We have had our heat pump (Samsung 16kw) for 9 years now and it is only in the last 2 years that I have understood how to get it working efficiently. Our installers did some things very badly and some not so badly. Firstly, for a 16kw heat pump, we should have had 35mm primary pipework, but we were given 28mm. As it turns out, this is not so bad, as our heat pump is massively over-sized and we don't actually need to deliver 16kw of heat, so the pipework is adequate. We already had mainly 22mm central heating pipes, going down to 15mm on the short runs to each radiator, so this is fine. The second bad thing they did was to give us 5 different zones, when actually we only need two, one for our cellars and one for the upper 2 floors of the house. The third bad thing was that they configured the heat pump to run at a constant 45c flow temp, when it should have been on weather compensation. For the first 7 years it cost us roughly double what it should have done to run, had an average SCOP of about 2.0 and our house wasn't as evenly warm as I would have liked it. HOWEVER, 2 years ago I took it upon myself to learn everything I could about our system and heat pumps in general. It turns out that our install is not actually that bad and that when configured correctly, our heat pump can run efficiently and can keep our house at a lovely, warm and even temperature. We don't have a buffer (that was a good thing on the part of the installers, as were the 3 panel radiators they installed), we now have it running on weather comp, with a max flow temp of 38c and a minimum of 27c. We leave it on 24/7, with a 2c setback at night. We have reduced the flow rate to hit an average of between 5c and 6c Delta T. We have reduced the flow to the UFH loops in the cellar and have made this open zone instead of 4 different zones. We have balanced the flow to all radiators and to the UFH loops so that we get an even radiator temp for all rads and an even indoor temp in all rooms. The net result is that our SCOP is now averaging 4.0 and our house is much warmer. Our heat pump costs half of what our modern condensing gas boiler does to heat our house, on Octopus Agile tariff (we have a hybrid system, so can use the heat pump or the gas boiler and can accurately measure costs for both). Heat pump performance is all about two things: quality of installation and quality of configuration.
Ken is a real heat pump pro with his own UA-cam channel and I've heard other top heat pumps engineers reference his work positively. If Ken can't do it nobody can!
@@robandrews9826 I don't know why UA-cam isn't posting my reply, possibly because of the link. It'll probably pop up later, but search for allthingsrenewable9017 and you'll get his channel.
This is a very informative and as such presents a scary picture of how heat pumps will / will not replace other forms of heating especially in older/larger properties. From your account of the installation you have retained microbore pipework and not enlarged the radiators as I can imagine they would be totally unacceptable from an aesthetic point of view. I dread to think how much your current system cost and how much more to try to make it satisfactory. I think you will be faced with having to install a conventional boiler to run in parallel with the HP to give you the room temperature needed especially on cold windy days. I await the next 'instalment' with considerable scepticism.
This is a very interesting video and exposes two of my main concerns regarding ASHP suitability in our house: 1) We have a fairly large old house but we have hydronic underfloor heating (two circuits, two pumps, sixteen zones and 14 thermostats), a thermal store and an oil boiler. The system was installed by the previous owner so is something like 20 years old (although the boiler is much newer). The house is pretty warm in all of the heated rooms but it does cost a bit to run. Were we to have to change our boiler for a heat pump based system, I would have nightmares about the possible upheaval and cost if floors needed to be ripped up and underfloor heating replaced. 2) So many installation companies seem to be jumping on the renewables band wagon but not applying modern heat pump principles and common sense to design and build. As this video demonstrates, gas and oil boiler based design doesn't necessarily apply to heat pumps. It seems like an affiliated company to something like Heat Geeks is the safest way to go because there is a chance that the designer of the system has passed the course and is applying the content rather than guessing and using old theories. I typed our address into the Heat Geek site and the algorithm claimed that our house wasn't suitable for a heat pump because it is too large and too inefficient! Hmmm ! Our boiler is running fine at the moment and we will continue with it. Hopefully, as the months and years tick by, the industry will become more knowledgeable with regard to designing heat pumps into old housing stock and more installers who have a clue will be available. For now though, it still seems like a bit of a lottery finding a decent installer. The chap in the video seems to be talking complete sense, as far as I can tell. Hold on to him!
Your UFH is likely not on 100mm centres. You'd need a heating engineer that's very good to tell you if a wider setting could deliver the rooms heat requirements with this in mind.
