General > General Technical Chat
Building thermal insulation.
<< < (10/13) > >>
tom66:
Yeah the 5hrs off peak do mean I have upwards of 9kW of load switch on around 8.30pm sometimes... Dishwasher, EV charger, tumble dryer, sometimes a late dinner and the hot water tank is now on off peak electricity as it costs less than gas to heat it that way.

I think the energy providers are offering off peak tariffs not because it is profitable during the off peak, but because by encouraging you to shift away from on peak, they aren't paying huge amounts per kWh.  On peak prices to providers can be upwards of £'s per kWh so even 1kWh shifted into the off peak could be worth giving a discount on during the off peak, especially right now where gas peaker plants are expensive to operate given the high cost of gas.
 
Someone:

--- Quote from: Zero999 on July 24, 2022, 11:19:06 am ---The fact is heat pumps don't make financial sense. A heat pump installation costs 10 times the price, compared an efficient gas boiler.
--- End quote ---
Expensive? 10 times the price? Heat pumps start well under 1000 dollarpounds:
https://www.saturnsales.co.uk/Mitsubishi-High-Efficiency-Heat-Pumps-Air-Conditioning.html

Heating your whole house and amortizing the cost of the device is not essential to being safe, that's being picky. If you want to throw up alarming figures, explain the basis for them. Because everywhere else sees heat pumps as the cheapest way to go be that lifecycle cost, installation cost, or running cost. That link above is to cheap air-air units with SCOP (seasonally averaged coefficient of performance) over 5, so even with the UK's broken energy market keeping gas synthetically cheap....   heat pumps still end up cheaper to run.
PlainName:
I fitted a heat pump to my office, which previously was heated with a fan heater.  It's about 5.5mx3.3mx2m so my main problem was finding a system small enough! I wound up with a DIY one (everything pre-charged, you just push in the bayonet-type fittings to connect the inside to outside). it cost £695 11 years ago and paid for itself within 3 years. Not only that, it's a much nicer warmth than a fan heater (no sudden cold feeling when the fan goes off, no hotspots and cold spots), and in the summer it can cool instead. One of my better purchases.

Downside is it can take a little while to get up to temperature, but that can be solved with some smarts, as can automatically turning it on low if the temperature drops below 12C.

As Someone notes, you don't need to heat the entire property to be safe. In older times it was common to have an open fire in the living room and the rest of the place would freeze, but people survived. I think looking at using a heat pump to deal with a single room, leaving the rest of the place to be the existing boiler which can then be turned off for most of the time, would save a few bob.
Miyuki:

--- Quote from: Someone on July 24, 2022, 11:13:34 pm ---
--- Quote from: Zero999 on July 24, 2022, 11:19:06 am ---The fact is heat pumps don't make financial sense. A heat pump installation costs 10 times the price, compared an efficient gas boiler.
--- End quote ---
Expensive? 10 times the price? Heat pumps start well under 1000 dollarpounds:
https://www.saturnsales.co.uk/Mitsubishi-High-Efficiency-Heat-Pumps-Air-Conditioning.html

Heating your whole house and amortizing the cost of the device is not essential to being safe, that's being picky. If you want to throw up alarming figures, explain the basis for them. Because everywhere else sees heat pumps as the cheapest way to go be that lifecycle cost, installation cost, or running cost. That link above is to cheap air-air units with SCOP (seasonally averaged coefficient of performance) over 5, so even with the UK's broken energy market keeping gas synthetically cheap....   heat pumps still end up cheaper to run.

--- End quote ---
I do not know how in the UK but in continental Europe, as most places have huge subsidies for installation, prices skyrocketed, especially with companies licensed to install the "right models" on the list for those subsidies.
And the installation cost billed by those companies is huge.

But those Mitsubishi units you posted look decently priced.
tom66:
You can also get monobloc heat pumps:
https://les.mitsubishielectric.co.uk/products/residential-heating/outdoor/ecodan-puhz-monobloc-air-source-heat-pump

which can be installed by a regular plumber, as all the air con stuff is in one self-contained unit.  These, in theory, just fit in place of the heating loop in your property, though you may require some radiators to be changed to handle the lower delta-T.

These cost ~roughly 2-3x the cost of a gas boiler right now.

Personally I'd keep the gas boiler as a backup and use air source heat pumps for the majority of the time.  For the odd day that goes below 0C where heat pumps roll off in efficiency, I can switch to gas.  It's a shame I'll have to pay a gas connection fee all year round but I guess someone's got to pay for the infrastructure.
Navigation
Message Index
Next page
Previous page
There was an error while thanking
Thanking...

Go to full version
Powered by SMFPacks Advanced Attachments Uploader Mod