Excellent discussion… so glad I removed our buffer tank. We needed to learn about energy carrying capacity of a few short runs of microbore within the existing few rads but everything now runs effectively down to 35c LWT using one circ. pump. Installer agreed to make changes FOC. (4 bed house, 8.5 ecodan, 15 rads twin coil 250L unvented tank.) cop 3.8 to 4.2 but possibly up to 18% underestimated efficiency as MELCloud sourced info. Perhaps manufacturers need to review and improve their own brand performance reporting as they are probably inadvertently damaging their own brand!
Hydronic design expert here. I've enjoyed the discussion, but it seems there are quite a few solutions that haven't been considered-like 2-port buffers (not volumisers), for instance. However, rather than focusing on that, I sense there's a lack of clarity about the primary goals of any heat pump installation. Is the aim efficiency (and if so, is it efficiency over the heating season or throughout the year)? Is it comfort and control? Or is it reliability across the lifespan of the unit? The answer, of course, is that it's all of these. But the challenge with retrofitting heat pumps is that these objectives aren't always aligned. For example, achieving high efficiency doesn’t necessarily guarantee good control-after all, the most efficient heat pump is one that’s turned off. I appreciate the open exchange of knowledge, but let’s make sure we’re not missing the forest for the trees.
Thanks for explaining the difference between a buffer and a volumiser I'm not sure if I have never had this explained before or not. Maybe just with all the info that gets thrown at you as a heat pump owner maybe I just never understood. Some thing I'm still not quite sure about though is can a volumiser have a negative impact on efficiency with a radiator only system no under floor if so can it be significant?
I can store energy in the accumulation tank when the kwh price is cheaper or when there is a lot of solar energy. The thing is that you need a shunt motor valve to regulate your heating curve. And a regulator connected to octopus say to the heatpump when to produce heat.
HI guys great content, very useful I am in the buying process at the moment. Do I need a buffer tank if I have a cascade system 2 x 10 KWh . Also I have a large house 300 Square meters. If a 18 KWh AHP could work would this be better than 2 x or 9 KWH..
According to Simon: “The client does not need a buffer for this system. We are actually installing a similar system on open loop, 2 10kw Vaillants. Our design is to size a distribution header on the flow and return. in our case this is 76mm pipe with both heat pumps flow plumbed into the same pipe and the same with the return. That pipe then changes to 35mm at the house which is what’s needed to meet the pressure drop and transport 20kw of energy around the system. It’s all open loop. Very unlikely to find an 18kw heat pump that actually doesn 18kw at dot say -3 with any flow temp….even 35 degrees. I think Clivet do one but that’s about it. It won’t be a patch on the efficiency of a well designed vaillant cascade.”
@@RenewableHeatingHubI need to see a video on this install, done quite a few cascade vaillant but always used the hex module this seems like an interesting approach.
Can I ask the definition of "open loop"? Does that mean emitters just have fully open pipework and lock shields are all wide open, or is flow restricted for balancing purposes? I assume there must be balancing of the emmiters or parts of the system farthest from the heat source wont get warm. Or is design that areas wanting warmer temperatures should be first in the routing of an open loop system?
Homely (an AI system to manage the heat pump) doesn’t work with a buffer tank. It needs the flow and return temperatures to accurately determine the efficiency of the system and the buffer tank disrupts its algorithms. Once we got written confirmation from Homely, and agreement from Midea that removing the buffer tank wouldn’t affect the warranty, the installer removed the buffer tank . COP then improved.
This is interesting I was considering I have a buffer 😕 so maybe a waste of time then. My circulation pump in the loft is loud and set to full speed. The Midea app and controller is pants 😅 The info on it is awful and probably inaccurate. My installer doesn't want anything to do with the noise produced... And will charge me to remove the buffer to try open loop...
