Air Source Heat Pumps

nethertonhall

Albyota, last year we used about £3500 worth of oil, this was for heating and the Aga - The Aga will use about £1000 of oil / year so for heating that is £2500. Our Electric bill was £90 x 12 = £1080 / year giving a total energy cost of £4580 / year.

With 2 x 10kw Danfoss units ( we only comissioned them in Sept 2009) we expect the following electricity usage (when averaged / month) 12 x £166 = £2000 / year ( we have not had a full year to prove this yet). We will keep the Aga, this should cost us £1000 / year in oil, our total energy cost is likley to be around £3000 / year.

As you can see we will be saving around £1500 / year, based on unit purchase, groundwork, installation and tuning (less grant) we are expecting a worse case pay off of 12 years. This will improve substantially once we recieve the new govt grants for generating energy from GSHP.

If we had the extra that Danfoss stated this would again substantially drop the payback.

We are just installing air source units on two new holiday cottages - no figures yet!


12

Hermann

nethertonhall wrote: »

................. This will improve substantially once we recieve the new govt grants for generating energy from GSHP.

If we had the extra that Danfoss stated this would again substantially drop the payback.

We are just installing air source units on two new holiday cottages - no figures yet!


12

Is the equipment and the installation MCS accredited?

Looking at the consultation document for RHI it seems likely that everything will have to be MCS to qualify.

nethertonhall

Yes both installation and the equipment are MCS accredited and will be able to claim the grant.

We are just developing 2 holiday cottages - these will be air souce heated - we had to check very carefully as the supplier was accredited but not the proposed units - Keep an eye on this!

albyota

nethertonhall wrote: »

Albyota, last year we used about £3500 worth of oil, this was for heating and the Aga - The Aga will use about £1000 of oil / year so for heating that is £2500. Our Electric bill was £90 x 12 = £1080 / year giving a total energy cost of £4580 / year.

With 2 x 10kw Danfoss units ( we only comissioned them in Sept 2009) we expect the following electricity usage (when averaged / month) 12 x £166 = £2000 / year ( we have not had a full year to prove this yet). We will keep the Aga, this should cost us £1000 / year in oil, our total energy cost is likley to be around £3000 / year.

As you can see we will be saving around £1500 / year, based on unit purchase, groundwork, installation and tuning (less grant) we are expecting a worse case pay off of 12 years. This will improve substantially once we recieve the new govt grants for generating energy from GSHP.

If we had the extra that Danfoss stated this would again substantially drop the payback.

We are just installing air source units on two new holiday cottages - no figures yet!


12

nethertonhall, are you calculating the £166/month (avg) on what the system is running at now...since commissioned....or have you factored in...less lighting, lower heating requirements in the summer, where are you measuring this from (electric meter?) along with heating the hot water from GSHP as opposed to oil for heating hot water last year? I do understand what you have been told (in writing?) for 3 free units from the ground rather than "up to" if Danfoss can't explain that ...they are going to have problems!! how were the heat loss calcs done?...Watts /M2?, was the system over/under spec'd`? what temperature are you running it at?, and what is the pump speed?

As for the Air source heat pumps for the holiday cottages, what make are they? ASHP are lot less money than GSHP's, much more accurate for calculating heat load, easier to calculate running costs, easier to install.

albyota

Mitsubishi Ecodan, Daikin Altherma, are good very Air to water HP systems and are on the MCS list, Sanyo CO2 are soon to be listed as we have put pressure on them. Other kit that is on the list, you have to look at very carefully as to Warranty, reliability, after sales, service and maintenance issues....

nethertonhall

The £166 / month is what I expect to pay / month over a year and would be measured at the meter - this would compare with £90 prior to install. I do have heat meters / input / output but are just working on the monthly total bill for electricity. For the COP calculations we take weekly readings from both input / output and allow for pump running when calculating - Danfoss are happy with this way.

We are engaged with our solicitor with Danfoss and having conversations - so far we are a long way from the calculated claim over 25 years we have submitted. I do believe this industry like others has suffered from some claims thay cannot support. I would be more than happy if they could show me the system giving me the 3 free units on average over a agreed time but they dont seem t be able to do this!

Heat loss calcs were done by an independent organisation who prepaired the SAP report - Danfoss then sized and configured the system to this report - It is refferenced in their quote. I am not sure of the details but could find the report if needed.

Operating temperature varies dependent on the heatcurve / outside temp - we have set a max of 50c and min of 35c (i think). Danfoss installers have played with the pump speeds - I know they dropped them and the underfloor heating struggled - they set them up a level and ok. Sorry I am unsure of the actual speed - I could get input / output temp if needed.

The ASHP for the cottage is one Hitachi Yutaki 9kw (they may need to change this as I cant see it is MCS accredited) shared between both cottages with a 400ltr tank and 100ltr buffer. They are calculating a seasonal COP of 3.8 - thats better than my Danfoss GSHP - so why did I go with GSHP and not air?

Hope this helps

nethertonhall

Sorry, I forgot to say my previous hot water was heated by electricity - economy 7 - this was in the £90 / month.

albyota

For the cottages, I would be putting a seperate Mitsubishi/Daikin 5kW in each with a 150 /180 L tank....would give better output and independance / metering /control than a shared system....Hitachi are not MCS listed equipment as yet.

nethertonhall

Albyota - thanks for this, I thought two systems would give greater flexability but both Danfoss and New Heat came up with the single config - not sure why, could it be to reduce start up load - we have limited supply!

I will let you know what units they re quote - I could not see Hitachi on the list!

What do you think of the performance / expected running costs on the Danfoss GSHP install, do they stack up?

Hermann

Ooohh is it this Netherton Hall?

http://www.netherton-hall.co.uk/index.html

Edit ... and also http://www.nethertonhall.co.uk