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

nennyrainbow

Cardew wrote: »

Your performance seems excellent, assuming that is an extra 170 watts

Sorry, meant watts, it was relatively late at night I wrote that:o

Yes, to jeepjunkie, about the 14kw models all being zubadans. I queried this with the installer as I thought we were getting an Ecodan. He said the zubadans were originally made for the japanese market but that the 14kw model here only comes as a zubadan but is essentially the same as the ecodan.

Cardew

nennyrainbow wrote: »

He said the zubadans were originally made for the japanese market but that the 14kw model here only comes as a zubadan but is essentially the same as the ecodan.

Could it be that the instructions for installation are only available in Japanese? Might explain a few things;)

John_Pierpoint

nande2000 wrote: »

Have you spoken to IceEnergy ? I almost went with them. If you get a local plumber to do the install and Ice do the supply and commissioning it worked out quite reasonable and you get a proper design for your new system too - a note of caution though, they admitted to me they were oversizing by half a kw.

Well it was a few years ago, and I have not got time at the moment to cross check the present relationships.

My rich acquaintance is proud to be the the steward of a medieval hall house with a Georgian addition on one end. Obviously it is listed and leaks heat and is difficult to double glaze.
[My most pertinent advice was to get the shutters working again in the south facing Georgian sash windows and install multiple thickness full length curtains with a layer "Velcro'd" to the frames.]

The "background" partial central heating is from a gas boiler.

Seal that home and it could well be death watch beetle here we come, as condensation forms somewhere in the interstices of the structure.

The Ice Energy rep suggested a ground source heat pump.

Worcester is owned by Bosch, which also now owns the Scandinavian manufacturer of heat pumps recommended by Ice Energy.
It features a oversized immersion heater for those cold periods (over night?) when the pump cannot cope .

I've spoken with senior reps at Worcester, who featured a film of their boss installing a proprietary ground loop in his garden, but their then knowledge of the technology was somewhat scanty - perhaps Ice Energy is a favoured installer allowing Worcester's workforce to concentrate on its [fracked ?] gas business?

If I have misunderstood these relationships, perhaps someone from Worcester Bosh could put us right.

nennyrainbow

We didn't have room for a meter as all the equipment bar the outdoor unit is currently in our kitchen and you can't swing a cat in there at the moment. We are extending the house next year, when the kitchen will become the utility room and there will be a new kitchen and 2 extra bedrooms, hence the need for a 14kW model, as it has been sized for the extended house. But I'm happy that the owl monitor gives a rough idea anyway. I have over a year's worth of daily readings from our import meter so I can be confident that I am estimating the daily usage from the heat pump fairly accurately.

lovesgshp

John_P
Ice Energy, were always the recommended installers by IVT in the UK, as we are in Italy. Bosch bought IVT in Sweden some years ago and IE are still the only UK recommended company on the IVT site.
Re the oversized immersion, it can be set at 3Kw, 6Kw, or 9Kw. It is controlled by a countdown timer (normally 1 hour ) before activating, if the heat output from the normal compressor cannot meet the heat demand within that time, but also can kick in for sterilisation, high domestic hot water temperature requirement. Ours here has only operated for 30 hrs over 6 years @ 3Kw.
It is also a backup in case of a compressor failure, as the pump can be switched to additional heat only, so the customer does not lose all heating requirement.

http://www.ivt.se/pages/static.asp?land=GREAT%20BRITAIN&lngLangID=1&lngID=47

http://www.bosch-thermotechnology.com/sixcms/detail.php/1630989

Diallingtone

I tried using my iplan meter from SSE to measure my ASHP running costs. The iplan sesnor normally clamps round the live (round) cable coming from the electric meter to the fuse board. I moved the iplan sensor to the flat cable coming from the fuse board to the ASHP, but the display only reads 0. I've tried twiddling the sensor round, but no joy. Shame, as that would have been a neat way of measuring consumption with graphs and stuff. I assume the flat cables don't generate the same magnetic field as the round cables and therefore won't work, but happy to take advice/suggestions?

Cheers,
Mark

albyota

No, diallingtone, the clamp goes around the single core, within the flat cable, the brown wire usually accessible from inside the consumer unit.

Al

Diallingtone

So I figured we can still get some very useful information from the iPlan meter, even if it's measuring the whole house consumption - I hooked it up to the PC today to see what it's telling me.

Although my solar PV would have a bearing during the summer months, during the night and generally at this time of year it has little impact on the overall readings.

This is for a Mitsubishi Ecodan 8.5 KW unit, retro-fitted to an all-radiator house (no floor heating).

This is the consumption for Thur 27th Dec:
flic.kr/p/dFngnS

<as a new user I cannot post links. please copy and paste, putting the http:// bit back in if necessary>

Some commentary:
00:00 - 03:00: room temp is 16º
03:00 - 04:30: hot water comes on for 90 mins
04:30 - 06:45: room temp is 16º
06:45 - 08:00: room temp is 21º
08:00 - 11:30: room temp is 19º
11:30 - 12:45: room temp is 21º
12:45 - 14:40: room temp is 19º
14:40 - 16:30: room temp is 21º
16:30 - 17:00: hot water boost for 30 mins
17:00 - 23:00: room temp is 21º
23:00 - 00:00: room temp is 16º

Total power used on the day was 40 KWh. On Christmas Day, with 2 ovens, a hob, a kettle and an ASHP going, we used 52 KWh. When it was really cold earlier in December and outside temps went down to -9º, we used over 60 KWh on 4 days.

That usage is my total electric, heating and hot water. I pay 12.46p per unit (inc VAT), so the total for Thur 27th was £4.98.

I still can't be certain how much less per month I'm better off until I have run it for a year. The overall return on investment will also be affected by the RHI payments due from Summer 2013.

In the summer, costs will be very different; heating much less and solar thermal/solar pv doing their respective things. The iPlan meter can't differentiate between net power in or out, so it can record solar PV export as usage (if you see what I mean). From the data I have recorded (I attached the sensor back at the end of July but never bothered to power up the wireless meter before) the average usage per day is as follows:

Aug: 14.89 KWh
Sep: 20.44 KWh
Oct: 27.34 KWh
Nov: 35.77 KWh
Dec: 46.06 KWh (so far)

Make of that lot what you will - I am a bit surprised how much power we're consuming, but will reserve judgement until a longer term picture has emerged. So far, every month has been less money than my combined electric and LPG payments before ASHP.

Cheers,
Mark

nennyrainbow

Interesting reading diallingtone. Do you know what your average daily electricity import was before you had the heat pump fitted? I thought your figures for August/ Sept seemed quite high considering the heating isn't usually on during those months (unless you live somewhere way oop north), but is that because it is adding the PV to the import figures?

hebridean

We just moved into a new self build three months ago, four bedrooms, two living, dining kitchen and three bathrooms, and had an 11kw Grant Aerona fitted with UFH on the ground floor and rads upstairs with additional electric UFH in the upstairs bathrooms. The electric ufh is only on for an hour or so in the morning and evening to take the chill out of the floor tiles.
We are on economy 10 and have been running the heating and heating the water during the periods that the cheap rate comes on, and are averaging about £6 a day for all our electical consumption.
On reading this thread over a period of time and as the general opinion seems to be that the pump is left on but thermostats are set back at certain times i've bought Danfoss TP5000m proframmable thermostats. These will be for the ground floor rooms but i'm at a loss to know what to about the radiatored upstairs rooms. They have trv's fitted but there are no room thermostats.
Any suggestions would be much appreciated. Many thanks.