@editor By the way, Performance of the heat pump (COP) has nothing to do with how leaky your house is. It has to to with the distribution system and how you controll it.
Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.
@heacol, that's a good point about COP and leakiness.
Our issue was heat emitters - when we added Stelrad K3s it made a world of difference in the coldest rooms in the house. K2s in the southern end have been adequate, and UFH has always been great.
Derek has been hammering at me and our weather compensation which we haven't been able to get working properly because the main controller (which reads the temperature) is inside the HW cupboard and it's always very warm in there. So I just set our flow rate manually. It's actually at 40C now (it was set to 35C), and will try to get through the winter at that temperature. We also have a bivalent system, so I've set up our oil boiler to take over heating when temps drop below 8C – the only reason I've done this is because of the insane price of electricity, so it's a bit of a balancing act. The oil boiler has been set to its lowest possible temperature to allow it to condense.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
Posted by: @editorPosted by: @heacol@editor Low flow temperatures = low bills. It realy is that simple.
Fabric first to achieve low flow temperatures I guess. Our insulation is good to very good, but we still leak some heat. Getting better though.
Hi Mars,
I am beginning to wonder if anyone bothers to read the information that I provide. Having been a Control Systems Engineer for over 50 years and worked on and designed systems for power stations and oil and gas processing plants, thermostats would only be used on the systems of low importance. The problem with using thermostats in home heating systems is that they normally have a deadband of 1C, which means that to maintain a comfortable temperature within the home, they are normally set higher than would need to be if continuous process control was used instead of a thermostat.
To confirm the point that Brendon and I have been repeatedly making, for maximum efficiency an ASHP needs to be operating at the lowest water flow temperature that is consistent with maintaining the desired indoor air temperature. At the moment, with an outside air temperature of 12C, our radiators are cold to the touch, with our heating system in full operation maintaining an indoor temperature of 21C. When the outside air temperature falls to 6C, the radiators are only just warm to the touch.
If you take the trouble to look at the spreadsheets and results that I posted several weeks ago, you will see that ASHP efficiency is most affected by outside air temperature, indoor set temperature, heat loss (level of imsulation) and size of heat emitters.
Even the most expensive, supposedly intelligent heating controls, are not often used correctly with heating system that employ an ASHP.
@derek-m, I always take on board what you write. The issues that arise, in our case anyway, is that we've asked Global Energy Systems several times to activate weather compensation and they say that due to the way that our system was installed and wired (as a retrofit) it's not possible. We did try to it in that mode a few months ago (when you first suggested it) and it didn't work at all well. So we've reverted back to manually tweaking it.
The decrease in flow from 45C to 40C has resulted in our COP going up to 3.1 from 2.7 – the house is plenty warm at this flow temperature. I suspect a drop to 35C may be a stretch a too far at this time of year.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@derek-m Thanks, I also feel like I am banging my heat against a brick wall. However, If one person listins, they may tell another and maybe the mssage will get out.
Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.
@editor Mars, Maybe you need to re-design your system. There is probably not much to alter to get good performance. If you send me some information, I will help.
Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.
@editor Weater compensation has nothing to do with the internal temperature. Do you have timers, TRV's on all radiatrs and a buffer tank or system seperation with 4 pipes?
Director at Heacol | Expert Heat Pump Consultant | Book a one-to-one consultation for pre- and post-installation advice, troubleshooting and system optimisation.
@heacol. Thanks Brendan. We probably have too many controllers and smart thermostats, which is probably an oil boiler mentality, and this prohibits us from having a single controller which could make weather compensation work. I also don't know how good Global Energy System's weather compensation logic is to be honest.
Another good example of the importance of system design – ours was "designed" by the sales guy, and this is an issue that the industry is also facing in my opinion. Systems that are sold by sales people, and that are installed by companies that take the sales reps 'recommendations', which leads to systems that are not fully functional.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
Posted by: @heacol@editor Weater compensation has nothing to do with the internal temperature. Do you have timers, TRV's on all radiatrs and a buffer tank or system seperation with 4 pipes?
Not sure what you mean by timers. Smart TRVs on all rads. Yes, we have a buffer tank. We also have three smart thermostats for UFH (in three zones) and three smart thermostats to call for heat for radiators.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@editor Hi Mars,
Sorry to hear about your foot, hope that it heals quickly.
I fully appreciate your problem in that your controller has been incorrectly located, but your installers should have been aware that this would pose a problem when they installed it. It is also bad practice to install electronic equipment in warm locations, which can adversely affect their operating life. For large control systems the panels would be located in air conditioned rooms.
Some of the other manufacturers provide remote sensors, both hardwired and wireless, you could ask your supplier if they can provide such a device. The alternative would be to relocate either the controller or the internal sensor.
For optimum efficiency of your ASHP, you should lower your water flow temperature to a level at which your ASHP is operating more frequently, for longer periods of time, and only increase the water flow temperature setting when it can no longer meet the heat demand. At the end of the day it is your choice.
