Optimising a heat pump

Spoonie_Turtle

matt_drummer said:

Spoonie_Turtle said:

matt_drummer said:

Spoonie_Turtle said:

TroubledTarts said:

matt_drummer said:

TroubledTarts said:

Yes I do wonder if the top of the scops on heat pumpmonitor bend the results and don't quite heat a home as many would like. I think the scops of 4 and a bit higher are achievable but when nearly getting to 5 that's just fudging and beyond most to be bothered with just to be top of the league.

I am fourth on the list. The first one is a GSHP and the second doesn't heat DHW with their heat pump. The third one is a nice Viessman heat pump. Mine is a Daikin installed by Octopus.

My house is heated to between 22c and 23c downstairs and 19c to 21c upstairs.

What do you think I am fudging?

All I do is heat my house with a heat pump and I have installed monitoring. I just worked out how to run it efficiently.

It runs continuously and used 16.6 kWh yesterday to heat the house and a tank of water at a cost of £1.20


So, @TroubledTarts, I can't wait to hear what it is that you think I have bent and fudged?

What I have seen on some of the top of the scops is them being run when, in my opinion, most would have them off during the warmer months and this is where they could achieve the cop of 6-7 that then bump up the scop stats for the year.

Does that actually happen? 

I know ours isn't a great example (and has a vampire load, to be fair) but as the weather warms up the COP absolutely plummets - I'm talking, from 3.9 in November to 1.4 in September.
(This is excluding the vampiric summer months when it can be 0.7, 0.2, 0.1, for some heat on a few chilly mornings, to literally 0 when it puts out no heat but guzzles up to 70kWh for 'heating'.)

I don't think you have a vampire load, you have a circulation pump running continuously would be my guess, drawing 50W to 70w continuously.

Check your settings.

If you don't need heating just turn it off at the isolation switch if you can't work out what is wrong with the settings, then it will use nothing.

Turning heat pumps on for quick `blasts' of heat on a few chilly mornings is likely to be inefficient, a lot heat pumps are not great at the beginning of a heating cycle.

We hear the circulation pump at night when it's cold, which as far as I can gather is the … frost stat? Something to do with not freezing anyway - but not at other times.

What settings should I check?

If it were my house and my responsibility I would turn it off at the isolation switch, but it's not and my parents aren't willing to risk it.  A few times the system has disconnected itself, or not reconnected after a power cut, and they don't want to run the risk of making it happen yet more often as every time it does we have to wait for someone to come out to fix it.  (Plus we do still use hot water in the summer months, and again if it were just me I would be willing to try and put up with the inconvenience of having to boil a kettle, but my parents have had enough decades of being cold and everything always being awkward and inconvenient so I'm not going to ask them to do that when they don't have to.)

The best I can try this year is prohibiting heating and hot water while we go away.  We prohibited heating last year in the summer and it still guzzled the same amounts of energy, so we ended up being cold in September for nothing!

[The bits of heating on chilly spring/summer mornings were the heating automatically kicking in as the room remp dropped below the thermostat setting, not us choosing to turn it on, just in case that wasn't clear.]

I can only suggest reading the manual and getting a full understanding of how it works.

It is what I have done.

They are complicated things and just leaving it to the automation isn't generally the best way of operating a heat pump in my experience.

The automated just turning on based on room temperature is fine but probably not the most efficient way of operating it, that's just running it like a gas or oil boiler. My heat pump is less efficient and uses more electricity if I use it like this.

I can't get into the details of your specific installation.

I would also suggest heading over to open energy monitor where much more information and help is available.

Thank you for the suggestion, reading the manual is the first thing we would have done if we had one or could find one online.  Like I said, literally everything I've found out has been from others online because we have zero useful documentation.  It is literally a few basic pages of 'here's how the wall controller works, your installer set everything up for you so don't touch anything, and call them if anything goes wrong'.  I didn't even know how to change the heating and hot water settings until someone here linked me a helpful video showing to press and hold the right button on the controller to get into the settings.  Then trial and error after that - although I've never worked out how to set different timings for different days, or even just have days off (from heating water), despite it looking like it should have that function.

The most useful thing I've found online is this https://library.mitsubishielectric.co.uk/pdf/book/FTC3-4_HOMEOWNER_QUICK_START_GUIDE_Version_2#page-1 
(But I'm open to any pointers for any useful documents I've missed!)

I thought your suggestion of checking settings was directly related to thinking that it's a circulation pump rather than vampire load, so I wondered what I was supposed to be looking for, but I must have misinterpreted then, sorry.

TroubledTarts said:

Spoonie_Turtle said:

TroubledTarts said:

matt_drummer said:

TroubledTarts said:

Yes I do wonder if the top of the scops on heat pumpmonitor bend the results and don't quite heat a home as many would like. I think the scops of 4 and a bit higher are achievable but when nearly getting to 5 that's just fudging and beyond most to be bothered with just to be top of the league.

