Taking the plunge Daiken Altherma HT

grahamc2003

jeepjunkie wrote: »

I
Anyway can't delete my account but have removed most of my posts and you can get one of your admin buddies to delete this one that would be great.

It sounds like your co-pilot grahamc2003 is unsure of what an ASHP is, perhaps you can enlighten him...

How very odd.

At times like this, I just think 'nowt as queer as folk'.

(Oh, and btw, whenever I fly, it's almost always as pic).

Cardew

jeepjunkie wrote: »

I came on here basically saying that if you go down the ASHP route then you need to do a lot of research i.e. speak to installers and owners read as much litrature as you can as there really is nothing on the web. They are not a one size fits all solution. Thats what we did so why have you harped on about the study??? Do you not think that I may have read that to learn what not to do...

How can I be a resource to the this forum when it is full of armchair experts that rubbish everything, now I know why other happy ASHP owners no longer contribute.

As it turns out you don't even have one so you have never done the research and put your money where your mouth is so why are you giving advice on stuff you know nothing about?

Oh and i've never met an ASHP saleman...

If you think £12k [and that is not what i paid if you had read my previous posts] is a lot of money then that says a lot to me...

Anyway can't delete my account but have removed most of my posts and you can get one of your admin buddies to delete this one that would be great.

It sounds like your co-pilot grahamc2003 is unsure of what an ASHP is, perhaps you can enlighten him...

So you have apparently concluded that I know nothing about ASHPs?


You haven't obviously read that I have owned a property with an ASHP. Even if I hadn't owned one, would that preclude me from investigating and researching?


As it happens I have done a considerable amount of research; but it seems, according to you, that unless you have 'put your money where your mouth is' it is not possible to have any knowledge.

The logic of that conclusion escapes me completely! Surely you can research and decide that an ASHP is not suitable? Or must all research lead to a purchase?


As for paying £12,000, I thought this quote from your post indicated that is what you spent:

As with most things in life you get what you pay for and £12k or whatever is sod all

I suspect also that many people would consider £12,000 a lot of money for a heating system. They complain about £2k for a gas CH system and £3k for an oil CH system.

Would you care to explain why thinking £12k is a lot of money 'means a lot to you'?

I really am surprised that you read the EST study and on the strength of that report decided to get an ASHP system! It would have put off most people.

Also wasn't it a rather tight timescale for you to have read the report and got the ASHP fitted. I also didn't think the report indicated the best systems.


I have given chapter and verse about why I have reservations about the way ASHPs are marketed and illustrated the poor performance of many systems.

You have not countered any points I have made, but just got upset.

Your post is typical of so many who make a decision and feel they have to attack anyone who raises reservations about ASHPs.

If you are happy with your decision - then fine; who is criticising your choice?

Wouldn't it be of interest on a Money Saving Forum if you gave some figures to explain why you are so happy?

lovesgshp

If the ASHP has been fully researched and the house thermal loading calculated correctly, there should be no reason for its inability to cope within the design criteria. The problem that seems to come to the forefront in the UK is many companies getting on the bandwagon without experience of sizing the unit.
We have turned down installations here in Italy due to clients/architects wanting lower capacity units than the property could manage.

grahamc2003

Geotherm wrote: »

If the ASHP has been fully researched and the house thermal loading calculated correctly, there should be no reason for its inability to cope within the design criteria. The problem that seems to come to the forefront in the UK is many companies getting on the bandwagon without experience of sizing the unit.
We have turned down installations here in Italy due to clients/architects wanting lower capacity units than the property could manage.

I think what you say is necessary but not sufficient.

Even with a full thermodynamic survey and a correctly specified system and the system working as specified, some owners may not be too happy with the performance under certain conditions (in the UK).

Firstly, aiui, some whole house (air to water) systems have 8-10kw heating elements to help out when the ambient conditions are such that the HP can't extract sufficient heat from the air - and that could be for a couple of reasons (icing of the heat exchanger, or simply insufficient volume of air when cold over the heat exchanger). Obviouly this only happens in cold weather - but it certainly affected at least a couple of owners (or at least users) of these forums last winter.

So if it's cold, and the HP switched in a 10kw heater to jolly things along, then it may well be operating as the spec says, but the user is unlikely to be very happy about it when his electrcity bill comes (as some users weren't on here a few months ago).

That's one 'problem' which I see for cold weather operation.

