JackofAll

We have rehashed our interior layout and the plant room will now be 2877mm long instead of 1777mm, better to have 1100mm than want it I guess.

@jack so your flow and return comes out the side of the upstand?, that seems a good idea rather than digging down like IanR did.

@IanRAm dreading showers especially the fitting of bases, will probably need to make up a 2x frame or 50mm piece of Pir or the like to countersink the bases. Am worried that we'll omit some duct or other, go over the plan enough times and we should be OK I guess.

No pain... very true I guess, re hydraulic resistance will need to look at more heat geek videos 🤓 to be honest I glaze over at some technical info, it's like a whole other language and sometimes feel that I ain't wired to understand.

32mm is big, for some reason would have thought 22mm or so would be the norm, kinda get where you're coming from, I also thought that if the temp requirement is high the diameter of the pipe would need to be bigger, think I read that somewhere.

Our plan is to fit it in line with the plant room however many mm out from the external wall so should be a short enough run, but runs like that may not lend itself well to sharpish bends especially with the twin wall insulated pipe. Possibly the only downside I see with insulated rafts(could be wrong though) is that all pipe locations need to be spot on.

How far out from the external wall does the pipe exit the ground/path? Not sure if there is a standard distance for heat pumps to be out from a wall or it varies from manufacturer to manufacturer, hence the question.

Tanner Structural Design

@IanRAs in who designed it?

Thanks @IanR The threshold is indeed over the EPS upstand but just looking at the drawing, see attached, the width at the top of the upstand is only 50mm in comparison to that in your drawing. The GRP L profile looks the same job just different material, though it comes in 3m lenghts which maybe cheaper than having to buy two lengths of phonotherm as i only see it in 2.4m lengths.

Hi, Engineer has speced 25mm thick phonotherm 200 for the thresholds of the doors to create a thermal break. Had to look up product and see its just like a piece of wood so my question is this, how is that fixed to the concrete in an insulated raft. I see that the upstands need to be recessed to accommodate the board. Could it be as simple as sinking several long screws in back of board to set in the concrete?

Thanks @IanR , was thinking that Ashp would need to be connected using copper pipe hence the question, as copper wouldn't lend itself to bending too well in this scenario.

Hi, for those who have fitted an ashp on an insulated raft what way did you route the pipes, down and under eps coming up inside or through the wall?

As in cavalok or the likes and why are they better.

Hi, Noticed on the latest draft of construction drawings that they have returned the block 200mm leaving 100mm gap between inner and outer leaf. Have not seen this detail on any wide cavities that I've seen online, seem to have box frames closing cavity instead or those pvc closers. Before I go back to engineer, is the return block OK to run with?

@jack as your PV is supplying hot water during summer months is your ASHP switched off?

Seeing that the washing machine and dryer will be in utility would the noise be louder than either of those? With 3 teenagers in the house there's a wash on everyday, twice when bed clothes are done. Is the Mhrv unit noisy?

Hi @PeterW Ours will not be much bigger, had hoped to get the Mhrv unit in and whatever bits required for solar but guess it would be too tight. Plan to put sliding doors on open side.

Just curious, probably a silly question, but is a Tony tray essential for a bungalow where there will be an airtight membrane under ceiling joists and the cavity is full fill?

Will look them up, thanks @Iceverge

Looking at cellulose,has a better u value than the omnifit from what I can see, just not sure price wise, may be a better alternative to sprayfoam, any opinions?

Just curious, with full fill did you not have to counterbatten below the slate?

Have to decide on what type of insulation for vaulted ceiling, most likely 9x2 rafters though am looking to see if 12 x 2 are available. If 9x2 was thinking onmifit 225mm followed by insulated slab(mineral wool) 62.5mm. Does anyone know what kind if u value that would get. Engineer reckons sprayfoam would lend itself better all round not just the shape of the roof but Airtightness too. Have heard enough stories as to why one should avoid.

Lots of info in that thread, much appreciated. I was always curious about trays above openings. Never have I seen weep holes above windows/doors. Come to think of it never seen them lower down below ffl either so always wondered what the point was apart from keeping moisture away from inner leaf, where's it suppose to go. Interesting idea re. pvc angle. Fair play for the level of detail offered up in your posts and what you would do differently, solid gold.