Nickfromwales

I am a man of few words... until 2 pints go in and then you can't shut me up Give me a slightly cold home and I'll pop a blanket over me, but give me a warm house and I'll kill everyone within a 50m radius.

A Passsive spec build? Please elaborate... Depending on how far north, your PHPP may have specified that you wear thermal undercrackers.

Cooling.

You are fine with either, as AT tests are a 50pa and not 'hurricane' levels. "As built" tests are done with water sat in traps, so this will be fine. You must consider that both negative and positive pressures occur, so a 'heave' in either direction will have differing effects; a 'suck' on a waterless trap will happen regardless, but not a 'blow'. These will only be momentary vs constant, and life goes on (even in a Passsivhaus) Same happens with MVHR, it becomes temporarily imbalanced when wind blows onto the fresh and exhaust. Worry about something more significant is my advice, after you have reflected on doing the best job possible. If you can connect to an internal SVP then I doubt any issue would ever occur.

Thanks, I did (before I responded).

I very much doubt this is advantageous to this thread? Random members working for free is not a benchmark is it? That also should remain off open forum too, please, as whatever reasons you had for doing that is between yourself and that member. I do similar, but I keep it to myself and help where I can in whatever spare time I get, off air. Please take this up via the PM system if you wish to continue such dialogue, but, for Joe Public, the subject is about the value for money of the quote, or is it deemed by others as "steep"; by comparison drawn from their own facts / experiences / costs / scope of works.

I've fitted scores of UVC's and you can 100% relax. Zero trapped air problems will occur here, ever. Blast them through once, go to pub, celebrate. 😎

Air will enter via the automatic air vents.

Motorised valves should only be on the flows, and the return should remain common. That way the appliance always sees the expansion vessel etc.

Is it in and bonded now? Did you seal at the perimeter? I don’t see you ever having a problem btw, and the Sika stuff is very good.

@Russell griffiths will buy it off you to put into his shower. https://uk.manscaped.com/?gad_source=1&gclid=CjwKCAjwh4-wBhB3EiwAeJsppLhk7T6msHWJqwLDERuPaiTVuQ-HMwEBW3lkxisRmdQsqURDwOqvFxoCiLEQAvD_BwE

Interesting place to have the safe btw....

If the shower spray hits the 'cold' end, then I'd just leave it alone. I'd not want a SR tray which is part bedded and part decoupled imo, due to risk of cracking over time.

Not ever a real world scenario or design particular, so completely moot tbf If the system is off and the valves are closed (which they should NEVER be in normal service) then it would be because a service / maintenance issue has occurred and somebody had shut them purposefully (so therefore in winter they'd also drain accordingly).

Yup. Cheaper than shoplifting. ASHP is a no brainer if you can, otherwise (as it’s an attic essentially) then A2A air con for heat and cool. Average CoP north of 3. Air conditioning in an office in a loft in the summer will be heavenly, and I doubt it would be otherwise survivable. Windows wide open / drafts / noise etc isn’t always practical in an office, unless it’s in the middle of nowhere and deadly quiet? I’d sack the UFH off and go A2A.

I know where you live.

Go add them to the pile mate.

Insulate both runs with at least 19mm wall insulation. FYI, you don't really need the more expensive black neoprene stuff as the thermal values are pretty much the same as the cheaper grey stuff. Just try to leave seams unbroken and slide the insulation down the pipe wherever possible as that save a mountain of awkward taping up along the lengths. Tape joints well, gaps are bad.

Cool. Just with 10mm there and back, or even just back, vs 15mm there and back, the delay in getting the cold water (dead leg) gone eg getting the loop to circulate hot water from the tank to the tap is quite significant.

Also, don’t use a router! Stanley and a chisel is fine to break out small chunks, then pop a 10mm hole in. Once fitted over the window brackets you inject foam through the 10mm hole to fill the void you left from rebating. Don’t forget to mask the window frame whilst the foam expands.

Looking good Timber frame is deliciously quick isn’t it. What’s the plan for insulation and AT?

Based on it being tempered or not running 24/7.

Hi @weslev, see below Firstly is it actually necessary, then... < Up to you, cost vs comfort. At 15m you’re just on the tipping point tbh. I would be installing in hep2o and am fairly sure that the HRC is ok to be done in the same barrier pipe, is this correct? < Yup. Flow and return both in 10mm hep2o or should the flow be larger? does it matter? < I’d do the lot in 10mm if the hot return is on and left running vs pulsed via a PIR etc. If pulsed, then flow in 15mm and return in 15mm too otherwise it takes a while to get ‘there and back’. My design for this set up would be to feed the whb's and sink from the main hot manifold but reduce to 10mm, have the HRC come back via 10mm to a return manifold specifically for these three returns, then from manifold run to an isolation valve, followed by a non return valve, then my secondary pump, a final isolation valve and then into UVC somewhere in the upper portion of it if at all possible. Is this logical. < The HRCs need to come back to individual manifold ports, each with their own isolation valves, same as the hot out manifold; so each pair of hot and hot return can be isolated. This avoids having 3x isolations and a lot of exposed pipework at the basins. To save faffing on any technical controls, run the HRC from a programmable pump. < Doesn’t need to be technical. It’s on or off / timed, or triggered by a motion sensor in that room. Typically I work on houses where we’ve installed a decent chunk of solar PV, so I just set these to run all day (if clients are retired / working from home) or on sensors / timed for all other situations. For the retired / other folks the system reverts to the sensors at night, and runs constant through the day, as losses are largely offset by PV anyways. So if you get up to go for a pee, by the time you’ve done the deed and want to wash your hands, the hot water is sat at the tap waiting for you. Resurrecting old threads is fine, good to blow the dust off them tbh.

Excellent price too. Cheers, not seen that one before tbh as I just run to Grundfos Comfort these days. 👍