I have attached a copy of a very detailed Ecodan manual kindly provided by Kev some time ago.
I would suggest that you make a note of all the DIP Switch settings (page C27 onwards) and ensure the correct settings for auto adaptation.
The Interval Timer is detailed on page C40 under 'Room Temperature Control'. I would suggest that the 'Mode' should also be set to 'Normal' rather than 'Fast'.
I'm currently doing some experiments comparing auto adapt with WC and I'm going to start a new thread about it. I need more data/different weather but so far I'm finding that, at similar outside temps, auto adapt cycles less and energy consumption and COP is the same or better, than WC.
I have revised the curve as derek suggested at midnight last night and house was too warm through the night and this morning.
I will leave for 24 hours to get a better feel but it looks like the energy used is going to be a lot higher although cycling does not seem to be an issue anymore?
On Auto adapt I would normally have at least 3 rooms throttled down on trv's as not really used much but I understand that using WC you should open up all TRV,s so we have a lovely warm house all over (but at a cost), if any rooms are excessive then is adjusting the lockshield the answer (Once the curve is optimal)? - Do you agree with this ??(Source Heat Geeks).
From what I am seeing I would agree with @kev that auto adapt may be the better mode, I am just curious as why my COP is struggling to reach 2, yesterday on WC mode it was around 1.95 but was cycling a lot, it will be interesting tomorrow to see how the cop is on dereks suggested curve over 24 hours.
Two screen shots attached at 4am and 9am today on dereks curve......FYI
I have revised the curve as derek suggested at midnight last night and house was too warm through the night and this morning.
I will leave for 24 hours to get a better feel but it looks like the energy used is going to be a lot higher although cycling does not seem to be an issue anymore?
On Auto adapt I would normally have at least 3 rooms throttled down on trv's as not really used much but I understand that using WC you should open up all TRV,s so we have a lovely warm house all over (but at a cost), if any rooms are excessive then is adjusting the lockshield the answer (Once the curve is optimal)? - Do you agree with this ??(Source Heat Geeks).
From what I am seeing I would agree with @kev that auto adapt may be the better mode, I am just curious as why my COP is struggling to reach 2, yesterday on WC mode it was around 1.95 but was cycling a lot, it will be interesting tomorrow to see how the cop is on dereks suggested curve over 24 hours.
Two screen shots attached at 4am and 9am today on dereks curve......FYI
Hi Dave,
If the rooms are too warm this would indicate that the WC slope is too high for your home. I would suggest adjusting the cold end to a LWT of 45C or even 40C. Once the room temperatures are within the desired range fine tuning with 1C increments can then be performed if deemed necessary.
The final objective is to balance your system, so that you achieve the desired indoor temperatures, with your heat pump operating in a reliable and consistent manner, at the lowest LWT. To achieve this objective it is necessary to balance the heat energy output of the heat emitters in each room to the actual heat loss of that room. In some rooms the heating capacity of the heat emitters may be greater than that required, so can meet the heat loss with a LWT of say 35C, whilst other rooms may require a LWT of say 37C or 38C to supply the heat loss.
Because it can take quite some time for room temperatures to stabilise, balancing the system can be a lengthy process.
I would suggest that you start by recording the setting of all the TRV's and then opening them fully. Allow the temperature in the rooms to stabilise, recording all the values. If the coldest room is still above the desired temperature then lower the WC slope slightly. If the coldest room is below the desired temperature then open the lockshield valve on the radiator fully, noting the number of turns required to do so. Allow the room temperature to stabilise and see if this is above or below that desired, adjust the WC slope to achieve the correct temperature.
Ideally, the lockshield and TRV should be fully open in the coldest room, with the temperature being achieved with the lowest LWT. In the remaining rooms the desired temperature should be achieved by adjusting the relevant lockshield valve.
Once the system has been balanced, the temperature in bedrooms, and possibly other rooms, can be lowered by means of the TRV's, though it should be remembered, that reducing the heating capacity of certain heat emitters, means that the remaining heat emitters may have to work harder to achieve the desired temperatures. This in turn may require a higher LWT, which can reduce the overall efficiency.
Once everything is operating in a balanced manner in WC mode, you may then wish to try auto adaptation mode.
On Auto adapt I would normally have at least 3 rooms throttled down on trv's as not really used much but I understand that using WC you should open up all TRV,s
Firstly, not exactly. Using any heat pump, it's better if the TRVs are open and the room holds its relative temperature because the designer was wise and selected a radiator that is the correct size for the room. The TRV should be set slightly above the desired temperature for the room, to stop unusual situations like solar gain running away with the temperature. As someone on another forum says, using TRVs and thermostats for basic control of a heat pump is like driving a car flat out all the time and only using the brake to control it: usually very not efficient.
Secondly, the same applies to both weather curve mode and auto adapt mode.
Others are writing good stuff about other parts of your message.
I have revised the curve as derek suggested at midnight last night and house was too warm through the night and this morning.
I will leave for 24 hours to get a better feel but it looks like the energy used is going to be a lot higher although cycling does not seem to be an issue anymore?
