Help me optimise my ASHP Pipework
I've got a Nibe F2040 ASHP which has been installed for over a year now.
Whilst trying to optimise the system I've wondered if the buffer is causing me issues.
See attached drawing of my system. I have noticed that the pipework at point '1' is cooler than at point '2' and '3'.
The PWM motor is controlled by the Heat Pump to maintain a deltaT and the other 2 pumps are fixed speed (currently setting 2).
Does anyone have any suggestions on how I can better match the circulation pumps to the HP, or how I can prevent the mixing in the buffer.
I'm tempted to ask my installer to add a couple of valves to the top and bottom of the buffer so I can try isolating this completely?
I would suggest that you check your schematic, since it appears to make little sense. A buffer tank would normally have at least 4 connections, 2 in and 2 out. I also don't understand why pipe '1' would be cooler than pipes '2' and '3', if the direction of flow is as shown.
There is often an arrow on the pump body to indicate the direction of flow.
The schematic is correct as drawn and the buffer is Tee'd off the pipework that then goes towards the other 2 pumps.
Apologies pipe '1' was meant to say warmer not cooler.
What is the temperature difference?
Looking at the schematic, I suspect that the combined flow rate through the two pumps on pipes '2' and '3' is greater than the pump on pipe '1'. This will probably have the effect of drawing the cooler water in the return pipe, through the buffer tank, and hence causing it to mix and cool the water from the heat pump. Try reducing the speed of the pumps on pipes '2' and '3' to see if this increases the temperature in the aforementioned pipes.
@luke remove the buffer and it will work properly. The schematic is not a Nibe 2040 configuration. There is no need for the buffer. If you have a blending valve and pump on your under floor manifold, this should be removed and, firstly, I would try to run the system on a single temperature with the internal sensor to control the house temperature, if that does not have adequate control, then set up 2 separate zones through the controller.
Professional heat pump installer: Technical Director Ultimate Renewables Director at Heacol Ltd
Posted by: @derek-mWhat is the temperature difference?
Looking at the schematic, I suspect that the combined flow rate through the two pumps on pipes '2' and '3' is greater than the pump on pipe '1'. This will probably have the effect of drawing the cooler water in the return pipe, through the buffer tank, and hence causing it to mix and cool the water from the heat pump. Try reducing the speed of the pumps on pipes '2' and '3' to see if this increases the temperature in the aforementioned pipes.
I have slowed the pumps down to speed 1 and will report back. I'm not sure of the temperature difference, but it was noticeable by hand. I have access to a thermal camera so I'll get hold of this.
Posted by: @heacol@luke remove the buffer and it will work properly. The schematic is not a Nibe 2040 configuration. There is no need for the buffer. If you have a blending valve and pump on your under floor manifold, this should be removed and, firstly, I would try to run the system on a single temperature with the internal sensor to control the house temperature, if that does not have adequate control, then set up 2 separate zones through the controller.
I agree that ultimately I want the buffer removed or at least put in series as I don't think it has any benefit and we should have sufficient volume in the circuits.
There is no blending valve on the UFH manifold and I run the whole system in WC using the internal sensor to 'adapt' the curve. All TRVS open and heating circulation pump thermostat set as a max stop limit only.
Looking at the below schematic, my system is I believe a similar setup to this, excluding CP6 and EB1 and any associated valves / pipework. CP5 is shown as the buffer vessel (which in my case is a Nibe UKV 20-40)
When looking at that installation manual for the UKV it doesn't actually show my configuration with the buffer, which I would say is different to the SMO20 installer manual screenshot?
Here are a couple of pictures of my setup before it was finished and insulated.
@luke Your valve is fine, remove the items circled and you will have very good performance. You have plenty of system volume for the heat pump.
Professional heat pump installer: Technical Director Ultimate Renewables Director at Heacol Ltd
@heacol thanks for this. I will take these comments back to my installer.
May I ask why you would remove the TF1 filter for a strainer? Is this just to improve flow? Will there be other detrimental effects?
Also I presume you are saying that the system will run from just the charge pump as you are suggesting removal of both heating medium circulation pumps. (I like this idea as it will reduce base load, but I expect my installer will be hesitant to recommend this considering he installed both!)
