Pipe Work Question?
I'm in that common situation where after having a heat pump installed and the performance isn't great, I've dived into youtube and forums like this only to realise that maybe my installer didn't design/install/set up the system particularly well.
I'm in a good situation that I still owe them over £600 for some of the work, which means I can hold that over them. The question I have is about the main pipe work for the flow and return from the HP unit. I have a 3.5m section in my loft that is plastic 22mm pipe, not copper like all the other pipe work. I understand that this will have reduced internal diameter and thus flow, maybe costing me efficiency. Should I hold back final payment and insist this is changed (along with a few other niggles I've found) or is it minor enough not to worry about?
(should add Samsung Gen6 8kw, on two bedroom victorian mid terrace)
Samsung Gen6 8kw ASHP in a two bed victorian mid terrace.
I think the 22mm plastic pipe might be a bit small for 8kw. 22mm copper is considered ok for 5kW I think. This link gives more detail. https://www.heatgeek.com/does-my-pipework-need-upgrading-for-a-heat-pump-with-cheat-sheet/
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
The issue with the 22mm plastic piping in your loft could potentially impact the efficiency of your heat pump system, especially if it differs from the rest of your installation in terms of diameter. We have this issue where the previous owners “narrowed” the pipework when they extended the heating to the north end of the house, creating a bottleneck which I think is the major issue that the rads at the far end of the house struggle.
Did your installers run all the pipework for your system - copper and the 3.5m run in the loft?
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 Yes so the pipe work from the HP that runs externally to the loft is copper, then the pipe work runs length of loft to the other end where the DHW tank is, that section inside the loft is plastic. I need to measure accurately to check diameters, but im fairly certain that it’s the same as the copper pipes.
Thinking about it now, all l the pipe work externally from the HP is insulated, I’ve assumed it copper, but don’t know for sure, I might have to check that.
Samsung Gen6 8kw ASHP in a two bed victorian mid terrace.
There is a good video explaining the pipe sizing issue here
https://renewableheatinghub.co.uk/forums/postid/29119
House-2 bed partial stone bungalow, 5kW Samsung Gen 6 ASHP (Self install)
6.9 kWp of PV
5kWh DC coupled battery
Blog: https://thegreeningofrosecottage.weebly.com/
Heatpump Stats: http://heatpumpmonitor.org/system/view?id=60
Posted by: @ecobakerI'm in that common situation where after having a heat pump installed and the performance isn't great, I've dived into youtube and forums like this only to realise that maybe my installer didn't design/install/set up the system particularly well.
I'm in a good situation that I still owe them over £600 for some of the work, which means I can hold that over them. The question I have is about the main pipe work for the flow and return from the HP unit. I have a 3.5m section in my loft that is plastic 22mm pipe, not copper like all the other pipe work. I understand that this will have reduced internal diameter and thus flow, maybe costing me efficiency. Should I hold back final payment and insist this is changed (along with a few other niggles I've found) or is it minor enough not to worry about?
(should add Samsung Gen6 8kw, on two bedroom victorian mid terrace)
That's too tight IMO, we would use 28mm copper, or 32mm MLCP
Technical Manager & Professional Installer: Ultimate Renewables
- 22 Forums
- 2,055 Topics
- 44.8 K Posts
- 21 Online
- 3,289 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
-
Win a 6-panel PV courtesy of egg and Renewable Heating Hub
Our epic giveaway just went live! Want to win a 6-pan...
By Mars , 7 hours ago
-
RE: Yes, the "zoning with ASHP" topic again...
James, thanks again for your thoughtful and persistent ...
By HarryRea , 7 hours ago
-
RE: Getting the best out of a heat pump - is Homely a possible answer?
Isn't that the whole point of homely - it does that fun...
By Johnmo , 9 hours ago
-
RE: Is this normal? Click of the DHW returning to space heating
So the Lone Ranger returned today! Even though we thoro...
By Grantmethestrength , 10 hours ago
-
RE: How To Balance Radiators & the Role of the Lockshield Valve: A Homeowner's Guide
@jamespa So settings to date are as follows for now. ...
By Alfapat , 10 hours ago
-
RE: Vaillant & OVO partner up to offer Heat Pump Plus
Hopefully iv done the right thing today by signing up t...
By Westkent , 12 hours ago
-
RE: IVT Greenline high pressure switch and electrical cassette errors
Hi, are you able to see the delta between GT8 vs GT9 te...
By abbote , 12 hours ago
-
RE: Battery sizing - How low can you go!
My own experience with connecting four batteries to thr...
By Transparent , 19 hours ago
-
RE: Plate heat exchanger considerations
Work on 2-3 percent per degree. This is a reasonable e...
By JamesPa , 1 day ago
-
RE: Advice for ground source heat pump in new build with PV and batteries
The useful bit is the bit that specifies the heat loss ...
By JamesPa , 1 day ago
-
RE: Volumisers in Heat Pump Systems: Does Placement Matter?
You’re absolutely right that during defrost the refrige...
By Mars , 1 day ago
-
@editor thanks Mars that’s the same table I found in th...
By Gary , 2 days ago
-
RE: Tariff and charging strategy advice please
They haven't asked me to prove that I have an EV (I do)...
By JamesPa , 2 days ago
-
RE: Solar Power Output – Let’s Compare Generation Figures
Took a while to find on the OFGEN site: ”The FIT sche...
By AgentGeorge , 2 days ago
-
RE: why solar diverters for HW instead of the heat pump?
For me there are few factors why you may want to heat w...
By Johnmo , 2 days ago
-
RE: Hydronic plinth heaters and ASHPs
@editor yes I think so. It will be a while until I get ...
By benson , 2 days ago
-
RE: Aira Heat Pump: Stylish Scandinavian Heating
I’m an Aira customer with a 6kW Outdoor Unit in a small...
By KevinPotts , 2 days ago
-
RE: Is your heat pump insured?
@richard24738 good to hear. I’ll also review them this ...
By Mars , 2 days ago
-
RE: Warm weather and heat pumps.
Just looked at my WC setting, it is programmed for 25 D...
By Johnmo , 2 days ago