So reason for the thermal store was to prevent short cycling of the boiler, such that it can heat the thermal store up to whatever it likes and then turn off waiting for the thermal store to cool sufficiently prior to pumping more energy into it..... otherwise I assume once the floor was warm it wouldn't take too much time for the water in the boiler loop to become hot enough to cycle the boiler off again. So in your case as long as there was pipework of a sufficient size to enable the correct flow rate to each UFH loop on each manifold AND the heat loss overall to the house can be met by a ASHP you probably wouldn't have too much of a problem, i.e. it is doubtful that the underfloor heating pipes cause a problem in that they are normally run at around 50 degrees in any case..... That is assuming you can get the correct size of Pipework from the manifolds to the position of the external ASHP, which is often the major problem in retrofitting these systems.
The UFH heating works very well. It's some rads that are the issue, and Ken's suggested throttling some of the underfloor to give more flow to the rads. A lot to plan and implement.
@@wino99999 Thanks to you (and others) for the information. Our UFH is not on 100mm centres, more like 200, but it's hard to tell at the moment as the ambient temperature is such that the UFH isn't really doing much and our thermal camera is struggling to acquire a decent image. The pipe work is poly pipe, OD is about 18mm so, I'd guess it's probably 15mm ID. I tend to run the inlet to each manifold in the upper 40's. At present the oil boiler is in the utility room and this is below the family bathroom which is adjacent to the cupboard holding the thermal store. It is theoretically possible to route pipework down, through the utility room and then outside as the manifolds are upstairs . We don't have neighbours near-by so an ASHP could be cited near the back door. The manifolds are by Far and the bore of the inlet is likely 15mm. It sounds like a different manifold arrangement might be required if an ASHP is used? It doesn't sound like a total disaster, probably a better situation than many people in old houses have.
Hi Mars - having followed your heat pump story from the beginning I am pleased to see this video and that you having an independent ‘root and branch’ review of your system. It would be really useful if your heating engineer could construct a ‘block diagram’ of the current system showing the DTs and flow rates at the key nodes in the system (he will have to do this for himself anyway to analyse what he is dealing with here) and of course when he makes changes for an amended diagram with DTs and flow rates - to illustrate the follow-up video. Are you going to take the opportunity to fit openenergy monitoring equipment? Best wishes.
Only one thing wrong how do you regulate the flow rate please enlighten me on that one mine is a Grant Aerona 17KW with a Low Loss Header only radiators 2 levels.Stumped I am and have had my fingers burned with cowboys how do you even know they are cowboys.Doing it myself with a little help from UA-cam,none yet haha
I would say having listened to Ken, he seems to know what he's talking about. In my experiance - I'm not a CH expert, but I do most of my plumbing myself - I can say it's more about the confidence in right sizing the radiators and the heat loss for the size of rooms, as well as ensuring has Ken stated, that the pipe size installed is capable of being able to transfer the correct amount of energy into those radiators in order to warm the rooms sufficiently. I didn't have enough confidence when sizing my boiler to pick one that was smaller than I choose, hence my system is still overpowered, and even though I'm running the boiler at lower temperatures to achieve high output, my radiators are really sized for 60 degrees C minimum when I should maybe have chosen larger ones. Ideally I would like to transition to under floor heating, but retrofitting this is not ever going to be a reality with solid concrete floors downstairs, even though I would also benefit by installing insulation in my 1980's built house..... I just can't imagine the mess! In the old days boilers were installed by 'engineers' who used rule of thumb to guess how much energy a property required - and it didn't matter much as the boilers oftern ran flat out with water temperatures up to or enev above 80 degrees C. Boilers were often oversized - so they short cycled, and efficiencies were not considered. Converting such old systems to run with heat pumps is a complete minefield, and they mostly will not run efficiently at low temperatures as there will be insuffficient energy within the water in the system and again as Ken said the flow rate has to be increased drastically to try and make up for this difference, with the old rad's changed out for much larger more efficient radiators, to try and extract the max energy from the flow.... However if the pipe size is too restrictive, you can't get the correct flow rates! www.youtube.com/@UrbanPlumbers also seems to know what he's talking about and is often saying there is too much control taking place even in new installations. This one in particular may apply to you: ua-cam.com/video/AXamAjE0juw/v-deo.html. When assuming you can achieve sufficient flow rates, and the radiators are right sized for the flow temperature, then balancing the system can often lead to high COP and even temperatures thoughout. Especially with underfloor heating, Mixing valves are not desirable or necessary with flow temperatures of 55 degrees or less, instead making sure the correct flow rate per loop is achieved to result in the correct amount of energy/loop being realised. This ensures the water temperature flowing back to the heat source is also optimised, and hence the source is able to pump the correct amount of energy back into the system without throttling down it's output. I wish you and Ken good luck with sorting out all the problems. Maybe being an older property it's possible to re-engineer some of the pipework under the floor - I crawled under my parents floor as a kid doing pipework for my dad, so dependant upon access and trhe height of the joists.... who knows. P.S. I'm 64 now, so probably wouldn't fit anymore and wouldn't want to do that sort of thing in any case!
