Duncan62

Passivhaus is as much for warm climate as it is cold. Cooling demand is in PHPP. As above. Recirculation of cooling air required to make any difference. Unlikely to work using the MVHR input with low flow rates - Unless you have a very well designed (i.e. certified) PH.

Sounds interesting, any schematics so I can fully understand your setup please? Just worried, given what @Nickfromwales has said before that a 22mm pipe will mean it'll take a long time to get HW at the tap as there is a large volume of cold to expel? (hence for the taps only: 10mm ring main - based on this suggestion)(further, 10mm chosen as I'm wanting to keep HW losses to a minimum, as there is a low volume of "wasted" water in the ring main).

32mm and 28mm was simply to preserve water pressure? Maybe I can simplify to 22mm once inside - and only have to buy one size of pipe! 15mm to bath/shower and 10mm to toilet - will the smaller toilet supply pipe help avoid any hot shower moments if the toilet is flushed? (even though the shower will be pressure balancing of course) This would free up space in the plant room and reduce the amount of pipe required. Will need to make the wet-room manifolds accessible. Had meant to add that. thanks. Honestly not sure what a "Cold outlet on the UVC inlet group" is. But if a NRV on the HW outlet fixes this, I'll add it. Thanks!

Given the advice here, maybe a split HW manifold and HW return system is best? Any obvious errors?

https://forum.buildhub.org.uk/topic/35099-streetfield-suds-system/?do=findComment&comment=513546

We're going to use blown wood fibre. List of all the insulation distributers below. Some of whom install too. STEICO_uk_distributor_map_construction_insulation_en_i(1).pdf

Thank you. That's much better than I was expecting.

what did they quote for TM59 please? cant see anything on their website.

Having tried with PHPP, and after initially positive conversations... I receive: So if I can justify PHPP is equivalent to TM59 criteria, its ok. if not, do TM59 analysis. Rather than accepting an alternative method of compliance (which is totally allowed), BC would like self builders to prove that PHPP = TM59 PH Trust have this document, but not useful https://www.passivhaustrust.org.uk/UserFiles/File/Policy papers/Overheating, Part O and PHPP v1.1 231107.pdf With this for overheating risk in PHPP https://www.passivhaustrust.org.uk/UserFiles/File/Technical Papers/Dynamic Thermal Modelling v1.0 230830.pdf TM59 analysis guide https://designbuilder.co.uk/helpv7.0/Content/CIBSETM59.htm Potential software with 30 day trial https://designbuilder.co.uk/download/release-software CIBSE weather data https://designbuilder.co.uk/software/cibse-weather-data-sets Anyone any experience of actually doing/commissioning dynamic modelling with a positive result? Design methodology for the assessment of overheating risk in homes.pdf

Any suggestions on who to use for TM59 analysis? Simplified is not working due to insufficient opening windows. Opening windows are far less energy efficient than fixed ones, hence I've limited them.

Could I mount this on the end of my intake and block off the other end. This would mean the filter would be working in reverse to what might be considered normal. Seems like that would work just fine too... And avoid the need for a sealed box. I could just put it in a rain cover on the outside wall.

Yes from my research this will be a problem. In the winter, people burning wood inside and delivering it to your property via their chimney will also cause your air quality to significantly degrade. My solution will be a huge carbon filter pre mvhr. https://globalairsupplies.co.uk/product/carboair-100-filter/

So standing on it during/after installation is ok...? Does attaching the manifold and pressurising it help against crush damage potentially? I'm just worried about contractors stepping all over it during concrete slab pour...?

Questions: Installation time. Lay/connect the pipe loops to rebar. Install manifold to 3x loops. Then connect garden hose to pressurise the system? Will pressurising the pipe work (16mm pert-al) mean I can walk on the pipes without damaging them against the rebar? If not, how on earth do I protect the pipes when the concrete contractors trample all over it?!

Interesting. So the fan coils run off a higher temp (~16) than they could (say ~7) and just run all the time. Higher temp = better COP too. Probably offset the fact you run it all the time?

Instead of the room thermostats, or in parallel, as a "master" on/off so to speak

Here we are approaching Summer again! Please critique my thoughts on the install for a passive class house for cooling in the (increasingly?) hot summers. 4 upstairs bed rooms to be served 5kw heating/cooling air source heat pump (unsure of brand, suggestions?) Single larger FCU, 4 ducts, 1 output duct to each room Intake from upstairs hall FCU: INNOVA Ducto Multi SLC+ 1000 - 7.2 kW 7kW is large, but the only option with 4 outputs, one for each bedroom £1600 one unit, compares to £500 per unit if I had one in each room? (plus, on the wall units are less attractive than big unit hidden in cupboard) Manual: https://www.innovaenergie.com/site/assets/files/2792/n421040a_manuale_installazione_ducto_multi_en.pdf Tech Spec: https://www.innovaenergie.com/site/assets/files/2792/scheda-tecnica-slc_multi_2022_-_en.pdf Control: INNOVA EEA649II Smart Touch Wall Control Panel - Black One per room. controls the fan speed. FCU has one fan per output duct. Ducting: Foam Ducting Ubbink 160mm About £25/m. Looking at plain plastic rigid pipe + insulating sleeve £20/m, so not worth the hassle? Postage: Possibility of sending to Italian friends, unboxing and man in van service to bring to uk? Heat Pump: How do I get the controls for the FCU to ask the HP to start making cold water to circulate? well done all, a great amount of info in this thread.

Have you considered DIY micro cement right at the end?

Another reason to use SCC!

The sketch was a generic from the brochure. I'm very happy with the design. Wooden 300 IBeam 2/3 on slab, 1/3 overhang to give continuity of insulation and reduce thermal bridge. Permanent compressive strength, creep (50 years, compression < 2%) 130 kPa (EN 1606). Also have a stability check of the 1/3 overlap of the wall over the XPS from the slab by the SE. House raft has two layers of mesh, garage now reduced to one.

Yes it is, phoned SE today and asked the question: low and behold - 1 layer A393 will be sufficient. Wish I was an SE who over spec'd - so I could reduce reinforcement by 50% and not worry.

Great, thank you. Eastern Concrete are only down the road from me too.

Have you used it? Got any hard won advice please?

Yes I'll give my SE a call this morning, see what she says. One layer would be ideal from labour (mine) point of view, tho will leave me with lefty over mesh. The pic is only representative. Our upstand is 180mm thick.

Mesh spacing for our garage 150mm slab. Bottom cover 75mm Top cover 25mm 2x layers of mesh is 20mm + 20mm = 40mm. So 75+25+40= 140mm = 10mm space between the layers... Doesn't seem worth having two layers?!