Heat pumps with evohome

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  • The evo Geek
    Automated Home Lurker
    • Mar 2020
    • 4

    Heat pumps with evohome

    Hi all,

    I noticed how little chatter there seems to be about using evohome with heat pumps. I thought it would be interesting to share information from those of us that do (there are some of us out there!). With heat pumps becoming more and more the norm, it would be useful to share good (and bad?) practice for heat pump system setup and optimisation with evohome.
    So, I've got a few questions to help share relevant information:
    1. What type of heat pump - ASHP, GSHP, WSHP, EAHP?
    2. Make / model of heat pump
    3. Heat pump controller make / model (if known, or separate to HP)
    4. Heat pump compressor type - fixed speed or inverter
    5. Buffer yes/no? If yes, buffer size and configuration - 2 (balanced/unbalanced), 3 or 4 pipe
    6. Direct heat pump control by evohome, or not?
    7. Number of evohome zones?
    8. Type of zones and quantity - TRV, UFH, Zone valve, other
    9. Typical daytime/nightime setbacks across zones?
    10. DHW provided by heat pump? If yes, hot water control by evo or heat pump controller?
    11. If valves used for heating and/or DHW, 2 port, 3 port diverter, 3 port mixer (eg Y plan type)?
    12. Heat pump controller settings - room control?
    13. Heat pump controller settings - other configuration changes?
    14. Property type, and approx floor area - flat/apartment/terraced/townhouse/semi/detached/bungalow/other
    15. Other relevant information, comments and observations


    Hope this proves useful catalyst to information exchange for those using heat pumps with evo and those going that way in the future.

    Vaughn.
  • kevinsmart
    Automated Home Ninja
    • Sep 2018
    • 257

    #2
    Out of interest Vaughn, what is your setup? I see myself eventually going down the GSHP route. My house was originally going to have one fitted but the previous owner heard negative feedback from someone that had one installed, related to not being able to control it. Well with Evohome I'm sure you could...

    Comment

    • The evo Geek
      Automated Home Lurker
      • Mar 2020
      • 4

      #3
      My own system details here.

      Originally posted by The evo Geek View Post
      Hi all,

      I noticed how little chatter there seems to be about using evohome with heat pumps. I thought it would be interesting to share information from those of us that do (there are some of us out there!). With heat pumps becoming more and more the norm, it would be useful to share good (and bad?) practice for heat pump system setup and optimisation with evohome.
      So, I've got a few questions to help share relevant information:
      1. What type of heat pump - ASHP, GSHP, WSHP, EAHP? - ASHP
      2. Make / model of heat pump - Trianco Activair 1200 (12kw)
      3. Heat pump controller make / model (if known, or separate to HP) - Trianco Activair buit-in
      4. Heat pump compressor type - fixed speed or inverter - Fixed speed
      5. Buffer yes/no? If yes, buffer size and configuration - 2 (balanced/unbalanced), 3 or 4 pipe - 4 pipe, 100 litre.
      6. Direct heat pump control by evohome, or not? - no, evo uses BDR91 to control the circulation pump on the heating side of the buffer.
      7. Number of evohome zones? - 11
      8. Type of zones and quantity - TRV, UFH, Zone valve, other - 11x TRV (HR92)
      9. Typical daytime/nightime setbacks across zones? - 21-22 daytime, 17-18 nightime
      10. DHW provided by heat pump? If yes, hot water control by evo or heat pump controller? No.
      11. If valves used for heating and/or DHW, 2 port, 3 port diverter, 3 port mixer (eg Y plan type)? None
      12. Heat pump controller settings - room control? - Disabled, buffer temperature controlled
      13. Heat pump controller settings - other configuration changes? Buffer temperature setpoint 50 degC, manually increased to 55 degC during cold spell
      14. Property type, and approx floor area - flat/apartment/terraced/townhouse/semi/detached/bungalow/other - 4 bed semi, 160m2, build 2002, located in Mid Sussex
      15. Other relevant information, comments and observations - Runs very smoothly, heat pump only runs to keep the buffer up to temp, whilst the evohome systems just takes as little or as much heat as it needs to satisfy heat demands across zones. Use smart weather for 1 degC temp uplifts in 6 zones during cold weather.


