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

[Deleted User]

Alfiethefish wrote: »

Thanks to all.

Actually as Jeepjunkie now knows I have received a quote since making the post originally to fit a Mitsubishi Ecodan system. The house is indeed total 1742 sq ft and 400 of that is a brick and double glazed ( to current standards ) conservatory.

The last two years LPG are at 2205 Pounds and 2400 pounds respectively. The house has solar water units so in summer ( when we get one ) like now, the heating is turned off as it the hot water and we are supplied by thermal. So if I add the net electric bill which is Pounds 480 less some rebate for sold on PV generated power that amounts to around Pounds 250 a year. Total energy bill Pounds 2650 a year + an increase due in LPG this winter.

So the Ecodan system quoted is going to cost UKL 8000.00 less hopefully a 1300 grant - maybe - but even without the specification for this heat pump says that it will provide all space heating required + hot water for around UK Pounds 980 per annum. The LPG boiler needs replacing and cheapest quote we have is around Pounds 3000 so we have to recover the extra 5K. If the bills drop by Pounds 1 K per annum then it shud return in 5 years. My problem is I simply can't find anyone independant to confirm that the figures I am being quoted are correct. I am clearly not a techie so am reliant on advice from where I can get it - hence the original question.

I think to get the answer you want then getting several quotes might be the answer i.e. if they predict roughly the same running costs...

To give you an idea our running our costs...

We are a tad smaller, c100odd years old, cavity wall 3m ceilings, detached bungalow err... former station, usual insulation, DG etc 4kWp solar pv and we pay £88 [for all electric use] per month with is spot on. Perhaps a bit less now with lots of LED and solar immersion recently installed...

We do however try heat the house as efficiently as possible i.e. a 20c baseline with as low a flow temp as we can get away with but have a couple of log burners for cosy nights as a lot our wood is free.

Our 14kw Ecodan is connected to mostly fancoils with ufh and towel rail rad in bathroom.

Have to say it has transformed the comfort of the house from the bad old LPG days.

System has been through two harsh winters and worked perfectly when most folk in my family had no end of issues with recently installed GCH combi's condensate freezing leaving them with no heating etc for days on end...

If I add FITs & proposed RHI into my running costs then the system is effectively free...

Hope this helps.

deano72_2

deano72 wrote: »

ecodan u1 fault keeps reapearing= pressure fault
its kingspan package with uf heating
the site agent got called out saturday to u1 fualt,he done a quick fix & just powered down as thats all he knows so fair enough. i went there yesterday & noticed the flow setter below 10,so set it between 12-15 as per mitsi recomendation,checked all valves open & pump speeds & flow setters on uf manifolds & 2 port valves & have 1.5 bar in the system dip swithces settings & all ok. i also took dhw target temp to 50c.advised occupant all mechanically running ok but no gaurantee that problem wont return as i know from other dans on site that u1 is common fault.get the call after work tonite that its gone out again on u1 so will have to attend in the morning.
these dans are coming up with u1 pretty often,tbh normally after a few tweeks here & there they usaully go away for atleast a month or two & no problem,pretty rare they appaer again the next day.
so whats your thoughts?
im just starting to wonder if its gas related,you can gaurantee the dans have not had the standing still period of 18hrs before swithcing on which im not sure would of efected the dan longterm

just to add a side note. i also disscovered about sw3 switch 5 setting,
weve been told by mitsi it is to be set to on,but this is maybe not the case.it depends if its new/old type pcb in ftc2.
you can find out what type it has by pressing few buttons on mitsi controlor. if its 300 or 400 sw3 no5 should be off
if its 500 then sw3 no5 should be on
if its set wrong what happens is the heating will not kick back in untill dhw times has finished its timed period rather than switch back to heating after dhw has reached its target temp.
its worh checking especially if you have quite generous dhw times programed

It's been a while .
With out going into to much detail, mitsi have updated the software on FTC and also the installations have now had the manual bipass swapped for an auto bipass on the UHF..will have to watch this space when winter arrives but suspect the mods carried out will now cure the problem

John_Pierpoint

We will look forwards to the update.;)

The message I keep on getting from these "green" trickle heating installations is that the architect, the heating designer, the installer, the commissioner, the landlord (if there is one) and the building user all have to know and understand what they are doing.

waltsalt

Anybody seen this - http://goo.gl/GhB1e3.