A great scop on an open loop system is great for the vain plumbers. My hp is switched on and off to make me comfortable. It costs a lot less to run than leaving it on all the time. BUT my scop is a bit less Scop is a vanity project
Ultimately run it according to your means and comfort that's all that counts at the end of the day. In winter we have ours on all day on the stat and that's by far cheaper than setting schedules. We do have a schedule set for a higher temp overnight downstairs with the much cheaper rate to warm the house up for the following day
Sure, in new systems, there's no excuse for using any unnecessary components but, buffers shouldn't become extinct. There are always going to be outlying cases in retrofits where it's possibly the only realistic option. I thought Simon was going to touch on this at one point, when he started talking about and pressure loss. How would he deal with microbore embedded in walls when the pressure drop of the index circuit it too great for the ASHP's internal pump? There are plenty of 70's and 80's properties where re-piping the whole place is just not a realistic option. Even more recent properties with plastic microbore. What if the customer doesn't want their property ripped apart because "it will be more efficient". Spend a bit extra each year on your heating bill, or spend thousands extra getting half the property re-piped and redecorated.
Production critique: please ask the folks with laptops to stop banging the table the laptop is sitting on. Their jiggling cameras are giving me a headache. The guy in the top left and top right keep doing it and it's not great.
😂 This was our launch episode and we learned a lot from a production perspective, from jiggling cameras, to audio feedback to lighting. We're recording our next video next week, and have a long list of dos and don'ts
Wow, so dangerous, yes heat pumps are inverter driven and hence output is variable, radiator/emmitor demand is variable, the two however are rarely equal, this is why you're promoting an "open loop". No discussion on compressor wear when buffer vessels are not installed. If you want a heating system you can control and one you can rely on use a buffer, use zone control on your heating. Decoupling your heat pump fro. Your home is one of the most critical aspects, what is being promoted here is saving cost on a buffer and piping to enable volume install.
This video had the potential to spark a great debate on heat pump system design. Unfortunately it was the equivalent of Question Time with a panel of MP’s from the same party…… Maybe next time do it with Brendon and Ken Bone, Paul Spence, a manufacturer and maybe a Heat geek…….now that would make for a much more diverse conversation. 🤣
Thanks for the feedback. As mentioned during the video, I invited over a dozen installers that I know are pro buffer tank to have that diversity in the conversation. They declined to come on. But I take your point. This was a test run, and we have Heat Geek and manufacturers lined up for other videos.
It's taking shape. It's a matter of scheduling. These are all busy guys with schedules that don't align a lot of the time. They're all on board to do it, and we're aiming to get it done in mid to end October if all goes well.
A very bias panel of people in this discussion that seam to single out certain business yet there are hundreds of company's large and small that are installing buffers for one reason or another, yet you assume they are bad installs! has any one you reached out to these bigger company's to find out why they are using the installation type they are ? as for this constant comparison of SCOP's there are hundreds of reasons why a SCOP could be low. Poor insulation, old windows etc and not always due to buffers. All these types of discussions are causing is more customer uncertainty. Why not show some positivity to what some of these company's are doing like enabling customers with any financial backing the chance to have a heat pump. lower tariffs and helping turn the industry from gas to renewables.
We invited over a dozen installers that fit buffers to have an objectives conversation. They all declined. I can’t force people into the show. But we will revisit this in a few months time.
@@RenewableHeatingHub Do you blame them i would have to ask " who the hell are you" bar a few designers/installers that have an opinion. you should never have made a podcast without getting the facts first!
In any of those circumstances you shouldn't be fitting a heatpump tho. First thing you fix is all of that stuff fitting a heatpump with poor insulation, old windows etc is just asking for trouble.
@@paulcornock8287who the hell do you think you are shouting from the cheap seats? It's really easy to sit behind a keyboard and moan about something harder to join the conversation and constructively put your point across without sounding like a butt hurt installer who has taken everything as a personal attack.
Excellent discussion… so glad I removed our buffer tank. We needed to learn about energy carrying capacity of a few short runs of microbore within the existing few rads but everything now runs effectively down to 35c LWT using one circ. pump. Installer agreed to make changes FOC. (4 bed house, 8.5 ecodan, 15 rads twin coil 250L unvented tank.) cop 3.8 to 4.2 but possibly up to 18% underestimated efficiency as MELCloud sourced info. Perhaps manufacturers need to review and improve their own brand performance reporting as they are probably inadvertently damaging their own brand!
