UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

rhubarbe

Well, not so much luck. We have trebled the loft insulation, installed cavity wall on all walls except those that get hit by driving rain; installed brand new A rated double glazed window frames and sealed all the suspended floors that we have.

The last batch of new windows are going in at the end of January and after that if I want more efficiency I will have to insulate underneath the suspended floors. of course, all this is subject to diminishing marginal utility - in order to extract the very last smidgeons of energy efficiency involves an exponential amount of money at it so I may stop soon.

I'd like to get the RHI payment to cover all the power requiremet of the house but doubt I'll quite get there.

Next project is PV solar...

richardc1983

rhubarbe wrote: »

Well, not so much luck. We have trebled the loft insulation, installed cavity wall on all walls except those that get hit by driving rain; installed brand new A rated double glazed window frames and sealed all the suspended floors that we have.

The last batch of new windows are going in at the end of January and after that if I want more efficiency I will have to insulate underneath the suspended floors. of course, all this is subject to diminishing marginal utility - in order to extract the very last smidgeons of energy efficiency involves an exponential amount of money at it so I may stop soon.

I'd like to get the RHI payment to cover all the power requiremet of the house but doubt I'll quite get there.

Next project is PV solar...

Ive a friend whos getting solar panels installed for electric, not sure how I rate it though.

U have miles more insulation than me, this is a converted victorian house im the ground floor rented flat, below me is a cold open cellar which is full of soil and dirt. My lounge floor is actually cold to touch it just sucks heat out of the room like a fridge would.

Double glazing is cheap stuff and 8 yrs old so is draughty and cold and obviously no cavities so insulation there is a no no.

Plus we have big high ceiling so even worse. I have ceiling fans but if I put them on reverse to bring the warm air down they feel draughty!

Cardew

richardc1983 wrote: »

My word we get ripped off then, I get 5.6kw units of electric for every £1 I put in and he says he isnt ripping us off!

If we had a proper bill we would benefit a bit from Tier 1 and then Tier 2 he just charges us a flat rate of 17.85p per unit.

It is illegal for a landlord to charge more than he pays for electricity.

Cardew

rhubarbe wrote: »

Cardew, I get upset when folk that have gas preach the disadvantages of a system that is possibly less versatile than gas but far far better than oil, to people who have no gas.

Simples.

My post was directly replying to 'Bushyh' on the merits of ASHP versus gas - which he raised.

So are you suggesting that the disadvantages of ASHP's mustn't be discussed in an internet forum lest it upsets you?

Incidentally ASHP are not 'possibly less versatile than gas' - they are in every way less versatile!

Also why are heat pumps 'far better' than oil? Granted the overall running costs are less than oil, but the installation costs are higher and arguably oil is better suited for larger properties and above all they produce very hot water for CH and HW - which is the Achilles Heel of heat pumps.

Heat pumps do have merit but also they have disadvantages. This thread is full of posts that seems to think that getting a house to 22C with an ASHP is an great achievment.

rhiwfield

Some advice please.

I'm thinking of replacing the base load (60-70%) of my oil CH with an ASHP (difficult site, no room for drilling). Purpose is to further reduce reliance on oil and take advantage of RHI if applicable. I would also expect it to be currently a bit cheaper than oil, much cheaper in long run.

1970's 2-storey house is about 2,300 sq ft, 17 windows all double glazed, cavity wall insulation and 250mm loft insulation. Currently using about 1500 litres of oil pa + 7 cu m of logs for woodburner in lounge/diner. Concrete floors, standard rads, most installed before improved insulation and glazing so prob oversized for current heat loss.

Boiler is WB non-condensing danesmoor utility 20/25 (22.5 kW, only 3 years old, Sedbuk 84% efficient and said to be very reliable) and a newish self bunded oil tank. I'd guess the max heat requirement is currently about 16kW, maybe less.

Am expecting quotes shortly for a bivalent system, probably ASHP for space heating only (not DHW) as all appliances are cold fill and we use electric showers.

As I understand it the oil CH will be retained and take over from the ASHP in very cold weather.

Any comments welcome but in particular:

• will there need to be an additional water tank
• is the ashp heated water kept separate from DHW
• is their any real risk of bacteria build up in existing tank or any new tank
• how do the twin systems work when the equilibrium point is reached
• what ASHP maintenance is required
• what is likely cost ballpark
• can I use oil boiler to heat hot water separate from ASHP

Thanks in advance.

bushyh

Firstly I should confirm that Bushy is a she not a he! My house is about 1800 sq ft. Last night I turned the thermostat down to 18 and left heat on - turned my bedroom radiator off (don't like the heat at night). This morning the temperature was 15 in the hall and 15.5 in the lounge compared to 13.4 and 13.5 the previous day when I had it off overnight. (Don't have an outside temperature). I turned the thermostat up to 22 at 7.30 am. It is now 11.30am and hall is 15.5 lounge 16.5. My electricity usage yesterday was 112 units (this includes everything - no washing or tumbledrying done but lights, TV computers etc). My electric bill for the last 26 days would come to £226! Tomorrow I will be phoning the builder again to say I feel I have done enouogh experimenting and that the pump isn't fit for purpose.

albyota

bushyh wrote: »

Firstly I should confirm that Bushy is a she not a he! My house is about 1800 sq ft. Last night I turned the thermostat down to 18 and left heat on - turned my bedroom radiator off (don't like the heat at night). This morning the temperature was 15 in the hall and 15.5 in the lounge compared to 13.4 and 13.5 the previous day when I had it off overnight. (Don't have an outside temperature). I turned the thermostat up to 22 at 7.30 am. It is now 11.30am and hall is 15.5 lounge 16.5. My electricity usage yesterday was 112 units (this includes everything - no washing or tumbledrying done but lights, TV computers etc). My electric bill for the last 26 days would come to £226! Tomorrow I will be phoning the builder again to say I feel I have done enouogh experimenting and that the pump isn't fit for purpose.

bushyh, Calorex make good swimming pool heat pumps......but that's where it stops...... I would say the system is just not up to the job. There are heat pumps and there are very good heat pumps, I would hope you don't 'Tar all with the same brush', I hope you get a solution from the builder....

bushyh

Alby. I will be careful not to tar all with the same brush as you say - I suspect the calorex one is probably cheaper than the others and that's how I ended up with it! At this stage I think I have to suggest that they replace the system with a gas boiler, on the basis I am worried that if I suggest a different pump and that doesn't work I'm in trouble whereas if they go for the gas then at least I know it will work.

albyota

Bushyh, stick with mains gas boiler, It seems as if it was a half *rsed attempt by builders / planners to satisfy the sustainability issue on a small development..... on a low budget.....ASHP's are great if they are spec'd and installed correctly, if they were serious, they would have payed more attention to the insulation of the building, put in underfloor heating on the ground floor (rads upstairs). Another purpose made cockup IMO to give developers more ammo against heat pumps.

bushyh

The bank pulled the plug on the builder ( unecessarily so if they knew the area and their business - which I do - both) and I think that hasn't helped in any of this. I bought off plan way before all of that and had to wait 2 years for it to be built - location, size and re-negotiated price were perfect which is why I stayed the course. Is it worth looking at a bivalent installation or do you think I should give up the idea of the pump. there's a part of me that is thinking what if it really is cheaper to run the pump over a milder winter. Thanks you all of you for your views, I appreciate I have been hogging the site for a couple of weeks but I think am now at decision making mode and ready to make the call tomorrow.