keyser

In my case I'm not sure I'm living in my 'forever home' and may sell it in around 10 years, so I'm still weighing up options - plus I'm around 3 years away from any future project. The way I see it is this (check my logic!): I'm on gas and currently using 6500kw for heating and hot water, so for heating alone lets say 80% 5200kw, using a gas boiler at 90% efficiency we can take off 10% if we want 1:1 energy usage vs heat usage (this may be where the logic falls apart :)) 4680kw of heating energy required per year. If I install insulation that number goes down. The general rule sounds like 'install as much as possible'. To get maximum SCOP you need massive radiators. OR if going UHF route you need 200mm of insulation from the ground floor or a lot of the heat will go into the ground. But what percent? 99% in the ground 1% in the flat (unlikely). Is it also possible to install UFH with substandard insulation, get an amazing SPOC but still be paying the price of not having enough insulation? by how much? Then there is also the air tightness and possible MVHR factor which I also like the idea of.

I saw this video and thought it was surprising he didn't go with extra floor insulation. But I take it he installed this some time ago and we can now see the data for the past year? COP 4.9 292 days of data. Winter is coming so might take a small dip. That's without floor insulation, sooo that's interesting. Future thoughts abound for my 1960s ground floor flat with concrete floor

OK thanks. Should I buy from ebay? I'd want to make sure I've got all the warranty and support for it. Have spotted the Ecodan's ticks all the boxes (quiet), except the thread about 200 idle vampire watts. I want 200 vampires to be busy not idle etc.

My estimate plumbingnation calc +20% was 4015 watts. My heat loss from that spreadsheet is 4019 watts. boom science, I mean boom guessing :). I did find more options in the drop downs in the end. So if my heat loss is 4kw does that mean I should spec to a 6kw heat pump for the extra 2 days a year on average it'll be below -3.7C?

I went by the Heat Geek youtube guys, their cheat sheet calculations for type 21 radiators @ 40C flow is 800W/m2, and 1140W/m2 for 50C flow. Of course they also say get a proper heat loss survey done which I will as I know that's necessary. Then I went on Plumbingnation calc and a few others and they all pretty much said the same thing, so I took that value and increased by 20%. Based on that its just a case of biggest radiators I can fit in, which I can. I don't actually need type 22 rads except in the kitchen. Surely if the system is designed around 40C flow then there is capacity to increase until the heat pump reaches maximum heat output of say 55C? The COP will go down but only 0.4% of the time. Surely I'm not the first person that owns a 1960s ex-council flat to install a heat pump? or maybe I am The same building can just be copy/pasted to the correct location in the UK and boom, heat loss calculated? Anyway the first problem I have is what option do I enter as 1960s walls, not cavity filled? or just fast forward to 'I will get those filled before the heat pump is installed'? And there is a heated flat above me so what do I put in as the roof? Thanks

Yeah either -7C outside and flow temp of 50C or -3C outside and flow of 40C probably translates into the same thing. I assume the rule of installing the largest radiators possible applies either way.

Beast from the East in Birmingham was -7C I think, that should probably do me.

I'm sure I'm wrong but if heat pumps generally don't do zoning for efficiently reasons, then the house/flat could just be treated as one big room for heat loss calculations? Just remove all internal walls and add up the roof, window space, or this will just give me a total for the property, not what size rads each room will need - assuming all the doors are closed and heat doesn't mix between each room? As Seinfeld says, that's about as likely as the coffee and milk to stay separate in a mug! But I do admit that my kitchen is a cold room, maybe 19C when the rest of my flat is 20/21C, that means my kitchen fire door has a fair amount of insulation effect. Anyway, my kitchen rad wasn't spec'd right when the council fitted it for that room, they just whacked a rad on the easiest wall and job done. These heat loss calculators are designed with a certain outside temperature in mind I take it? I've often heard to design around -3C outside, as that is a typical winter temperature, but does that mean it'll need an extra 1-2kw in the system (heat pump, pipe diameter, rads) to make sure it's able to go some way past that? -5C -7C? I haven't tried to use the heat loss calc spreadsheet that is posted here sometimes, as when I opened it my face melted off.

