Air to water heat source system

matelodave

Here's a breakdown of my heat-pump costings

The unit - Daikin 11kw LT system including a 200l pressurised hot water tank cost me £7995 + 5% vat fully installed and commisioned in 2010. I'm not sure what an LPG or oil installation would have cost but with the civil works for the tank plus the aggravation of an external tank & pipework I'm guessing about 4K + 17.5%vat

I also got the u/f heating system at 5% vat insted of 17.5% so that was another substantial saving. So ignoring any savings for vat on the actual heating system etc I reckon my heatpump cost me about £3.5-4k over an oil or lpg system.

Now to actual running costs. I estimate that the heat-pump is using about 4500-5000kw of electricity a year costing 10.6p a unit (last year it was 10p a unit) so it's costing about £500 a year for heat and hot water.

Using Cardew's estimation of what lpg would cost for an average home (and I reckon a 140m2 detached bungalow built in 1986 is about average - it also correlates with our MCS certificate estimate for heating of 13741kw) it would cost us about £1155p/a which means we are "saving" £655 a year. So if the h/p cost us £4k more then we'd break even in just over 6 years.

I can't be ever so precise because I dont have a heat meter and the h/p consumption is included in the whole house, but based on what we use in the summer versus what is used in the winter then 4500-5000kw is a reasonable estimate.
With our electricity at 10.6p/unit and an annual estimated heat requirement of 13741kw then we are paying less than 4p a kw for our heating and hotwater needs, which I dont think is all that bad, however I confidently expect it to increase a bit when our present fixed deal runs out in November.

We didn't get any up-front payments nor am I expecting a RHI payments

The only incentive I've had was the 5%vat and thus we paid £1000 less for the heating system as well (as it became part of the total installation). So we should break even at about 5 years unles the price of lpg or oil plummets in the meantime.

Cardew

matelodave wrote: »

Here's a breakdown of my heat-pump costings

.

I would agree that a well set up ASHP that achieves a COP of 3.0(many don't) could save around £500 over a LPG system.

You have based your savings on a £4,000 difference between installing oil/LPG and your heat pump. However 'dullnote' already had a two year old LPG boiler which he took out and states his break-even point is 5 years.

Incidentally I would think that a £4K difference is on the low side for many people; and of course you need to take into account the interest payable for a loan, or lost interest on the capital if you pay cash.

matelodave

Cardew wrote: »

I would agree that a well set up ASHP that achieves a COP of 3.0(many don't) could save around £500 over a LPG system.

You have based your savings on a £4,000 difference between installing oil/LPG and your heat pump. However 'dullnote' already had a two year old LPG boiler which he took out and states his break-even point is 5 years.

Incidentally I would think that a £4K difference is on the low side for many people; and of course you need to take into account the interest payable for a loan, or lost interest on the capital if you pay cash.

I can only think that your total animosity and desperation to denigrate heatpumps is either that you have a vested interest in someting else or that someone has really upset you.

It appears that you find it really hard to accept that they do work for a lot of people and for some reason have a need to get the last word in everytime to try and shoot them down

dullnote

Hi the system cost me £6k after getting the £1k back from the government and some money back from the ASHP supplier.

My running costs, LPG cost £166 a month, now paying £96 a month for all electric, taking off £36 a month for normal use leaves £60 a month for the heating. Taking meter readings every week over the winter I think I am low will cost approx £850 a year to run, so saving just over £1k, so pay back just over 5 years.

Please note house is well set up for the system, which runs at 35 degrees and house is well insulated, also remember I have not added the cost of the LPG boiler, wrote that off as a error in building the house approx cost £850 trade price and friend gas safe plumber so fitting cost nothing, taking that into account pay back 6 years.

Cardew I must thank you because of you I spent much more time looking at my house and proposed systems , I may be luck, good installation, matching way of life to max out efficiencies of the system, or a bit of all, but I am very happy with the system and glad I have fitted it

[Deleted User]

dullnote wrote: »

Hi the system cost me £6k after getting the £1k back from the government and some money back from the ASHP supplier.

My running costs, LPG cost £166 a month, now paying £96 a month for all electric, taking off £36 a month for normal use leaves £60 a month for the heating. Taking meter readings every week over the winter I think I am low will cost approx £850 a year to run, so saving just over £1k, so pay back just over 5 years.

Please note house is well set up for the system, which runs at 35 degrees and house is well insulated, also remember I have not added the cost of the LPG boiler, wrote that off as a error in building the house approx cost £850 trade price and friend gas safe plumber so fitting cost nothing, taking that into account pay back 6 years.

Cardew I must thank you because of you I spent much more time looking at my house and proposed systems , I may be luck, good installation, matching way of life to max out efficiencies of the system, or a bit of all, but I am very happy with the system and glad I have fitted it

Hi,

Nice to read your running costs

Figures similar to my myself for both the LPG then the ASHP.

Recently installed the solar immersion which from looking at my spreadsheet of readings is working well. Currently chipping into, what was the leccy bill prior to the ASHP, by initialy fitting LEDs to replace the regularly used halogen lights. Then there are all the standby items etc... Lot's of scope to further reduce bills.

Cheers

Cardew

matelodave wrote: »

I can only think that your total animosity and desperation to denigrate heatpumps is either that you have a vested interest in someting else or that someone has really upset you.

It appears that you find it really hard to accept that they do work for a lot of people and for some reason have a need to get the last word in everytime to try and shoot them down

Your assumptions are incorrect, and I see little point in trying to make this a personal issue.

Of course I accept that heat pumps work for some people - the WHICH article suggests 13%!

The study found that only 13% of all sites in the trial achieved a level of efficiency the EST considers to be a 'well-performing' system, with the rest scoring below this benchmark. Ground source heat pumps were found to be slightly more efficient than air source heat pumps.


The report concluded that the worst-performing sites illustrate how customers need to be completely sure they're investing in the best system for their property and lifestyle.

See post #37.

bernithebiker

We have a 10k Euro 10kW air/water heat pump in one gite (France) that replaced LPG. Underfloor heating, + a few rads.

Very pleased with it despite some teething problems, we are now spending 400 Euros/year on heating instead of over 1000. (hot water is by immersion as before).

Also have fitted 3 other gites with a 4-5kW air/air heat pump each (2 cheapos + 1 Mitsubishi). Current heating is LPG, elec rads, and fuel respectively.

Very pleased with them too. Each one has cut down on the main heating bill significantly, and they are very quiet too. The Mitsubishi has a COP of up to 5.3!

I would say very roughly that the cost of 1kW of elec = 1kW from LPG = 1kw from fuel. Therefore, if I can get a COP of 4 from my heat pumps (and I don't see why not, winters are mild in Brittany) then I am saving 30c for every hour that they run. (10c/kwH)

10 hours per day = 3 Euros = 21 Euros per week = 84 Euros per month, = 500 Euros per winter.

This means the cheap air/airs are paid off in less than 2 years, and the Mitsubishi 3 to 4 years.