      Hope this proves useful catalyst to information exchange for those using heat pumps with evo and those going that way in the future.

      Vaughn.

      Comment

      • kevinsmart
        Automated Home Ninja
        • Sep 2018
        • 257

        #4
        Great. Might be useful to understand typical electricity consumption/costs too.

        Comment

        • spiralp
          Automated Home Lurker
          • Nov 2020
          • 6

          #5
          My house uses an ASHP for CH and DHW, and I use Evohome for control. I will try to provide the relevant information, but I am not certain that I fully understand all the points. Anyway, here goes.

          Originally posted by The evo Geek View Post
          Hi all,

          I noticed how little chatter there seems to be about using evohome with heat pumps. I thought it would be interesting to share information from those of us that do (there are some of us out there!). With heat pumps becoming more and more the norm, it would be useful to share good (and bad?) practice for heat pump system setup and optimisation with evohome.
          So, I've got a few questions to help share relevant information:
          1. What type of heat pump - ASHP, GSHP, WSHP, EAHP? ASHP
          2. Make / model of heat pump Panasonic WH-MXC12H6E5 12kW
          3. Heat pump controller make / model (if known, or separate to HP) Panasonic
          4. Heat pump compressor type - fixed speed or inverter Inverter
          5. Buffer yes/no? If yes, buffer size and configuration - 2 (balanced/unbalanced), 3 or 4 pipe Not sure that I understand. The heat pump feeds a 26litre buffer tank (2 pipes, in/out) and hot water is taken out via 2 pipes (in and out)
          6. Direct heat pump control by evohome, or not? No - this is the way the heat pump installers set it up. Evohome controls the CH pump. The Evohome was installed prior to the ASHP and controlled the old oil fired boiler
          7. Number of evohome zones? 10
          8. Type of zones and quantity - TRV, UFH, Zone valve, other Zone valves
          9. Typical daytime/nightime setbacks across zones? Not sure what a 'setback' is. Temps vary across all zones
          10. DHW provided by heat pump? If yes, hot water control by evo or heat pump controller? Yes. Hot water controlled by the heat pump. We are not entirely happy with this, but our installer says 'Tough, that is how it works'. Previously HW was controlled by evo.
          11. If valves used for heating and/or DHW, 2 port, 3 port diverter, 3 port mixer (eg Y plan type)? 3 port diverter, so can have either heating or hot water (but not both) at random times dictated by the heat pump controller. Previously we had an S Plan system controlled by the evo, but the HW controller has been left redundant
          12. Heat pump controller settings - room control? No. Heat pump controls buffer temp - nominally 50 degC
          13. Heat pump controller settings - other configuration changes? Hot water on at a tank temp of 44 degC and off at 49 degC
          14. Property type, and approx floor area - flat/apartment/terraced/townhouse/semi/detached/bungalow/other Converted 3 storey industrial building, built 120 years ago and converted 25 years ago. Approx 300 sqm, with tall ceilings.
          15. Other relevant information, comments and observations We are having problems with CH air locks and the heating is marginal when outside temps are -5/-6 degC


          Hope this proves useful catalyst to information exchange for those using heat pumps with evo and those going that way in the future.

          Vaughn.
          I have updated the Evohome firmware to the latest version, but I cannot see how it changes how the heat pump is controlled. I would be very interested to hear how others have integrated Evohome with a heat pump. Previously we used 3,500 litres of oil and around 8,000 kWh of electricity p.a. (we have an EV and pre Covid we did around 25,000 miles pa in it). We are now using 18k/19k kWh of electricity pa (yes, we are probably melting the grid!). Solar is very difficult because of the layout of the building and we are in a prominent position in the centre of a conservation area.
          Last edited by spiralp; 2 April 2021, 06:41 PM.

