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Air to Water Heat Pump - Ever installed or used one? Need advice and recommendations

Prevch
Prevch Member Posts: 111
in Radiant Heating
I am in the process of replacing a propane boiler with an electric solution. In one of my other threads, someone brought up the idea of an electric air to water heat pump system. As I have been doing research online, it looks like there are some mixed reviews in colder climates. I live in Northern, WI, so it can get pretty cold here as you might expect.

Does anyone have any experience installing or using an air to water heat pump in a cold climate? What was your experience like? Do you happen to have any recommendations on brands?

Thank you everyone for your help and insights.

Comments

  • jesmed1
    jesmed1 Member Posts: 967
    The big question is, how hot do you need your radiator water? If you have large radiating surfaces, ie radiant floor hydronic loops, then you have a lot of radiation surface area and can keep your water temps relatively low. This is favorable for a heat pump. OTOH, if you have a relatively small radiation surface area, eg old cast iron radiators designed for higher water temps, that's bad, because heat pumps have to work much harder to get higher water temps.

    I live in a 4-unit condo building with old cast iron rads heated with oil boilers. I looked into air-to-water heat pumps, but the problem was that we need 130-140 degree water to get sufficient heat out of our radiators. And a heat pump that could do that was going to be very expensive.
  • Hot_water_fan
    Hot_water_fan Member Posts: 2,114
    Here's a great resource: https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf

    Heat pumps will work in Wisconsin, you'll probably use some backup for the coldest days.
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,137
    Once the outside air drops below 32 the outside condenser will start to frost. That is physics and has nothing to do with whatever brand unit is installed or how well or how poorly it is installed. The unit will have to go into defrost mode because of this. Also since there is less heat available in the outside air the efficiency drops and the heat avail to the space drops.

    None of the above means a HP is a poor choice they are just facts to consider. you have to consider everything including what will provide heat in really cold temperatures. Electric back up or some other source.
  • WMno57
    WMno57 Member Posts: 1,408
    Hot_water_fan said:

    Heat pumps will work in Wisconsin, you'll probably use some backup for the coldest days.






    Hot_water_fan
  • Hot_water_fan
    Hot_water_fan Member Posts: 2,114
    @WMno57 I’ve lived in Wisconsin, I know it’s cold. Hence the backup for the coldest days :smile:
  • WMno57
    WMno57 Member Posts: 1,408
    Hot_water_fan said:

    @WMno57 I’ve lived in Wisconsin, I know it’s cold. Hence the backup for the coldest days :smile:

    Great, so tell us, what do you think the ATW heat pump expertise in rural northern WI is? In another post the OP was having problems having someone come out to fix a gas line.
    https://forum.heatinghelp.com/discussion/191270/my-utica-mac-205-boiler-sounds-like-the-horn-of-gondor#latest
    @prevch in one of your posts you mention you have AC and I assume ductwork. Is a propane forced air furnace an option for you? Your not going to find much hydronics expertise in the great white north. Even less ATA heat pump experience. Probably zero ATW heat pump experience.
    You said the Utica was installed 2018. Seems a shame to give up on that.


  • Hot_water_fan
    Hot_water_fan Member Posts: 2,114
    @WMno57 I’m not trying to argue, I am simply answering a question. 
    GGross
  • Prevch
    Prevch Member Posts: 111
    jesmed1 said:

    The big question is, how hot do you need your radiator water? If you have large radiating surfaces, ie radiant floor hydronic loops, then you have a lot of radiation surface area and can keep your water temps relatively low. This is favorable for a heat pump. OTOH, if you have a relatively small radiation surface area, eg old cast iron radiators designed for higher water temps, that's bad, because heat pumps have to work much harder to get higher water temps.

    I live in a 4-unit condo building with old cast iron rads heated with oil boilers. I looked into air-to-water heat pumps, but the problem was that we need 130-140 degree water to get sufficient heat out of our radiators. And a heat pump that could do that was going to be very expensive.

    Thanks for this info. I have in-floor radiant, so hoping that it would be a good fit.
  • Prevch
    Prevch Member Posts: 111
    Hot_water_fan said:

    Here's a great resource: https://www.caleffi.com/sites/default/files/file/idronics_27_na.pdf

    Heat pumps will work in Wisconsin, you'll probably use some backup for the coldest days.

    Thank you very much for that resource.
  • Prevch
    Prevch Member Posts: 111
    EBEBRATT-Ed said:

    Once the outside air drops below 32 the outside condenser will start to frost. That is physics and has nothing to do with whatever brand unit is installed or how well or how poorly it is installed. The unit will have to go into defrost mode because of this. Also since there is less heat available in the outside air the efficiency drops and the heat avail to the space drops.

