previous experiences make me nervous. Hopefully in a few years they will be rock solid reliable.
Heat pump water heaters are relatively new, but heat pumps for interior heating and cooling have been around for decades. I have a 14 year old system that works well.
Heat pumps for indoor climate control work great.
We had our electric bill go down by 1/4 after installing our AO Smith Signature 900. Then the heat pump broke 13 months into a 12 month labor warranty (it no longer blew cold air, so it wasn’t working). We found out nobody even fixes the heat pump part. AO Smith agreed to take it back and refunded us but we had to hire a plumber to put in another one, this time a less expensive one.
I’ve had a heat pump for heating and cooling the house for three years and the only thing I’ve had to do is clean it
I’ve got one in a small closet and it has the added advantage of chilling that room enough to store wine
Not a word about recovery time
And they think a low power one is good?
YMMV of course, and will highly depend on how many people are in your house and how you use hot water, but a 50 gallon heat pump water heater easily supplies a dishwasher and two long showers with 1/3 of a tank of available water left in our house (and I take pretty hot showers that are not always as short as they should be). Sure, it takes an hour or two to fully recover but we aren’t ever looking to use much more hot water at one time. If you have a household of four, it may be a bit more of a problem, but then you can easily schedule other hot water uses to happen “off peak” like a dishwasher.
Yeah, I need to adjust the way I think about such things. As my kids go away to college, I no longer need such a continuous supply
The recovery time, aka first hour rating, should be in the specs for the models to find one that suits your needs. There’s more detailed research on them available as well if you’re so inclined.
Sure, I know the info will be there. But someone generically selling the idea needs to address or at least mention the impediment. I’m not to the point of wasting my time trying to find the details so the pitch is a failure
I have a pool with a new 80 gallon heat pump. This past summer, 3 full families took hot showers before the water became warm and not hot.
Recovered to hot enough for another family in an hour.
As opposed to resistive electric heaters? Well, that’s hardly a surprise. It’s not going to come close to being as cheap as NG though, and an NG heater is 1/4 of the price.
Heat pumps are nearly as cheap in Ohio as NG and save you money over the life of your house. Despite being run by MAGA, Ohio has some pretty sweet green energy subsidies and tax write-offs.
Great substitute for geothermal.
It’s also more energy efficient and therefore less environmentally burdensome in a lot of cases to use natural gas to generate electricity and transmit that electricity to your house to power a heat pump, than it is to directly pipe gas into your house and burn it even in a high efficiency appliance. This is because a heat pump literally gathers ambient energy from the environment and can typically concentrate 4x as much heat per unit electricity input than the electricity itself can provide if directly converted into heat.
Basically, they’re the closest thing we have to one of those fake overunity machines where a motor turns a generator that’s powering the motor.
That’s another important point: if you are using a heat pump water heater, the source for your heat is the air in your house. If you have a gas furnace and a heat pump water heater, all winter long you are heating your water with gas, and using extra electricity to do it.
Heat pump water heaters make perfect sense in the summer, though. And they’d make even more sense on the top floor of your house than in a cool basement.
There are multiple kinds of heat pump water heaters.
For the one I have, only the tank is inside. The full heat pump is outside, and water is piped between it and the tank.
I haven’t seen those offered in my area, but In that case, I’ll have similar criticism in about 6 months, when I have to run a separate AC unit to pull heat out of the house. It’s almost like the water heater should be able to use either internal or external air as a source.
This is example highlights the benefits of heat pumps as the heat from the gas furnace is waste heat from something functioning on an entirely separate purpose that will occur independently from the water heater. In turn this situation benefits the heat pump as it is actually more efficient to scavenge the wasted heat from the gas furnace. It is super odd that your post is suggesting that it is not efficient because it is using “extra electricity” when the efficiency is from reduced running costs(money) and not hype fixating on just electrical usage. On the flipside, a gas water heater will use extra gas to heat the water, too! This is just silly
A furnace puts BTUs into the house. A heat pump furnace pulls BTUs from the atmosphere and pushes them into the house; a gas furnace extracts BTUs from fuel and puts them into the house. An electric furnace extracts BTUs from electrical energy, and puts them into the house.
The heat pump water heater pulls BTUs from the house and pushes them into the water. They use internal air as their heat source. They do not draw heat from the outside atmosphere; they draw heat from the furnace-heated air inside the house.
The two systems are not “separate” or “independent”. The heat pump water heater is daisy chained to the furnace. Both use the same, household air for opposite purposes: one sinks heat into the house, the other sources heat from the house.
And how is it a bad thing that it is making good use of the heat around the furnace to heat up water? You do realize that the electricity in the heat pump also is making some heat on its own.
All that energy can be harvested for a hot shower or bath instead of having a heat pump outside in the colder temps running at a lower efficiency. On top of that, the furnace will not always be running throughout the year, and the warmer months will be more beneficial to have the heat pump than a gas water heater.
