Heya, I'm in the UK where we use heating around 6 months a year and could use AC around 3. (I say could because I don't have it, but it's warm enough that it'd be nice for 3 mo).

I'm going to renovate my small top floor flat soon (55 sqm) and was planning on having underfloor heating to heat through the long winter months. My flat is in a grade 2 listed building, which means it leeks a lot of heat through bad insulation and single glazing, both of which I will be fixing with my work.

Also, I'm lucky in that I have a south facing roof terrace, great for getting sun in summer, but the downside is it can reach 30c (around 86f) and barely cools in time for sleep.

This means, for example, that half the year I'm sleeping in a really cold room, and for a quarter I'm sleeping in a really hot room, neither is which is ideal!

So I've been looking into whether an hvac system would be a good solution to maintain a more optimum climate throughout the year - a) to heat in winter (roughly 6mo) and also b) to cool in summer (roughly 3mo).

I came across the Unico system, which seems good in theory as it can fit in smaller walls, and I have a roof terrace and attic space so gives space for an outside unit and some storage in the attic for a distributing unit.

The cost seems a lot compared to other solutions, although our government is trying to encourage cleaner energy to are helping with the cost of things like this, so part of the cost would be covered which has left me intrigued.

I spoke to a sales guy who said the Unico system can replace me boiler for hot water, which I was very skeptical about, but actually in theory would be very nice for my place as it's so small.

Due to my buildings age, I currently risk getting mould, and I live in London which is very dusty. Again, the sales person said the Unico system would help by circulating the air, and also by filtering some of the dust.

I am skeptical about most of this. I know our American friends have central air throughout but it's very uncommon in the UK, and naturally I'm quite cautious about it.

But in theory, a system that can heat, cool, circulate the air, remove dust, and which lets me remove my boiler, and which the UK government will help pay to install, sounds pretty sweet obviously.

I was wondering if anyone has any experience with this sort of situation, and if they would or would not recommend I look further into either a general Hvac system or specifically the Unico system (price depending)? Do you have any advice or thoughts or suggestions that might help direct or sway me in either way?

Thanks so much if you can help!