Replacing Storage Heaters

KathrynPenguin

I know this gets asked over and over but everything keeps changing.  We have no gas. 

Long story short I've spent 25k on solar etc to reduce my electricity bills and just as I was about to get onto the Tesla Energy Plan (my powerwall finally arrives on 19th August) the TEP prices went from 11.2p to 25p, I really thought I was actually going to beat the October price rise!

Mum lives in the granny annexe and it's heated with storage heaters, only 1 really works.  Having spent ages working out the best replacement and always getting mixed answers about ASHP which is the most expensive option, it keeps coming back to storage heaters.    These are my current calculations, but I could be way off and TBH they may not even be enough to heat the space.  

		Installed
Dimplex Quantum	3.3 kw	£4,500
		Total (4)
Rate (kwh)	3.3	13.2
Hours Charging	6	79.2
Days a month	31	2455.2
Current rate	£0.18	£438.87
TEP	0.2515	£617.48

That's the monthly cost, just for the storage heaters. The current rate I'm paying is cheaper but that's the capped Economy 7 rate which isn't staying at that price as it's not fixed.  We ended up on that when Symbio went bust.

It's a 1 bedroomed annexe with a flat roof and cavity wall insulation.  The bedroom was previously a double garage, the lounge is about the same size and as well as a kitchen and bathroom there is a poorly built conservatory.  The main house has a hot air oil heating system that heats all the water.

We have 6.2kw of solar plus an older (ringfenced) 4kw system on FIT.  A Powerwall is being installed next month and another is on order.

markin

A/C mini split, aka Air to Air heat pump, Average cop of 3.5 would almost match the cost of Gas.

£25K for a 6kw system and a PW2 seems about 6K too much, to me.

https://forums.moneysavingexpert.com/discussion/6269423/7-8k-for-aircon-system

KathrynPenguin

markin said:

A/C mini split, aka Air to Air heat pump, Average cop of 3.5 would almost match the cost of Gas.

£25K for a 6kw system and a PW2 seems about 6K too much, to me.

https://forums.moneysavingexpert.com/discussion/6269423/7-8k-for-aircon-system

Thanks - 5 k was to replace my 13 amp electric aga with a much more efficient one.  That has made a massive difference in the consumption!

I also upgraded everything on the panels 

QrizB

KathrynPenguin said:

It's a 1 bedroomed annexe with a flat roof and cavity wall insulation.  The bedroom was previously a double garage, the lounge is about the same size and as well as a kitchen and bathroom there is a poorly built conservatory.

You've specced a *lot* of storage heater for a 1-bed annexe. A typical 1-bed flat might only have two storage heaters total.

markin said:

A/C mini split, aka Air to Air heat pump, Average cop of 3.5 would almost match the cost of Gas.
https://forums.moneysavingexpert.com/discussion/6269423/7-8k-for-aircon-system

I agree with Markin; it would be worth getting a quote for a air-to-air heat pump. The author of that thread, danrv, is heating a semi with one and it's costing him a lot less than his storage heaters did.

KathrynPenguin

QrizB said:

KathrynPenguin said:

It's a 1 bedroomed annexe with a flat roof and cavity wall insulation.  The bedroom was previously a double garage, the lounge is about the same size and as well as a kitchen and bathroom there is a poorly built conservatory.

You've specced a *lot* of storage heater for a 1-bed annexe. A typical 1-bed flat might only have two storage heaters total.

markin said:

A/C mini split, aka Air to Air heat pump, Average cop of 3.5 would almost match the cost of Gas.
https://forums.moneysavingexpert.com/discussion/6269423/7-8k-for-aircon-system

I agree with Markin; it would be worth getting a quote for a air-to-air heat pump. The author of that thread, danrv, is heating a semi with one and it's costing him a lot less than his storage heaters did.

Thanks - this is way less storage heaters than recommended for the size of the rooms, each big room has very large windows to two aspects.  At the moment there are 6 storage heaters there and it was never amazingly warm!  There is a wood burner in the lounge that does a great job for that 1 room but it’s quite an effort for mum who is 78.

the bedroom was a double garage and the living room is the same size.  I could easily make this a 3 bed by splitting the rooms.

wrf12345

The really cheap option is £50, just buy a decent halogen heater and stick it on the wall.

Another option is a monoblock air source heater that is attached to the wall (and has two large holes going through the wall for air in), these are terribly overpriced on eBay at £800-£1000, COP is probably around 3 in winter. They do not need professional installation as they are all-in-one so no gas to add, just need to drill two big holes plus mounting holes.

Unfortunately, the serious air-source industry is rather overpriced in the UK