I am fourth on the list. The first one is a GSHP and the second doesn't heat DHW with their heat pump. The third one is a nice Viessman heat pump. Mine is a Daikin installed by Octopus.

My house is heated to between 22c and 23c downstairs and 19c to 21c upstairs.

What do you think I am fudging?

All I do is heat my house with a heat pump and I have installed monitoring. I just worked out how to run it efficiently.

It runs continuously and used 16.6 kWh yesterday to heat the house and a tank of water at a cost of £1.20


So, @TroubledTarts, I can't wait to hear what it is that you think I have bent and fudged?

What I have seen on some of the top of the scops is them being run when, in my opinion, most would have them off during the warmer months and this is where they could achieve the cop of 6-7 that then bump up the scop stats for the year.

Does that actually happen? 

I know ours isn't a great example (and has a vampire load, to be fair) but as the weather warms up the COP absolutely plummets - I'm talking, from 3.9 in November to 1.4 in September.
(This is excluding the vampiric summer months when it can be 0.7, 0.2, 0.1, for some heat on a few chilly mornings, to literally 0 when it puts out no heat but guzzles up to 70kWh for 'heating'.)

It really does happen with some. For some SCOP is the be all and end all of life hence that heat monitor leader board

The rest of us do the sensible thing and turn the heating off 6 months of the year and instead of upping our scop with heating when it's not required we just put up with the winter time only scop.(Note this might have been passed down in generations of turning the heating off in April and not back on til October/November 🤣)

Turning the heating off for those 6 months will mean less kwh used but lower scop overall (of course those with solar and battery they can up their scop all summer if they like to be top of the scops as it will be free energy) albeit they can't export that used energy for profit if they use it on unnecessary heating and scop boosting.

In the summer if it's 10-20oC outside definitely 5-7+ cop is achievable.

On to your vampire load what make and model is your heat pump as I have read that some have been reported to have this issue in the region of 2.4kwh for the day.

Oh wow.  And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!)   Still, everyone has different hobbies, I suppose.

It's a PUZ WM115VAA

QrizB

We seem to have hijacked the OP's thread somewhat.

Maybe we can take discussion of heat pump tweaking over to a new thread on the "heat pumps" forum?

TroubledTarts

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

I think that's the power of a league where you aim for the top of the scops it's more a game than anything else and then it's all about the game which is why (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

However, the cop since changing to Octopus Cosy is a little more warped as we advance the heat pump in the cheap hours and set it back during the expensive hours or off during peak 4-7pm. So it is more like 3.4-3.6 but only because that makes sense cost per kwh wise as we don't have batteries(or solar but we might just go batteries) yet to not set it back.

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

For the poster of they are considering a heat pump they have to also consider the right tariff that suits them for the extra kit they may have like solar and batteries and how they might work their heat pump around any shortfalls in cheaper energy and expensive peak periods where they can. All I can say is that the more kit you get to go with your heat pump the cheaper it will be to run and insulation or course insulate as much as possible but that goes for any form of heating not just a heat pump.

debitcardmayhem

QrizB said:

We seem to have hijacked the OP's thread somewhat.

Maybe we can take discussion of heat pump tweaking over to a new thread on the "heat pumps" forum?

Can’t agree more, 1 page of on topic turns in to 2 extra pages of ins and out of heat pumps and how they are used. There is a heat pump sub forum for that.

Spoonie_Turtle

TroubledTarts said:

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

… (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

…

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

Right, and real world is going to be majority a mix of people like you, like me, and like matt_drummer, (and only a relative handful of the extreme outliers) so - back to the original topic - that's probably why so many people use a relatively conservative COP of 3 for general calculations, unless they specifically know the audience is going to be capable of and willing to make sure it's installed well and spend time optimising it.  That way nobody's too disappointed if it doesn't exceed that, exactly because there are so many different factors

TroubledTarts

Spoonie_Turtle said:

TroubledTarts said:

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

… (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

…

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

Right, and real world is going to be majority a mix of people like you, like me, and like matt_drummer, (and only a relative handful of the extreme outliers) so - back to the original topic - that's probably why so many people use a relatively conservative COP of 3 for general calculations, unless they specifically know the audience is going to be capable of and willing to make sure it's installed well and spend time optimising it.  That way nobody's too disappointed if it doesn't exceed that, exactly because there are so many different factors
How old is your system?

Yeah it's a good debate but out three togetherz you, me and Matt Drummer actually come in at over a cop of 4.

How old is your system

I did so a search for your model and did find some references to vampire load in some instances.

Did you ever get your unit checked out by an electrical engineer or similar that could track where the load was coming from?

