How do I bathroom / kitchen / extension? etc.

That’s me

Aha - DBR is Franke Wave advocate then I think

Is this an apartment or house and how are you fixed for outdoor space? I wouldn't put in electric heating of any sort under any circumstances as it will break you to run it... dig deep and get a heatpump and underfloor heating or wet radiators at least. It'll be more expensive than new electric heating but it will add to the value of the property and be waaay cheaper to run going forward...

Leasehold apartment so electric is the only game. I'm not sure if wet underfloor is an option - can you run it off an electric powered boiler?

Depends on how efficient it is and if you can cover it in solar panels.

Can you stick anything to the outside of it? Options are very limited if not.

You can fit an indoor air source heatpump with ducting for air but would depend on logistics on site... I'd be looking into doing anything I can to achieve that though...

Franke Wave 4lyfe (in the kitchen)

Ex-display-ebay Vola in the bathroom

Speak to a qualified supplier & installer.

Heat pumps are obviously a no-go if it's a flat, and an internal ASHP would be a terrible idea - they're not quiet and you'd be sacrificing valuable floor space to a noisy metal box...

Electric UFH would be good for heating a bathroom (Schluter do a good ditra-mat combined soultion), and you could also put in an electric-only heated towel rail, but heating a whole flat this way would be inadvisable. You want an electric boiler heating water for wet radiators.

Thanks

No problem - if you go down the electric towel rail route, I like these:
https://en.termaheat.com/radiators

Relatively inexpensive, nice designs, and they offer a really nice neat element option with a concealed cable. Also nice accessories (hooks/rails) for various radiators.

How well insulated and draught-proof is it? Electric-only is the future but it only works if your place is thermally efficient.

heating a whole flat this way would be inadvisable. You want an electric boiler heating water for wet radiators.

Out of interest, what makes electrically heating water then pumping it around better than electrically heating the floors?

The later should be maintenance free and much less of a headache to install and use but obvs. if it costs 10x to run or something…

It's a bit of a longevity issue. Never run into an issue myself, but it's got a reputation for failure. I'd be nervous if it was my primary heating method.

Interesting, thanks.

Pretty well insulated and draught proof. It was built circa 2000, so done to whatever building regs prevailed then. It is the ground and first floor of a four storey building, with a concrete ceiling so not much heat loss through the roof. Circa 50% of walls are external facing. I think there is PIR or equivalent in the walls. Obviously double glazed.

We used to live in a 2 bed in the same place, and we never updated the convection wall heaters. They were useless, but our electricity bills weren't too awful. I just want to get something as efficient as possible in the new place.

I guess wet underfloor is an option, but would mean raising the ground floor a couple of inches I think? The ceilings are very high so could be viable. The other option some neighbours have is ceiling mounted heaters, but I don't know much about them.

Respectfully disagree. Modern inverter driven HPs are very quiet (I've worked in HP industry for fifteen years). I'm literally putting one in my own apartment at the moment however my outdoor unit will be in the garden as it's a ground floor apartment.
Depending on whether @revenant. can put anything on outside walls the outdoor unit could be wall mounted too... they're basically just an AC unit (of sorts and size)...

would mean raising the ground floor a couple of inches I think?

There are contractors who specialise in retrofitting wet UFH. They use a machine kind of like a walk behind cut-and-break saw to cut tracks in the floor which the pipes are then laid into. You could DIY it either if you're handy and have the time but it is a rather messy job.

Maximum cop on electric heating will be a theoretical 1.00
With a HP you should be getting c. 4.00.

This means for every 1kw of electricity put into electric UFH or radiator you will get 1kw of heat.

With HP for every 1kw of electricity put into your HP you'll get c.4kw of heat energy.

Yeah I get that, it was the comparison between electric direct and electric boiler feeding a wet system that I found interesting.

Your HP will pretty much be 1:1 in the middle of winter when you need it most, no?

At least 1:4 isn’t the minimum efficiency they run at, is it?

Fwiw to get either to feel like a really great solution I think you need solar panels to feed them and a really well put together house.

No not at all.
The HP I'm installing is a Viessmann Vitocal 222-A 8kw unit and COP is still 2.89 at air -7/ system temperature +35.

COP is 4.71 at air +7/ system temperature +35.

That's great if you can heat your place with a flow temperature of 35 degrees.

With underfloor heating, no problem at all. With modern aluminium radiators you should be able to get very low too. Ancient cast iron or chappy steel radiators would admittedly require a higher temperature.

Here are the heating curves/ COP for the unit I'm installing. (Edit as I uploaded the wrong chart)
Also keep in mind annual average air temperature in London is 10.8°c and average temperature in January (coldest month) is 4.8°c...

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With underfloor heating, no problem at all. With modern aluminium radiators you should be able to get very low too

Looking at the charts, as long as you don't need more than 7-8kw of heat, you are golden.

That chart is for a unit rated for 8kw nominal output. If you need more you can just get a bigger one!
The project I'm finishing up at the moment in our workshop is a 120kw air source plantroom with two 60kw HPs...