Stiebel WPL 25 heat pump in South Wales with no insulation
Stiebel WPL 25
South Wales
5 Bed Detached 1900s build with cavity Wales, no insulation
Underfloor heating downstairs, rads upstairs
EV, Solar, Batteries
That's an early date to find cavity walls in Wales @shaeney
The practice became widespread after the Great War.
What material is each leaf constructed from?
What feature(s) of the Stiebel WPL 25 made you opt for it?
Or was it the installer's preference?
Save energy... recycle electrons!
Ah, perhaps all that blubber helps to insulate …. (In the ‘cavity Wales’) Sorry, couldn’t resist! 😊 Regards, Toodles.
Toodles, heats his home with cold draughts and cooks food with magnets.
@transparent so its weird construction.
Double engineering brick outer wall and single skin inner wall. Our buyers inspection engineer said the walls were bombproof!
Makes for very deep window recesses.
Went for Steibel because the high efficiency and high output.
That's a really sturdy outer leaf!
It's unusual to find such an over-engineered approach... especially as it's the inner-leaf which supports the roof.
As for the Steibel - are you actually achieving the level of efficiency you were after?
Have you got a controller which tells you the COP?
Save energy... recycle electrons!
@shaeney welcome to the forums. So I simply must ask given the amount of articles that persist saying that heat pumps don't heat old buildings, especially with no/little insulation. Are you warm and what are your running costs like? Did the Stiebel replace an oil boiler?
Buy a copy of the The Ultimate Guide to Heat Pumps
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@editor Steibel replaced an old gas boiler.
When we bought house, boiler needed replacing. We wanted all the radiators gone off kitchen walls, so wanted under floor heating......
So we ripped up downstairs floors, put under floor in and went with a Heat Pump. just 2 rad changes needed upstairs, rest were already oversized.
Downstairs is mainly open plan but we do have a log burner mainly for really cold winter nights, but its for the look and feel more than heat. heating keeps up even at -6 the other night.
Running costs is about half what gas was, I estimate, but thats mainly down to the cheap overnight tariff. So I heat the underfloor mass etc with cheap energy.
I think people say you need COP of 3 to "break even" at 7p gas and 30p leccy, so I am above COP 3, then factor in average I pay for leccy is around 16p (I think), it makes a huge saving.
@shaeney super interesting. In the absence of insulation, I’m very curious to hear what the heat loss survey was. Can you walk us through that? Also what was the target temperature? 21C?
Buy a copy of the The Ultimate Guide to Heat Pumps
Subscribe and follow our Homeowners’ Q&A heat pump podcast
@editor the main living room is approx 30m2 with a design temp of 21 degrees at 74w/m2 for a total of 2,264. No idea how that compares to anyone else!
Theres a LOT of glass in that room with 1 set of French Doors and a triple bifold. Ceiling height is around 8 and a half foot
Total area of living space is 185m2
Posted by: @shaeneyI heat the underfloor mass etc with cheap energy.
For clarification @shaeney
so that UFH pipe is all running through a new solid/concrete floor, correct?
Concrete thickness?
Insulation below it?
I suspect that approach allows your heat-pump to operate more efficiently.
The high thermal mass, slowly heating over many hours will diminish/eradicate the HP from cycling.
Here's part of my house with the UFH pipe stapled to insulation prior to the concrete pour.
@editor -- it would be great if this could in some way be reflected in one of the heat calculators you're contemplating for this site.
But I'm unsure how to achieve that.
It needs input from one our tame HP physicists/engineers 🙂
It would be a useful feature for members here to evaluate the different efficiencies which be obtained depending on how they implemented the heat-emitting elements for their home:
- radiators
- UFH (suspended floor)
- UFH solid floor with high thermal mass
Maybe this would be better illustrated with a theoretical house, rather than the householder putting in their own details.
Save energy... recycle electrons!
@transparent so the old flooring came out, down about 8 inches, I think.
Then 4 inches of insulation went down, foil side up. The underfloor heating coils were secured to the foil side, then a few inches of "biscuit mix" screed went down over the top
Probably a total of 70m2 underfloor heating went in. Abut half is covered with quick step laminate, the other half with tiles
Great. That's what I'd imagined @shaeney
Got any photos during the works?
Was this all DIY, or did you buy in contractors?
I have tiles in the kitchen area, and engineered oak boards over the rest.
But it was more complex because that oak boarding spanned across to an area with suspended floor, running across joists. 😲
Did you fix your laminate to the screed to increase the heat-transfer?
Or does it 'float'?
I consulted Bostik technical support, who recommended a primer and an adhesive "Laybond Wood MS Polymer".
That's proved very successful, despite my fears of differential expansion rates.
Bostik really know their stuff!
Details are useful here on the forum.
Others will come across this topic in months/years to come and be able to copy the best practices from what we've achieved.
Save energy... recycle electrons!
- 26 Forums
- 2,208 Topics
- 48.7 K Posts
- 69 Online
- 5,868 Members
Join Us!
Podcast Picks
Latest Posts
-
RE: Forum updates, announcements & issues
We've had a slight glitch with our security software fo...
By Mars , 32 minutes ago
-
@bontwoody I rather feel that this drawn out episode is...
By Toodles , 40 minutes ago
-
RE: Samsung Heat pump with Yonos Pico circulating pump running all the time
I think you said you have a buffer. Is it the primary ...
By JamesPa , 2 hours ago
-
RE: The Hidden Secret to a Successful Heat Pump: Pipe Size Matters
Er...no comment!
By JamesPa , 2 hours ago
-
RE: 4 Year Ongoing Heat Pump Battle With Poor Heat Pump Installation
@fiona sorry to hear that, and I sympathise with you be...
By Mars , 2 hours ago
-
Um, not accurate, I’m afraid. CCS type 2 connectors a...
By Majordennisbloodnok , 2 hours ago
-
RE: Samsung Heat Pump – Can't Activate TW2 Pipe Sensor (for Delta T Control)
If you do suggest you consider repurposing it as a 2 po...
By JamesPa , 12 hours ago
-
RE: Say hello and introduce yourself
Fully agree with @cathoderay. My journey took 2 years ...
By JamesPa , 14 hours ago
-
RE: RDSAP10 effect on existing heat pump EPC rating?
Tim, Yes ChatGPT thought I could get another...
By Mike Patrick , 22 hours ago
-
RE: Enabling WiFi: Samsung ASHP on Smart Things App
No problem, @richdorm; glad it helps.
By Majordennisbloodnok , 24 hours ago
-
RE: Help me keep the faith with my air source heat pump installation
If that makes you feel happier then go ahead, but it wo...
By JamesPa , 1 day ago
-
RE: Testing new controls/monitoring for Midea Clone ASHP
I do already have the same basic setup, all room influe...
By cathodeRay , 1 day ago
-
RE: IVT Greenline high pressure switch and electrical cassette errors
OK. You dont say whether it is from the feeds to/from ...
By JamesPa , 1 day ago
-
RE: How can I programme a setback for my Samsung Gen6 8kW heat pump?
Yes, and probably also Adia although the latter has a m...
By JamesPa , 2 days ago
-
@editor I am all in favour of provocati...
By GrahamF , 2 days ago
-
RE: How to Understand Wiring Up a Heat Pump
Morning, On top of what everyone else I would deffo loo...
By Grantmethestrength , 2 days ago
-
RE: Sizing a heat pump: Save me from my headache
Got the results back from the one we’re ...
By Mikeatthezoo , 3 days ago