UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

richardc1983

bushyh wrote: »

oh god this is really not good is it, I'm sorry to keep pestering you but would you recommend I basically use your comments in a letter to builder or do I now do this through a solicitor I am starting to feel a bit out of my depth albeit I fully understand and take on board everything everyone has very helpfully said.

I would challenge the builder and document everything that is said. I work in the air conditioning industry and facilities so I know what I am talking about. I would perhaps go back with the comments that I have put forward above and perhaps say you have spoken with a proper refrigeration/air con company.

Have you seen my other post bushyt?

http://forums.moneysavingexpert.com/showpost.php?p=39895532&postcount=698

Cardew

bushyh wrote: »

oh god this is really not good is it, I'm sorry to keep pestering you but would you recommend I basically use your comments in a letter to builder or do I now do this through a solicitor I am starting to feel a bit out of my depth albeit I fully understand and take on board everything everyone has very helpfully said.

On the strength of that report your system is quite clearly not fit for purpose.

I think most of us would not find options 1 or 3 acceptable; they are too full of 'ifs and buts'. Not least noise from 2 ASHPs when even one unit bothered you.

As discussed in other threads a 'killer' for ASHPs is the dreaded defrost cycles(basically the heat pump stops working at heating to defrost itself) so the margins they are talking about can get eroded and once again you are back to reliance of the immersion heater in the buffer tank. They don't even take this issue into account.

You might wish to involve the local Trading Standards office rather than the expence of a solicitor - they might take it up!

I would really play hard ball with the builder now, threaten with small claims court, not only for unfit system but extra running costs incurred etc.

bushyh

anyone care to glance over this for me please

I have considered further the options posed and would respond as follows. Firstly I would like to confirm that we all seem to agree that the present system is not fit for purpose and that an efficient, economic solution that will provide satisfactory warmth with the sort of low temperatures we have seen over the last few weeks is essential. In this respect it must be borne in mind that the condition of the last few weeks may not be replicated in the near future and it is in my view reasonable to ensure that any changes made are guaranteed to work when needed whether that be next winter or in 10 years time. It has been very disappointing and unacceptable to have moved into a brand new property and to be experiencing these problems. I have been very patient through this process but I feel it is now time for me to state what I consider needs to be done.

I wonder if you have really considered the content of your email ' Option 1. In the event that this is not successful, then Option 3 will be investigated followed by the last resort of Option 2.' in my shoes would that fill you with confidence that the matter is going to be resolved and quickly, rather it reads to me we are starting with the cheapest solution and hoping it works if not we'll move onto the next one.

Can we go back to the basic problem that the Calorex pump is not designed to cope with the low temperatures we have experienced and is not of a big enough capacity for the house. It is ridiculous that we are playing with solutions that may or may not work in order to keep a pump that is infinitely inferior to others on the market and/or a gas boiler. However you look at it if the Calorex stays it is a botch job. In my mind there are two solutions

1) to take away the Calorex and put in a gas boiler which we know will work
2) to replace the Calorex by a pump fit for purpose that will operate at temperatures down to -15C.

There are plenty of pumps on the market designed to work down to -15C without resorting to booster/backup systems and I am advised that there are systems which even though not top of the range are still 100 x better than the Calorex (eg LG Therma V System). Putting in an additional pump will provide me with 2 compressor units which will run flat out when the outdoor temperature drops, not creating much heat but using double the power (and making double the noise). The additional pump is going to cost more money to run and it would appear that the model quoted is mainly for use as a swimming pool heat pump rather than home central heating. Is this not the crux of the problem that Calorex have a fine reputation for swimming pool heat pumps but not in the home heating business - I don't think there are many engineers in the ASP business who would even think of Calorex let alone recommend them for home installation.

The proposed reliance of the immersion heater for raising the temperature other than once a week (the majority of systems are responsible enough do this automatically thereby fulfilling legal responsibility in respect of legionella control)is unnecessary with a good system; the current unit is using very old style refrigerant and even if changed it is not what the modern units use which is R410a; having a pick and mix of units/operating systems is going to make the system complicated and even more costly and noisy to run and there will undoubtedly be issues in how they are controlled and respond to each other. All of these issues lead me to believe that the options presented by Calorex are not acceptable and I would doubt that any independent installer would support any of those ideas.

In conclusion I feel that it is now appropriate for 4 independent quotes to be obtained, 2 in respect of installing a gas boiler and two to review and recommend appropriate action for a single air source heat pump system. Our aim should be to put the most cost effective solution for both parties but with the overriding priority that a fully operational, simple and satisfactory heating system is installed.

