Heat Pump Water Heater

ctechbob

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Interesting concept, never heard of this style of water heater before. For an old house up north would they be good to put in a basement to keep the air dried out? Not electric, gas powered.
I think the equation becomes a lot more difficult when you're up north and have access to other forms of energy for sure. I would have given it a second thought if mine was installed in a living space since you'd be pumping cold air into it in the winter when you're trying to keep it heated. I think I've certainly got the absolute best-case scenario for one.

No available gas
Not in a living space
The garage is usually a few degrees warmer than outside in the winter and HOT in the summer (southwest facing)

I don't know that it gets a lot better from a water heater point of view in that case (Other than living in the tropics), unless I wanted to do roof mount thermal solar.
 
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ctechbob

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I can't wait for hybrid heat pump electric clothes driers to become more common. There's one or two out there but they aren't commonplace yet.
Yep, I'm keeping an eye on that development as well. We wash a ton of laundry. Some of it air dries, but the vast majority of it gets tossed in the rotary iron, again, electric resistive heated.
 
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Yep, I'm keeping an eye on that development as well. We wash a ton of laundry. Some of it air dries, but the vast majority of it gets tossed in the rotary iron.
I was thinking about this as well. The biggest problem is the reliability and clogging of the coils with lint. In location where natural gas dryer is a PITA (in the middle of the house) for potential leak or running a gas line with permit, switching from resistance heating electric dryer to heat pump dryer make sense, especially if you can use the heat inside the house with winter heating. In the summer weather without a dryer exterior exhaust, it might be a problem with the heat pump actually heating your house though (however if they can still vent but cool the house in one coil and heat the clothes in another, eliminating lint stuck on the coils, then it would be pretty awesome.
 

ctechbob

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I was thinking about this as well. The biggest problem is the reliability and clogging of the coils with lint. In location where natural gas dryer is a PITA (in the middle of the house) for potential leak or running a gas line with permit, switching from resistance heating electric dryer to heat pump dryer make sense, especially if you can use the heat inside the house with winter heating. In the summer weather without a dryer exterior exhaust, it might be a problem with the heat pump actually heating your house though (however if they can still vent but cool the house in one coil and heat the clothes in another, eliminating lint stuck on the coils, then it would be pretty awesome.
It's my understanding that the air runs in a closed circuit for the most part, so it is venting very little heat or cold to the surrounding air. From the few I looked at, it looks like they have fairly beefy filters, they also looked disposable, so there would be a consumable that you'd have to take care of when using it.

 
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how much electric is needed for one of these? I’d consider one when time for replacement since I run a dehumidifier in my basement 8 months a year.
 

ctechbob

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how much electric is needed for one of these? I’d consider one when time for replacement since I run a dehumidifier in my basement 8 months a year.


Unscientific comparison, but gives you a decent enough idea. Guy in the video is in PA, so a 'colder' climate, but it is also in his finished basement.
 
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It's my understanding that the air runs in a closed circuit for the most part, so it is venting very little heat or cold to the surrounding air. From the few I looked at, it looks like they have fairly beefy filters, they also looked disposable, so there would be a consumable that you'd have to take care of when using it.


Ah, that's the problem or advantage.

Heat is an energy that cannot be destroyed, you can use electricity to generate it inside the house or you have to spend energy to pump it out of the house, or pump it into the air and then pump the air out of the house.

So what would the electricity used by the heat pump dryer do? where would they go? They will slowly heat up the house. It is better for you if you need heat in the winter, just like your computer warms you up, but it is bad for you in the summer because it heat up the house.

What about the evaporation and condensation? They just transfer the water from the wet clothes to a box or bucket to dump out later, water to water means a net neutral in energy state, unlike dryer dumping hot wet air outside the house in the traditional sense.

I am not sure if those filters are disposable but as you know most filters are not perfect and eventually coils getting stuck seems to be a complain, or at least some works, more than a traditional vented dryer.

If they can vent hot wet air out but just cool the room in a different coil, hot air from the other side of the coil is open loop, dry the clothes and dump it out of the house, without going through the coil at all, then that would eliminate lint on coil problem and you can cool the house with it. Better if you can just change it based on the season too.
 

ctechbob

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Just got a notification that the order has shipped. Although it is saying that the delivery date is 3/22, pretty sure they're not going to make that, or they are going to scare the everloven crap out of my wife :)
 
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I have a Bradford White 50 gallon heat pump hybrid water heater located in basement of our Massachusetts home. This has taken over hot water making duty from our oil fired boiler that provides baseboard hydronic heat. We like it a lot and run it in heat pump mode all the time with exception of maybe 3 days per year (usually during holidays, big family gatherings, etc where additional visiting family may be using more hot water, more hot water is being used in the kitchen, etc). On those days, we just switch it to hybrid or electric mode to make hot water more quickly. It does make our basement fairly cold from Dec-Feb, but very nice dry and cool the rest of the year. No need to run a dehumidifier in basement anymore. I clean the top mounted air filter about 3X per year using a bench brush to loosen the dust then use a battery powered leaf blower to blow it clean.
 
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Certainly not an expert in the field, but my parents had a Rheam heat pump hybrid water heater installed years ago. It was an absolute dud. Problems all the time. They ended up replacing it with a traditional electric a few years later. The cooling effect on the room was nice though.
 

ctechbob

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I did some looking through my power usage last night when work was a little slow. Our local EMC uses smart meters that do a pretty good job of tracking your power usage, down to hourly details. There was a day last week when the girls weren't home and my thermostat shows that the HVAC didn't run all that afternoon. The only thing that I had done was get up and take a shower and go to work. The result was 4kw/h used at that time (Makes sense, the elements should be something like 3500 watts ea). Doing the math with my $.11/kwh rate gives me $.44 electric cost for my shower. Over the household, with me taking a shower every day, and the wife and kid probably 90% of the time doing one every day, gives me a total electric cost for JUST showers of $35.20 / Month (30 Days).

