Dreadnaught

Yes, I would be happy to tinker over weeks or months. What is the alternative? I wonder how else one could attempt to put the right amount of energy in to the house over a 24h period to maintain the temperature at an approximately constant level while the weather varies? I think @TerryE has a custom computer algorithm to do it linked to a weather forecast. But that's the only alternative I can recall.

I don't have any details about the weather compensation, other than: "sensoCOMFORT comes with an outdoor sensor which provides an understanding of the thermal behaviour in and around the property and adjusts the flow temperatures to ensure optimal efficiency". Oh, and it has a pretty LCD screen so it so it must be good.

Good point. Perhaps it will be as effective as having separate heating zones within the house. But as a standard feature of the "SensoCOMFORT" ASHP controller (don't you love those marketing names), I suppose it can't do any harm.

Next I will be putting on the external cladding of my timber frame (Cedral Lap planks). Beforehand I am looking at all the penetrations through the exterior wall. One penetration is the wire for the ASHP controller's weather-compensation sensor (see image below of the sensor). The manual says "Connection wire is 2 x 0.75 mm²".Google says this is "2192Y" wire, which seems to be a common type cheaply available from Screwfix, etc. Should I … just buy a roll of that wire? install it through the wall with a loop outside and a longer loop inside? Should I use a cover plate (see below in orange)? Or instead just slope the penetration downwards and back fill with silicon? This is my first bit of "wiring" so would appreciate any advice and suggestions.

Ah thanks @shuff27, that's helpful to know.

By the way, I intend to put a in-line pre-filter box on the intake like this. This will be a coarse filter so as not to add too much resistance to the air flow. And which will catch errant flies and so on. WIth the new duct runs, this could now be in the neighbouring Utility Room: more easily accessible for filter changes. I am a bit cornered about condensation forming, on the inside in summer and outside in winter. I may look to have a tray underneath to catch any condensation.

I have a question about how high to drill the the holes. Back on site, I had another careful look at the position of the holes. I realised that I cannot drill through the span of a posi-joist as I planned. This because I would be cutting through the top of the wall cassette, so hitting the horizontal I-beam that is its cap. This means that I will instead lower the holes beneath the ceiling of the plant room, which will make the drilling easier anyhow. (This in turn means that, to achieve my desired separation between intake and exhaust (of 1.5 m) that I will run the intake duct through the stud wall in to the neighbouring Utility Room.) My new question: I have high ceilings, 2.8 m. Now that the holes are below the ceiling, how low can they go? Could be at 2 m height? Could they be even lower? Or is higher better?

The pozijoist is touching the wall. Ingenious! Thank you to everyone once again for more ideas. I'm back on site on Saturday and I will be up on my step ladder again for another look… and think.

I checked them with a tape measure so all looks well. Good point. It is foam mass-flow ductwork so I think it should be OK. It should absorb any vibration. And, too, the joist in question only serves a utility room and the main bathroom, fortunately not a bedroom.

Good suggestions. Thanks all! One problem. For the inside holes I will be cutting through the span of a posi-joist, which is positioned against the wall. I don't think there will be enough space for a jigsaw. The posi-joist is 304mmm, so a 200mm howl will only just fit, as follows:

How do I go about drilling holes in my exterior walls for MVHR ducts (2x) to atmosphere? What tools should I use? How should I do it? Guidance, suggestions & tips most welcome! External walls (closed cassettes) OSB, 12.5mm, Smartply Propassiv – inside Empty cavity 240mm, to be later filled with blown-cellulose insulation. Studs every 600mm. Magply, 9mm – outside House warp: Tyvek Firecurb Ducts (2x) Ubbink 160mm (internal diameter) insulated ductwork External diameter: 192mm External cladding (not yet installed): Cedral lap planks (190mm, 30mm overlap), over treated battens. External wall terminals (x2):

Oh, and I positioned the MVHR unit as far away from the bedrooms as I could, even taking the precaution of placing it on the far wall of the plant room. In a well-insulated house, which is airtight and triple-glazed, and which therefore tend to be whisper quiet inside, even small sounds become noticeable, sounds that would normally blend into the background of a normal house.

The two main sources of noise are (i) the unit itself and (ii) the high speed air in the ducts. And for (ii) especially the turbulence caused when the velocity of that air changes at, for example, the point where a duct joins a larger valve, such as at the point where air is supplied in to a room. (i) is addressed by buying a better quality Passive-House certified unit and fitting silencers. (ii) is addressed by slowing the speed of air flow in the ducts by increasing their cross-sectional area by doubling them up. The rule-of-thumb for noise in ducts is to keep the speed of the air below 2.5 metres per second on boost level. I went even lower.