Hydronic design expert here.
I've enjoyed the discussion, but it seems there are quite a few solutions that haven't been considered-like 2-port buffers (not volumisers), for instance.
However, rather than focusing on that, I sense there's a lack of clarity about the primary goals of any heat pump installation. Is the aim efficiency (and if so, is it efficiency over the heating season or throughout the year)? Is it comfort and control? Or is it reliability across the lifespan of the unit?
The answer, of course, is that it's all of these. But the challenge with retrofitting heat pumps is that these objectives aren't always aligned. For example, achieving high efficiency doesn’t necessarily guarantee good control-after all, the most efficient heat pump is one that’s turned off.
I appreciate the open exchange of knowledge, but let’s make sure we’re not missing the forest for the trees.
Thanks for explaining the difference between a buffer and a volumiser I'm not sure if I have never had this explained before or not.
Maybe just with all the info that gets thrown at you as a heat pump owner maybe I just never understood.
Some thing I'm still not quite sure about though is can a volumiser have a negative impact on efficiency with a radiator only system no under floor if so can it be significant?
Love the point that efficient heat pumps protect grids from requiring reinforcement. This point needs to get to DESNZ, ENA, DNOs and NESO
Thoroughly enjoyed this, thanks for the informative discussion
Thank you. Glad you found it interesting.
I can store energy in the accumulation tank when the kwh price is cheaper or when there is a lot of solar energy. The thing is that you need a shunt motor valve to regulate your heating curve.
And a regulator connected to octopus say to the heatpump when to produce heat.
HI guys great content, very useful I am in the buying process at the moment. Do I need a buffer tank if I have a cascade system 2 x 10 KWh . Also I have a large house 300 Square meters. If a 18 KWh AHP could work would this be better than 2 x or 9 KWH..
According to Simon: “The client does not need a buffer for this system. We are actually installing a similar system on open loop, 2 10kw Vaillants.
Our design is to size a distribution header on the flow and return. in our case this is 76mm pipe with both heat pumps flow plumbed into the same pipe and the same with the return. That pipe then changes to 35mm at the house which is what’s needed to meet the pressure drop and transport 20kw of energy around the system. It’s all open loop.
Very unlikely to find an 18kw heat pump that actually doesn 18kw at dot say -3 with any flow temp….even 35 degrees. I think Clivet do one but that’s about it. It won’t be a patch on the efficiency of a well designed vaillant cascade.”
@@RenewableHeatingHubI need to see a video on this install, done quite a few cascade vaillant but always used the hex module this seems like an interesting approach.
Can I ask the definition of "open loop"?
Does that mean emitters just have fully open pipework and lock shields are all wide open, or is flow restricted for balancing purposes? I assume there must be balancing of the emmiters or parts of the system farthest from the heat source wont get warm. Or is design that areas wanting warmer temperatures should be first in the routing of an open loop system?
Homely (an AI system to manage the heat pump) doesn’t work with a buffer tank. It needs the flow and return temperatures to accurately determine the efficiency of the system and the buffer tank disrupts its algorithms. Once we got written confirmation from Homely, and agreement from Midea that removing the buffer tank wouldn’t affect the warranty, the installer removed the buffer tank . COP then improved.
This is interesting I was considering I have a buffer 😕 so maybe a waste of time then.
My circulation pump in the loft is loud and set to full speed.
The Midea app and controller is pants 😅
The info on it is awful and probably inaccurate.
My installer doesn't want anything to do with the noise produced... And will charge me to remove the buffer to try open loop...
A great scop on an open loop system is great for the vain plumbers. My hp is switched on and off to make me comfortable. It costs a lot less to run than leaving it on all the time. BUT my scop is a bit less
Scop is a vanity project
renewableheatinghub.co.uk/heat-pump-scop-arms-race
Ultimately run it according to your means and comfort that's all that counts at the end of the day. In winter we have ours on all day on the stat and that's by far cheaper than setting schedules. We do have a schedule set for a higher temp overnight downstairs with the much cheaper rate to warm the house up for the following day
Sure, in new systems, there's no excuse for using any unnecessary components but, buffers shouldn't become extinct. There are always going to be outlying cases in retrofits where it's possibly the only realistic option.
