JamesFR

@SteamyTea You think you might get permission? Or are you just commenting that it would be needed for flats generally?

I think these are good points. I think I currently have a pretty high tolerance for noise relative to the train outside the window at night. But I think the issue for me is that without a specific product in mind and a ready installer I probably can't do it. I acknowledge I'm probably on the wrong forum given this. I just do not see any examples of any splicing their MVHR with an internal ASHP or air conditioner.

Thanks for this. Combined with this, @JohnMo's comments, and the low ACH (which I'm not sure I've calculated correctly) from the cheap MRXBOX, I think this option is a no.

Green is the cupboard where the MVHR is, red are extracts and blue are vents. The hoses in/out of the MVHR are flex PVC into the ceiling, then hard rectangle PVC. Total area is about 70m2. The idea is interesting, but I've read that the ducting has to be larger for AC than for MVHR.

Unfortunately this is correct, the water systems are like these: https://www.coolyoudirect.co.uk/apartment-air-conditioning-systems/. Notice they never say the running costs or water usage.

HA Is this really something people do? I think I'd be too nervous it would be a major hang up if I wanted to sell up. Plus, surely someone would notice me drilling a hole in the side of a medium-rise block.

Thanks so much for your reply. This makes sense to me, but what doesn't make sense is that the maker of this unit is a Dutch company (HomEvap). Isn't it just as humid there? Are all these products this company sells just a scam? I like this idea a lot, but I have a difficult time believing I can get permission from the freeholder.

Hi All, I am writing to see if there is a good way to add cooling to an existing MVHR system. I have read quite a few topics from this forum on this, but they don't exactly seem to answer the question, mostly because I live in a flat where a split system is not feasible: This thread has the most information concludes that an ASHP seems to be the best option, which is not possible. This thread hints that comfort cool is ineffective. This thread stops quite inconclusively and is quite focused on a house. Here is a discussion about summer bypass, but unfortunately the unit that came with my flat seems to be the cheapest and does NOT have a summer bypass (MRXBOX95-WM2) This thread went off the rails a bit but has some ideas. The flat has huge windows on both aspects. I have done what I can to reduce heat gain with reflective film on part of the windows and big curtains, but outside shades are not an option. The flat is very well insulated and is on the 4th floor, leading it to get quite warm at night even without hot weather. For example, I aired it out yesterday and went to bed with it being 22C, but woke up with it at 25C despite the outside temperature being 12C. I suspect the cheap MVHR is part of this, but the bathroom does not have windows so I don't have much choice but to keep it on all the time. I can't seem to get it off boost mode either. Why not just open the windows at night? Unfortunately, it is quite close to a very active train line, and I find it difficult to sleep with loud trains going by constantly. As far as I can tell, these are my options: Portable A/C Pros: Cheap Cons: Loud, ugly, inefficient especially because windows are only inward opening, have to open window Get water cooled A/C installed Pros: Effective Cons: Very expensive to have done, loss of most storage space in the flat, increased water bill (??) Adiabatic cooling on MVHR, such as https://www.ventilationland.co.uk/en_GB/p/homevap-mvrh-cooler/9745/#pdpBlogs Pros: Goes onto existing system, cheaper than water cooled A/C Cons: Very little info on effectiveness (could work moderately? not enough airflow?), unclear if there are many who install these MVHR system with cooling, such as https://www.nuaire.co.uk/product-list-page/mrxbox-hybrid-cooling-system Pros: Same ductwork Cons: Can't find any reviews on effectiveness or cost I know this forum is more focused on homes, but I would appreciate any thoughts any knowledgeable folks might have.