ASHP – Should do better - Must Do Better

lovesgshp

Just a quick question albyota, which I hope you dont mind me asking. What is the size of your house and the Ecodan spec?

albyota

The house is a four bed detached, selfbuild, 140mm stud insulated timber frame, brick skin, 20mm double glazed, about 175 M2 total floor area over 2 floors, UFH both floors laid at 100 and 150mm centres, using the 8.5 kW Ecodan, flow temp 36 degrees, room thermostats in most rooms, downstairs rooms using night set back stats to 18, 22 or 23 for evenings. Ecodan provides all domestic hot water via standard 0.9m2 coil to 53 degrees twice a day...takes about 45 mins each time.
Sorry was this too much information?

Cardew

albyota wrote: »

on MSE we are reading an increasing number of 'unhappy' end users saddled with the cheapo system which has just been 'bunged in' to satisfy the 'green blingers' or 'sold' to the unsuspecting builder/developer/tenant/client by people who don't either know how to specify the equipment correctly, or install it properly, or even know how to commision it to its most efficient setting.

This is a money saving forum and whilst I appreciate and sometimes agree with the title of this thread, I think it should not be used to slate all ASHP's in general, we have read about hideous costs, systems struggling to provide any heat at all, the energy saving trust trial carried out in 2008 was for 29 systems,

The best thing about this site is being able to discuss these topics and for us all to learn from the varied information and to make our own educated decisions on the facts.


Please, Lets keep it informative, and using true facts.

Albyota,

As I said at the beginning of this thread, it is precisely my aim to produce some facts and put the enthusiasm for all things 'heat pump' into perspective.

There are people on this forum, yourself and Chippy to name but two, who fit the systems and are a mine of information.

However you just cannot dismiss the EST field trial of 19 ASHPs. This trial was held with the manufacturers involved in the trial. As well as a raft of technical consultants. So that rules out poor installation, incorrect sizing etc wouldn't you think?

If they can't get it right, what chance will there be if a cowboy has installed the wrong system, or the correct system incorrectly.

The results over a year were a huge disappointment! The BBC and EST say investigations are needed.

Further study needs to be undertaken on an installation-by-installation basis, to record what has been done wrong (or well), what could be donebetter, and what exactly should be done in the future.

Even if you are correct and that it is all down to poor installation/incorrect speccification (which I don't think is correct) that is still an indictment of the ASHP industry.

Pay £6,000+ and hope the installer knows what he is doing!!! and be aware that you need to juggle constantly with all the controls etc to conform to prevailing weather conditions.

From EST report:

Many householders said that they had difficulties understanding the instructions for operating and using their heat pump.

There have been about ten cases on MSE(not all in this section) recently of frankly horror stories; and loads more if you search the web. Also bear in mind that there is always a reluctance for those who have spent good money on a system(or any project) to admit they are disappointed.

Those include Ecodans and other reputable manufacturers.

Not all are like AndyASM who admits he ripped out his ASHP system.

You must read the specialist plumbers/refrigeration forums and you will find professionals who state openly that air to water ASHPs are a disaster. The Chippy is not a fan of air to water either.

People on MSE, in brand new well insulated homes, are running up huge bills keeping their systems running.

retire_at_50_2

albyota

Have you calculated what COP you are achieving for each year?
Some very rough calculations suggest over 10!

Are you using a standard electricity tarriff?

albyota

retire_at_50 wrote: »

albyota

Have you calculated what COP you are achieving for each year?
Some very rough calculations suggest over 10!

Are you using a standard electricity tarriff?

How do you get to that ....10....?

I am on British gas Click energy 6 (due to expire june 2011)

lovesgshp

albyota wrote: »

The house is a four bed detached, selfbuild, 140mm stud insulated timber frame, brick skin, 20mm double glazed, about 175 M2 total floor area over 2 floors, UFH both floors laid at 100 and 150mm centres, using the 8.5 kW Ecodan, flow temp 36 degrees, room thermostats in most rooms, downstairs rooms using night set back stats to 18, 22 or 23 for evenings. Ecodan provides all domestic hot water via standard 0.9m2 coil to 53 degrees twice a day...takes about 45 mins each time.
Sorry was this too much information?