    None of the above means a HP is a poor choice they are just facts to consider. you have to consider everything including what will provide heat in really cold temperatures. Electric back up or some other source.

    Thank you for that info. Yes, I do have backup electric heat via forced air right now, but want to take advantage of the hydronic in-floor loops we have throughout the home.
  • WMno57
    WMno57 Member Posts: 1,408
    Two types of ATW heat pumps, monobloc and split system.

    Monobloc
    • No refrigerant to run through lineset into house
    • Comes pre charged with refrigerant
    • In theory easier to DIY
    • Requires glycol
    Split System
    • Refrigerant runs between evaporator outside and condenser inside (like traditional AC)
    • Harder to DIY, need gauges, refrigerant, more knowledge. EPA says you need license.
    • Should NOT require glycol if used for heating only (But Spacepak might require it anyway, see below)
    • Requires glycol if used for cooling
    https://forum.heatinghelp.com/discussion/193273/spacepak-split-inverter-heat-pump-sis-060a-glycol-head-loss
    Do you have Glycol in your system now? Glycol opens a whole new can of worms.
  • Prevch
    Prevch Member Posts: 111
    WMno57 said:

    Hot_water_fan said:

    Heat pumps will work in Wisconsin, you'll probably use some backup for the coldest days.






    I don't live that far from there actuall
    WMno57 said:

    Hot_water_fan said:

    @WMno57 I’ve lived in Wisconsin, I know it’s cold. Hence the backup for the coldest days :smile:

    Great, so tell us, what do you think the ATW heat pump expertise in rural northern WI is? In another post the OP was having problems having someone come out to fix a gas line.
    https://forum.heatinghelp.com/discussion/191270/my-utica-mac-205-boiler-sounds-like-the-horn-of-gondor#latest
    @prevch in one of your posts you mention you have AC and I assume ductwork. Is a propane forced air furnace an option for you? Your not going to find much hydronics expertise in the great white north. Even less ATA heat pump experience. Probably zero ATW heat pump experience.
    You said the Utica was installed 2018. Seems a shame to give up on that.


    Thanks for that info. So as you saw in my previous post, I had tons of problems with that boiler. We also ended up having multiple gas leaks, one of which made my family sick. So between the constant break down issues, having no one able or willing to fix it and the gas leak incidents, I ripped it off the wall and it's going to be scrap metal now.

    You are right though, I am guessing no one will be able to help me with the heat pump either, so I am going to have to do it myself. I will figure it out, but it is going to be a learning process. That's one of the reasons I appreciate this forum so much.

    When I installed the ductwork and AC, I also put in a backup electric coil, so I have electric forced air heat right now that works fine until it gets maybe -5 or so and then struggles to keep up. That being said, I prefer the comfort of the hydronic loops. When the gas boiler actually worked, which was rare, I loved it with the in floor heat. I might not be able to get a perfect direct replacement for gas, but I will do my best with the resources I have. For super cold days, we also have a couple of wood burning stoves that can keep our whole house toasty.
  • Prevch
    Prevch Member Posts: 111
    WMno57 said:

    Two types of ATW heat pumps, monobloc and split system.

    Monobloc

    • No refrigerant to run through lineset into house
    • Comes pre charged with refrigerant
    • In theory easier to DIY
    • Requires glycol
    Split System
    • Refrigerant runs between evaporator outside and condenser inside (like traditional AC)
    • Harder to DIY, need gauges, refrigerant, more knowledge. EPA says you need license.
    • Should NOT require glycol if used for heating only (But Spacepak might require it anyway, see below)
    • Requires glycol if used for cooling
    https://forum.heatinghelp.com/discussion/193273/spacepak-split-inverter-heat-pump-sis-060a-glycol-head-loss
    Do you have Glycol in your system now? Glycol opens a whole new can of worms.
    Thanks for that info. Nope, I do not use Glycol at all, I never had a need for it really, but I know a lot of people around here do use it.
  • hot_rod
    hot_rod Member Posts: 24,339
    If you have low temperature radiant you have a better match for using an A2WHP.

    This journal shows a system going on its 4th winter in upstate NY. Maybe a similar climate to yours.

    These is maybe 12 ccA2WHP cold climate on the market now, contact a rep for a knowledgable installer.

    https://idronics.caleffi.com/magazine/27-air-water-heat-pump-systems
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • jesmed1
    jesmed1 Member Posts: 967
    edited September 2023
    One of the cold climate ATW heat pumps I looked at for our condo building was the Arctic 060ZA:

    https://www.arcticheatpumps.com/specifications.html

    Turns out it would have been too difficult to make it work with our old cast iron radiators, but since you have radiant floors, that's an ideal application.

