Air to Water Heat Pump Quote Received (Daikin Altherma 3H HT) 27 June 2021 at 1:46PM edited 27 June 2021 at 3:43PM in Green & ethical MoneySaving 17 replies 842 views

Screwdriva

Following successful installation and operation of our LG Bi-facial panel PV system, focus has now shifted towards reducing gas imports to heat our SE London Home.

We currently have installed:

1) Partial underfloor heating (only ground floor). 1st & 2nd floors have radiators
2) Megaflo tank and Bosch Greenstar 18Ri boiler. 
3) Gas fireplace

We consume 21000 kWh of gas energy for heating and hot water. This translates to around £800 per annum spent on heating and hot water.  

Our 3 primary objectives are:

1) To reduce emissions and recurring expenses (even if faced with a recoverable upfront cost)
2) To add cooling to our home for the summer months
3) To take advantage of the RHI payback scheme (estimated by the vendor to be £9000)

Below is the quotation received by a Daikin recommended supplier, New Heat Solutions:

Description of Proposed Works:

New Heat Solutions will drain down the existing central heating system to allow the decommission of the existing wall mounted gas system boiler. The existing boilers flue hole will be cemented internally and externally. The existing Megaflo will be drained down and removed as it does not have the required coil size rating for an ASHP.

To supply/install a Daikin Altherma 3H HT high temperature air to water heat pump in the rear of the property in agreed location with 28mm diameter primary flow & return pipework being installed to supply the existing hot water cylinder cupboard location. A 32amp rotary isolator will be located behind the outdoor unit for localised powering down of the system.

New Heat will supply/install a Daikin 300Ltr indirect unvented high gain hot water cylinder which is heat pump compatible along with all required control wiring for the Daikin system. A 22mm condense pipe will be run from the bottom of the ASHP outdoor unit and into the nearby external drain or into a made soak away installed by New Heat. The hydro-box which is of similar size to the existing boiler will be installed where the boiler was removed. Dimensions for the hydro-box are 800mm high x 380mm wide x 280mm deep.

Prior to the new Daikin unit being installed, the central heating system will be drained down and power-flushed using high quality cleaning/flushing chemicals which work to breakdown and eradicate any magnesium oxide sediment within the concealed system. This process takes a day to complete and involves radiator by radiator cleaning using our power-flushing unit with built in pump. A neutralizer chemical is used to remove all traces of the cleaning agent and inhibitor will be added on completion of the heat pump installation.

All pipework will be fully insulated using 19mm wall thickness pipe insulation to minimise thermal loss and protect against freezing in the adverse weather conditions.

The system will be filled and tested, drained to remove any traces of flux etc and then be refilled adding glycol which is a heat transfer fluid to provide protection of the outdoor unit’s heat exchanger and any external pipework from freezing in the adverse weather conditions. It also embodies inhibitors that provide adequate protection against the build-up of scale, corrosion, and magnesium oxide sediment within the concealed system. This will be followed by an air dispersing procedure to ensure all remaining air pockets are eradicated from the circuits.

New Heat will commission the new Daikin Altherma system thoroughly and leave heating & hot water operations in good operational working order. User interface tutorial will be provided to the end user and all warranties related to our kit registered with the relevant manufacturer.

On receipt of the final payment for the project, New Heat will begin the MCS application process and on completion issue a MCS certificate for the system.

Upon receipt of the balance payment, an MCS certificate will be produced and submitted to the homeowner which with the homeowner’s EPC (Electrical Performance Certificate) within two years old can be used to complete the domestic RHI application process at www.ofgem.gov.uk

Estimated RHI payback is around £9,000 but will require a recent EPC certificate number to confirm actual amount. The RHI payments are paid quarterly for a period of seven years from the completion of the application.

Total Cost - £13,626.77+ VAT @ 5%

Exclusions:

• Making good/Decorational Works

• Waste Removal

  
  

My preliminary questions to those with installed system are:

1) Is the Daikin high temperature solution the best available to achieve the above objectives?

2) What did you annual consumption/ expense change to? 

