Air to water heat source system

albyota

Cardew and new and existing readers, owners of heat pump systems, people who are looking into such a purchase.

I know you mean well with your advice, but lets have balance.

Let prospective purchasers research for themselves with unbiassed information, I'm sure, if they are likely to be spending £10K on anything, they will research fully....then ask for recommendations from installers, neighbours etc...as one would make with any purchase of this importance. They are not likely to just read this forum.
If they do....They will heed your warnings/advice, and mine and others.

for those looking for information here are some links.

There will be no need for any of us to cherry pick to suit.

http://www.eci.ox.ac.uk/publications/downloads/fawcett11b.pdf

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48327/5045-heat-pump-field-trials.pdf

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/48574/4805-future-heating-strategic-framework.pdf

http://oro.open.ac.uk/31521/1/

https://restats.decc.gov.uk/cms/assets/Uploads/Results_2011/ABSTRACT-energy-production-in-2011-from-heat-pumps-in-the-UKv2FINAL.pdf

https://www.gov.uk/government/uploads/system/uploads/attachment_data/file/153584/rhi_rhpp_deployment_data_march_2013.pdf

See you all back here in a month......when you have read all of the above.;)

lovesgshp

Such a pity, that in the UK that they do not do the same system as we have in Italy. Here for the past 5 years, you have been able to claim 55% of the costs back for a renewable energy system through your income tax over 5 years, for a retrofit system. It includes all costs associated with achieving a minimum 20% saving off the system you were previously using. So double glazing, plumber/electrician costs, loft insulation, extra insulation are all covered, subject to invoices being supplied. We also have a much lower electricity tariff for heat pumps through a dedicated meter.
VAT on the above is also reduced to 10%, unless it is a new house where 4% is applied, but you cannot also get the 55% off.

crash_ndie

as an installer PLEASE make sure the survey is done right ! If they undersize the a/s pump it will never be off and costing shed loads to run for very little heat. If you have an existing central heating with radiators DON'T fit low temp air source, UNLESS you are going to fit new over sized radiators to cope with the lower running temp of the air source and factor this in to the sizing of your chosen pump. I would recommend Hi temp air source pumps such as the dakin altherma ht. hope this helps:)

albyota

Hi, have you got a Daikin Altherma HT fitted in your house?

crash_ndie

yes in both of mine, and i must say am impressed with them cheap easy to use although it is a bit slower to reach max temp than a boiler but is cheaper than oil !!

matelodave

As a response to Cardew & others, yest I've read the EST report and Whitch? as well. I also read up on a lot of other stuff before I made up my mind what to install.

A lot of systems have been sold by salesmen rather than system engineers and I would always be wary of someone trying to flog me a system based on savings alone in the same way that I wouldn't buy double glazing from a door-to-door salesman however there are millions of people out there who are easily conned.

I would agree that there are a lot of poor installations out there and the EST/Which reports were based on earlier installation whilst people were learning how to put the systems in - thats no excuse for poor system design or installation but I'd hope that later systems would be better designed and implemented.

As I said previously the system works differently to a conventional system and it's pointed out in the reports that some of the controls are overly complicated - I'm not sure whether thats a feature of the heat-pump it'self or the system design - some are more complex than others. I would suspect that a lot of the poor performing systems are not setup properly and possibly being tweaked by their owners.

It's not easy to see from the reports whether the systems have been optimised and the controls monitored as well or they've just done a relativly simple electical input/ heat output measurement. Unmonitored fiddling could make a big difference to the results. (I have to keep my wife away from the controls otherwise it all goes haywire)

I've got a Daikin LT system and the HP programmer is a bit complex to set up and could be made a lot easier to drive than it is - although you could argue that once it's been optimised it dosen't need to be fiddled with. Likewise because of building regs, some systems have more controls on them than you could shake a stick at and it all makes the system a lot harder to set up and optimise especially if the householder doesn't have a clue.

I would think that there could be a good case for a properly networked control system that could be managed/adjusted remotely so it could be optimised by an "expert" from the installation company or controlled by a laptop or smartphone by the user. It has taken me some time to get it running the way I want and to suit my lifestyle and I have two pages off settings recorded.

dullnote

Hi I have read this for or against ASHP on this site for approx two years,no one will win. I installed a ASHP in sep last year, removing a LPG boiler, two year old, house is now warm all day, and running cost down.

It is a simple matter of horses for courses, get the house insulated, remover the heat pump will have to run all day so if you intend only to heat house at night and morning heat pump may not be the right thing.

Heat pump is low grade heat, lower the temp better efficiency mine running at 35 degrees no use for radiators.

I am very happy with my system, also glad for this forum, which made me looking the systems and question my logic before buying. Was stil offered systems which were far from adequate so much so when I asked for calculations never heard from them again.

In short ASHP in the right house, proper design and installation, with you knowing there limitations and there benefits, they will save you money compared with LPG, will never save you money over mains gas

lovesgshp

dullnote wrote: »

Hi I have read this for or against ASHP on this site for approx two years,no one will win. I installed a ASHP in sep last year, removing a LPG boiler, two year old, house is now warm all day, and running cost down.

It is a simple matter of horses for courses, get the house insulated, remover the heat pump will have to run all day so if you intend only to heat house at night and morning heat pump may not be the right thing.

Heat pump is low grade heat, lower the temp better efficiency mine running at 35 degrees no use for radiators.

I am very happy with my system, also glad for this forum, which made me looking the systems and question my logic before buying. Was stil offered systems which were far from adequate so much so when I asked for calculations never heard from them again.

In short ASHP in the right house, proper design and installation, with you knowing there limitations and there benefits, they will save you money compared with LPG, will never save you money over mains gas

We did a study over here in Italy a few years ago now , albeit for a GSHP unit, compared to LPG and mains gas. This came out that on LPG the break even point for the installation without the incentives, that were introduced after the study were 4 years. Mains gas came out at circa 7 years.
Having had a gshp unit for over 6 years now, my electricity consumption for the whole house 250 years old is around 10,000 Kwh a year, with low/medium insulation.

dullnote

Without incentives I would think the break even point would be 5 years for me.

But my house is much warmer and very comfortable, compared with LPG

Cardew

dullnote wrote: »

Without incentives I would think the break even point would be 5 years for me.

But my house is much warmer and very comfortable, compared with LPG

Could you please give a breakdown of your figures for a break-even point in 5 years.

As I understand it, you had an existing 2 year old LPG boiler removed and fitted a ASHP.

Most people pay £10,000+ for an ASHP system. If that is the case you must be saving £2,000pa on heating and hot water??

LPG costs approx 7p/kWh. The average house uses 16,500kWh gas for heating/hot water so that should cost £1,155 pa with LPG.

With a 2 year old boiler you should get at least 80% efficiency - so 13,200 kWh. delivered heat.

If you were lucky enough to get an ASHP that gave an overall COP of 3.0, that means you would consume 4,400kWh electricity at, say, 12p/kWh and cost £528.

So for that 'average' house the savings would be around £600.