SBMS

No. But there are wall units that are basically the same as the a2a units they just run chilled/warm water as opposed to refrigerant. https://www.aircon.panasonic.eu/GB_en/product/aquarea-air-smart-fan-coil-wallmounted/

We are Doing this but driven by the heat pump instead of a separate air con. for reference - the cost difference to install fan coil units upstairs (7 units) with fully lagged pipe work (allowing us to run the fan coils at 9degrees when cooling) is around £7k (over first and second floors). This is only a bit more than quoted price for UFH for those floors. This is much less than price of air con and means our heat pump isn’t sitting idle for half the year. Fan coils are also pretty efficient at running at low temps as well. I hope the strategy works, but in theory it makes sense??

Thanks. We’ve got 254mm joists and would only put 100mm pir in between but still fiddly not as good as all on top etc…

Agreed. Their analysis looks sound - and they don’t account for mvhr which probably helps even more. Even still.. I feel a niggle…

Why?

In two minds… about to start on our flat roof. Originally had planned for 200mm PIR as a warm roof. Due to a number of design issues we are looking at reducing this down and potentially looking at a hybrid roof. have had an interstitial analysis done by Unilin. By their reckoning if we put 100mm between joists and 140mm on top that yields no risk of condensation.. My thinking is whilst aesthetically we can reduce the parapet wall by a course (60mm) to improve aesthetics… is it worth it for the ‘risk’ perceived with a hybrid roof? Anyone else done this?

Probably not answering your question but I spent ages going round in circles on this and decided to go wall mounted fan coils upstairs. Panasonic aquarea system. Means we can do heating and cooling. 2 Temperature zones (natively supported by the system) so can run UFH and fan coils at different temps (low if needed for cooling). I’m not sure the cost of UFH upstairs is justifiable but I do think the cost of proper cooling (AC level cooling) is justified - the way our summers are going. Got Panasonic coming out in a couple of weeks to provide a technical assist on the system design if you had any questions

Am using UFH - why is this not ideal? Sorry I am not the OP re the large garage/ pool. Mine is a 10mx6m pool hall with a ln 8x3m in ground swim spa in it.

Got You - but that’s not its normal mode of operation? That would just be a mode to put it in extract only?

That’s interesting… does that mvhr unit not pull in outside air and extract indoor air?

Panicked when I read your first reply!! Though I’d f’d up so thanks for clicking! I think that’s a good idea try it for a bit and see. I’m wiring for a wall mounted dehumidifier as well with a condensate drain just in case but can try without and see? I’m guessing that in the summer if it’s humid outside that through wall mvhr would struggle to dehumidify?

Was significantly more expensive for me for similar thermal properties.

Thanks. I might stick with my vent axia through wall mvhr as main house mvhr in now. I don’t known if ill Also need a separate dehumidifier for when the roller cover is open and pool is in use? https://www.fastlec.co.uk/vent-axia-hr500?utm_campaign=smartsh&gad_source=1&gad_campaignid=17190426677&gbraid=0AAAAAD8Nz9eer1SHaUpDoIs41_1ki6pT_&gclid=CjwKCAiAlMHIBhAcEiwAZhZBUsg0RPymwbeyCjlQAQTXTAJLWtxkDB6mW6L364S1toSkcRFJIjFJixoCix4QAvD_BwE

Did the rounds settled on warmcel. About 200m2 at 304mm deep is about 6.5k installed. Was by far the cheapest. The cellulose is currently on site due to be installed in next couple of weeks so can let you know.

Which MVHR units out of interest? We are installing an indoor in ground 8x3 swim spa and was looking at through wall mvhr units. Most manufacturers I asked weren’t willing to certify their units due to risk of corrosion, so I can’t use our zehnder whole house unit in the pool room.