Going from Coal to Air Heat Source Pump and PV's using ECO4 grant scheme

Pec123

QrizB said:

Pec123 said:

What do you think?

In all honesty, they're an installer. You shouldn't need any technical support from them once the system is installed, and if you do have questions, it's probably better to email them and get a reply in a couple of days.

What questions do you have? Could you list them here?

It was regarding the flow rate a few posts above or can we tinker with that after the install?

And we need to maybe ask to change radiators as posted as we are getting them for free under ECO4?

QuestioReed_Richards said:

In order to use a lower flow temperature and cut your costs the two difficult rooms to deal with are the kitchen and the lounge.  These are already specified as k2 radiators and you would need a larger output in both cases.

Kitchen: Is there room for a larger radiator, perhaps a vertical one that is 800 cm long but, say, 1400 cm high?

Lounge:  Is there room to fit a bigger radiator, like the one intended for the dining room?  Or if not, is there room for a second radiator?

QrizB

You should be able to tinker with flow rates.

You can certainly ask the installer what flow temperature they have designed for, and (if you don't like the answer) ask if they could size radiators for a lower one. However, if you set it up correctly, your system will only need the max flow temp on really hard winter weather.

I've got gas (not a heat pump yet) and I suspect my system was designed for an 80C flow temp. But it's rare that I need more than 50-55C.

Pec123

Thank-you I have asked the installer to design for a flow temperature of 45C but they have said we may need to contribute to the bigger radiators.

Is there an ombudsman for this kind of thing because I can see quite a few people who are entitled and not receiving a good system. I am sure there must be cowboy outfits making a quick buck!

Pec123

Yes, there is an ECO4 ombudsman. If you need to make a complaint about an energy efficiency measure installed in your home, you can follow the steps outlined below to resolve your complaint 1:

Find out when the measure was installed.

Find your paperwork and contact the installer.

Find your guarantee of warranty.

Contact the relevant oversight body.

Contact the energy supplier.

Alternative options.

If your complaint has not been resolved within 8 weeks or if you are not happy with the provider’s response, you can contact the Green Deal Ombudsman 2 at enquiries@os-energy.org or by calling 0330 440 1624.

Please note that this information is current as of November 2023 and may be subject to change.

1: https://www.ofgem.gov.uk/eco4-complaints-process 2: https://www.gov.uk/complain-green-deal

Reed_Richards

I would really strongly recommend that you try to get the central heating flow temperature reduced to 50 C at maximum.  To do this you would need some radiators to be bigger (i.e. have a larger surface area) and your kitchen and your lounge are the two rooms where this looks as if that will be most difficult.  Also, with the present arrangement it's quite important where your room thermostat and controller are sited.  If they are in the dining room, which has a huge radiator, that room will heat up quickly and then other rooms may remain cold.

When I had my heat pump installed we went through three attempts to get the right arrangement of radiators before the installation.  And even after that there are a couple of things now that I wish we had done differently. 

Reed_Richards

QrizB said:

You can certainly ask the installer what flow temperature they have designed for, and (if you don't like the answer) ask if they could size radiators for a lower one. However, if you set it up correctly, your system will only need the max flow temp on really hard winter weather.

This is both true and misleading.  If you set the system up to operate with a flow temperature of 55 C instead of (say) 50 C it will only need to run at 55 C in the coldest weather but throughout the year it will run at 5 C higher than for the 50 C set-up so it will be less efficient and more expensive to run every day that you require heating.

Pec123

Reed_Richards said:

QrizB said:

You can certainly ask the installer what flow temperature they have designed for, and (if you don't like the answer) ask if they could size radiators for a lower one. However, if you set it up correctly, your system will only need the max flow temp on really hard winter weather.

This is both true and misleading.  If you set the system up to operate with a flow temperature of 55 C instead of (say) 50 C it will only need to run at 55 C in the coldest weather but throughout the year it will run at 5 C higher than for the 50 C set-up so it will be less efficient and more expensive to run every day that you require heating.

Does that mean 45 C is too low?

QrizB

Pec123 said:

Reed_Richards said:

QrizB said:

You can certainly ask the installer what flow temperature they have designed for, and (if you don't like the answer) ask if they could size radiators for a lower one. However, if you set it up correctly, your system will only need the max flow temp on really hard winter weather.

This is both true and misleading.  If you set the system up to operate with a flow temperature of 55 C instead of (say) 50 C it will only need to run at 55 C in the coldest weather but throughout the year it will run at 5 C higher than for the 50 C set-up so it will be less efficient and more expensive to run every day that you require heating.

Does that mean 45 C is too low?

The ECO4 scheme will have rules that the installers have to meet.

Those rules might permit a 55C flow temperature from an ASHP.

If you want them to do better than that, whether 50C or 45C, you might have to pay the difference (since the scheme won't cover it).

Reed_Richards

It would be a very bad thing if the Eco4 scheme rules do permit a 55 C flow temperature from the ASHP.  That will give you a system that has a lower SCOP than for a 50 C flow temperature and so a higher running cost.  And this scheme is for people with low incomes and/or are on benefits, the last thing they need is a heating system that costs more to run than it might do.

45 C is not too low; it's really good but it might be more difficult to find suitable radiators in rooms where there is limited space to fit one.

Here's an example of a radiator scheme that would work at 45 C flow, a bit less actually

Room	Heat loss?	H x L	Type	Manufacturer		Divisor	Output	% of required
dining room	725	700x1600	k2	centre rad	3195	3.0 (HEG)	1065	147%
kitchen	824	700x1600	k2	centre rad	3195	3.0 (HEG)	1065	129%
bedroom 1	490	450x1400	k2	centre rad	1954	3.0 (HEG)	651	133%
lounge	822	700x1600	k2	centre rad	3195	3.0 (HEG)	1065	130%
hall	253	600x1000	k1	centre rad	949	3.0 (HEG)	316	125%
bathroom	663	700x1000	k2	centre rad	1982	3.0 (HEG)	661	100%
bedroom 2	404	600x900	k2	centre rad	1575	3.0 (HEG)	525	130%
bedroom 3	587	600x1600	k2	centre rad	2828	3.0 (HEG)	943	161%
	Total						Total
	4768						6291

I have changed every radiator except the ones in the dining room, the hall and in bedroom 3.  The figure in the new 5th column is the radiator output at a delta T of 50 C, taken from the CenterRad Compact leaflet on the Wolsey website.  I have divided this number by 3, rather than 1.9, which corresponds to a Delta T of about 22 C.

To get enough heat output in the kitchen and the lounge I have used the same large radiator as was suggested for the dining room and you would have to look and see if there is actually room for a radiator that big, particularly in your kitchen as kitchens rarely have much blank wall space.  The actual power consumed by all these radiators combined is less (by over 1 kW) than in the scheme that was suggested because they are running at a lower temperature.  The radiator in the bathroom is the least powerful compared to the actual requirement so there's room for improvement there, perhaps a smaller radiator and also a heated towel rail?

Please note that this is all based on guesswork that I am correctly interpreting the figures given to you.

Pec123

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