It's the latest report from the Energy Saving Trust about heat pumps. Seems pretty positive.

[Deleted User]

ASHP update...

Having run the ASHP 24/7 [and them some...] over the summer months, taking full advantage of the PV, to get the house up to temp. Fortunately with the continued running of the ASHP day and night the house seems to be holding its heat taking care not to open any windows or doors for any length of time

Of course it is still only September so thinking I may have to buy in wood and coal to max out the stoves when the ASHP starts to ice up

On the plus side the house is warm but on the downside it's costing more than the old LPG system to run??? At least I'm doing my bit for the planet :cool:

Cardew

jeepjunkie wrote: »

ASHP update...

Having run the ASHP 24/7 [and them some...] over the summer months, taking full advantage of the PV, to get the house up to temp. Fortunately with the continued running of the ASHP day and night the house seems to be holding its heat taking care not to open any windows or doors for any length of time

Of course it is still only September so thinking I may have to buy in wood and coal to max out the stoves when the ASHP starts to ice up

On the plus side the house is warm but on the downside it's costing more than the old LPG system to run??? At least I'm doing my bit for the planet :cool:

More than LPG to run? Is that a change from earlier posts?

Have you run the ASHP 24/7 over the summer for heating? or hot water?

lovesgshp

Cardew wrote: »

More than LPG to run? Is that a change from earlier posts?

Have you run the ASHP 24/7 over the summer for heating? or hot water?

That has confused me as well Cardew!!

[Deleted User]

jeepjunkie wrote: »

ASHP update...

Having run the ASHP 24/7 [and them some...] over the summer months, taking full advantage of the PV, to get the house up to temp. Fortunately with the continued running of the ASHP day and night the house seems to be holding its heat taking care not to open any windows or doors for any length of time

Of course it is still only September so thinking I may have to buy in wood and coal to max out the stoves when the ASHP starts to ice up

On the plus side the house is warm but on the downside it's costing more than the old LPG system to run??? At least I'm doing my bit for the planet :cool:

I was not being serious but it would appear that is how most people think they work...

nande2000

Just started using our Ecodan 8.5kw for central heating, came on first time no issues at all after only using a handful of times for dhw in the summer. In contrast my neighbour who has a 3 year old Worcester oil boiler, tried his heating for this first time and now it wont fire up and he's waiting for an engineer to come out.

matelodave

Our 11kw Daikin has been heating the hot water all summer, using about 2.5-3kw a day, the heating was turned on last week but as the weather has now warmed up it's not doing anything or costing any more. Our detached bungalow is 1350 sq.m and we haven't used any other form of heating over the past three winters as the system keeps the bungalow warm enough even for my wife.

As discussed above, the heating is slow to respond to rapid temperature changes but just gently ticks over keeping the u'f heating warm. We are at home all day and each room is thermostatically controlled (programmable stats) by regulating the flow in each room. The heatpump flow temperature is weather compensated - ie it gets warmer as it gets colder outside - the max temp is set to 42 degrees when it goes down to -5 outside. The min is 25 degrees when its +15 outside. I can tweak it a bit if it gets a bit colder (we had a couple of days last year when it went down to -14 outside) - the unit has an inbuilt 6kw back-up heater for the really cold days.

Our total energy usage last year was about 8800kw which is up a bit on my 8500kw estimate due to the long and cold winter and I'd guess that the heating/hotwater accounts for about 4500-5000kw of that.

We don't shut it down overnight but the stats "set back" by about 3 degrees so the place doesn't get cold.