Top man is our Ken. Sadly this type of install is far too common, chuck a heat pump in and dont do any design inside thouse. If you are getting quotes heat loss and internal design and commission is needed as part of the qutation. Im a tech support engineer for Stiebel Eltron and we can help with all this side.
That is too true. Countless cases like ours in the forums: renewableheatinghub.co.uk/forums But Ken is a top guy, so we’re in safe hands. To complicate matters, our heat pump might now also be undersized which is also an all too common issue.
@@RenewableHeatingHubWell if this proves to be true - it may only be true for x weeks per year - Ken should be able to determine that and if x =small, then supplemental heating may be cost effective rather than upgunning on the heat pump.
@@normanboyes4983 Don't change the HP if it's undersized! Supplimental heating is a much better idea than sizing for the two coldest weeks of the year. Usually nobody does this with a heat pump because MCS regs forbid it for the BUS grant. I'd strongly advise you to add a small (cheap) minisplit a/c unit into the house a) for supplimental heating b) for redundancy c) for cooling. You might actually find it's all you need for most of the year.
Hi Mars. Sorry your ASHP not working out as you hoped. I’ve followed your discussions and selection and installation progress. You interviewed me on your channel about my ASHP. And I continue to post my ASHP SCOP and running costs on your Renewable Heating Hub information site. So I’m slightly surprised by your system revelations. I don’t know the chap discussing your installation having undertaken a review. He sounds sensible and knowledgeable. But please seek alternative views. That’s my top tip. Given your knowledge and experience (perhaps it came after your installation) I was wondering why you didn’t enquire about all your system components? Numbers of pumps. Valves. Controls on controls. Good luck with the investigations. What about the original installers? Why did they make it so complex? There are definitely two schools of ASHP: ones who fit buffer tanks and those that don’t.
That chap is Ken Bone, he is one of the best in the UK, in fact Elite status. Kind of like the Special Forces of Heat Pumps, I think you get the picture. JK
It's definitely been a slog for us Julian. Mediocre installation at best. We've identified so many things over the years as we've educated ourselves on what comprises a good system, but weren't confident to assign the work to anyone that would potentially bodge it further. So we're over the moon to connect with and get Ken to do the work - he's a top installer. To answer your question, previous installers just didn't have the skills or the knowledge to fix it. Their solution to everything was just add another distribution pump, which is why our utility room looks like a Grundfos showroom.
@@RenewableHeatingHub Credit where it's due. Personally I have been blocked on twitter by Ken during a heating argument, but I'm still one for giving credit where it's due regardless of personal circumstance or moments of anger. Jay K.
The greatest thing since sliced bread last week.They have that many excuses don’t they I can bring another guy that says micro bore.Designed they just rammed mine in disconnected my Combi and have put two different heat pumps in and ran away.First one DearDear swooped it for another one and Dear Dearer haha I kid you not.All fitted from start to finish by MCS accredited so called TRADESMEN MCS waste of time.
