Submitted 3 weeks ago by pageflight@lemmy.world to [deleted]
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cross-posted from: lemmy.world/post/34021020
I recently installed an Emporia Vue with monitoring for the individual circuit my water heater is on. It captured the very significant difference in energy usage from replacing resistive heat with heat pump.
bravo! Double check if your city offers subsidies. Got $200 for mine.
The utility company for me. They chipped in $1,600!
Had no idea this was a thing.
Oh boy. So the heat pump is probably one of the most important inventions without which modern society wouldnt exist. It uses a refrigerant that has a low boiling point. It is liquified through the pressure of a pump on one side, and let to evaporate on the other side.
Because of the evaporation it can draw heat from there and then give it off at the other side. This way it can cool the cold side more and warm up the warm side more, subsequently “pumping” the heat from one to the other side.
Your fridge uses a heat pump. Most AC units use heat pumps. Any industrial room cooling like warehouses, trucks etc. involves heat pumps.
Now comes the neat thing. For heating a heat pump can have an efficiency factor up to around 4. So 1kW of electrical power can give you up to 4kW of heating power. This is because the electricity isn’t transformed to thermic energy, but rather used to move thermic energy from the outside inside.
Heat pumps are amazing, especially as modern ones provide both AC and heating efficiently. Only caveat is that the efficiency is dependent on the temperature difference it needs to surpass. Because of that older radiator installations that were designed for a higher temperature might need replacement with newer larger radiators. Also if it gets really really cold you might need a classical heater to support the system.
Not to be ungrateful for the explanation, but I’ve had heat pump HVAC for years. I’m originally from Oklahoma and everyone has a heat pump. In fact, I find it weird that they’re controversial in any way!
I meant I had never heard of a heat pump water heater. Which sucks because I just had a new unit installed last year. :(
Are they extra expensive? More complex install?
Are these things reliable? I’m not in a position to replace currently but I do like to think about these things before the need arises.
I’ve had gas tanked for years. What I appreciate is that they need nothing from me. I flush the tank once a year and that’s it. They just do their job quietly and without need. I don’t think about it, and I love that.
I’ve been burned with crappy modern appliances. Tried front load washers, three and they were all crap. Sometimes wouldn’t spin, they were smelly, expensive and unreliable. Switched back to top loader because it just works. Same experience with a dishwasher. Used very little energy, but did a lousy job, was expensive and had to fuss with it constantly.
I’d like lower energy costs but not if the thing won’t work or have weird conditions. If five people who live in the house can overrun it with two showers, thats not useful or if it takes an hour to heat a tankful.
At the core it is the same thing like an AC unit or the cooler in your fridge. The technology itself is very reliable.
You need to check though if your house installation is suitable for it and that it has the appropiate size and can be placed in the right place outside.
It might make sense to combine systems. Maybe keep the gas-heater for hot water but run your heating on the heat pump.
I have been running a Rheem one for almost 5 years now and I haven’t had a single issue with it. It’s nice that it will keep the garage dehumidified. I also set mine to 140F and it does pretty well with multiple showers. We occasionally run out but that doesn’t happen very often, maybe a handful of times per year. With rebates and installing it myself it was able to pay for itself in about 2.5 years.
Enjoy your savings! These are wonderful!
I bought my first heat pump water heater in 2007 (GE Geospring) and was sold on the technology ever since. When I moved to a new house I put that upgrade on the shortlist and now have one in this house too. There isn’t much savings in winter (as I don’t exhaust it to the outside air), but for the other 9 months of the year the savings are significant!
I’ll have to watch how it changes in the winter.
I have a State, and actually the resistance heating is the 1st unit after the heat pump failed; then I got it replaced under (parts-but-not-labor) warrantee. So I’m a big fan of the technology but not the brand. However, the new State does have duct connections, maybe it’d be worth hooking those up. You like the Geospring?
I did like my Geospring, but GE sold the entire division off to another company some years ago. Since then I can’t speak to the units. My new one is a Rheem. I got it fairly inexpensively from Home Depot and have been happy with the performance of it thus far.
One word of warning for the Rheem units. They make two lines and they DO NOT call out this major difference between them.
If you want full service and support options or go cheap for savings will be up to you.
i wonder what role technology connections had in this?
Hah, I do watch the channel, though was planning the upgrade before his specific influence. But I am inspired by his description of only running the WH at certain times of day (haven’t figured out how to do that yet).
I am very, very interested in these. We have many more days that the house needs cooled, rather than warmed, and heat pump AC has been the standard for 40 years - grabbing the heat being pulled out of the house and using it for hot water (or anything needing heat -clothes drying, maybe) is absolute genius tech and I want it.
It’s great for hot water. It’s not so great for clothes. They’re much more prevalent in Europe as you can use the chilled side of the circuit to condense moist area, eliminating the need for venting, and they use less energy. They also take hours to dry clothes, and those clothes often still need to be hung to dry for awhile afterwards. We had one, we now just hang our clothes to dry.
Got one last September and works really well. Used about 2000 kwh over the winter for central heating for a big house, central Europe. Thats nothing compared to previous use of wood pellets and/or oil.
We also have solar water heating (via vacuum tubes) so water heating is practically free in the summer. Though you do need a large tank to store it.
Out of curiosity, is your new water heater inside your house in a heated area? If so is your house heated with electricity (heat pump or resistance) that would also be on this chart? Or do you have fur6nace burning NG or propane?
Not that heat pumps are bad, they are fantastic. But if your house heat isn’t also on your graph, you’re not seeing the whole picture. The water heat pump is actually using the very warm air in the house to heat the water. But it’s making your house colder and then your house heater needs to run more to make up the difference.
Unheated but insulated unfinished basement. And this unit does have duct connections that I haven’t made use of (yet).
For areas where you want to cool or dehumidify the air these help though. So where I live, during the summer these would effectively be “free” - you were going to use that energy to cool the house anyway with your AC, now you’ve just put that heat in water instead.
You can also connect it through the wall so that it uses outside air for its energy. Modern heat pump technology is so good it can remain effective all the way down to -25C.
Veedem@lemmy.world 3 weeks ago
What’s the upfront price difference in the water heaters?
cymbal_king@lemmy.world 3 weeks ago
My utility company chipped in $1,600, so it ended up being the cheapest option anyway.
This 65gal Rheem heat pump water heater goes for $2,150 plus shipping and install.
This 55gal Rheem resistance water heater goes for $820 plus about equivalent shipping and install as a heat pump water heater
dan@upvote.au 3 weeks ago
In my area there’s barely any upfront cost, as there’s something like $5k in rebates plus the 30% federal tax credit.
rainwall@piefed.social 3 weeks ago
2-3x more expensive, but they normally pay off in about 5 years.
glitch1985@lemmy.world 3 weeks ago
Home depot regularly has them on huge sales and it paid for itself within two years just by the electric savings.