Taking the plunge Daiken Altherma HT

Cardew

Geotherm wrote: »

Could not find the original manufacturer details, from the EST trial, but came up with some other information from field trials in Germany and Switzerland from EST and another source. There you can see that ASHP's performed well. Obviously we do not know what insulation levels/ thermal loss in the properties are, but, it shows that the units can operate in temps, that can be the same or lower than the UK.
I cannot see why Earth Energy Systems could be the specialist ASHP heat pump contractor, as they are bore hole and GSHP providers, as their website says.
http://www.earthenergy.co.uk/

The other links I mentioned:
http://www.gshp.org.uk/documents/1ESTFieldTrials.pdf
http://www.all-energy.co.uk/userfiles/file/jennifer-arran-180511.pdf

Thanks - The UK results for ASHPs compared with German and Swiss systems are abysmal - and Germany and Switzerland have colder winters than UK(I lived there for years!)

What I fail to understand is the role of the Manufacturers during the EST trial. You would think that they and the other technical experts would very easily be able to identify glaring errors in installation that caused such poor performance. Yet the trial has been extended for a year to find reasons.

The field trial has been extended for a second year to:
• Collect data for an additional year
• Attempt to improve underperforming sites
• Identify and understand good performing sites
• Undertake additional analysis of existing data
• More engagement with manufacturers & installers
• Add new sites

These are the issue they will be giving attention:

• Load factors?
• Are the sinks and sources large/small enough?
• System sizing?
• Were the installations under or oversized?
• Use of controls?
• Can the occupants use the controls?
• Customer behaviour?
• Do certain lifestyle patterns or tenure type affect the results?
• Insulation and air tightness?
• Do heat pumps in well-insulated houses perform better?
• Better now with MCS?
• Has MCS improved the quality of installations ?

TiredGeek

Cardew wrote: »

If a firm installs, say, an Ecodan in an unsuitable house, or installs it badly, there should be some comeback – IMO Mitsubishi should take on some responsibility.

I'm not going to point any fingers at Mitsubishi as I've gone over the heads of my installer and spoken directly to their technical who were very helpful, but regrettably unable to assist.
I did glean they are keen to protect the product and are not happy at all when the EcoDan starts to feature in discussions about problems on forums. I also think they do take an interest on the QT, I won't say more for fear of upsetting someone

Personally, and I'm shocking myself by saying this, I don't think it's the EcoDan per se at fault. I place the blame for my problems squarely on the shoulders of the installers.
They had plans of the house, they had a SAP report, they did a survey, there was nothing hidden from them and they said it would work and be cheap to run. It is neither.
I think if the units are installed correctly, plumbed correctly, and the house is suitable, then the system has potential to be brilliant.
Unfortunately, my house fits non of those criteria, and I'm left with an unreliable and expensive to run heating system.

REAL are showing some promise, but before they will do anything other than write to the installer they require a BRE engineers report. That's costing, well lets just say I could have fitted an oil boiler for the cost of them going through all the paperwork and doing a site survey, followed by a written report!
It may be worth it though as they have already flagged a couple of things that may prove useful if (when) we end up in court

What we really need is for somebody, REAL for instance, to underwrite the industry.
If the "installer" promises something, and the system can be shown not to provide it, then REAL should step in, pay for an examination, and refund the customer if the complaint is upheld, then chase the installer to refund them.
That way the customer is protected to a degree and REAL would grow some b***s as it's their own money they're chasing.

TiredGeek

I looked at air to air heat pumps initially as that is what my brother uses with great success in northern Norway. I figured if they work there then northern Scotland won't be an issue. Maybe I should have gone for those, but fitting would have been a nightmare through the thick stone walls, so air to water seemed to fit the bill better..... we all know how that went :mad:

I also fail to understand why the various companies techies can't spot the problems at a glance. They should know the things inside out and be able to know whats wrong within a few minutes.
Maybe they have fixed them, and the test is going to run a further year to see what effect it's had?

lovesgshp

Tiredgeek.
Without going back through a lot of old posts, what is your house sq mtr, UFL or rads and ASHP pump size?

lovesgshp

Hi Cardew.
What I fail to understand is the role of the Manufacturers during the EST trial. You would think that they and the other technical experts would very easily be able to identify glaring errors in installation that caused such poor performance. Yet the trial has been extended for a year to find reasons.

I also wonder to what extent they were involved, or were they just on the end of a phoneline. They should have been able to comment on the EST report, as to what they thought the reasons for poor performance of their own units. My view is it is mainly down to poor/inexperienced/badly trained installers in the first place.