![АЛАУДИНОВ у Скабеевой: эти их ВСУ нас НЕ ДОГОНЯТ 😁 [Пародия]](http://i.ytimg.com/vi/an0anqU4WGQ/mqdefault.jpg)
We have had our heat pump (Samsung 16kw) for 9 years now and it is only in the last 2 years that I have understood how to get it working efficiently. Our installers did some things very badly and some not so badly. Firstly, for a 16kw heat pump, we should have had 35mm primary pipework, but we were given 28mm. As it turns out, this is not so bad, as our heat pump is massively over-sized and we don't actually need to deliver 16kw of heat, so the pipework is adequate. We already had mainly 22mm central heating pipes, going down to 15mm on the short runs to each radiator, so this is fine. The second bad thing they did was to give us 5 different zones, when actually we only need two, one for our cellars and one for the upper 2 floors of the house. The third bad thing was that they configured the heat pump to run at a constant 45c flow temp, when it should have been on weather compensation. For the first 7 years it cost us roughly double what it should have done to run, had an average SCOP of about 2.0 and our house wasn't as evenly warm as I would have liked it. HOWEVER, 2 years ago I took it upon myself to learn everything I could about our system and heat pumps in general. It turns out that our install is not actually that bad and that when configured correctly, our heat pump can run efficiently and can keep our house at a lovely, warm and even temperature. We don't have a buffer (that was a good thing on the part of the installers, as were the 3 panel radiators they installed), we now have it running on weather comp, with a max flow temp of 38c and a minimum of 27c. We leave it on 24/7, with a 2c setback at night. We have reduced the flow rate to hit an average of between 5c and 6c Delta T. We have reduced the flow to the UFH loops in the cellar and have made this open zone instead of 4 different zones. We have balanced the flow to all radiators and to the UFH loops so that we get an even radiator temp for all rads and an even indoor temp in all rooms. The net result is that our SCOP is now averaging 4.0 and our house is much warmer. Our heat pump costs half of what our modern condensing gas boiler does to heat our house, on Octopus Agile tariff (we have a hybrid system, so can use the heat pump or the gas boiler and can accurately measure costs for both). Heat pump performance is all about two things: quality of installation and quality of configuration.
Do you have solar/battery storage?
Ken knows his stuff for sure. You can rest easy once he is onboard.
Agreed! Big sigh of relief.
Ken is a real heat pump pro with his own UA-cam channel and I've heard other top heat pumps engineers reference his work positively. If Ken can't do it nobody can!
Link to Ken’s channel please.
What's Kens channel called? I'd like to see more content
Ken has a great rep. We’re in good hands.
@@robandrews9826 I don't know why UA-cam isn't posting my reply, possibly because of the link. It'll probably pop up later, but search for allthingsrenewable9017 and you'll get his channel.
@@robandrews9826 youtube.com/@allthingsrenewable9017
I'm glad you got one of the best in to fix the problem.
I cannot agree more. We’re in safe hands! 🙌
This is a very informative and as such presents a scary picture of how heat pumps will / will not replace other forms of heating especially in older/larger properties. From your account of the installation you have retained microbore pipework and not enlarged the radiators as I can imagine they would be totally unacceptable from an aesthetic point of view. I dread to think how much your current system cost and how much more to try to make it satisfactory. I think you will be faced with having to install a conventional boiler to run in parallel with the HP to give you the room temperature needed especially on cold windy days. I await the next 'instalment' with considerable scepticism.
This is a very interesting video and exposes two of my main concerns regarding ASHP suitability in our house:
1) We have a fairly large old house but we have hydronic underfloor heating (two circuits, two pumps, sixteen zones and 14 thermostats), a thermal store and an oil boiler. The system was installed by the previous owner so is something like 20 years old (although the boiler is much newer). The house is pretty warm in all of the heated rooms but it does cost a bit to run. Were we to have to change our boiler for a heat pump based system, I would have nightmares about the possible upheaval and cost if floors needed to be ripped up and underfloor heating replaced.
2) So many installation companies seem to be jumping on the renewables band wagon but not applying modern heat pump principles and common sense to design and build. As this video demonstrates, gas and oil boiler based design doesn't necessarily apply to heat pumps. It seems like an affiliated company to something like Heat Geeks is the safest way to go because there is a chance that the designer of the system has passed the course and is applying the content rather than guessing and using old theories. I typed our address into the Heat Geek site and the algorithm claimed that our house wasn't suitable for a heat pump because it is too large and too inefficient! Hmmm !
Our boiler is running fine at the moment and we will continue with it. Hopefully, as the months and years tick by, the industry will become more knowledgeable with regard to designing heat pumps into old housing stock and more installers who have a clue will be available. For now though, it still seems like a bit of a lottery finding a decent installer.