I feel that throughout the long and drawn out sale process we have had a good working relationship and I wish for that to continue but feel strongly that if you unable to take this route then I will be placed in the position of seeking further professional advice on the matter

richardc1983

Bushyh

Good letter, I would state in there that the low temperatures we are referring to are not uncommon in the UK in any winter its just we have had a sustained period. -5C at night time is not uncommon even in milder winters as we always have a bought of cold spells. What you dont want them doing is coming back saying that this extreme weather is not going to return again for a while etc. It doesnt matter because as soon as we get a cold frosty night of -2C like we get every winter you will be struggling for heating.

What we have had recently has been sustained cold and sub zero day time temps of nothing above 0C. THe Calorex system is designed for temps of 5C anything less than that and it just becomes a chocolate fireguard so it was never going to work!

In theory what they are suggesting by adding more KWs with another heat pump should give you the right ammount of heating at mild outdoor ambients. What they are not taking into consideration is how much output is lost when temps drop below 5C and even at 0C which is typical winter conditions! A company that mainly makes swimming pool heat pumps is not going to cut the mustard in this case.

Take out the bit that says "model referred to is mainly used as a swimming pool heat pump" I got this bit wrong. THe model number they are quoting when you put it into google brings up another heat pump. Like a rebadged version that another company is using as their own but still has the same model number.

Page 6/8 http://www.calorex.com/heat-pumps/documents/DomHeatv.4.pdf shows the power inputs of the other unit and the charts only show the heat output at 0C which has lost approx 2.5kws output at a 7C air temp drop. So even if they put another Calorex unit in if its 0C outside which is what temps usually get down to regulary in winter at night (even mild winters) you are still going to be well below the heat you require for your house as it simply cannot extract the heat from the air. They need to be basing the heat load requirements on the worse case scenario. If they were going to stick with the calorex unit they would need to fit another 3 units to be anywhere near coping when outdoor temps approach 0C.

Going back to the immersion heater, most top end systems have the immersion heater this automatically raises the water tank temp once a week but its only 15 minutes once a week so would have no affect on electricity usage. However them expecting you to rely on them as soon as it gets cold or below 5C outside is unacceptable.

THe therma V has a quiet compressor in it, you will not hear it through the walls of your house you will hear it in summer if your outside or have the windows open.

MY LG air con unit is right outside my window and I dont hear it in winter and in summer it isnt working so hard so its quieter.

albyota

great letter Bushyh, the options have got to be either a 14kW Ecodan or 14/16kW Daikin Altherma LT or 14/16kW LG Therma V, bear in mind that the LG therma V is not yet on the MCS list so does not qualify for the proposed RHI, or...... as there is gas on site get them to fit a Vaillant or Worcester Bosch system boiler with a 210L DHW cylinder, Hope you get it sorted.
AL

by the way, although it does not matter in your case, two units would not be twice the sound level.

richardc1983

albyota wrote: »

great letter Bushyh, the options have got to be either a 14kW Ecodan or 14/16kW Daikin Altherma LT or 14/16kW LG Therma V, bear in mind that the LG therma V is not yet on the MCS list so does not qualify for the proposed RHI.

Ensure you get this into your letter Bushyh,

The LG therma V is going to be cheaper but as albyota says not yet on the MCS list YET.

richardc1983

albyota wrote: »

two units would not be twice the sound level.

Could you explain why it wouldnt be more noise?

albyota

Adding Equal Sound Pressure Levels Calculator

Lws - sound power level (dB)

n - number of sources
Sound Pressure Level (dB) :

Number of Sources,.. Increase in Sound Power Level (dB),.. Increase in Sound Pressure Level(dB)
2 3 6
3 4.8 9.6
4 6 12
5 7 14
10 10 20
15 11.8 23.6
20 13 26

that didnt come out very good did it? try this link http://www.engineeringtoolbox.com/adding-decibel-d_63.html

very useful site!

bushyh

albyota wrote: »

Adding Equal Sound Pressure Levels Calculator

Lws - sound power level (dB)

n - number of sources
Sound Pressure Level (dB) :

Number of SourcesIncrease in Sound Power Level
(dB)Increase in Sound Pressure Level
(dB)23634.89.6461257141010201511.823.6201326

A whole new language, haven't I got enough confusion to cope with. Thank you as ever I owe you all :beer: I will let you know how things go but suspect there will be more to the saga yet.

richardc1983

albyota wrote: »

Adding Equal Sound Pressure Levels Calculator

Lws - sound power level (dB)

n - number of sources
Sound Pressure Level (dB) :

Number of SourcesIncrease in Sound Power Level
(dB)Increase in Sound Pressure Level
(dB)23634.89.6461257141010201511.823.6201326

Kind of understand what your saying but if the smaller unit has a different compressor which it likely does it could be a different type of sound that this one produces.

It could have a higher tone to it for example.