          Comment

          • Davide
            Automated Home Lurker
            • May 2021
            • 1

            #6
            Originally posted by spiralp View Post
            My house uses an ASHP for CH and DHW, and I use Evohome for control. I will try to provide the relevant information, but I am not certain that I fully understand all the points. Anyway, here goes.



            I have updated the Evohome firmware to the latest version, but I cannot see how it changes how the heat pump is controlled. I would be very interested to hear how others have integrated Evohome with a heat pump. Previously we used 3,500 litres of oil and around 8,000 kWh of electricity p.a. (we have an EV and pre Covid we did around 25,000 miles pa in it). We are now using 18k/19k kWh of electricity pa (yes, we are probably melting the grid!). Solar is very difficult because of the layout of the building and we are in a prominent position in the centre of a conservation area.
            Hi spiralp,

            It's useful to see your Evohome setup with an ASHP. We moved into a 478 sq m property in September last year - an ex-Anglian Water filter house with a new extension - which already had a 16-zone Evohome system installed (badly, with binding issues ++) alongside an oil fired boiler. Our oil usage would be a bit more than yours. The house is well insulated, hence a HLC of 28 kWh. We also have EV x 2, although they're low mileage. We've added 5.6 kW PV panels with battery storage plus an immersion diverter. Finn Geotherm are due to install a Panasonic Aquarea T-CAP WH-MXC16H9E8 16 kW heat pump once UKPN have upgraded our power to 3-phase, which in turn, is dependent on Octopus Energy having a 3-phase smets2 smart meter in stock. I suspect the learning curve will get much steeper once everything is installed, so any real world experience will be much appreciated!
            Last edited by Davide; 26 May 2021, 01:24 PM.

            Comment

            • sandyman
              Automated Home Sr Member
              • Mar 2016
              • 85

              #7
              hi all
              really interested to hear how those who already have heat pumps with evohome have it setup. in particular, what plumbing topology and what controls what? referring to the evo installation guide page 47:

              evohomeheatpump.jpg

              I expect that 99% of boiler based installs use the same topology as diagram 3 (just change the words on the Heat Pump to Boiler) and this is my topology now for a boiler based system. I'm really keen to learn the details of the control behaviour in diagrams 1 and 2 as those are the common heat pump based topology. . Having spoken to a number of different installers, I can't find a single one who understands heat pumps and evohome - so I guess we have to do that ourselves. Also, given that a heat pump can cool as well as heat - how does the control side of that work with evohome?

              thanks
              Ian

              Comment

              • spiralp
                Automated Home Lurker
                • Nov 2020
                • 6

                #8
                My heat pump is wired as diagram 1. On my controller the cycle rate is set to 3 (lowest available setting) and the minimum on time is set to 5 (maximum available setting).

                Comment

                • sandyman
                  Automated Home Sr Member
                  • Mar 2016
                  • 85

                  #9
                  Originally posted by spiralp View Post
                  My heat pump is wired as diagram 1. On my controller the cycle rate is set to 3 (lowest available setting) and the minimum on time is set to 5 (maximum available setting).
                  thank you that is appreciated. That is the one that I have been scratching my head about so good to hear!

                  Do you have the "optional heat pump control connection" as well? if yes how is it wired and what does it do? is it activating the secondary and primary sides via seperate connections?

                  if its not there then does your evohome controller / BDR simply activate the secondary side pump?
                  In that case, how does the heat pump know when there is a need for heat ? does a buffer tank stat activate the heat pump and the primary circulation pump ? how is that ANDed with the demand for heat from the house? (don't want natural cooling of buffer to fire up heat pump if there is no demand)

                  thanks
                  Ian

                  Comment

                  • spiralp
                    Automated Home Lurker
                    • Nov 2020
                    • 6

                    #10
                    I wasn't sure that I knew the answer to your question, because the heat pump installers never discussed this with me. However, I have had a closer look. The cable from the BDR91 goes into the back of the Panasonic heat pump controller and a separate wire comes out of the heat pump controller to the secondary pump. This implies I am using the "optional heat pump controller connection". However, on checking the Honeywell controller I can see the BDR91 is not set for hear pump controls, hence it looks more likely the evohome is only controlling the secondary pump. In order to answer your question fully I will need to get back to my heat pump installer, or perhaps I might just have a play and see what I can find.

