oranjeboom

A lot of companies that sell the retro-stuff sail very close the wind with regards to their suitability for a house with no/or very little insulation. I nearly went down that very path. I've had issues with digging up all my floors and it's delayed things by far. Then had some cowboy anchor screw up the concrete pour - still rectifying the last few rooms now! But the property is a long term home for us, so I didn't want to heating the local moles and went down the more difficult route by adding 300mm+ of EPS under the slab. You may even be better sticking to radiators than going for retrofit UFH.

wowser: https://www.advanceappliances.co.uk/product/175-willis-heater-1kw-for-secondary-return/ think they sell many?

It's a difficult choice....

Bit of a price difference though! But yeah, an average plumber may have more interest in fitting this than a willis heater which just draws a blank face when I mention it.

I think there are a few of us on here @Nickfromwales who are looking at the Willis solution so why not create a new topic? I've contacted a few plumbers locally who either haven't responded or who are telling me this isn't possible (what do clients know anyway?). So having a dummies guide to Willis Heating for UFH would make a good sticky on BH! EDIT: Looks like a similar request in UFH already! Shall e continued this Willis Heating there?

Guess they are being inundated with orders from BuildHubbers! First potential installer I was speaking to is now off my list. They just don't like to communicate. So had another come and have a look and estimated that I would need a 16kW unit (???!!) instead of my anticipated 10-12kW, but waiting to hear back on his quote later this week. Another local company is now an official sunamp installer so keen to hear what they have to quote for an ASHP as they can fit my sunamp unit at the same time. I'd be up for a bulk buy if there's sufficient discount and not bothered about RHI as if that does double the price, there seems little point!!

Well BPC only supplied me with one silencer, so hope that is sufficient! I have no option but to fit mine horizontally.

Can't comment on the damp issues. I have mine in the loft and have it sitting on a timber platform on the ceiling joists (with circa 200mm loft roll). The timber platform has a foam type mat to reduce any vibration to room below. Plan was then to insulate the whole unit further with 150mm PIR and any left over loft roll. It can get to 50C up there in summer, so hoping to protect the unit from that. Just bear in mind that any insulation you add has to be removable to get to the filters and maybe the control panel.

Depends on floor area I think. IIRC I have around 170sqm for UFH. Do you know what model you went for Joe?

I should have mentioned model! It was the 510M which has an inverter: https://ctc-uk.com/wp-content/uploads/2017/08/CTC-Data-Sheet-EcoAir-510-520.pdf

So my installer asked whether I wanted to go with a small 100litre buffer for my UFH. As I think the house will have areas that will be colder (older bungalow areas) I fitted room stats in each room, so now reverting to a one zone approach would not enable us to control room temps individually. Is there anything I should be aware of with having a buffer tank? The buffer vessel will have some heat loss, but will be within the heated envelope rather than attic, so not a big issue. Although I keep coming back to Mitsubishi, the installer is looking to get a CTC Eco Air unit (Swedish) so parts may be a bit more pricey with fewer experts around to service the latter I guess. Any particular buffer tank I should be considering? I came across this unit (only 2yr warranty though) but was thinking that the 3kW element may be useful for limited heat if there's ever any issues with the ASHP. https://www.advanceappliances.co.uk/product/141-buffer-stores/

I had a very nervous day when the scaffolding came down! Big heavy windows that took a lot of effort to get into place and lovely fresh cedar cladding. Impossible to protect really, but what I did do, was take lots of photos the day before of every window so that if any were damaged I had some proof at least in case I needed to bill them! Despite their reputation, I think most scaffolders are more responsible than your average tradesman.

Best to be safe. Especially if you get some muppet tradesman doing work after you and decides to sit/lean/swing from them! I won't bother using the illbruck stuff then- maybe that is meant to as a sealant when going through walls etc. Now that it's cooler, I'll force myself into the attic to finish that job I started months ago...

Bet you're glad that faff has been completed! At least you have no ceiling in place yet so a bit easier to tape the joins. Did you end up CT1'ing all the connections or just taping?

In that video, the water appears to be percolating THROUGH the wood and bubbling up - is that the case? Even if you have only painted the door on the exterior, I don't think that should be happening!! Is there a gasket between the glass and the wood on the exterior side at all? If not, then the water may simply be dripping down the glass and between the wood and glass at the bottom!

