Air Source Heat Pumps

captainhindsight_2

Cardew wrote: »

Absolutely!


How does Mr and Mrs Average find such an installer.


From all the reports we get, not to mention the EST trials, it is quite clear that many installers do not 'know what they are doing'.


To make matters worse customers do not know if they have a good installation until they start getting huge bills(or not) a year or two down the line.


Although more complicated, look at the troubles technically minded posters have with their installations in the GSHP thread, and 'lovesgshp' sadly isn't available to help out all with a faulty installation of an ASHP system.

Thankfully the manufactures are being more selective who they sell their equipment too. The like of nibe and dimplex will sell to any monkey who's been on the course, where as some other manufactures are very selective who they sell to .

So Mr and Mrs average can go to the better manufactures and they can recommend an installer and help with the system design to ensure it works as it should

richardc1983

matelodave wrote: »

Most heatpumps are specified to work at 35 degrees and I read somewhere that every degree above that increases the cost of running it by about 2,5% so the lower the temp you can run the system the better. A 50 degree flow temperature could therefore cost 37.5% more than 35 degrees, just by reducing it by 5 degrees could reduce your consumption by 12.5%


It shouldn't be too hard to get operating, installation and commissioning instructions from the internet which would help with tweaking it. You can also then see if they are running the system on the edge of the booster heater, like wise, at what temperature are they keep the hot tank. The lower the temp the better otherwise the immersion might be kicking in. Check the temperatures where the heaters cut in and try to run the system below that.


I run my system with weather compensation which means that the unit only winds up it's temperature when it cold and reduces it when it's warmer. If you can optimise your flow temperature to match the house heat loss you should be able to reduce the running costs a bit. If you need 50 degrees when it's zero outside you should be able to get away with 40 degrees when it's plus 10.


Do some heatloss calculations for each room and check the radiator sizing for the flow temperatures that you are using and add them together to make sure that the unit is big enough to heat the place without flogging its heart out.
It took me a couple of winters to tweak mine but it's now pretty well optimised - we've used 500kwh less this December than last and 600kwh less this January compared with last years. That's a saving of over £120 over the same period last year

My partners mum has a Samsung ehs heat pump and it was set for a max flow temp of 50c under compensation. She's had a bill for 400 for two months. Temp is at 20c during timed on and night set back to 19c it runs for about 8 hours a day during the timed on periods. We're getting no where it's the company that installed it they have been out and recommisioned it made a right hash of it, there was zero pressure in the system and the radiators were cold half of them because they haven't bled them of filled the system properly. All rads had their balancing valves fully open so some rads further away were stone cold, I've balanced the system properly and we're getting a 10c drop between the send and return flow temps.

I sorted the above yesterday as I decided enough was enough. Her husband is in his last year of terminal cancer and she is sat in a coat in the house, the stupid install company are useless and don't care. Even though it's never worked properly in the 2 years it's been in with extortionate energy bills. I've adjusted the max flow temp to 45c and the house is still toasty. Theres a +-5c option where the user can increase or decrease the flow temp. I've turned it down to -5c so flow temp is now 40c and rads still nice and warm. This morning the unit has used £1.04 since midnight rather than the £3.50 it would have used. She's a fan convector in the kitchen which also helps to put heat into the house quite efficiently. Is there anything else we can do to optimise this system, I am thinking of trying max flow temp at 40c if house is warm enough meaning at -5c setting flow temp will be about 35c. It is tweaking it now and as I work in this area in HVAC I have a full understanding. Hot water cylinder temp is 48c and the system is set to use no immersions at all apart from the weekly boost to 60c for disinfection purposes.

Heat curve is set at outside temp of -2c as per Samsungs suggestion but it also suggested setting it for -6c for Scotland? Any reason for this? Surely -6c would be better as your giving it more scope to adjust down and be more efficient.

