PeterW Posted January 16, 2021 Share Posted January 16, 2021 Ds02 : 12 ds04 : -3 ds06 : -2 Means that the temperature will increase at -2°C by 3°C and will ramp down to 0°C increase over 12 degrees so at 10°C your set point will be the same. What is current set point out of interest ..? Link to comment Share on other sites More sharing options...
Chriswills Posted January 16, 2021 Author Share Posted January 16, 2021 The HP unit settings are based on the return temperature which I have set to 37. The flow is then 5 degrees more at 42, or it’s supposed to be anyway. When the pump picks up a return of 34 it starts up again. 3 degree delta. I have been trying to reduce it but the rads suffer, so for me atm this is the best setting. Do you think it’s worth trying the compensation settings instead? Link to comment Share on other sites More sharing options...
PeterW Posted January 16, 2021 Share Posted January 16, 2021 Can you change the delta setting ..? Link to comment Share on other sites More sharing options...
Chriswills Posted January 16, 2021 Author Share Posted January 16, 2021 12 minutes ago, PeterW said: Can you change the delta setting ..? Good question. I’ll check. what’s your reason for asking? Link to comment Share on other sites More sharing options...
PeterW Posted January 16, 2021 Share Posted January 16, 2021 You have a flow to return delta of 8°C as a composite view which is ~20% which seems high. Also, the pipe stat you are using will be quite slow to respond and pretty inaccurate so may be worth getting some digital sensors and sticking them on the pipes under some insulation. May have a better view of the settings then. Does the buffer have any spare pockets for sensors ..? Link to comment Share on other sites More sharing options...
Chriswills Posted January 16, 2021 Author Share Posted January 16, 2021 Yes some on the back here. They have plugs in there at moment. So to fit something would have to drain down I guess Link to comment Share on other sites More sharing options...
TonyT Posted January 16, 2021 Share Posted January 16, 2021 At work a plumber removed a blank on an 800 litre buffer tank, to insert an immersion heater, he didn’t drain it down and the water leaking minimal. the immersion was at the bottom of the tank? wouldn’t fancy doing it myself Link to comment Share on other sites More sharing options...
Chriswills Posted January 16, 2021 Author Share Posted January 16, 2021 7 minutes ago, TonyT said: At work a plumber removed a blank on an 800 litre buffer tank, to insert an immersion heater, he didn’t drain it down and the water leaking minimal. the immersion was at the bottom of the tank? wouldn’t fancy doing it myself Me neither. That’s a job for when I do a full system flush in the summer Link to comment Share on other sites More sharing options...
Chriswills Posted January 16, 2021 Author Share Posted January 16, 2021 1 hour ago, PeterW said: You have a flow to return delta of 8°C as a composite view which is ~20% which seems high. Also, the pipe stat you are using will be quite slow to respond and pretty inaccurate so may be worth getting some digital sensors and sticking them on the pipes under some insulation. May have a better view of the settings then. Does the buffer have any spare pockets for sensors ..? Not using the pipe stat at all. I think it’s waste of time. So in accurate and if garage is cold then it goes off and when I get up house is cold. All sorts of issues Link to comment Share on other sites More sharing options...
Chriswills Posted January 16, 2021 Author Share Posted January 16, 2021 1 hour ago, Chriswills said: Good question. I’ll check. what’s your reason for asking? I have the manual here for the controller, but very difficult to find the delta differential, not sure if you can help: 8MA10222_SBW600_EN_1209_low - google search this Link to comment Share on other sites More sharing options...
Chriswills Posted January 17, 2021 Author Share Posted January 17, 2021 (edited) On 16/01/2021 at 11:54, PeterW said: Ds02 : 12 ds04 : -3 ds06 : -2 Means that the temperature will increase at -2°C by 3°C and will ramp down to 0°C increase over 12 degrees so at 10°C your set point will be the same. What is current set point out of interest ..? Temp outside is now 6 deg C and ASHP I now comes on at a return temp of 32. Is that right? may be a bit cold for rads upstairs, I think it needs to come on at 35. which DS values could reflect this Edited January 17, 2021 by Chriswills Link to comment Share on other sites More sharing options...
Chriswills Posted January 20, 2021 Author Share Posted January 20, 2021 Not had any replies now for a while ? Latest update is that I have found setting the return to 37 on the ASHP and temp stats to about 18 for the UFH, leaving on 24 hours give me about 50kwh. That’s for the whole house, not just the heating. how does that sound? I tried to switch the pump off from midnight to 5am but makes no difference to electricity consumption. Guess it uses quite a lot of energy to get the slab up again. I would like a bit more experimentation on the temp compensation, which I did start to do using Peters recommendations but didn’t quite work. Peter - would you like to discuss further? Link to comment Share on other sites More sharing options...