I am assuming that the heat pump water tank and gas furnace are in the basement, or garage. not inside the well insulated house…
On top of that, the hot air is directed out of the gas furnace to the house, while the air surrounding the gas furnace is lost heat that can be scavenged by the heat pump. They are independent and work for separate reasons.
I am assuming that the heat pump water tank and gas furnace are in the basement, or garage. not inside the well insulated house…
Ah. That’s the issue. Your assumption is faulty.
Water heaters have water lines leading to them. Anywhere the temperature regularly falls below freezing, the water heater must be located inside the heated structure, not exposed to the elements. Otherwise, the plumbing could freeze. The basement may be colder than the rest of the house, but it is still part of the heated structure.
If your basement, garage, or whatever room contains your water heater is not within the heated structure, you are living well south of Ohio.
Heat pumps are nearly as cheap in Ohio as NG
I’m in the market for a water heater in Ohio. The cheapest heat pump water heater I could find is more than twice the price of a typical NG heater. Where are you finding them for anything remotely close to the same price?
One important thing to note: heat pump water heaters take heat from the house and put it into the water. In an Ohio winter, that might not be desirable: you’re paying for the heat from the furnace, then paying for the same heat again into the tank.
There’s a federal tax credit worth 2k for HPWH. I’m not aware of any Ohio specific subsidies, although there are programs coming through the IRA that are run through the states and will offer more incentives.
Up to* $2k. Just for the sake of clarity.
The tax credit is 30% of the total project price, up to $2k. If the HPWH is over double the cost of NG, you’re still paying quite a bit more even with the tax credit.
Wow that’s wild, man, maybe it’s because I had to do a whole rip job on my heater? I sunk $20k into my heating and cooling system this year. Was a fuckin nightmare. Maybe if you’re going whole cloth the savings show up more?
You’re talking about HVAC while everyone else is talking about water heaters. I think it’s pretty well demonstrated that heat pumps for HVAC are the way to go but not for heating water.
That makes sense.
As a fellow Ohioan with old ass HVAC and a furnace. Where can Iearn more?!
Replace your furnace with a heat pump long before you even think about upgrading your water heater.
Think of a HPWH as an air conditioner, that dumps heat into water instead of the outside air. Do you want your furnace and your air conditioner running in your home simultaneously? All winter long, that is what a HPWH will be doing. Because your furnace heats your house, and the HPWH gets it heat from your house, your furnace will be providing the heat for your water as well.
In summer, HPWHs make perfect sense. The HPWH will be working with your AC instead of against your furnace.
If you have a heat pump HVAC system, a HPWH is just a second stage heat pump. Your HVAC is still going to be providing the heat for your water as well as the house, but the heat pump HVAC can provide heat more efficiently than a gas water heater or resistive electric water heater. Since the HVAC heat pump is more efficient than a traditional water heater, it is reasonable to shift that water heating load onto your HVAC with a HPWH.
Make sure your HVAC heat pump installer knows you want to install a HPWH in the future. You’ll want to make sure your HVAC heat pump is sized a little larger than normal.
I’m expecting US methane gas prices to rise to match the much higher global LNG price due to the large number of export terminals under construction.
Right now, and that’s not even the case everywhere in the world. In many parts of Europe, the operational costs of heat pumps are already lower than those of gas furnaces.
Gas is cheaper to run as well, although that is more subject to the wonders of international incidents.
I like the idea of a renewable energy way to heat the home, as trickling the heat in would work there, run the electricity when it’s cheaper and that, but for hot water, gas is just so convenient. A heat pump is never going to produce enough concentrated energy to run a bath or have a shower more powerful than a piss.
Hated having a water tank when I had a rubbish old gas boiler, and I’m not going back to one if I can avoid it.
There are electric water heaters that can take the preheated water from the general system and give it the last boost to exactly the temperature you desire. Ideally those would be installed relatively close to wherever you need the water. They are less efficient, but on the plus side, they only heat whenever and exactly how much you need
I’ve contemplated a heat exchanger on the tub drain line to capture the heat from my shower to preheat water into the tank.
A small, non-functional gas water heater, located in a hot, summer attic, and with a small fan blowing air down the exhaust stack, makes an excellent pre-heater.
Stick a small window air conditioner in there, and it becomes a redneck heat pump water heater.
Unrelated but honorable mention for indirect fired water heater tanks… For anyone who lives with a boiler for heat. It turns out not having a flame under your tank works wonders for longevity. I also really appreciate the built-in early warning throughout the warmer months if there might be a boiler problem before it gets cold.
https://notesfrompoland.com/2023/04/28/heat-pumps-boom-in-poland-europes-fastest-growing-market/
This coming from Poland, one of the most coal-dependent countries in the world.
