JohnMo

Grand designs this week was a single storey, would guess about 180m² came in at £500k. MBC kit, ASHP, good kitchen etc, but a pretty simple design. All work by others. So about £2700 per m². Ours lots of work done by myself with others where needed, about £1800 per m², but quite a complex design in comparison to the above. All depends on complexity, quality of finish etc. how long is my piece of string really. Less airtight, no MVHR, double glazed not triple grazed and way less glazing would have saved tens of thousands. Different kitchen and bathrooms could have added tens of thousands easily. Not adding 100m2 of elevated (structural) decking to the front of the house and glass balustrade again 10s of thousands could have been saved. Bit like asking how much does a new car cost - it depends on...

You would need all the receipts and make sure it's a new replacement policy. A company I worked for had a shipping container with tools in it, until one weekend the whole lot was emptied. Not a penny came back from the insurance. All sorts of exclusion clauses.

It's just a money printing exercise for insurance companies.

It's a sauna, so a cold only shower outside - job done. Or cold plunge pool?

I have mine in the wall and use coander nozzles to throw the air across the room. Used in 3 bedrooms, lounge and long hallway. Lounge two dots at extreme edge of the image by ceiling. Air comes out following ceiling and drops about 7m later. All heated to room temperature, so you don't feel any air movement.

Walk away that is way too small. I chose 90mm to limit number of runs and keep away from noise issues. Costs depend on quality of stuff installed and layout of house and ease of piping runs. I used coander supply nozzles to reduce duct runs but about 50m+. I found with some upfront planning and quite a bit of getting your head around stuff, quite straightforward in the end to self install.

I used their duct (90mm) and various terminals and connecting plenums (90 to 125mm) no issues. Also used the foam 150 and 125mm ducts, again no issues. Ubbink also connects with various other brands if you want to mix other companies components.

Poor sheep and cows. But than live in the same field as solar, a double use of the field.

Not sure you really save anything by not heating rooms, the unheated rooms just suck in the heat from other rooms, so net energy input really doesn't change. Would really try to move to a single zone per manifold, the loops in that manifold get balanced to get room temps you want. Having room sensors in each room allows you run all loops or none just by switching pump. So example, room 1 is targeting 20 and rooms 2,3 and 4 targets 20.5. if any room drops below there target all loops come online and later all go off. But better still balance the whole lot to run WC. If suitably balanced all should be ok. Issue I found was if you are shutting down loops you can run into the situation where only one zone is calling for heat and the boiler goes into meltdown, short cycling and all the gain just get burnt with excess gas consumption. Share your current boiler and mixer model/make?

Easiest analogy is car car anti freeze. You can mix manufacturer but not the chemical makeup up. Car antifreeze is easy, as it's colour coded, blue, orange etc. the colour determines the chemical makeup up. If you try to intermix chemical makeup you are asking for trouble.

And optimisers where they are likely to get periods of shade over part of the array. Or the shade bits on their own MTTP.

If you have a mismatch in floor output the simple first step is to reduce output from downstairs and/or increase upstairs. If downstairs gets too hot decrease output, by knocking off 0.5L/min off each room loop that gets too hot. Get downstairs to have a stable temperature before messing with upstairs. You may need to revisit this a few times over a few days. Then increase output from upstairs, go to manifold increase each loop flow by 0.5L/min. Leave for 24 to 48hrs between adjustments to see what happens. You need to ensure any thermostats are set to not influence anything while you set things up.

Forgot to mention your current mixing valves are unlikely to work or work well with WC. They may require to run at circa 50 degs to have any authority of manifold temperature. A boiler suitable for X or W plan or 4 pipe will have suitable control for switching between the two duties (CH and DHW). Look at Viessmann, Atag, Intergas boilers. Size about 20 to 24kW. If you are doing a new cylinder, buy a heat pump cylinder (3m² coil) so you get decent condensing and or rapid reheat when doing DHW.

For me, I would reduce to the number of zones down to a minimum. Your issue is you will have a slow system response and you room temps could fluctuate quite a lot of you are bouncing of a thermostat. Next choice of mixers, IVAR or electronic (ESBE etc) only. Or do you even need a mixer anywhere? Can your system boiler provide enough flow for all loops on its own? If not, heat only boiler and keep manifold mixer and pump. Then a single thermostat per manifold. Run an almost flat WC curve of about 35 to 40 degs. Low loss header - no Flow needed will drive system or heat only I suspect. I would start by looking at the longer loop and all pipes to and from that loop and look at pressure drop. Once you have that, it will set pressure drop for system, then add all the flows you need together all loops). Now you have a pump duty point. You can now make a sensible choice of system or heat only. Thermostats, implement in each room - but don't give all active control, use for analysis for system balancing. Don't install manifold actuators. Use a manifold wiring centre to just switch pump on or off if you keep the mixers. No mixers and balanced system still leave off you add later if you have a problem room that overheats.

I would just do it in 3x2 or 4x2 wood, was forced to use some metal studs behind our stove, much prefer the wooden stud walls - nice sturdy.

I was looking at our almost North facing roof over the summer and was really surprised by how much sun it actually got. North facing is seasonal producer, fine in summer, pants in winter - but all PV is pretty pants in winter anyway. Best way is model it on https://pvgis.com/en We have have loads of shading in general (loads of trees). The way I thought about is panels are cheap (£140 per kWp) so we have quite a few, yield isn't the best, but the number panels helps. Can you do a solar fence or similar or ground array?

If they don't know or cannot tell off the top of the head, gets new plasterers, as they don't know what they are doing. Plenty of metal tapes for doing such things.

Not really it's designed for cold climates which isn't the same thing. It has a Condensing rotary heat exchanger which us better at heat recovery in cold climates - or so they say. A very quick look at the install manual and it clearly states, DOMEKT units are designed for installation in household or technical rooms with an air temperature of 0 °C to +40 °C, relative humidity from 20% to 80% (non-condensing). It is recommended to install the air handling unit in a separate room or in an insulated attic So not sure it's suitable for your location - most units aren't really well suited for a cold or very hot loft space. Hence the issues you currently have. I would remove insulation from under MVHR and then build a box from 100mm+ PIR or insulated stud walls and box the whole unit in. Make a wall removable or add a door for maintenance. Then the unit is in loft, but within a heated envelope. Then just keep the unit you have. Other option is every time it's cold you have issues.

With the proposed falls are you simply inviting trouble. Any blockages from autumn leaves etc could lead to water accumulation at the house interface. Possibly water in the house. You would never slope a patio towards the house, so why would you do that with a roof? I would be sloping away from the house, simple and safe.

You need to do the pressure drop calculation really. Depends on flow rate, length and number of bends in the duct. But would suspect 160mm is fine and 250mm overkill. I just taped between membrane and duct (foam ducts)

Can you adjust your pump speed to a higher setting? This will increase flow available.

Is it really a down side? If you only allowed UFH return back to boiler the flow through the boiler would be very low and most likely just short cycle.

So they took the merry p!ss really. Scottish grant is something like £9500, so they charged £11500 for a heat pump and cylinder? Still completely unconvinced by MCS, glad I did the self installation.

That raises a question - do you not run WC all the time, are you trying to run WC and a schedule at the same time? Or running WC and thermostats? You need every loop on really, otherwise you get a miss balance of flows.

I don't want or need a buffer - it's a thought process, and as @Nickfromwales says captures the details in one place for others. This is not a volumiser thread either. I had already had 2 coffees and been out with the dog, before writing the original - decided it was too cold outside to do much else.