3) Is the above quote standard/ higher/ lower than normal?

4) What kind of cooling can one expect compared to air-conditioning?

Many thanks, in advance!

QrizB

Screwdriva said:

My preliminary questions to those with installed system are:

1) Is the Daikin high temperature solution the best available to achieve the above objectives?

2) What did you annual consumption/ expense change to? 

3) Is the above quote standard/ higher/ lower than normal?

4) What kind of cooling can one expect compared to air-conditioning?

Many thanks, in advance!

Re. your Q4. This system will not provide cooling. More generally, heat pump systems that provide cooling are not eligible for RHI payments. You can have cooling or you can have RHI but you can't have both in the same system.

matelodave

Ok my take on the quote- an HT system is desigend to run at the higher temperatures required for existing radiators and so may not be as efficient as a low temperature system with oversized radiators.(check on the proposed COP)

Most people seem to have a Low temperature system so you might find that info on running costs is a bit thin on the ground. However that said, the heating requirements for the house wont change (it will still need the same number of kw/hr a year to heat it as it would with gas) so if you require 21,000kwh a year for gas then you'll need 21,000 divided by the COP for leccy - assume a COP of 2.5 then 21000/2.5 = around 8400kwh of leccy.

If 21,000 of gas at 3p/kwh costs around £630 then 8400kwh of leccy at 15p/kwh will cost £1260 - twice as much which is about right

Dunno about the quote, although if I cant see why you should need a glycol antifreeze if the unit has an internal hydrobox and it fed with refrigerant from the external unit.

As QrizB says, an HT heapump wont provide cooling, only heat. For a system that provides cooling you need either a reversible heatpump with fancoil units, which might attract RHI as it's an Air to water system.

 However if you get an air-air system you wont get the RHI but you will get cooling.

It's also worth bearing in min that you'll use most energy in the winter when the days are short, the sun doesn't shine much and the solar panels wont be generating anywhere your leccy requirements. I reckon to use around 70% of my leccy consumption between November and March so take that into accoun when you are doing your sums

shinytop

I can't answer all the questions but your heat consumption is similar to ours and your quote is broadly in line with what we paid.  Daikins seems to have a good name. 

Was there any talk of replacing radiators?  It's not always necessary but sometimes is. If the supplier has not done a heat loss calculation then it's possible that when they do (using the MCS spreadsheet) they could find new radiators are needed.  If you can, it would be worth trying your gas heating out with the water temp reduced to 50 degrees or so.  It might be hard to guage the effect in summer but it might give you an idea. Or if you go to the Stelrad website you can size your own radiators based on your room sizes and house construction.  I did this and the results were similar to the MCS calcs.  

Reed_Richards

My LG ASHP is supposedly capable of cooling as well as heating.  However I cannot use it for cooling because:

1. That would contravene the requirements to receive the RHI.
2. That would contravene the Planning Permission waiver  

EPC stands for Energy Performance Certificate (not "Electrical").  That should be the first thing you do because the right wording on the EPC is crucial to getting the RHI (if the EPC says you need more loft or wall insulation that has to be done first and the EPC re-assessed).  My installer arranged for my EPC as the first step before anything else happened and it's a bit worrying that New Heat Solutions don't seem to take any responsibility in this area.  The other thing that was done way before the installation started was a heat loss survey, calculating the radiator requirements for each room (and corridor) and therefore the capacity of heat pump that would be required.  I'm pretty sure this is a requirement for MCS certification and doing that after the installation would be putting the cart before the horse - except that the cart is the heat requirement of the property and the horse is the the heat pump so you could end up with a huge cart and a horse too weak to pull it or a little cart and a huge horse, much bigger than is needed.

You should be able to achieve a promised CoP of better than 2.5 (in @matelodave's example) by replacing your radiators to allow a lower water temperature.  That would boost your RHI payments (if you can get them).  

Minor point but the amount of condensate water produced by my heat pump is huge compared to what a condensing boiler produces, I would recommend taking it to a drain if possible. 