                    Comment

                    • sandyman
                      Automated Home Sr Member
                      • Mar 2016
                      • 85

                      #11
                      Originally posted by spiralp View Post
                      I wasn't sure that I knew the answer to your question, because the heat pump installers never discussed this with me. However, I have had a closer look. The cable from the BDR91 goes into the back of the Panasonic heat pump controller and a separate wire comes out of the heat pump controller to the secondary pump. This implies I am using the "optional heat pump controller connection". However, on checking the Honeywell controller I can see the BDR91 is not set for hear pump controls, hence it looks more likely the evohome is only controlling the secondary pump. In order to answer your question fully I will need to get back to my heat pump installer, or perhaps I might just have a play and see what I can find.
                      I wonder if the panasonic heat pump controller is doing all the hard work, and the evohome BDR just being an external "call for heat" . See if you can see from the panasonic controller manual what the input that the BDR 91 is wired to does - if its labelled "3rd party thermostat" or something like that?
                      Ian

                      Comment

                      • spiralp
                        Automated Home Lurker
                        • Nov 2020
                        • 6

                        #12
                        Originally posted by sandyman View Post
                        I wonder if the panasonic heat pump controller is doing all the hard work, and the evohome BDR just being an external "call for heat" . See if you can see from the panasonic controller manual what the input that the BDR 91 is wired to does - if its labelled "3rd party thermostat" or something like that?
                        Ian
                        I think you are correct. From what I can see I have the earlier BDR91, which only allows for basic switching, rather than the later version which allows some heat pump control. I have looked through the documentation I have, but I do not have anything showing how the controller is wired. In fact, I think the documentation I have does not include everything that should have been provided. This is probably because my heat pump installation was completed just as we entered the first lockdown in March 2020, so the 'hand over' was done by phone. My relationship with the installer is good so I will go through all the documentation with them in March next year when the heat pump is next serviced.

                        Comment

                        • sandyman
                          Automated Home Sr Member
                          • Mar 2016
                          • 85

                          #13
                          Originally posted by spiralp View Post
                          I think you are correct. From what I can see I have the earlier BDR91, which only allows for basic switching, rather than the later version which allows some heat pump control. I have looked through the documentation I have, but I do not have anything showing how the controller is wired.
                          if it was me, I'd download the manuals, take the cover off and follow the cables, buts its your system so your choice (btw I'm not suggesting that you change anything)

                          I think given that you have a control system that is still treating the heat pump as an on/off boiler, you'll be getting a TPI input to the heatpump control - which may not be ideal for what the heatpump expects. Given that you have a good relationship with your installer, I'd be really interested to hear what they think . I don't know what the difference in behaviour is if you use the new BDR that has the "heatpump" binding options.

                          Comment

                          • sidepipe
                            Automated Home Jr Member
                            • Oct 2015
                            • 18

                            #14
                            I'll absolutely be an outlier here but I'm using Evohome with a combination of a gas boiler and air source heat pumps ( Daikin ) in several rooms. No direct link... just using BDR91s as dummy actuators plus room stats and using Domoticz for IP control of the heat pumps, tracking the EvoHome set point for the rooms in question.

                            Comment

                            • spiralp
                              Automated Home Lurker
                              • Nov 2020
                              • 6

                              #15
                              An update to my earlier experience of using Evohome with a Panasonic heat pump. My installer has decided the two products are not compatible and has completely disengaged all Evohome control of the heat pump. All my Evohome now does is control the TRVs. The heat pump decides as and when to produce heat and at what temperature based on a weather compensation curve. This has eliminated cycling and significantly improved my heat pump efficiency. I am now of the opinion that heat pumps are best controlled by radiator sizing, radiator balancing and flow temperature (weather compensated).

                              Comment

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