I'll need a cylinder that fits into my cloak/thing room 65x140cm space, its slightly bigger than that in places but 65-75cm once past some existing and unmovable gas piping to the neighbour above. So there seem to be a few options, slimmer ones etc. My water use seems to be 10 cubic metres a month, I'm on a water metre. I use the shower daily, its just a mixer from combi boiler so not a power shower. I back off the water rate a bit when showering as I know this will save water and cost of heating the water. I did measure the current flow rate to be 6L/min, it could probably go double that at full whack, so based on that I roughly need 60 litres for a 10 min shower, I should probably x2 or x3 that for when I have someone staying over. Maybe over spec it to 200L or is that too much? Do ASHPs have an option to do a weekly higher temp fill to say 55C-60C to kill off legionnaires - rather than using the cylinder heater with a COP of 1? or would this be a manual setting change (ie never gonna happen)? Or is once a week 50C water to 60C, not too bad in terms of cost? I take it I would set the hot water to get reheated around midday to benefit from the warmer air outside. On that note my garden is north east facing and can be nice but from midday onwards is increasingly in the shade - does that mean I'll get slightly lower COP than if this was south facing?

Thanks, I suppose the noise tolerance is different from person to person is a factor as well. I'm on the fussy end of the spectrum. The fridge freezer will be a quiet one the next time it's changed - it's secondary job is to cool things :). Maybe the gas boiler is making slightly more noise as its 10 years old now. When each noise is eliminated it just reveals the next loudest noise. The gas boiler/pump isn't loud but I can hear it for sure, I just want to make sure if my radiators are on 24/7 with ASHP in the winter I won't be bothered about the noise.

Ah yeah that makes sense, finally people realise quiet things are a good idea, thanks.

Sounds like a daft question but I will still ask it I'm used to a fair amount of noise when the gas boiler comes on and a part of that noise is the water pump for the radiators. I like things quiet! I take it all the noisy parts will be outside if I had an ASHP monoblock? The water gets actually pumped from the pump inside the monoblock and nothing else? Then a diverter kicks in sometimes to heat up the hot/warm water tank? Thanks

Yeah having a think on this it does sound like UFH isn't worth it here unless I dig up the floor, that might be a pass on that. The carpets can be renewed to a higher tog that would be something. The place needs a new kitchen and bathroom on top of everything else, doesn't have be high end, just nice. It looks like the doors might be metal frames and from what have read pinned into the breeze block, but I just get quotes for these things and see if I need new frames or just get better fitting doors/latches. I guess I'll find out how much hassle this is (and what is even possible) once I get the asbestos survey. I do like the idea of MVHR if only for an automatic shower/bathroom humidity control and general fresh air.

Thanks. I don't mind spending more on some better solution, I may stay here for longer but at the moment probably will be here for about 10 years and over that time I can make various improvements. It's a ground floor flat, which has solid floors, flats are offset to the neighbour so the kitchen is the coldest room with 2 outer walls. It would be nice to fix the cold floors with UFH, but would prefer to have some insulation too (25mm I guess) off the cold floor and a screed of 35mm, so that would be 60mm height minimum. All of that would then raise the height which would need new doors and door frames, which would need asbestos removal! So it would be a longer project. oh yeah I'm 6'4" 😀 The flat isn't cold and isn't draughty, it had some basic council improvements, the whole road got double glazing around 20 years ago and that's still fine. It was the original 60s warm air gas boiler and elec emersion heater for water until 2012 when the council upgraded to gas combi boiler, that's still going fine no issues, gets an annual service. It probably could be improved from an efficiency pov, my bills have doubled now with the recent increases to £140/month although I won't know for sure until the year is done. Usage is about 3350kWh elec, 6240kWh gas per year. In the summer it stays cool which is nice, while my neighbour above complains about how hot his place is. I think I would invest in a portable air con unit if it got really bad but so far I haven't had that issue. MVHR - yes this might would be a quiet unit in the utility room next to the front door, the in/out vents would only need a short run down the hall. Could they just go as far as the top of the doors or should it run to the middle of each room? I had a quick google for these terms No I don't think EWI would be an option, I mean maybe but it would look better if the neighbour above had it done too, so on that basis probably not. IWI would be possible. CWI should be possible and I don't think has been done down this road. No the communal path links to a communal back door, ground floor gardens, build in sheds, first floor has no garden. The path also carries on inbetween the gardens goes to old garages which is now sold land but the land buyers can only build housing on there and so far haven't done anything with it. That might be a whole can of worms, I would like to dig out the old 1 foot high concrete posts and start again, but worst case my fence would be directly in front of the existing fence, from my garden it would look great.. Also there is only access via the communal door or my flat so no room for any diggers, just person size equipment.

Hi, I'm here to learn more about MVHR, UFH and heat pumps. Interested in retrofit where I am I now, 1960s ex-council flat. Plenty to learn with this. I think what money I do spend on a retrofit and improvements would mostly come back with increased property price so I think it's worth it. I should get an asbestos test, remove some of all of it. Rewire the place, currently its on top of the walls in plastic trunking. And a new fence both sides, make the garden more secure (one side is next to a disused communal path).