Click here to Find a Contractor in your area.
Welcome! Here are the website rules, as well as some tips for using this forum.

If you've found help here, check back in to let us know how everything worked out.
It's a great way to thank those who helped you.
Need to contact us? Visit

Hydronic air to water heat pump that makes 140F !?!?

There are some companies making "air to water" hydronic units that claim to make 140F water. Is this sort of like a car maker telling you car performance while red-lining the engine?

I would love to hear about contractor experience with air to water heat pumps and the "supply water design temperature" folks are using when designing systems with these units.

Any tips and unexpected things learned on hydronic air to water installations, would be highly appreciated.


  • mikeg2015mikeg2015 Member Posts: 1,178
    It’s possible with r134a rather than 410a. But efficiency isn’t as good and they are pricey last I checked.
  • hot_rodhot_rod Member Posts: 13,313
    There are more on the way, price will continue to drop.

    A friend in upstate NY is running this winter on the Mesteck/SpacePak low ambient HP. He is connected to radiant floor and a buffer so he probably will not need to run 140F.

    The efficiency will directly relate to the operating temperature that you are driving them to. So the lower the SWT required the better the performance, like any HP.

    He sent a video last week of the unit in defrost. It uses heat from the buffer to defrost instead of air temperature like splits do.

    So far he is happy with performance. he tried running without a buffer tank, not good result, too much cycling.

    Here is a Swedish brand supposed to be coming over. I've heard that Enertech, Water Furnace and Climate Master are all owned by this company.

    Bob "hot rod" Rohr
    trainer for Caleffi NA
    The magic is in hydronics, and hydronics is in me
  • jumperjumper Member Posts: 1,450
    I believe that Canadian CO2 heat pump is available.
    Sanden CO2 Heat Pump Water Heater - SanCO2 - Sanden
Sign In or Register to comment.


It looks like you're new here. If you want to get involved, click one of these buttons!