SBMS

Thanks for the comprehensive answer! 🫡

lol Sorry. Had to put my fingers in a bowl of ice after that.

What did you parge with? Are you brick and block? Where did you use soudatight? How come you taped and didn’t just use soudatight? Are you doing AB before or after plasterboard? Have you had a blower test done? sorry for the onslaught of questions!!

It seems Aerobarrier themselves recommend doing after plasterboarding. I guess if the system is designed to find air paths under pressure you want the physical model to be as close to the finished one as possible. Doing dot And dab would create a service cavity that changes the airflow And would potentially create leakage paths which weren’t present pre PB??

Okay fair enough (and you’re right my cracks comment was a bit stupid!)…. But if it does all that does it matter if the plasterboard is in place or not? Still Can’t see the benefit of doing it after boarding rather than before if all first fix is done?

Understand that first fix needs to be done (but this behind the PB typically).. but if we PB first then AB that puts the AT layer at the PB layer. If there are any cracks etc in plasterboard later then that’s a path that AB will miss? But if the AT layer is behind PB then boarding (with full perimeter dabs) can only increase airtightness? Or am I missing something

So AB after dot and dab? Would have thought having AB at the block layer would be best so pre PB?

Indeed! Think I might have a go myself with soudatight and see where I get?? Any other aerobarriers out there? What did you do pre aerobarrier

Not yet but am not sure what it would tell me. I’ve seen case studies that get airtightness from 6 to 1.0 so if I blew 6 today would that mean I should still crack on with aerobarrier? I worry that aerobarrier gets you a great result on the day but does it persist long term? I know they’ve tested longevity of the material itself but presumably this is fairly controlled. Does it cope with movements around junctions well for example 🤔

Am considering aerobarrier… so far we haven’t done any airtightness detailing for - window junctions/across cavity - slab floor to wall junctiob - liquid membrane/parging of internal block work (traditional masonry, 200mm cavity with eco beads) I have implemented a Tony tray and done airtight board in room in roof with taping.. Does aerobarrier negate the above entirely? Or should I do it (was thinking of using soudatight and parging with it as well). do I need to? I know that aerobarrier gets good results for air blower but does that hold up over time? Eg does it deal with the movement at window joints that tape/liquid membrane does? And if I go around with liquid membrane do I then need to shell out £5k on aerobarrier? I wonder if it’s diminishing returns - the difference in heat loss between a 1.0 blower test result and 2.0 For example is about 150W!

I wonder if anyone on here has ever managed to find the minimum heating capacity/modulation figures for the Aquarea M Series range? I've tried searching the whole of the Panasonic Pro Club and can't find any technical information? Part of the reason I wonder is because the 12kW and 16kW are exactly the same dimension. I remember that two of the larger vaillant arotherm models were actually the same hardware, with the output software limited... so I wonder whether panasonic does something similar but have a similar modulation floor?

Thanks everyone for your input. Have already got swim spa sorted and appreciate the advice John but the spa comes with a pump included and don’t want to confuse the spa installer and the heat engineers so will keep them separate! I think I’m going to go for the 12kW but I have also asked Panasonic to do a full heat loss calculation as well so interested to see what they come back with. Both mine and heatpunk predict 9-10kW so I think a 12kW will work. It’s £1500 less for the heat pump as well - not to be sniffed at. I did hesitate momentarily because I wondered if the cooling load could end up above this… but I’ve had a very lengthy thread elsewhere with @JohnMo where he said my predicted level of cooling was mad so 12kW cooling through fan coils should also be enough for the hot days…

Thanks John. I did account yes, it’s got An insulated cover 95% of The time but also the room it’s in will Be a bit warmer as well. it sounds like you would err on the 12kW side. One frustration is Panasonic don’t seem To publish their modulation figures for these machines so I don’t know what they would typically modulate down to. If they both modulated to a similar level I probably wouldn’t be as concerned. My upfront cost is a bit more for the bigger machine granted and if I didn’t use the extra kW it wouldn’t matter… but if for some reason I’ve undersized it I’m a bit stuck. Sound logic? the installer says they haven’t come across a build that’s averaging 19w/sqm before and think they’re nervous we will be cold. They’ve used higher air change figures in their calcs I think as well (as per mcs).

no - the spa has its own heat pump. It’s basically a big hot tub so a closed system driven from its own a2w pump. We are going to put some insulated plasterboard to reduce bridging of the steel lintel…

Going to answer my own question here.. I guess my heat losses is worst case rare day not the average…. has anyone else ended up oversizing? Or tracked whether their heat pump was oversized?