My earlier comment about being ignored is in relation to quite a number of posts to which I have responded recently and there has been no response. I therefore wonder if I am wasting my time when there are still members who continue to switch the heat pumps on and off.
Posted by: @heacol@derek-m Thanks, I also feel like I am banging my heat against a brick wall. However, If one person listins, they may tell another and maybe the mssage will get out.
I appreciate your efforts and patience – when you're familiar with the way something works, it's easy to get frustrated when people don't get it. Heat pumps, maybe because they're not always installed properly, take getting used to. For us, it's been a huge learning curve, and I see comments all the time where homeowners are tweaking them because they're not running as they should. But I can understand your frustrations.
I think more companies should be forced to provide 'designs' with their proposals, as opposed to a sales guy (I speak to our experiences) looking at the rads and house and saying, "yeah, no problem, the heat will replace your boiler. No problem." When the system's installed, its only then that the issues surface.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@derek-m, thanks Derek. In our case, the installers asked us if we wanted to "keep things as they were" – the answer from us was yes, because this is what was recommended to us. So they replaced the boiler controller with the heat pump controller – in hindsight, it was the easiest solution with the least amount of work which is why they were happy to do that. Locating the heat pump controller to say the hallway would have been a lot more work, which was never suggested or recommended at any point.
Essentially, we had our oil boiler replaced by an air source heat pump, with no other changes to the system. And this is not the right approach, but as homeowners that know very little about such matters, you rely on the expertise of installers – this is also why we went down the MCS-accredited route.
Much more heap pump education is required to empower homeowners in my opinion.
Buy Bodge Buster – Homeowner Air Source Heat Pump Installation Guide: https://amzn.to/3NVndlU
From Zero to Heat Pump Hero: https://amzn.to/4bWkPFb
Subscribe and follow our Homeowners’ Q&A heat pump podcast
-
Help with understanding my Mitsubishi Ecodan air source heat pump
1 week ago
-
Efficiency Concerns on newly installed Mitsubishi Ecodan 8.5kW
2 weeks ago
-
Ecodan consuming 100kwh per day in new build!!!
3 weeks ago
-
Have Consumers Been Lied to About the Efficiency of Heat Pumps Made in China?
2 months ago
-
Running my new Nibe ASHP efficiently
3 months ago
- 22 Forums
- 2,046 Topics
- 44.6 K Posts
- 90 Online
- 3,273 Members
Join Us!
Trusted Installers
Struggling to find a reliable heat pump installer? A poor installation can lead to inefficiencies and high running costs. We now connect homeowners with top-rated installers who deliver quality work and excellent service.
✅ Verified, trusted & experienced installers
✅ Nationwide coverage expanding
✅ Special offers available
Latest Posts
-
RE: Renewables & Heat Pumps in the News
No, sorry it's not. It was a press call*. Plus I think...
By Lucia , 7 minutes ago
-
@editor I had my second ‘Annual Service’ carried out by...
By Toodles , 1 hour ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
@grahaml I cannot agree that it is a small percentage o...
By benson , 13 hours ago
-
RE: Warm weather and heat pumps.
You’re welcome @lucia - thanks for watching. I’ve alway...
By Mars , 15 hours ago
-
RE: Commencing on an ASHP Installation Process
In that case treating it as a separate space seems emin...
By JamesPa , 20 hours ago
-
For me, the Questions are here: 1) Does a Volumiser t...
By iantelescope , 1 day ago
-
RE: Yes, the "zoning with ASHP" topic again...
This aspect of control is a bit variable from manufactu...
By JamesPa , 1 day ago
-
RE: Samsung Gen6 16kW tribulations
@emceed, can you please give us an update on your syste...
By Mars , 2 days ago
-
RE: ASHP Ecodan L9 error - No Heating but Hot Water
@phoenix15 Sorry to hear that, we are all the way down ...
By ASHP-BOBBA , 2 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
@editor Well last MAY i know was not the greatest for s...
By Andris , 3 days ago
-
What's the problem you are trying to solve. The answer...
By JamesPa , 4 days ago
-
Good luck. For what it is worth my system was very def...
By JamesPa , 4 days ago
-
RE: Massive Electricity Cost for Running My Air Source Heat Pump
I agree @mark-h The Building Regs are now very readable...
By Transparent , 5 days ago
-
RE: Help me understand my Mitsubishi Ecodan system
@carpenterstation When changing settings in the ser...
By RobS , 5 days ago
-
RE: Ecodan Legionella cycle - immersion heater problem
Thanks for letting us know @clockworks I admire your ...
By Transparent , 6 days ago
-
RE: Revised version of MCS-020 (noise standards for heat pumps)
As you say this is no change, which I personally think ...
By JamesPa , 6 days ago
-
RE: What happens when the outside temperature exceeds the upper WC point?
@editor not via the WC curve but as @old_scientist ment...
By bontwoody , 6 days ago
-
RE: MHHS and Heat Pump compatibility
@toodles to be clear I don't know if there will be a re...
By Scalextrix , 7 days ago
-
I did not know this concept, although others might. I...
By Morgan , 7 days ago