    Here's a discussion thread with some people who have installed Arctics and seem to have good things to say about them:

    https://www.greenbuildingadvisor.com/question/im-looking-for-user-experience-with-arctic-heat-pumps
  • Prevch
    Prevch Member Posts: 111
    hot_rod said:

    If you have low temperature radiant you have a better match for using an A2WHP.

    This journal shows a system going on its 4th winter in upstate NY. Maybe a similar climate to yours.

    These is maybe 12 ccA2WHP cold climate on the market now, contact a rep for a knowledgable installer.

    https://idronics.caleffi.com/magazine/27-air-water-heat-pump-systems

    Thank you that is very helpful
  • Prevch
    Prevch Member Posts: 111
    jesmed1 said:

    One of the cold climate ATW heat pumps I looked at for our condo building was the Arctic 060ZA:

    https://www.arcticheatpumps.com/specifications.html

    Turns out it would have been too difficult to make it work with our old cast iron radiators, but since you have radiant floors, that's an ideal application.

    Here's a discussion thread with some people who have installed Arctics and seem to have good things to say about them:

    https://www.greenbuildingadvisor.com/question/im-looking-for-user-experience-with-arctic-heat-pumps

    Thank you very much that is helpful
  • Prevch
    Prevch Member Posts: 111

    Just to update everyone who was previously following / replying to this thread, so far, I still have not installed an air to water heat pump. When I ripped the old gas boiler off the wall, I temporarily used my heat strip in my forced air system to heat the house, but that could not take advantage of our in floor radiant heat.

    Eventually, with the help of some fellow forum member suggestions, I settled on installing an electric boiler the EB-MX-20 by Electro Industries. It is a 68K BTU unit that can heat my house even on the coldest of days. It is -17 here right now as I type this and the boiler is having no problem keeping up in a house with cthaedral ceilings and tons of windows. The higest temperature setting on the boiler is 190 degrees F, but I don't run anything remotely close to that. In terms of getting the job done, the boiler works great. That being said, unsurprisingly, it is pricey to run so I am still interested in an A2W heat pump system.

    Just wondering if anyone has heard any new information / updates on products in North America? Looks like Space Pak and Artic are stilll selling, though Space Pak won't talk to you unless you are a contractor. I also found this one:

    https://www.mbtek.com/collections/air-to-water-heat-pumps/products/apollo-heatpump-60k-btu

    Anyone have any familiarity or experience with it? Anything else new on the market that may be useful? I am googling now, but seems like not much has happened in temrs of USA market advancement in this area since I made the post in September of 2023.

    Thanks everyone!

  • hot_rod
    hot_rod Member Posts: 24,339

    I have a few months on my Viessmann VitoCal. The components are all top quality. It comes with a buffer tank. It was well crated and arrived in perfect shape. Tanks are not so easy to ship.

    Local support it’s important if you depend on others to install and service it.

    I like the U.S. Boiler system for its control module. Entertech, Artic, Nordic, and SpacePak are other well known brands.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
    John Ruhnke
  • DCContrarian
    DCContrarian Member Posts: 993

    Efficiency Vermont has a list of all air-to-water heat pumps being sold in the US:

    https://qualifiedproducts.efficiencyvermont.com/evt/products/browse?search.searchGroup=Heat%20Pumps%20-%20Air%20to%20Water&search.IncomeQualified=False

    In your climate you want something with vapor injection for cold weather performance. You can pretty much tell by comparing the column with the 5F capacity with the nominal capacity, with vapor injection it will be close to 90% and without it will be 50-75%.

    John Ruhnke
  • John Ruhnke
    John Ruhnke Member Posts: 1,019

    I would stay away from Apollo.

    They lied to me about a R290 Heat Pump. They said it had UL listing. When I asked to see the UL number they then changed there minds and said UL listing was delayed. I told them that R290 is highly flammable and illegal in the USA. They just went silent. They then said I would have to talk with a manager. I was then put on hold. After twenty minutes my phone disconnected. I called back asked same stuff again and was told a manager would call me back. Nobody called back.

    I read other bad stuff on the internet about them.

    Stay Away.

    I am the walking Deadman
    Hydronics Designer
    Hydronics is the most comfortable and energy efficient HVAC system.
  • DCContrarian
    DCContrarian Member Posts: 993
    https://forum.heatinghelp.com/discussion/comment/1836342#Comment_1836342

    Now you've got me curious if I can get an illegal R-290 heat pump. Just for bragging rights.

  • pecmsg
    pecmsg Member Posts: 5,673
    edited January 20
    https://forum.heatinghelp.com/discussion/comment/1836342#Comment_1836342

    I haven’t heard of an R290 heat pump being sold in the USA!


    where do you get this?