PeterW Posted January 20, 2021 Share Posted January 20, 2021 Sorry @Chriswills I missed the responses. If you put the “@“ in front of the name you can tag someone I’m wondering if there is a curve setting on the heat pump as it seems to indicate there is. It may work better than manually changing the set point as it’s doing something odd with those numbers. Link to comment Share on other sites More sharing options...
Chriswills Posted January 20, 2021 Author Share Posted January 20, 2021 @PeterW is this what you mean? what’s your opinion on my consumption? Link to comment Share on other sites More sharing options...
PeterW Posted January 20, 2021 Share Posted January 20, 2021 How big is the house ..? Link to comment Share on other sites More sharing options...
Chriswills Posted January 20, 2021 Author Share Posted January 20, 2021 (edited) @PeterW ground floor ufh approx 14m x 12m with 5 zones first floor about same with rads third floor too but don’t use rads very much it’s an attic room Edited January 20, 2021 by Chriswills Link to comment Share on other sites More sharing options...
PeterW Posted January 20, 2021 Share Posted January 20, 2021 That’s nearly 500sqm, so not small by any stretch of the imagination ..! Your heat losses could be quite high. Have you got any EPC or SAP for the house ..? Link to comment Share on other sites More sharing options...
Chriswills Posted January 20, 2021 Author Share Posted January 20, 2021 (edited) @PeterW I have somewhere. Will have to look. Im only really interested in getting the ground floor sorted. The rads are switched on as and when needed. Edited January 21, 2021 by Chriswills Link to comment Share on other sites More sharing options...
Chriswills Posted January 21, 2021 Author Share Posted January 21, 2021 @PeterW found them Peter, please see images below: Link to comment Share on other sites More sharing options...
Chriswills Posted January 21, 2021 Author Share Posted January 21, 2021 @PeterW is that the information you require? Link to comment Share on other sites More sharing options...
Chriswills Posted January 22, 2021 Author Share Posted January 22, 2021 21 hours ago, Chriswills said: @PeterW is that the information you require? Just an update @PeterW I can’t seem to get the consumption in Kw of electricity below 50. My return temp to ashp is 37 and is left on 24/7 for ufh. Would really like to try weather compensation if any good. Or anything else really. What do others burn per day on electricity? Link to comment Share on other sites More sharing options...
Temp Posted January 22, 2021 Share Posted January 22, 2021 (edited) I'm a bit late to this thread but.. If one pump is managing to push 2 L/min through the UFH then Id probably leave it alone. If you had said the rads were getting hot but not the UFH then I would recommend a different approach. A manifold loop pump and mixer is the standard way of doing UFH but is there much point to a mixer if you don't need it to mix down the temperature? Some houses need higher UFH flow temperatures than others. 50kWH per day equates to 50/24 = 2.1kW average. Not sure what COP you get in the cold weather but if you managed a COP of 2 that would mean the heat loss is around 4.2kW. Less because some is used for DHW. Edited January 22, 2021 by Temp Link to comment Share on other sites More sharing options...
Chriswills Posted January 22, 2021 Author Share Posted January 22, 2021 1 hour ago, Temp said: I'm a bit late to this thread but.. If one pump is managing to push 2 L/min through the UFH then Id probably leave it alone. If you had said the rads were getting hot but not the UFH then I would recommend a different approach. A manifold loop pump and mixer is the standard way of doing UFH but is there much point to a mixer if you don't need it to mix down the temperature? Some houses need higher UFH flow temperatures than others. 50kWH per day equates to 50/24 = 2.1kW average. Not sure what COP you get in the cold weather but if you managed a COP of 2 that would mean the heat loss is around 4.2kW. Less because some is used for DHW. @Temp thanks for the feedback, I don’t use the ASHP for DHW but have a solar and immersion heater. Do you think it’s performing OK as it is? What would the COP be? Link to comment Share on other sites More sharing options...
Temp Posted January 22, 2021 Share Posted January 22, 2021 In winter the solar won't be producing much on average and the immersion heater "COP" is 1. The COP of the ASHP might also be quite low ifvits been cold where you are. So overall I don't think its doing too bad. Link to comment Share on other sites More sharing options...
Chriswills Posted January 22, 2021 Author Share Posted January 22, 2021 2 minutes ago, Temp said: In winter the solar won't be producing much on average and the immersion heater "COP" is 1. The COP of the ASHP might also be quite low ifvits been cold where you are. So overall I don't think its doing too bad. Thanks @Temp that’s reassuring at least. I did try to switch the ashp from 12am until 5am to save a bit but the consumption is the same as I guess it has to reheat the slab. Link to comment Share on other sites More sharing options...
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