The chap in the video seems to be talking complete sense, as far as I can tell. Hold on to him!
Thanks for the detailed feedback. Our added complication might be that our heat pump might also be undersized. Crunching the numbers.
Your UFH is likely not on 100mm centres. You'd need a heating engineer that's very good to tell you if a wider setting could deliver the rooms heat requirements with this in mind.
So reason for the thermal store was to prevent short cycling of the boiler, such that it can heat the thermal store up to whatever it likes and then turn off waiting for the thermal store to cool sufficiently prior to pumping more energy into it..... otherwise I assume once the floor was warm it wouldn't take too much time for the water in the boiler loop to become hot enough to cycle the boiler off again.
So in your case as long as there was pipework of a sufficient size to enable the correct flow rate to each UFH loop on each manifold AND the heat loss overall to the house can be met by a ASHP you probably wouldn't have too much of a problem, i.e. it is doubtful that the underfloor heating pipes cause a problem in that they are normally run at around 50 degrees in any case..... That is assuming you can get the correct size of Pipework from the manifolds to the position of the external ASHP, which is often the major problem in retrofitting these systems.
The UFH heating works very well. It's some rads that are the issue, and Ken's suggested throttling some of the underfloor to give more flow to the rads. A lot to plan and implement.
@@wino99999 Thanks to you (and others) for the information. Our UFH is not on 100mm centres, more like 200, but it's hard to tell at the moment as the ambient temperature is such that the UFH isn't really doing much and our thermal camera is struggling to acquire a decent image. The pipe work is poly pipe, OD is about 18mm so, I'd guess it's probably 15mm ID. I tend to run the inlet to each manifold in the upper 40's.
At present the oil boiler is in the utility room and this is below the family bathroom which is adjacent to the cupboard holding the thermal store. It is theoretically possible to route pipework down, through the utility room and then outside as the manifolds are upstairs . We don't have neighbours near-by so an ASHP could be cited near the back door. The manifolds are by Far and the bore of the inlet is likely 15mm. It sounds like a different manifold arrangement might be required if an ASHP is used?
It doesn't sound like a total disaster, probably a better situation than many people in old houses have.
Hi Mars - having followed your heat pump story from the beginning I am pleased to see this video and that you having an independent ‘root and branch’ review of your system. It would be really useful if your heating engineer could construct a ‘block diagram’ of the current system showing the DTs and flow rates at the key nodes in the system (he will have to do this for himself anyway to analyse what he is dealing with here) and of course when he makes changes for an amended diagram with DTs and flow rates - to illustrate the follow-up video.
Are you going to take the opportunity to fit openenergy monitoring equipment?
Best wishes.
Great suggestions Norman. I’ll definitely request that. I am interested in metering too… might consider openenergy monitor
Only one thing wrong how do you regulate the flow rate please enlighten me on that one mine is a Grant Aerona 17KW with a Low Loss Header only radiators 2 levels.Stumped I am and have had my fingers burned with cowboys how do you even know they are cowboys.Doing it myself with a little help from UA-cam,none yet haha
I would say having listened to Ken, he seems to know what he's talking about.
In my experiance - I'm not a CH expert, but I do most of my plumbing myself - I can say it's more about the confidence in right sizing the radiators and the heat loss for the size of rooms, as well as ensuring has Ken stated, that the pipe size installed is capable of being able to transfer the correct amount of energy into those radiators in order to warm the rooms sufficiently. I didn't have enough confidence when sizing my boiler to pick one that was smaller than I choose, hence my system is still overpowered, and even though I'm running the boiler at lower temperatures to achieve high output, my radiators are really sized for 60 degrees C minimum when I should maybe have chosen larger ones. Ideally I would like to transition to under floor heating, but retrofitting this is not ever going to be a reality with solid concrete floors downstairs, even though I would also benefit by installing insulation in my 1980's built house..... I just can't imagine the mess!