I suspect he may have also blamed you for the issues had you NOT painted it! What type of softwood is it? Always amazing how much it can 'move' after fitting. I've tried to acclimitise all timber in my house before fitting and will have to lay some door frames flat again with weights because they have shifted so much. Timber can be re-shaped to an extent and even doors can be taken out and re-shaped with a bit of effort, but a bit more tricky with glazed ones. Pic 1 - Is that a door? After rain? Even if that door had warped a bit, I don't think it should have that kind of water infiltration coming through. Did the joiner fit any rubber seals around the door? Pic 3 - Did you have them fitted after the concrete floor/screed was poured? Would have been a lot of humidity at that point, but if the same builder was doing the concrete who should have realised and mentioned something about leaving the doors/windows open! If you painted them on the outside, and your builder then fitted them, he should have then mentioned to you that it would be best to paint them on the inside sooner than later. A bit late to be pointing that out to you now!

Think I looked at that unit also and just seemed to be too cheap to be a decent unit. The seller's name put me off even more. Personally, I would be looking at a known make that has an inverter, even if it is 2nd hand. Anyway, to be slightly more useful, have a look here:

So I think I have decided that using a HT ASHP to charge a Sunamp Dual and my UFH does not make sense. So will probably stick with: eDual for DHW (charged by grid and PV) low temp ASHP for UFH However, I still am thinking about getting the ASHP sitting there doing nothing when there is no call for heat. So with an additional Dual (PCM58, only fed by a heat source only) it's clear that using a low temp ASHP won't get the water to a high enough temp for the sunamp to re-charge. But what about getting a Willis heater in the mix? ASHP temp (35c) -> Willis heater (+30c) -> Sunamp (65c) Means that I get the water efficiently heaterd to 35c with a decent COP but obviously grid (in winter) to charge the willis. Could a willis even be set up in this arrangement or would I still need a tank/cylinder? Was hoping that the willis could simply be integrated into the plumbing between the ASHP and the Sunamp but presume this would depend on the flow rate that the Willis needs? Would just be nice to have the use of the ASHP when it's not needed by the UFH. the Dual sunamp can then be charged for DHW (and UFH if needed).

But will the MOT man like them??

At least @Onoff should win on the lowest cost factor!

I use the Everbuild brand. The last batch of 12 cans were Soudal and they were a pain. If you left a can 1/2 used for a few weeks it would just go off and lose it's 'fizz' ending up in a dribble. I've just gone back to Everbuild. You can leave the cans lying around without having to use them up in a few days. I prefer hand-held as with the gun grade stuff you have to keep cleaning the gun ceremoniously. With the hand held you just let the foam dry in the straw and then pull it out on next use with a longish screw. With a gun you have a bit more control with how much you squirt out, but you soon learn how to go careful even handheld method. I recall reading on ebuild @JSHarris creating some device that would fine tune the exact amount of foam to the nearest mm. Or was that something else?

What will be completed first - Brexit or the bathroom?

@Wagas Have a read here. Some entertaining discussing on some 'revolutionary technology'

?? Mechanical and electrical boff? HWC = Hot water cylinder? Can't answer all of your questions, however: - If you have gas, that may work out cheaper for you as gas boiler is cheaper install than sunamp and ashp. Yearly gas checks though, standing charges etc. I think in many cases, gas will still win if ASHP has a lower COP than anticipated, house leaks heat like a tent etc. - A high temp ASHP can modulate down. So once it's done your high temp input into Sunamp for DHW, it can reduce temp down to your UFH temp. - Heating costs of DHW using cheap (E10/E7) or 'excess PV via HT ASHP may be cheaper than gas if the ASHP is appropriately sized I think. I am sure others can comment with some facts, figures and science.

Thanks Jeremy, Ed. I knew that would all have been too simple an approach! As the literature says "The standard models of the Sunamp heat batteries are supplied with PCM58 and these heat batteries can be used with any heat source which can run at flow temperature greater than 65oC. The discharge temperature from these standard heat battery models will be between 52 and 55oC". I was then thinking of using PCM34 instead as would be able to use a low temp ASHP then as the PCM requires flow temp from heat source at over 45oC. Only downfall then is that the discharge temp is only around 32oC and too cool for our DHW needs. And I'm not aware of where things stand with PCM34 in any case. So I can discount this UNiQ variant then! Back to the Dual and choosing a high temp ASHP then! The mind's beginning to crumble!