Air Source Heat Pumps

kellogs71

just floating through the forum reading peoples problems etc. I had a heat pump fitted in October last year and its d=saved me £1,800 per year. Admitedly I have a large house, 6 bed and the gas boiler was old. i switched to Eon where the discounted rate for elec is around 7p making the break even for a heat pump a COP of 2.3. I used a local company who only launched themselves last year and I have to say their heat pump was everything they said. The COP is 3.5(at 6/7C) producing water at 50C which is enough for my size of radiators. I did alot of research beforehand and found that condensing boilers do not condense at temps above 60C. Thus seeing that a heat pump produces water at 60C then if I needed larger radiators for a heat pump, I would need larger radiators for a condesing boiler too. Ive been told I will be eligible for the RHI scheme when (if) it goes live in APril next year. Thats a payment I will receive from Ofgem of around £2,500 every year. Its a no brainer. Alfie, maybe your problems are over. They install their system for around £4k! Anyway, since this company is local, I will give them a plug- huskyheatpumps.co.uk

Cardew

kellogs71 wrote: »

just floating through the forum reading peoples problems etc. I had a heat pump fitted in October last year and its d=saved me £1,800 per year. Admitedly I have a large house, 6 bed and the gas boiler was old. i switched to Eon where the discounted rate for elec is around 7p making the break even for a heat pump a COP of 2.3. I used a local company who only launched themselves last year and I have to say their heat pump was everything they said. The COP is 3.5(at 6/7C) producing water at 50C which is enough for my size of radiators. I did alot of research beforehand and found that condensing boilers do not condense at temps above 60C. Thus seeing that a heat pump produces water at 60C then if I needed larger radiators for a heat pump, I would need larger radiators for a condesing boiler too. Ive been told I will be eligible for the RHI scheme when (if) it goes live in APril next year. Thats a payment I will receive from Ofgem of around £2,500 every year. Its a no brainer. Alfie, maybe your problems are over. They install their system for around £4k! Anyway, since this company is local, I will give them a plug-xxxxxxx.co.uk

Firstly you are not allowed to give companies 'a plug!!'

Secondly a heatpump system for a 6 bed house costing £4k?

How do you reach a figure of £2,500 pa from RHI? - especially retrospectively.

KG-THPP

2.5k is roughly the return of a 16-17kW system.
Perhaps an imported chinese low cost unit.

peat

An imported Chinese one would not be MSC accredited therefore not eligible for RHI

KG-THPP

peat wrote: »

An imported Chinese one would not be MSC accredited therefore not eligible for RHI

Unfortunately, neither are the installers on the MCS approved lists at this time.
You would have to wait until both the installers and this unit were approved by the MCS BEFORE installation to benifit from the RHI.

bernidefish

albyota wrote: »

Hi, firstly.... minus 20 at night.....(when you are asleep) for how long? how many Days/weeks? In Austria (correct me if I'm wrong) your houses have far better insulation levels and good quality tripple glazed windows. Most good quality Air Source Heat Pumps (Mitsubishi, Daikin, Sanyo amongst others) work down to minus 25 degrees. With flow temperatures of 35 - 40 (avg 37) for use with underfloor heating systems, they work at their most efficient at lower water flow temperatures, and can still look after the domestc hot water (60 degrees). Underfloor heating when installed correctly, with the thermal mass of the concrete screed acts like a storage heater so (Heat loss) will not be noticed when the unit goes into defrost. (4 mins/hour)
Solar P.V will have to be grid tied but with the correct array i.e. amount of panels, this should offset the extra electricity usage.

We have gone ahead with the a s h p and ordered one made by Hoval.
The initial pipework is in and we are now waiting for windows, plasteres and floor screed.
I am very optimistic on our system as our insulation is very very thick all over the new house.
we are also going to install a wood burning stove in the lounge which will also heat the water in the house. This should allow the heat pump to not have to run so much in the colder days of winter.
We expect to be able to move in around crimbo or new year. i will keep you all posted as to how efficient the whole system is.:T

Cardew

bernidefish wrote: »

we are also going to install a wood burning stove in the lounge which will also heat the water in the house. This should allow the heat pump to not have to run so much in the colder days of winter.

Not clear on the configuration of your system.

When you say 'also heat the water' I assume you don't mean the wood burner is connected into the radiator/underfloor heating system?

How will you heat hot water in the summer?

This should allow the heat pump to not have to run so much in the colder days of winter.

The above quote seems to indicate that the heat pump will be providing the hot water.

I take it you are aware of the dangers in connecting stoves to other heating sources without sophisticated(and expensive) safeguards?

realsurfer

I hope this is appropriate but if not I will start a new thread.
My mother is to have an ASHP and oversized radiators fitted free under a scheme from HEES delivered by eaga. Great its free. However when the eagaheat installation engineer came to draw up the plans he said that the pipework had to be in the ceiling and down the wall and across the skirting to each radiator because he was Quote "not allowed to bury the pipework in concrete".
Since then I have discovered the bungalow has screed floor into which are neat channels (4 "x 2" with mdf sides and removable tops) that carry the existing pipework for the old lpg central heating. When I recently asked him to reconsider and put the pipes to the radiators in the existing ducting he has said that it was under the rules of the grant scheme that he was not allowed to run pipework under the floor and all had to be from the ceiling down. Anything else would be in danger of failing inspection and he would be forced to have it replaced at his cost. Frankly this doesnt ring true considering the suitability of ASHP and underfloor heating. I wonder if anyone has experience of ASHP and radiator installation with eaga or Warmfront under grants that can comment?
Obviously I don't want to hack off the installer company by repeatedly questioning the truth but I wonder how to find out the rules that govern this installation.
Thanks

KG-THPP

These schemes get the job done for nothing but don't look very good on the eye. I could only speculate on why an installer (who would have quoted at lowest cost) would seek to do the job as quickly as possible, when he is payed per installation by the government.

bobmedley

Interesting comment in the article;

"Unlike conventional boilers, that you can retrofit relatively easily, heat pumps are very, very sensitive - it is imperative they are designed to heat the relative load; if they are undersized or oversized, then the efficiencies are significantly reduced."

I know that bigger units tend to have lower COPs, but the EST state that oversized units are signifcantly lower in efficiency, so being oversized is not a good thing?

http://www.bbc.co.uk/news/science-environment-11200063