Albyota. Looks like a perfect setup for a well insulated house, 175 sq mtrs with a 8.5kw unit shows your insulation levels are virtually spot on . Normally we would look at a 19C room temp with underfloor, but your setup looks great. The only thing I would comment on is the DHW, as would think it would be better to give the priority to this at all times, but that is only my opinion.

lovesgshp

Cardew wrote: »

Albyota,

As I said at the beginning of this thread, it is precisely my aim to produce some facts and put the enthusiasm for all things 'heat pump' into perspective.

There are people on this forum, yourself and Chippy to name but two, who fit the systems and are a mine of information.

However you just cannot dismiss the EST field trial of 19 ASHPs. This trial was held with the manufacturers involved in the trial. As well as a raft of technical consultants. So that rules out poor installation, incorrect sizing etc wouldn't you think?

If they can't get it right, what chance will there be if a cowboy has installed the wrong system, or the correct system incorrectly.

The results over a year were a huge disappointment! The BBC and EST say investigations are needed.



Even if you are correct and that it is all down to poor installation/incorrect speccification (which I don't think is correct) that is still an indictment of the ASHP industry.

Pay £6,000+ and hope the installer knows what he is doing!!! and be aware that you need to juggle constantly with all the controls etc to conform to prevailing weather conditions.



There have been about ten cases on MSE(not all in this section) recently of frankly horror stories; and loads more if you search the web. Also bear in mind that there is always a reluctance for those who have spent good money on a system(or any project) to admit they are disappointed.

Those include Ecodans and other reputable manufacturers.

Not all are like AndyASM who admits he ripped out his ASHP system.

You must read the specialist plumbers/refrigeration forums and you will find professionals who state openly that air to water ASHPs are a disaster. The Chippy is not a fan of air to water either.

People on MSE, in brand new well insulated homes, are running up huge bills keeping their systems running.

If the system is sized correctly then there should be no problem. The problem that seems to be in the UK, as it is here, with plumbers, that all these heating experts jump on the bandwagon. Do you check if they are certified installers, or just look at their websites for the blurb!!

albyota

Geotherm wrote: »

Albyota. Looks like a perfect setup for a well insulated house, 175 sq mtrs with a 8.5kw unit shows your insulation levels are virtually spot on . Normally we would look at a 19C room temp with underfloor, but your setup looks great. The only thing I would comment on is the DHW, as would think it would be better to give the priority to this at all times, but that is only my opinion.

Geotherm, the DHW is looked after by the heat pump but the controller has two inputs one for heating temp 35C - 55C, and one for hot water temp 58C. I use a standard Danfoss 24/7 two channel programmer to time the hot water to heat up twice a day, its no use heating more water than you can use, so after morning washes/showers, is left until the heat pump does its second hot water run later in the afternoon, the tank is well insulated. I did not change the tank for the larger 3M2 coil when I fitted the heat pump, so I could get better efficiencies if this was changed. Once a week I have the timeclock for the Immersion heater on for 2 hours for thermal disinfection.

welda

There are plenty courses popping up all around UK to train up for renewable installations, can't speak for all of them but, before being able to apply and train for say GSHP, the trainee will have to have appropriate qualifications ie: BPEC, C&G plumber quals, same for sparks looking to get involved in renewables ie, SELECT registered ect...

However, you will always find the cowboys manage to muscle in to a degree?

:beer:

lovesgshp

albyota wrote: »

Geotherm, the DHW is looked after by the heat pump but the controller has two inputs one for heating temp 35C - 55C, and one for hot water temp 58C. I use a standard Danfoss 24/7 two channel programmer to time the hot water to heat up twice a day, its no use heating more water than you can use, so after morning washes/showers, is left until the heat pump does its second hot water run later in the afternoon, the tank is well insulated. I did not change the tank for the larger 3M2 coil when I fitted the heat pump, so I could get better efficiencies if this was changed. Once a week I have the timeclock for the Immersion heater on for 2 hours for thermal disinfection.

With your DHW temp @ 58C, I would suggest you turn the thermal disinfection down to a max of 30 mins. At 58C it should not be needed for 2 hrs.