From what I've been able to find online, you are looking at using 1/3 as much power for the HP Heater, so I'll be saving right around $20 a month, just for showers, not including Dishes and clothes, which, if I had to guess would be just about the same load as showers since we tend to do a good bit of laundry.

End result for me looks like it will be between $20-40 a month saved, at an initial cost of $700 installed, so right at a 2 year ROI. (My current power bills range from a low of about $160 to $230 in the summer).

It all looks pretty good considering my current tank is 15 years old and is probably reaching end-of-life and I want to replace it anyway.

YMMV, but the $500 rebate my EMC is handing out made the cost of the unit just about the same as a non-hybrid version.
 
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The result was 4kw/h used at that time (Makes sense, the elements should be something like 3500 watts ea). Doing the math with my $.11/kwh rate gives me $.44 electric cost for my shower.

Your heating element runs for an entire hour for a shower? Mine only runs for maybe 5-10 minutes after I finish taking a shower. And my shower is maybe 5-10 minutes. I did add an inline valve between the showerhead and the pipe coming out of the wall to reduce the water flow, because most shower valves give you no control over flow, only temperature.
 

ctechbob

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Your heating element runs for an entire hour for a shower? Mine only runs for maybe 5-10 minutes after I finish taking a shower. And my shower is maybe 5-10 minutes. I did add an inline valve between the showerhead and the pipe coming out of the wall to reduce the water flow, because most shower valves give you no control over flow, only temperature.
No idea how long it runs, but over a period of an hour it uses 4kw. It is possible it runs both elements for a short period of time. Either way, it uses 4kwh for my shower. It is pretty repeatable as there are other days when that is the only thing going on, I don't have a super granularity that you would have with a true monitoring system, but that is about as close as I can get picking the data out over time. With 3500 watt elements, that amount tracks with what I would think is a logical amount of power to use for the activity.

And yes, I know the refrigerator can be in there somewhere as well, like I said, it is pretty dirty math, but it should be close..or rather close enough for my purposes.
 
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No idea how long it runs, but over a period of an hour it uses 4kw. It is possible it runs both elements for a short period of time. Either way, it uses 4kwh for my shower.

Most water heaters are wired so only one element comes on at a time. And, if you don't use much hot water, it's entirely possible for the lower one to be burned out and not notice it, like it was on mine.
 

ctechbob

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Most water heaters are wired so only one element comes on at a time. And, if you don't use much hot water, it's entirely possible for the lower one to be burned out and not notice it, like it was on mine.
Possible, not likely though as it still recovers quickly, all 3 of us can take a shower and be just fine. One element wouldn't do that, been through that before at the old place.

I've already informed the wife that it will be 'different' and that she should pay attention and not start a massive load of laundry before she showers because I'm planning on locking out the resistive elements for the majority of the time.
 
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Possible, not likely though as it still recovers quickly, all 3 of us can take a shower and be just fine. One element wouldn't do that, been through that before at the old place.

I only noticed a problem when I took a shower and the water was only lukewarm. I checked the water heater and the breaker/thermal protector had tripped. Pushed it to reset it and all seemed fine. Water heater seemed to be working correctly.

A few days later when I had some time, I checked both the upper and lower elements and found that the bottom one had burned out. Unsure why it tripped the protector when it burned out. I replaced both elements with "Limelife" low watt density elements because I have hard water and they had a lot of mineral deposits on them. It's been fine since.
 

ctechbob

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Figured I'd post here as a warning if you are in the Southeast and want to buy something that will need to be shipped freight by Home Depot.

Avoid.

The last-mile service they use is a company called 'Fastmile Atlanta'. If you want to see some stellar 1 star reviews, google their name and have a read. Needless to say, they are apparently the worst delivery service in Atlanta.

Link to reviews: https://tinyurl.com/4cvznjbe

I got a text on March 30th saying that my delivery was scheduled for 3/28 and that they would get back in touch with me. Later that day, my delivery was marked as 'delivered' in their and HomeDepot's tracking. No water heater.

Conversation with Home Depot resulted in them cancelling that order and placing another one. Again. I get notices that the item has shipped and that it will be delivered on 4/5 (Tuesday). Tuesday comes and goes and HD's system is updated to reflect that it will now be delivered on 4/9 (Today). I wait patiently until about 1730, and decide that its not coming and that I've had enough of this game.

Also, the shipper does not answer their phone, or at the times I called, even a voicemail. Somewhere between the first and second orders I look into the company and see that I'm not the only one, a lot of people are having problems with the company delivering things.

I print all my invoices, shipping notices, etc etc and head to the local store. I talk to an outstanding assistant manager and explain that its not his fault or problem and that I understand that, but can he help me, knowing that he could easily tell me to pound sand and I would be ok with that.

Instead, he spends about 30 min with me and corporate on the phone and gets things straightened out and I leave with the water heater in the back of my truck.

All in all, Home Depot service has been great with handling this, they just need to pick another last-mile freight shipper.

So I'll finally get to install it tomorrow, hopefully I bought enough PEX fittings to get it done, although knowing me, I probably forgot at least one of something I'll need.
 
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