On Auto adapt I would normally have at least 3 rooms throttled down on trv's as not really used much but I understand that using WC you should open up all TRV,s so we have a lovely warm house all over (but at a cost), if any rooms are excessive then is adjusting the lockshield the answer (Once the curve is optimal)? - Do you agree with this ??(Source Heat Geeks).
From what I am seeing I would agree with @kev that auto adapt may be the better mode, I am just curious as why my COP is struggling to reach 2, yesterday on WC mode it was around 1.95 but was cycling a lot, it will be interesting tomorrow to see how the cop is on dereks suggested curve over 24 hours.
Two screen shots attached at 4am and 9am today on dereks curve......FYI
Dave,
the first screen shot isn't cycling; it looks like the ASHP is lowering the LWT in a controlled way. The drop in LWT is gradual and I think the ASHP is still running. I'm not sure why it shoots up just before 5am - is that maybe your HW? The second is cycling; the flow temps are much lower and the LWT drops sharply. The ASHP will have stopped for a while.
A couple of questions - what is the heat loss for your house and which Ecodan do you have? That will give some indication of when (i.e. at what outside temperature) the ASHP is likely to start cycling. BTW cycling may not affect the COP; it doesn't seem to for my system. Cycling less than twice an hour like yours isn't necessarily anything to worry about. If you didn't have Melcloud you wouldn't even know.
Yes the spike was DHW run, I have attached the heat loss and MSC Compliance certificate to show Heat Loss etc.
I have the 8.5KW Ecodan unit despite the installer stating Samsung on the front page of the heat loss calc.. there is no rad shown in the kitchen as we had no space but I have added since a stud wall and fitted a radiator rated at 1000W @ deltaT30.
I have lowered the cold end of the curve now down to 40C @ -5 and the house is still holding steady at about 1 degree over target temperatures, the cycling still seems to be okay with maximum of 2 / hour.........yesterdays cop was still just under 2.?
Am i correct in thinking that cycling more an issue in warmer weather / low flow temps?
Not sure if i am allowed to attach docs with personal detail??
Thanks Derek....I am still sorting the optimum WC curve as you suggested, gone from a sweltering 50 at the cold end to 45 and now to 40C but considering today has been around 4C outside the rooms have not really cooled so thinking it might need to come down a bit more, the curve is getting quite shallow is that normal??
Cop still no better than 2.
Once stabilised I will try to balance as you kindly suggest........just to clarify in unused rooms would you still keep them heated to the design temp and set TRV's just above so no interference except for solar gain etc?
Once all set up correctly I will try Auto Comp Mode set as you advised and see what the results are.
Thanks Derek....I am still sorting the optimum WC curve as you suggested, gone from a sweltering 50 at the cold end to 45 and now to 40C but considering today has been around 4C outside the rooms have not really cooled so thinking it might need to come down a bit more, the curve is getting quite shallow is that normal??
Cop still no better than 2.
Once stabilised I will try to balance as you kindly suggest........just to clarify in unused rooms would you still keep them heated to the design temp and set TRV's just above so no interference except for solar gain etc?
Once all set up correctly I will try Auto Comp Mode set as you advised and see what the results are.
Whether you fully heat unused rooms is a personal choice.
ASHP's are more efficient when operating at the lowest LWT, but to get the maximum amount of heat energy from this lower LWT it is necessary to utilise the maximum heating area of your heat emitters. The other factor to consider is that internal walls are unlikely to provide the same degree of insulation as external walls, so there will still be heat loss from heated areas to unheated ones.
In unused areas it may be more energy efficient and cost effective to still heat, but at a lower temperature, using TRV's as the controlling device.
It is a balancing act, between matching heat energy supply, to heat energy demand, and having a shallow WC slope is actually a good thing, since it indicates a good level of insulation.
I have no idea why your indicated COP is only 2, since with your present operating parameters I would anticipate one in the 3 to 4 region. Do you have a booster heater in your installation, and if so is it functioning? What is your present electricity consumption?
It's been close to freezing all day and the Curve is still maintaining the whole house comfortably, it's now down to 39C at -5C (getting flatter) and still monitoring but based on yesterday's figures from Melcloud the cop was still under 2!! (See attached Screenshot)
I don't have any boost heating, only set for the legionella once every two weeks, hot water only set @ 45C and scheduled twice a day but firly short cycles as we never run too much off between cycles.
It's getting frustrating as based on the way the WC mode has performed over the last 4 days it seems like the house is not a heat sink as rooms have held up well as the curve has been reduced day by day.
Yesterday the unit show's 23.3 KW consumed and based on the smart meter reading for the day I would say that cannot be too far away from correct, I am beginning to think that Melcloud is not giving accurate outputs as I have read elsewhere that this has been questioned.
I have attached some melcloud report screenshots over the last two days and a typical hourly shot today which seems to show steady running.
I don't like to keep asking for help but just puzzled on the cop figures, I may have to accept that "it is what it is" and it's not costing a fortune (it is relative to last year 😫 ) as all rooms are heated to just above design temps still.
Its looking like todays spend is going to be around ten pounds but it's been very cold.
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