PeterW

Solar gain for a heat pump is negligible but the air sensor on the back may be susceptible to solar warming. There is nothing intrinsically wrong with that set up. Emmeti are a decent brand, it just seems like it has been half installed ..! Depending on how “handy” you are then you can probably re-pipe a lot of that as it stands with some off the shelf components rather than use a new manifold and pump set. Couple of things to check though. Is there a sensor or thermostat on the buffer tank ..? What triggers the circulation pump to run..? What triggers the heat pump to run ..? What timer / controller is installed ..?

How are you storing heated DHW from a combi..? Or are you suggesting that you use the heating circuit to keep a local tank hot and then replenish it from the combo flow when it kicks in ..?? Not likely at all. A 250 litre tank at 60°C holds around 330 litres of shower temperature water when blended down. That’s around 14 minutes for a pair of showers running together before the tank is cold. In a 5 bed/ 3 bath I would recommend 400 litres in a UVC. Anything smaller and you will need a bigger system boiler with a higher output to keep up with usage. Secondary circulation loop would work here but you need to design in the outlets too - which need hot water “instantly” and which can wait. If you go the traditional route of running large bore to the bathrooms and then tee off from this for the shower / basin / bath you need to get the return as close to the basin as possible as otherwise the response time will be too slowed @Temp points out. Baths and to a point showers are less of an issue due to the volume of water involved, so consider a secondary loop run in 10mm that only serves the basins and kitchen / utility tap as that will be more than adequate. We changed a permanent running install to one that ran 5 minutes every hour in a commercial building and reduced the water heating costs by £100/yr using a £20 timer. A well insulated pipe doesn’t lose that much heat and usage will also ensure it stays hot.

That’s helpful, do you know the flow rates ..? And what heat transfer you are getting from intake to supply and the extract temperatures ..?

Yes and .. yes.. So that needs re-fitting with a mixer if possible - you may have to take the manifold off the wall although it looks like someone removed the board with a spoon anyway ... Depending on how far from the buffer that manifold is, the manifold pump may well pull the hot water into the system anyway. If you can move the “other” pump and make sure it’s before any tee to the mandifold even better. You could wire the rads to a zone valve - use that to switch the pump on only when the rads want heat and let the manifold pump be controlled by the actuators. All pretty easily doable

Haven’t fitted a pre heater but have fitted a post heater as I’m not convinced that heating the cold air coming in will extract as much heat from the outgoing air. Out of interest does anyone else have sensors in their intake / extracts and can log the temperatures..?

Double charged could be what they are referring to. That means they get double thickness of the glaze or pattern applied. @nod may be able to elaborate a bit more.

If it faces North then how about putting a couple of pairs (see your 1 is now 4..!!) standard Velux Windows on 15 degree upstands, with two facing east and two facing west ..? Probably find it cheaper using 4 Velux than a single or even two large flat panels. You could have them automated too... would look like a sub launching missiles if they all opened together ..! 🤣

Compromise your design slightly so you dont alter the roof at all, and just crack on with the extension assuming it’s under the neighbour approval scheme.

Make a brew and get a pack of digestives out and have a long read of Pete Wards website. He’s incredibly knowledgeable about old houses and buildings and his explaination of “rising damp” is well worth a read. https://www.heritage-house.org/damp-and-condensation/types-of-damp-what-have-i-got/what-is-rising-damp.html

Ok so disturb the minimum amount possible and just change it where you can get to it. You could easily swing a pipe behind the current manifold from the bottom of the “return” and use the other existing elbow to connect up so that would mean you only need to re-pipe the flow.

Yes that’s fine - can’t see that in the pics ! Those grey fittings look like the older poor quality ones too - may want to consider swapping things for Hep2O.

I would check if there is not a better route such as using a secured storage provider (not a storage unit..!) as the data she has is very much classified as sensitive personal data under GDPR, and should be stored under the guidance from the ICO. Does she need to keep physical copies or are electronic copies not acceptable. The costs of building the store would be a business expense - she can claim the VAT back through the business plus the cost of the building but it would need to be registered as a fixed asset on her accounts. You would also need to ensure her business insurance covered it as your household insurance would be unlikely to cover the building and contents.

The thermostat valve will be working in reverse...! So if you turn it down (ie cooler) then the top sensor will see warmer water and it will try and compensate. It’s not that difficult to fix but you would need to move the wiring centre from the right. The manifolds are modular - looks like that has a leak too so a good time to fix the leak - and you can essentially drain it down, undo the pump set and swap it to the other end using the same fittings. You would probably want to clean all the joints up and use something like JetBlue on all the joints as they are older and also look to be brass, and that would allow you to correctly install the pump to the right and the return to the left. It’s a half days job for a competent plumber.

If this was me, I would not bother with the concrete and screed but back fill with MoT1 to 275mm below FFL, compacted in 100mm layers. Then lay 25mm EPS as a blinding layer, DPM lapped 600mm up the wall (well past current DPC) and then use 130mm PIR with 30mm to all walls. UFH pipes into the bottom of this and then self compacting concrete, leaving a 5-8mm layer for SLC to even off the slab when everything else is complete as you want to do this in sections. I would ensure your blue/yellow sections break at doorways and I wouldn’t worry about securing them together - in fact I would insert 10mm foam to give and expansion gap and allow movement. Injected DPC is a waste of time - they don’t work. Unless someone is insisting for a mortgage (which is very shady practice) then lap the DPC up the wall, bond it on with a PU Adhesive and then board and skim as normal. As long as the internal DPC goes above the external ground by 2-300mm you will be fine. If you are doing EWI also consider digging down and putting a French drain around the property as it will help with reducing localised moisture levels.

Can you mark which pipes you think are flow and return and which is hottest ..? And a better photo of the pump ..? Thanks