  • John Ruhnke
    John Ruhnke Member Posts: 1,019

    I saw an add on the internet for a Apollo r290 HP. In the add they claimed they had UL listing for it. False Advertising.

    I also am a rep for Arctic Heat Pumps. We tried for two years to bring in R290 in the USA. I followed everything closely and know they never legalized it.

    I am the walking Deadman
    Hydronics Designer
    Hydronics is the most comfortable and energy efficient HVAC system.
  • John Ruhnke
    John Ruhnke Member Posts: 1,019
    edited January 20

    @DCContrarian

    If anything goes wrong insurance will deny the claim. With out passing any countries safety standards you have no idea how safe it is. Everyone I talked with seemed brand new and didn't know much. If anything goes wrong good luck hunting in China for the responsible parties. What if they get shut down or sued? They will just walk away and go back to China. Good luck getting them to honor that warrantee when all the parts start breaking.

    I am the walking Deadman
    Hydronics Designer
    Hydronics is the most comfortable and energy efficient HVAC system.
  • pecmsg
    pecmsg Member Posts: 5,673
    https://forum.heatinghelp.com/discussion/comment/1836349#Comment_1836349

    and your point.
    not going to happen for several years so why the speeches. ?

  • John Ruhnke
    John Ruhnke Member Posts: 1,019
    edited January 20

    Arctic Heat Pumps spent a lot of money to try and bring in R290. They played by the rules. In the end we brought in another High Temp Heat Pump. Arctic spent a lot of money to get legal approval for our Two Stage High Temp Heat Pump. It received UL listing

    It is just unfair for Apollo to spend nothing on these approvals bringing in an illegal product and take market share from the many companies selling legal heat pumps in America.

    Also I read there recent Apollo adds. Good till -31f? SCOP 4.88? I would ask to see verification of those claims to. You just can't trust them.

    I am the walking Deadman
    Hydronics Designer
    Hydronics is the most comfortable and energy efficient HVAC system.
    PC7060
  • pecmsg
    pecmsg Member Posts: 5,673

    again

    All this preaching of equipment that’s not available and won’t be for a long time!

  • John Ruhnke
    John Ruhnke Member Posts: 1,019
    https://forum.heatinghelp.com/discussion/comment/1836166#Comment_1836166

    @pecmsg

    My comments were in response to a post by Prevch.

    I am the walking Deadman
    Hydronics Designer
    Hydronics is the most comfortable and energy efficient HVAC system.
    PC7060
  • Prevch
    Prevch Member Posts: 111
    https://forum.heatinghelp.com/discussion/comment/1836186#Comment_1836186

    Awesome haven't heard of that one will check it out

  • Prevch
    Prevch Member Posts: 111

    That is super useful thank you!

  • Prevch
    Prevch Member Posts: 111

    Good to know thank you!

  • Prevch
    Prevch Member Posts: 111

    Good to know, John! If I go the Artic Heat Pump route, I will message you. Thanks!

  • Kaos
    Kaos Member Posts: 457

    I got one of these:

    https://www.dettson.com/en-ca/products/heat-pumps/gree/versati-iv.aspx

    Cost was good and with local support. R32 EVI, low temp performance is decent but still need to design for low SWT.

    I recently saw the LG R32 monoblocs for sale. Much better low temp capacity maintance and COP. Not cheap though:

    https://www.lg.com/global/business/heating-R32-silentmonobloc

    PC7060
  • DCContrarian
    DCContrarian Member Posts: 993
    https://forum.heatinghelp.com/discussion/comment/1836352#Comment_1836352

    Good points, I should just order one direct from China on AliBaba.

    I'm being tongue-in-cheek. But it is a problem all of the sellers of ATWHP's seem to have is that they're all importers and not manufacturers, and the manufacturers seem willing to undercut them.

  • DCContrarian
    DCContrarian Member Posts: 993

    My understanding is that EPA rules currently limit R-290 systems to 500 grams (about 1.1 pounds) of refrigerant. This is enough for an ATWHP of about two ton capacity.

    I can't imagine that the EPA would waive that rule just for one manufacturer. But it seems like small systems are legal.

  • John Ruhnke
    John Ruhnke Member Posts: 1,019
    edited January 20

    @DCContrarian

    The limit is 150 grams for r290 and it isn't even enough for a small monobloc ATWHP. I think some small refrigerators are legal in residential with r290 but no HP can operate with that small a charge that I know of.

    I am the walking Deadman
    Hydronics Designer
    Hydronics is the most comfortable and energy efficient HVAC system.

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