Cardew

TiredGeek wrote: »

I'm not going to point any fingers at Mitsubishi as I've gone over the heads of my installer and spoken directly to their technical who were very helpful, but regrettably unable to assist.
I did glean they are keen to protect the product and are not happy at all when the EcoDan starts to feature in discussions about problems on forums. I also think they do take an interest on the QT, I won't say more for fear of upsetting someone

Personally, and I'm shocking myself by saying this, I don't think it's the EcoDan per se at fault. I place the blame for my problems squarely on the shoulders of the installers.
They had plans of the house, they had a SAP report, they did a survey, there was nothing hidden from them and they said it would work and be cheap to run. It is neither.
I think if the units are installed correctly, plumbed correctly, and the house is suitable, then the system has potential to be brilliant.
Unfortunately, my house fits non of those criteria, and I'm left with an unreliable and expensive to run heating system.

REAL are showing some promise, but before they will do anything other than write to the installer they require a BRE engineers report. That's costing, well lets just say I could have fitted an oil boiler for the cost of them going through all the paperwork and doing a site survey, followed by a written report!
It may be worth it though as they have already flagged a couple of things that may prove useful if (when) we end up in court

What we really need is for somebody, REAL for instance, to underwrite the industry.
If the "installer" promises something, and the system can be shown not to provide it, then REAL should step in, pay for an examination, and refund the customer if the complaint is upheld, then chase the installer to refund them.
That way the customer is protected to a degree and REAL would grow some b***s as it's their own money they're chasing.

I accept that there is nothing fundementally wrong with the Ecodan(and other manufacturers ASHPs). However surely if Mitsubishi allow their systems to be bought and installed by 'cowboys' then they must shoulder the responsibility.

After all it is Mitsubishi that advertise their Ecodan can achieve at least a COP of 3 and work at -25C.

It surely wouldn't take more than half a day for a Mitsubishi expert to visit a property and give an approved installer a specification.

Hopefully they would be honest enough to tell a potential customer that their house simply wasn't suitable for an ASHP.

TiredGeek

Cardew, I hear you. I tend to agree also, they should take a much more active role, particularly if the system proves to be "troublesome". It's more their reputation that suffers than the instaler, you'd think they'd realise that wouldn't you? I think they prefer to work in the background at the moment without taking a direct customer facing role, it's a mistake, maybe they'll realise eventually.

A quick rundown for Geotherm:
~170sq/m total. 700mm thick solid stone walls, oversized rads (32 rads in total, mostly doubles), 28 & 22mm pipes, loft insulation to 400mm, no wall or floor insulation possible. Fully double glazed. SAP report said we needed 16kw, fitted two 14kw Ecodans to give headroom for very cold weather. Approx running costs - £10/day using either one or both ASHP, somedays less, somedays more. Far north coast of Scotland.

grahamc2003

Cardew wrote: »

I accept that there is nothing fundementally wrong with the Ecodan(and other manufacturers ASHPs). However surely if Mitsubishi allow their systems to be bought and installed by 'cowboys' then they must shoulder the responsibility.

After all it is Mitsubishi that advertise their Ecodan can achieve at least a COP of 3 and work at -25C.

.

While the ecodan may work (depending on what that means!) at -25, the user may not be too pleased with how it works, or the cost of it working at those temperatures.

I can't recall whether the graphs I've seen for the cop vs ambient temp were for the ecodan or not, but they explicitly showed the cop falling below 2 for low temperatures - and that ignored the (very energy costly) effect of defrosting. The lowered cop is just physics anyhow, no amount of better design can stop that cop fall off (although better design can affect the rate of cop fall off)., so I'd expect the ecodan to 'suffer' in a similar manner. For them to say it always has a cop above 3 is perverse imv, and just gives users unrealistic expectations of low temperature performance, and that's for a perfectly installed system.

Like others, I expect the poor UK performance overall is due to poor or sloppy installation.I know with air-to-air systems, the correct amount of refridgerant is quite critical, and some pre-loaded systems have to be drained (by a calculated amount) depending on the pipe run length, or have to have extra refrdgerant added, again calculated on site from the pipe run. I don't know whether air to water systems have exactly the same critical procedures during installation, but I bet they have a few of their own.

lovesgshp

Thanks TiredGeek.
A quick rundown for Geotherm:
~170sq/m total. 700mm thick solid stone walls, oversized rads (32 rads in total, mostly doubles), 28 & 22mm pipes, loft insulation to 400mm, no wall or floor insulation possible. Fully double glazed. SAP report said we needed 16kw, fitted two 14kw Ecodans to give headroom for very cold weather. Approx running costs - £10/day using either one or both ASHP, somedays less, somedays more. Far north coast of Scotland.

Would have thought that 17kw would have been suitable for you. Is there a buffer tank for the rads, or are you running direct from the pumps? Have the rads got TRVs with bypasses?

paceinternet

TiredGeek, your SAP requirement of 16kw would be costing you around £1 an hour if you were using oil. How does that compare with the ASHP running cost?