@luke TF1 filter for a strainer? Is this just to improve flow? Will there be other detrimental effects? just to improve flow and stop parasitic losses. It will have no detrimental effect. It can be put back in parallel with the strainer if you are worried.
The installer will probably balk at removing them, but you are the customer.
Professional heat pump installer: Technical Director Ultimate Renewables Director at Heacol Ltd
- 25 Forums
- 1,438 Topics
- 30.2 K Posts
- 30 Online
- 1,224 Members
Join Us!
Latest Posts
-
RE: No-code, plug-and-play monitoring for your heat pump
I can't agree with this. A conventional forecast is a p...
By cathodeRay , 36 mins ago
-
RE: Is this a bad installation and is there something wrong with my Samsung heat pump?
@david999 I asked a few installers to look at your ques...
By Mars , 11 hours ago
-
RE: Samsung ASHP scheduling help
@elgreco69 worth reading the GitHub here as that will a...
By morh , 12 hours ago
-
RE: Aira Heat Pump: Stylish Scandinavian Heating
@ivanopinion where are you up to and have you made any ...
By Mars , 12 hours ago
-
RE: ASHP sizing - value of Heat Transfer Coefficient
@toodles Thanks for the explanation I get it now as I h...
By Jancold , 12 hours ago
-
RE: Questions about yearly heat pump maintenance
For the installer, I believe servicing and maintenance ...
By Majordennisbloodnok , 13 hours ago
-
RE: Rate the quality of your heat pump design and installation
@retrorich It is very worrying that any of this should ...
By Toodles , 17 hours ago
-
RE: Spacing for roof fixing bolts ?
There is another consideration...but alas this doesn't ...
By Transparent , 20 hours ago
-
RE: Air source heat pumps and noise
Yes, but when they go wrong things get really sticky. D...
By Majordennisbloodnok , 22 hours ago
-
RE: Noise problems with newly installed Samsung 8kW ASHP
Hi, Bit of an update. I bought a decibel meter and moni...
By Lokisam , 22 hours ago
-
RE: Incorrect Billing of Customers with a Smart Meter
I have provided them with a link to this discussion and...
By KoRWraith , 23 hours ago
-
RE: Are You Getting the Most Out of Your Renewable Energy?
As I mentioned, there are going to be some follow-up ar...
By Majordennisbloodnok , 24 hours ago
-
RE: Tell us about your Solar (PV) setup
Now, I know that this may be a little simplistic and pe...
By Toodles , 2 days ago
-
RE: Are Octopuses Slowing Consumer Adoption of Heat Pumps?
I find increasingly staggering that the MCS rules don't...
By JamesPa , 2 days ago
-
-
RE: Save the Energy Save the World using Daikin Altherma 3 operation mode and schedules settings.
Hello Mevl, I won't be able to answer all your question...
By HCas , 2 days ago
-
I have been watching, with interest, the rebuild and re...
By iantelescope , 2 days ago
-
RE: Making best use of Agile with a battery and ASHP
On the subject of automating battery charging schedules...
By jamesw , 2 days ago
-
Safety update; RCBOs supplying inverters or storage batteries
BEAMA have issued a safety update (March 2024) regardin...
By Transparent , 3 days ago
-
RE: Home energy storage & battery register
Hanchu ESS - Home-ESS-LV9.4K (9.4kWh)
By IRMartini , 4 days ago
Heat Pump Humour
Latest Topics
-
Spacing for roof fixing bolts ?
By heat-pump-newbie 4 days ago
-
ASHP sizing - value of Heat Transfer Coefficient
By jamesw 4 days ago
-
Incorrect Billing of Customers with a Smart Meter
By KoRWraith 6 days ago
-
Home energy storage & battery register
By Mars 7 days ago
-
Meter Readings - What are theses meters telling me?
By Potatoman 1 week ago
-
Have Octopus Energy discovered a way to Narnia?
By Davesoa 1 week ago
-
Making best use of Agile with a battery and ASHP
By jamesw 1 week ago