In the old days boilers were installed by 'engineers' who used rule of thumb to guess how much energy a property required - and it didn't matter much as the boilers oftern ran flat out with water temperatures up to or enev above 80 degrees C. Boilers were often oversized - so they short cycled, and efficiencies were not considered. Converting such old systems to run with heat pumps is a complete minefield, and they mostly will not run efficiently at low temperatures as there will be insuffficient energy within the water in the system and again as Ken said the flow rate has to be increased drastically to try and make up for this difference, with the old rad's changed out for much larger more efficient radiators, to try and extract the max energy from the flow.... However if the pipe size is too restrictive, you can't get the correct flow rates!
www.youtube.com/@UrbanPlumbers also seems to know what he's talking about and is often saying there is too much control taking place even in new installations. This one in particular may apply to you: ua-cam.com/video/AXamAjE0juw/v-deo.html. When assuming you can achieve sufficient flow rates, and the radiators are right sized for the flow temperature, then balancing the system can often lead to high COP and even temperatures thoughout. Especially with underfloor heating, Mixing valves are not desirable or necessary with flow temperatures of 55 degrees or less, instead making sure the correct flow rate per loop is achieved to result in the correct amount of energy/loop being realised. This ensures the water temperature flowing back to the heat source is also optimised, and hence the source is able to pump the correct amount of energy back into the system without throttling down it's output.
I wish you and Ken good luck with sorting out all the problems. Maybe being an older property it's possible to re-engineer some of the pipework under the floor - I crawled under my parents floor as a kid doing pipework for my dad, so dependant upon access and trhe height of the joists.... who knows. P.S. I'm 64 now, so probably wouldn't fit anymore and wouldn't want to do that sort of thing in any case!
Top man is our Ken.
Sadly this type of install is far too common, chuck a heat pump in and dont do any design inside thouse.
If you are getting quotes heat loss and internal design and commission is needed as part of the qutation.
Im a tech support engineer for Stiebel Eltron and we can help with all this side.
That is too true. Countless cases like ours in the forums: renewableheatinghub.co.uk/forums
But Ken is a top guy, so we’re in safe hands. To complicate matters, our heat pump might now also be undersized which is also an all too common issue.
@@RenewableHeatingHubWell if this proves to be true - it may only be true for x weeks per year - Ken should be able to determine that and if x =small, then supplemental heating may be cost effective rather than upgunning on the heat pump.
@@normanboyes4983 Don't change the HP if it's undersized! Supplimental heating is a much better idea than sizing for the two coldest weeks of the year. Usually nobody does this with a heat pump because MCS regs forbid it for the BUS grant. I'd strongly advise you to add a small (cheap) minisplit a/c unit into the house a) for supplimental heating b) for redundancy c) for cooling. You might actually find it's all you need for most of the year.
Hi Mars. Sorry your ASHP not working out as you hoped. I’ve followed your discussions and selection and installation progress. You interviewed me on your channel about my ASHP. And I continue to post my ASHP SCOP and running costs on your Renewable Heating Hub information site. So I’m slightly surprised by your system revelations. I don’t know the chap discussing your installation having undertaken a review. He sounds sensible and knowledgeable. But please seek alternative views. That’s my top tip. Given your knowledge and experience (perhaps it came after your installation) I was wondering why you didn’t enquire about all your system components? Numbers of pumps. Valves. Controls on controls. Good luck with the investigations. What about the original installers? Why did they make it so complex? There are definitely two schools of ASHP: ones who fit buffer tanks and those that don’t.
That chap is Ken Bone, he is one of the best in the UK, in fact Elite status. Kind of like the Special Forces of Heat Pumps, I think you get the picture. JK
Well put - Ken will love that reference! 😂
It's definitely been a slog for us Julian. Mediocre installation at best. We've identified so many things over the years as we've educated ourselves on what comprises a good system, but weren't confident to assign the work to anyone that would potentially bodge it further. So we're over the moon to connect with and get Ken to do the work - he's a top installer.
To answer your question, previous installers just didn't have the skills or the knowledge to fix it. Their solution to everything was just add another distribution pump, which is why our utility room looks like a Grundfos showroom.
@@RenewableHeatingHub Credit where it's due. Personally I have been blocked on twitter by Ken during a heating argument, but I'm still one for giving credit where it's due regardless of personal circumstance or moments of anger. Jay K.
The greatest thing since sliced bread last week.They have that many excuses don’t they I can bring another guy that says micro bore.Designed they just rammed mine in disconnected my Combi and have put two different heat pumps in and ran away.First one DearDear swooped it for another one and Dear Dearer haha I kid you not.All fitted from start to finish by MCS accredited so called TRADESMEN MCS waste of time.