That's me! You embarked on your path 7-years ago; I am taking my first steps on mine. (I am presently ruminating on the daunting prospect of installing 4,820 brick slips during the winter.) You were once the pupil; now you are the master.

I have just specified and bought my MVHR kit. But I have not installed it yet. I purchased it directly from the manufacturer of the unit I chose. Great service from them, by the way, even including a site visit, when he was in the area visiting someone else (!) Like you I was keen on whisper quiet. First, I chose a PH-certified MVHR unit and bought the ducting from he same manufacturer. Choosing a quite unit I think is key to having a quiet system. And I slightly over-specified the unit too. There was a smaller model available that would have been sufficient but the price difference was small. To tackle the risk of noise, it wasn't required by the MVHR designer who did the calcs for me, but I chose to pay a little extra and double-up almost all the duct runs (other than very very short ones). I also chose to have 1m-flexible-silencers on both the supply and extract from the dwelling. And I have bought a supply manifold which has extra baffling inside too. The ducting is semi-flexible and radial, so no cross talk and I used the wider (90mm external diamater) ducts rather than the smaller ones (75mm external diameter). The expert who sold me the system said that my system should indeed by whisper quiet and the marginal increase in cost will be modest.

I have a copy of the 2017 Sunamp manual. Here's (part of) the replaceable parts list. Could it be the "Heater cartridge 2.8 kW x 250 mm"? Message me if you want a copy of the whole manual.

I wonder if it is worth simply writing to the council citing the relevant time limits and appropriate sections and simply stating that you now deem approval to have been granted as it has timed out. And let them contradict you if that is not so. You could add something like: "if I do not hear from you by X then I shall deem approval to have been granted" or such like. In my situation, when I did this on a planning condition, my planning officer was kind enough to play along and mark the condition as approved in the system. He did not seem at all surprised that the particular domain specialist in the council (trees in my case) did not provide any comments within the time limit. And he was probably relieved to have one fewer issues to deal with himself. He also told me that I was the first person in his experience to use this mechanism. Just my tuppence.

Thanks all! Marvellous. That's really helpful advice. I think that my first try will be: sacrificial timber inside, tape outside, and a fine hack saw.

Outside cladding > Cedral Lap planks > Aluminium corner profile (1mm thick, 3m length, powder coated). What tool to use to cut it? Tin snips? Something else? Want a nice clean cut. And want to re-use the off-cut somewhere else on the façade.

Yes, I had both my planning fees refunded and one of the conditions discharged automatically because of non-determination deadlines. They work. Statutory limits are by far the best but correspondence like this can also be useful: "I shall will expect your response by X but in the event that I do not hear from you by this date then I shall deem/assume that…", etc.

Just an idea: perhaps find a new electrician, explain the situation, and then ask your previous electrician if he would be willing to do a one-off handover, either by phone or in person, with the new electrician. Although I am not in a similar situation, I plan to use a local electrician who I have found to be reasonable in his approach and I imagine would creatively help me solve a problem like yours. They are possible to find. Personally I'd go for a middle-sized firm of electricians, not a sole operator, and speak directly to the boss. (Unusually, I chose my electrician from his YouTube channel! A first for me.)

I used Sky Plastics and was happy with what I received and the customer service.

Aren't surveys copyrighted by their authors? I inherited a bunch of surveys when I bought my building plot. I used them all without asking for permission from the authors but my understanding is that is is generally accepted that it is OK to use them for the "purpose originally intended", i.e. building a house on the plot in question. A neighbour copying and posting wouldn't, I assume, fall under that purpose and therefore could fall foul, but presumably this is likely only to be a theoretical risk as who is policing it. There is also the matter of liability risk. I imagine this is only important for structural and soil surveys and such like where you'd want an engineer's liability insurance in case of any cock-ups.

My fridge will be in the open plan living room/kitchen, under the kitchen island. It will be a larder fridge only; the freezer will be in the utility room. I am now planning to surround the back of the fridge with sound-absorbant foam panels. I got the idea from @ProDave. And I will buy a decent fridge with a low decibel rating. It is helpful that all appliances now have a decibel rating (although I am not sure how definitive are the figures). I know that even quite noises can become intrusive in a well-insulated airtight house as the background noise levels are so much lower, but hopefully these measures will do the trick.