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Topic Title: Heat Pumps
Topic Summary: Co-Efficient of Performance (COP)
Created On: 11 December 2012 09:03 PM
Status: Post and Reply
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 16 March 2013 09:50 AM
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Avatar for sparkiemike.
sparkiemike

Posts: 1549
Joined: 24 January 2008

Originally posted by: IvanWeekes

Hello Mate,

I might not have permission to answer you here as I am a new bee. I understand a lot about Heat Pumps as I am a Heating Engineerfor over 15 years...

If you want to expand your knowledge about heat pumps of boilders please visit my profile and from there you can understand the whole thing about Heat Pumps as well. Click the link at the right side of my BIO for more details...

Regards,

Ivan


Thanks, but no thanks, your webiste did not provide sufficent technical detail for my needs.
 16 March 2013 10:36 AM
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OldSparky

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all i will say is keep away from an air source pump
 16 March 2013 05:09 PM
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AMN

Posts: 644
Joined: 29 June 2007

Originally posted by: OldSparky

all i will say is keep away from an air source pump


Can't say I agree with that. I have a simple air to air inverter heat pump 5kW output and it heats most of our downstairs. Once it's got the temp stabilised it runs at between 1.2 and 1.6 kW. I would like to see a panel heater do that! Yes, when it gets really cold it requires more power, but I knew that would be the case before I bought it.
It seems the main problem with heat pumps is that people don't understand they are not a direct replacement for a gas or oil boiler, the systems need to be designed and installed properly and matched to the environment it is to work in.

AMN
 16 March 2013 06:37 PM
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Avatar for OldSparky.
OldSparky

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Joined: 28 June 2011

Originally posted by: AMN

Originally posted by: OldSparky



all i will say is keep away from an air source pump [IMG][/IMG]




Can't say I agree with that. I have a simple air to air inverter heat pump 5kW output and it heats most of our downstairs. Once it's got the temp stabilised it runs at between 1.2 and 1.6 kW. I would like to see a panel heater do that! Yes, when it gets really cold it requires more power, but I knew that would be the case before I bought it.

It seems the main problem with heat pumps is that people don't understand they are not a direct replacement for a gas or oil boiler, the systems need to be designed and installed properly and matched to the environment it is to work in.



AMN


i agree with some of what you say,

i have a customer who has been sold an air source pump and its crap, couldnt heat a water bottle, told her it would cost £500.00 a year to heat her house.. she is up to £300.00 now and it was only installed in Jan..
Needs an immersion for legionnaires once a week.

the problem is the salesmen in this case.
 18 March 2013 02:06 PM
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Parsley

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 18 March 2013 03:54 PM
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AJJewsbury

Posts: 11553
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For the record I do not read the Daily Mail!

You might prefer the local paper (T&A)'s version then...

http://www.thetelegraphandargu...ve_up_to_eco_promise/
http://www.thetelegraphandargu...after_sky_high_bills/

sounds like one almighty cock up (no unknown in these parts - just ask locally about the "Westfield development"). At least the authorities seem to be trying to fix things now.

- Andy.
 18 March 2013 04:58 PM
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Parsley

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I heard recently of a 3000m2 warehouse unit that has had a Genie on hire for the last 3 weeks powering a load of fan heaters. The total hire and fuel cost so far has reached 5 figures.

This is because the warehouses ASHP/under floor heating system doesn't work and the workers were threating to walk out in the last batch of bad weather. Apparently the system has never worked, it's18 months old and apparently everyones blaming each over. I understand there are some big names involved.

Regards
 18 March 2013 05:24 PM
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OMS

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It happens - ASHP isn't the magic bullet some people think it is.

It has to be designed right, selected right, installed right and commissioned right - including sesonal commissioning.

Designers need to understand the implications of moving to significantly lower temperatures and how that impacts heat emitters

Purchasers need to drill down into the details of what they are getting so they are comparing apples with apples - much manufacturers data is very misleading until you get into the small print - which buyers can't be bothered with

Installers need to understand that what they've done in the past doesn't neccessarily work on these systems

Commissioning engineers also need to know how the heat pump works in context of the system and they need to ensure commissioning is actually carried out - not always a given by any means.

As I've said, the technology is mature, it has a proven history - it just needs to be considered holistically

I can see in the above morass of information flows, that everyone would be blaming each other - even more so with the bigger players -

Regards

OMS

-------------------------
Failure is always an option
 18 March 2013 09:13 PM
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sbrown2

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What interests me about this thread is what I have learn't over the past three years looking into the domestic market. I could argue that the builder I was working with nearly took this route but I will say he understood insulating the properties he built correctly and he understood the need for underfloor heating and oversized radiators. But as I became exposed to more people in this environment I realised the words design solution are alien. Although they give lip service to get accreditation you need to understand the fundamentals of the EPC's and how to extrapolate this heat pump, radiator and underfloor heating sizing. Granted new properties are, or should be, easier to create that solution but in the cases shown it is clear that the integration of differing technologies has been recognised. The builder I work with has worked with me as a manager in manufacturing and is aware integrating differing technologies but I do feel that in this example, in bradford, that word incorporation has been overlooked.

Regards

sbrown2
 21 March 2013 03:02 PM
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WM

Posts: 1
Joined: 21 March 2013

Hi, newbie here and first post.
Done the Ecodan design and installation course then went on to install a few.. be very wary of putting in an ASHP unless you have a very well insulated property and stay in a warmer part of britain than I.
The figures Mitsu.. give out about a 5-1 return on kw hours used can only ever be returned when the temp outside is around the 30 deg mark (who needs their heating on when its 30 deg outside?)...the colder it gets outside the more kw hrs it takes to stay at same temp inside...eventually dropping to a return of every kwh you use you get a kwh of heat in return, nothing to do with things having to defrost for 10-15 mins The colder the air outside the harder the unit has to work to extract what little heat there outside..
Also as has been previously mentioned you need to keep using immerser every now and then to stop leginella in hw tank.
Hope this is of use?
 03 July 2013 12:14 AM
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PerryNing

Posts: 1
Joined: 03 July 2013

Hello All,
1) The COP is fixed to be meaningful. In Europe, ground source heat pump units are standard tested at is 35 °C (95 °F) and is 0 °C (32 °F).
2) COP of 3 is possible and will go down when the unit get old or just simply get dirty.
3) The extra heat is not generated but pumped from (inside in summer or outside in winter)

Thanks, Perry from Link removed
IET » Wiring and the regulations » Heat Pumps

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