Regards
Richard

c13pep

I have been reading with interest the posts on the technicalities of ASHP`s perhaps my own experience will be of use to the uninitiated. My house is a 6 bedroomed well insulated 1960`s brick built semi with 23 radiators that used to be run by a 60000 btu lpg Worcester bosch boiler. (costing £200/month to run) In 2013 I had installed solar panels for electricity generation and a Mitsubishi Ecodan system using a 14Kw outdoor unit supplying heated refrigerant to a loft mounted Ecobox heat exchanger unit. The installation involved most of our radiators being swapped for doubles and our gravity fed hot water tanks were replaced by a 300Ltr high efficiency stainless tank. Our existing hot water circulating system was retained in order to provide virtually instant hot water to every tap. The remit for the system was that it had to provide a room temperature of 24 degrees due to my wife's medical condition and supply plenty of hot water. After 2 months and much head scratching the system was finally set to deliver our needs and has done so for the past 17 months.
Running costs for our, now, all electric house are £146/month direct debit to Eon but I get back via RHI £70/month for the Ecodan and £60/month for the electricity generated (4Kw solar panel system), so as can be seen we actually pay £16/month for all our electricity needs. The solar panels (black Canadian Solar) cost £6000 and the Ecodan system cost £12500, I view this as an investment in my house which was confirmed by a local estate agent saying that my home would command a premium price because of its low running costs. Compared to our old LPG system we are saving money without any government payments. I hope this helps potential buyers for ASHP`s but I must be clear in that set up is crucial as is the system fitted.

vince31

c13pep wrote: »

I have been reading with interest the posts on the technicalities of ASHP`s perhaps my own experience will be of use to the uninitiated. My house is a 6 bedroomed well insulated 1960`s brick built semi with 23 radiators that used to be run by a 60000 btu lpg Worcester bosch boiler. (costing £200/month to run) In 2013 I had installed solar panels for electricity generation and a Mitsubishi Ecodan system using a 14Kw outdoor unit supplying heated refrigerant to a loft mounted Ecobox heat exchanger unit. The installation involved most of our radiators being swapped for doubles and our gravity fed hot water tanks were replaced by a 300Ltr high efficiency stainless tank. Our existing hot water circulating system was retained in order to provide virtually instant hot water to every tap. The remit for the system was that it had to provide a room temperature of 24 degrees due to my wife's medical condition and supply plenty of hot water. After 2 months and much head scratching the system was finally set to deliver our needs and has done so for the past 17 months.
Running costs for our, now, all electric house are £146/month direct debit to Eon but I get back via RHI £70/month for the Ecodan and £60/month for the electricity generated (4Kw solar panel system), so as can be seen we actually pay £16/month for all our electricity needs. The solar panels (black Canadian Solar) cost £6000 and the Ecodan system cost £12500, I view this as an investment in my house which was confirmed by a local estate agent saying that my home would command a premium price because of its low running costs. Compared to our old LPG system we are saving money without any government payments. I hope this helps potential buyers for ASHP`s but I must be clear in that set up is crucial as is the system fitted.

Thanks for the very positive post above, gives me more confidence that I've made the right decision as my set up will be similar to yours with a 12 KW ASHP, new large double radiators and a 4KW PV feeding my excess electricity into it. due to get ASHP installed mid April with annual RHI of £660.

c13pep

I would suggest that you consider investing in micro inverters to offset the effects of shading and in my case multiple bird droppings causing the system to shut down totally. With this system each panel acts individually and is not effected by one panels poor performance.

trevs

I am interested in the IVT AirX ASHP, has anyone had experience with these ?
Would be interested to see the data at the different water temperatures.

lovesgshp

trevs wrote: »

I am interested in the IVT AirX ASHP, has anyone had experience with these ?
Would be interested to see the data at the different water temperatures.

These pumps were only released at the beginning of this year, but saying that here in Italy they have been very popular. It may well be marketed in the UK under the Worcester Bosch brand.
Most of the info I have on them is in Italian, but even my boss has installed one!!
Performance is fairly close to a GSHP. If you can read Italian, then can link you to his post on it. Otherwise this is from a site which I have no affiliation with.

http://www.energysuperstore.ie/#!ivt-airwater-technical-data/cwzl

trevs

Many thanks, good performance then, is your boss's outside and does he find them noisy and does it heat the water up to a decent temperature ?

lovesgshp

Hi trevs.
Yes the main fan unit is outside. I have linked the post he made, so you can get a idea of the installation. Copy and paste the text into a translator and it should give you a good insight into it all.
http://www.geotherm.it/blog/quanto-costa-installare-una-pompa-di-calore/

beanyman1000

Hello All
Are there heat pump installers, that would be willing to speak with me over the telephone?
I would like to ask a few questions. re circulation pumps and stuff like that.