Another one is related. Afaiui, some of the better HPs don't have resistive heating, so, in fact, can't suffer from the above problem. But, of necessity, they still have the problem of extracting heat from the air at a rate approaching 10kw, which is obviously difficult the lower the temp, and obviously more difficult still with ice deposition on the heat exchanger (which are likely to be more precisely designed and engineered the higher the model). So the defrost strategy with no other heating becomes critical. As well as operating in a domain where the cop is probably well below 2, the need to defrost would or could push the true cop well below 1 (at the low temperatures we experienced in the uk last winter). Again, the HP may well be operating within spec while doing that, but I doubt many owners appreciate it could happen (i.e. they get high electricity usage for not a lot of heat at that time).

Appreciate your comments on the above, you have control.

Cardew

grahamc2003 wrote: »

I think what you say is necessary but not sufficient.

Even with a full thermodynamic survey and a correctly specified system and the system working as specified, some owners may not be too happy with the performance under certain conditions (in the UK).

Just one aspect to consider.

Eight ASHPs on the EST year long trial had an overall system COP of 1.6 or less.

The systems were used all year, including Summer for Hot water, and Spring and Autumn for heating when ambient temperatures were say 15C or even higher, when the COP should have been in excess of 3.0 or more - according to their specification sheets.

So to drag down the annual overall system COP to 1.6 or below, it seems to me it is a racing certainty that these systems in Winter must have been below 1.0 during the cold weather and it would have been cheaper to turn the ASHP off and heat with Granny's 1/2/3 bar fire and an immersion heater!!

What I find unbelievable is that prospective customers are advised to find a good installer - how the hell do any of us know who is good and who is incompetent?

We simply shouldn't be put in a position to spend £12,000 on a gamble that we might get a good system.

EDIT
Hadn't seen the last paragraph of the post above!!!

Ally74

grahamc2003 wrote: »

So if it's cold, and the HP switched in a 10kw heater to jolly things along, then it may well be operating as the spec says, but the user is unlikely to be very happy about it when his electrcity bill comes (as some users weren't on here a few months ago).

That's one 'problem' which I see for cold weather operation.

Hi

My housing association fitted my house with an ASHP a few months ago. Are you saying they can consume up to 10kw per hour in winter?

The HP fitted is a 8.5kw (i'm sure) Mitsubishi Ecodan.

Cardew

Ally74 wrote: »

Hi

My housing association fitted my house with an ASHP a few months ago. Are you saying they can consume up to 10kw per hour in winter?

The HP fitted is a 8.5kw (i'm sure) Mitsubishi Ecodan.

That isn't actually what he is saying.

The major problem with all ASHPs is that their performance gets worse as the outside temperature falls.

There are many factors that affect how much the performance drops - in the main your type of house and the method of installing.

It is possible that if it gets very cold like last winter that your ASHP will not cope and keep the house warm enough. Some installations overcome this by having a 'normal' resistive heater to 'help' the ASHP.

There is also a potential problem that the ASHP outside unit will 'freeze up' in certain conditions, and that has to be thawed with electricity.

I wouldn't get too worried about possible problems, just monitor your electricity consumption and record details.

The important point for you is to follow the instructions carefully - in particular note that an ASHP is not like Central heaing that can be switched on and off as required. With an ASHP you must run it for much longer period for it to be effective.

Ally74

Cardew wrote: »

That isn't actually what he is saying.

The major problem with all ASHPs is that their performance gets worse as the outside temperature falls.

There are many factors that affect how much the performance drops - in the main your type of house and the method of installing.

It is possible that if it gets very cold like last winter that your ASHP will not cope and keep the house warm enough. Some installations overcome this by having a 'normal' resistive heater to 'help' the ASHP.

There is also a potential problem that the ASHP outside unit will 'freeze up' in certain conditions, and that has to be thawed with electricity.

I wouldn't get too worried about possible problems, just monitor your electricity consumption and record details.

The important point for you is to follow the instructions carefully - in particular note that an ASHP is not like Central heaing that can be switched on and off as required. With an ASHP you must run it for much longer period for it to be effective.

Thanks Cardew. After reading a few threads on here i'm concerned about how the HP will perform this winter. A couple of things :-

A) How much electricity the HP will consume leaving me no other option than to turn it off because i can't afford to run it.

I have a young family (2 kids aged 5 & 7) and if the HP fails to cope i will be left with no heating system and will have to do with a few halogen heaters all winter.

Sorry if i seem to be hi-jacking this thread, i will try and keep an update of how it is performing in a more suitable one.

Cardew

As said above, don't get worried about the situation. The Ecodan is supposed to be one of the best ASHP's on the market.

All you need to do is carefully monitor your electricity consumption in the winter and if it is excessive then contact the housing association.

You don't say what heating you had before the ASHP?

Ally74

We had storage heating. I contacted the HA as we had a problem with damp and my son has asthma. They agreed to help and said they were currently carrying out a trial of 4 ASHP systems. After a survey my house was fitted with one.