 

Cardew

On a Money Saving Website, in the ‘Green and Ethical money saving’ section of the forum, to consider an initial outlay of £14,000 to double heating costs, and probably reduce the value of the property, seems remarkable. 

Reed_Richards

Screwdriva said:

Our 3 primary objectives are:

1) To reduce emissions and recurring expenses (even if faced with a recoverable upfront cost)
2) To add cooling to our home for the summer months
3) To take advantage of the RHI payback scheme (estimated by the vendor to be £9000)

If you are prepared to sacrifice objective number 3 then a few air conditioning units based on an air-to-air heat pumps may be what you need.  With the right type you can run these in heating mode in spring and autumn reducing the load on your gas boiler.  And you should get free cooling from your solar panels.

1. That would certainly reduce emissions and you could get enough of a CoP under those conditions (spring & autumn) to reduce recurring expenses a little.
2. You get the benefit of cooling.  But you might well never recover the full upfront cost
3. You don't get any RHI but the outlay is a lot less than an ASHP

shinytop

Cardew said:

On a Money Saving Website, in the ‘Green and Ethical money saving’ section of the forum, to consider an initial outlay of £14,000 to double heating costs, and probably reduce the value of the property, seems remarkable. 

This argument crops up quite often on MSE.  I thought MSE was about finding the best value for money for the things/services we want, not just spending the least money.   Don't you also find it remarkable people extol the virtues of £50k EVs on the EV forum?  At least there is some scope to shop around and get a good deal with an ASHP, unlike with the £50k EV.  

 

Coastalwatch

Reed_Richards said:

Screwdriva said:

Our 3 primary objectives are:

1) To reduce emissions and recurring expenses (even if faced with a recoverable upfront cost)
2) To add cooling to our home for the summer months
3) To take advantage of the RHI payback scheme (estimated by the vendor to be £9000)

If you are prepared to sacrifice objective number 3 then a few air conditioning units based on an air-to-air heat pumps may be what you need.  With the right type you can run these in heating mode in spring and autumn reducing the load on your gas boiler.  And you should get free cooling from your solar panels.

1. That would certainly reduce emissions and you could get enough of a CoP under those conditions (spring & autumn) to reduce recurring expenses a little.
2. You get the benefit of cooling.  But you might well never recover the full upfront cost
3. You don't get any RHI but the outlay is a lot less than an ASHP

I think you've got it spot on there RR. We've installed two air to air heat pumps at a fraction of the cost quoted here which supply all our space heating requirements and with a return figure of 4:1 places heating costs similar to that of harmful gases. Plus of course we get free air conditioning in the summer which is likely to show a growing benefit in the coming years given the experiences of what Canada is going through at the moment and the US & Oz prior to them.

Cardew

shinytop said:

Cardew said:

On a Money Saving Website, in the ‘Green and Ethical money saving’ section of the forum, to consider an initial outlay of £14,000 to double heating costs, and probably reduce the value of the property, seems remarkable. 

This argument crops up quite often on MSE.  I thought MSE was about finding the best value for money for the things/services we want, not just spending the least money.   Don't you also find it remarkable people extol the virtues of £50k EVs on the EV forum?  At least there is some scope to shop around and get a good deal with an ASHP, unlike with the £50k EV.  

 

Yes I certainly do find it remarkable how some people attempt to justify a £50k+ EV. However there is at least an argument - however weak - that an EV reduces running costs and are very smooth to drive. Also there are many types of EV, both new and second hand so plenty of scope to shop around.

However in this thread the OP, who has Gas CH, and has asked for comments on his detailed £14k quotation. Even if he shopped around and shaved a couple of grand off the price I would still be of the opinion that it was a remarkable decision.

Reed_Richards

@Cardew I think you may be looking for the MoneyHoardingExpert forum where you can discuss wearing plenty of clothes and so not bothering with central heating.  Over on this forum it's more about spending on what you choose (or have) to but saving money on so doing.  Regrettably, trying to be green (or ethical) often costs more (in the short term).  Choosing to be green when it costs more may strike you as "remarkable" but it strikes me as remarkably good.