I thought Simon was going to touch on this at one point, when he started talking about and pressure loss.
How would he deal with microbore embedded in walls when the pressure drop of the index circuit it too great for the ASHP's internal pump?
There are plenty of 70's and 80's properties where re-piping the whole place is just not a realistic option. Even more recent properties with plastic microbore. What if the customer doesn't want their property ripped apart because "it will be more efficient".
Spend a bit extra each year on your heating bill, or spend thousands extra getting half the property re-piped and redecorated.
I think you should have invited HeatGeeks or UrbanPlumbers 👍
We have extended invites to a lot of installers. We're going to have Heat Geek on future videos.
James Clarke is a "Heat Geek Elite" and has featured in at least one Heat Geek channel video...
Good point. Simon Murray is also a Heat Geek. I assumed Chandre meant some from Heat Geek like Adam.
Production critique: please ask the folks with laptops to stop banging the table the laptop is sitting on. Their jiggling cameras are giving me a headache. The guy in the top left and top right keep doing it and it's not great.
😂 This was our launch episode and we learned a lot from a production perspective, from jiggling cameras, to audio feedback to lighting. We're recording our next video next week, and have a long list of dos and don'ts
Wow, so dangerous, yes heat pumps are inverter driven and hence output is variable, radiator/emmitor demand is variable, the two however are rarely equal, this is why you're promoting an "open loop".
No discussion on compressor wear when buffer vessels are not installed.
If you want a heating system you can control and one you can rely on use a buffer, use zone control on your heating.
Decoupling your heat pump fro. Your home is one of the most critical aspects, what is being promoted here is saving cost on a buffer and piping to enable volume install.
Most installers won't omit a Buffer from their system......what then?
That's the million dollar question.
This video had the potential to spark a great debate on heat pump system design.
Unfortunately it was the equivalent of Question Time with a panel of MP’s from the same party……
Maybe next time do it with Brendon and Ken Bone, Paul Spence, a manufacturer and maybe a Heat geek…….now that would make for a much more diverse conversation. 🤣
Thanks for the feedback. As mentioned during the video, I invited over a dozen installers that I know are pro buffer tank to have that diversity in the conversation. They declined to come on. But I take your point. This was a test run, and we have Heat Geek and manufacturers lined up for other videos.
@@RenewableHeatingHub Now that will be valuable - when is it likely to happen?
It's taking shape. It's a matter of scheduling. These are all busy guys with schedules that don't align a lot of the time. They're all on board to do it, and we're aiming to get it done in mid to end October if all goes well.
A very bias panel of people in this discussion that seam to single out certain business yet there are hundreds of company's large and small that are installing buffers for one reason or another, yet you assume they are bad installs! has any one you reached out to these bigger company's to find out why they are using the installation type they are ? as for this constant comparison of SCOP's there are hundreds of reasons why a SCOP could be low. Poor insulation, old windows etc and not always due to buffers. All these types of discussions are causing is more customer uncertainty. Why not show some positivity to what some of these company's are doing like enabling customers with any financial backing the chance to have a heat pump. lower tariffs and helping turn the industry from gas to renewables.
We invited over a dozen installers that fit buffers to have an objectives conversation. They all declined. I can’t force people into the show. But we will revisit this in a few months time.
@@RenewableHeatingHub Do you blame them i would have to ask " who the hell are you" bar a few designers/installers that have an opinion. you should never have made a podcast without getting the facts first!
Can you please specify what you found factually inaccurate?
In any of those circumstances you shouldn't be fitting a heatpump tho. First thing you fix is all of that stuff fitting a heatpump with poor insulation, old windows etc is just asking for trouble.
@@paulcornock8287who the hell do you think you are shouting from the cheap seats? It's really easy to sit behind a keyboard and moan about something harder to join the conversation and constructively put your point across without sounding like a butt hurt installer who has taken everything as a personal attack.