Spoonie_Turtle

TroubledTarts said:

Spoonie_Turtle said:

TroubledTarts said:

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

… (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

…

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

Right, and real world is going to be majority a mix of people like you, like me, and like matt_drummer, (and only a relative handful of the extreme outliers) so - back to the original topic - that's probably why so many people use a relatively conservative COP of 3 for general calculations, unless they specifically know the audience is going to be capable of and willing to make sure it's installed well and spend time optimising it.  That way nobody's too disappointed if it doesn't exceed that, exactly because there are so many different factors
How old is your system?

Yeah it's a good debate but out three togetherz you, me and Matt Drummer actually come in at over a cop of 4.

How old is your system

I did so a search for your model and did find some references to vampire load in some instances.

Did you ever get your unit checked out by an electrical engineer or similar that could track where the load was coming from?

True.

2019, yes that's what I've found hence calling it a vampire load, and no although it is serviced every year through whomever the Housing Association contracts to do so.

I have an old little thread about our ASHP here where it would make sense to migrate any further discussion: https://forums.moneysavingexpert.com/discussion/6409743/ashp-question/

TroubledTarts

Spoonie_Turtle said:

TroubledTarts said:

Spoonie_Turtle said:

TroubledTarts said:

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

… (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

…

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

Right, and real world is going to be majority a mix of people like you, like me, and like matt_drummer, (and only a relative handful of the extreme outliers) so - back to the original topic - that's probably why so many people use a relatively conservative COP of 3 for general calculations, unless they specifically know the audience is going to be capable of and willing to make sure it's installed well and spend time optimising it.  That way nobody's too disappointed if it doesn't exceed that, exactly because there are so many different factors
How old is your system?

Yeah it's a good debate but out three togetherz you, me and Matt Drummer actually come in at over a cop of 4.

How old is your system

I did so a search for your model and did find some references to vampire load in some instances.

Did you ever get your unit checked out by an electrical engineer or similar that could track where the load was coming from?

True.

2019, yes that's what I've found hence calling it a vampire load, and no although it is serviced every year through whomever the Housing Association contracts to do so.

I have an old little thread about our ASHP here where it would make sense to migrate any further discussion: https://forums.moneysavingexpert.com/discussion/6409743/ashp-question/

Thanks will do I had not found that

matelodave

TroubledTarts said:

Spoonie_Turtle said:

TroubledTarts said:

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

… (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

…

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

Right, and real world is going to be majority a mix of people like you, like me, and like matt_drummer, (and only a relative handful of the extreme outliers) so - back to the original topic - that's probably why so many people use a relatively conservative COP of 3 for general calculations, unless they specifically know the audience is going to be capable of and willing to make sure it's installed well and spend time optimising it.  That way nobody's too disappointed if it doesn't exceed that, exactly because there are so many different factors
How old is your system?

Yeah it's a good debate but out three togetherz you, me and Matt Drummer actually come in at over a cop of 4.

How old is your system

I did so a search for your model and did find some references to vampire load in some instances.

Did you ever get your unit checked out by an electrical engineer or similar that could track where the load was coming from?

read this to find out what causes the famous "vampire" load. - https://heatpumps.co.uk/2013/08/13/stand-by-power-and-air-source-heat-pumps/

TroubledTarts

matelodave said:

TroubledTarts said:

Spoonie_Turtle said:

TroubledTarts said:

@Spoonie_Turtle

Oh wow. And there's me just chuffed any month our COP reaches 3 (annual never has), and positively giddy if it flirts with 4 (3.96 for heating, one month!) Still, everyone has different hobbies, I suppose

… (getting back to the original discussion) when discussing the scop of a heat pump it's difficult to come up with the average but what I don't want to do is play heat pumps down when buyers think they will only get 300% efficiency.

Our aging heat pump manages 3.6-3.8 depending on the weather that year without any major settings changes just weather compensation.

…

As with most things in life it's not as simple as it first seems one person's scop over another's there are so many factors.

Right, and real world is going to be majority a mix of people like you, like me, and like matt_drummer, (and only a relative handful of the extreme outliers) so - back to the original topic - that's probably why so many people use a relatively conservative COP of 3 for general calculations, unless they specifically know the audience is going to be capable of and willing to make sure it's installed well and spend time optimising it.  That way nobody's too disappointed if it doesn't exceed that, exactly because there are so many different factors
How old is your system?

Yeah it's a good debate but out three togetherz you, me and Matt Drummer actually come in at over a cop of 4.

How old is your system

I did so a search for your model and did find some references to vampire load in some instances.

Did you ever get your unit checked out by an electrical engineer or similar that could track where the load was coming from?

read this to find out what causes the famous "vampire" load. - https://heatpumps.co.uk/2013/08/13/stand-by-power-and-air-source-heat-pumps/

Thanks.

But that doesn't fully explain why it happens to some and no others of the same models that I have read about and I wouldn't want the OP to be put off by thinking all heat pumps come with a vampire load or others reading.