Air Source Heat Pumps

TiredGeek

£15, OK, not crippling then, my bad

The installers have been in touch, they're gonna have another poke about with a Mitsubishi tech.
They're not going to find anything as sods law says everything will work fine while they're there.

Time to start to apply gentle but firm pressure for a refund or GSHP system methinks

TiredGeek

Just a follow up for anyone wondering what's happening with my system.
The conversation has moved forums
I'm getting good advice here "refrigeration-engineer.com/forums" (sorry, can't post a direct link) and I actually think I see a glimmer of light down the tunnel :j :beer:
Thanks to everyone who chipped in on this site

richardc1983

TiredGeek wrote: »

Just a follow up for anyone wondering what's happening with my system.
The conversation has moved forums
I'm getting good advice here "refrigeration-engineer.com/forums" (sorry, can't post a direct link) and I actually think I see a glimmer of light down the tunnel :j :beer:
Thanks to everyone who chipped in on this site

Told you that forum was a wealth of knowledge and im glad you are now getting the confidence to trust the equipment. You will resolve this and once you get someone who knows what they are doing with it you will be up and running in no time.

FOr those that want to follow the topic over at RE forum here is the link... http://www.refrigeration-engineer.com/forums/showthread.php?p=219734#post219734

marshdaisy

Hi
Looking to change our oil boiler for something a bit more economical. Anyone got any up to date experience of ASHP systems?

npreston1

Cardew wrote: »

Most interesting - thanks.

A couple of quick questions.

I have read that the minimum temperature for Domestic Hot water was supposed to be 65C - prevention of Legionnaires' disease? Could that be the reason for the 'booster' immersion heater?

I appreciate that it is early days yet, but do you think that moving to an Economy 7 tariff would be cheaper?

Never thought about the noise problem.

In unventented system there should be no scope for legionnaires disease as the system is sealed. However the systems are designed to increase the hot water from 50-55 to 60-65 once every couple of weeks or so and this is a pre installed function usually set up by the commissioning engineer that installs the system The immersion is indeed installed in all heat pumps not only to carry out this function but also to ensure that when the temperature gets below freezing the hot water is always available as some heat pump systems are unable to cope with the heating and hot water production at such a level.

Econony seven is great for heat pumps as the lower tariff rate is through the night when the temperature drops and the heat pump works harder so the money saving and return on investment is much better for you. However before taking the leap check what it costs to have it fitted if not already installed and see what the tariff is as some are higher and don't work out as cheap as a normal domestic electric rate.

Mitsubihi heat pumps are great for well insulated small domestic properties but looking at this running cost compared to say a Danfoss heat pump the efficiency level is lower and also the running costs do seem higher but that is more likely to be down to the difference in refridgerant solution and heat losses between the external heat pump and the property as all the heat is generated outside and submited through the pipework into the property.

Hope this helps

Neil

npreston1

adr0ck wrote: »

samtheman1k thank you for a very informative thread

Could you please tell me how many radiators in total the Mitsubishi Heat Pump Boiler is heating?

Also does anyone know if this system could work in conjunction with a LPG boiler?

Thanks

Heat pumps can work as a boiler tie in but this is not always the most suitable method of use and it really comes down to what type of property you have and its heat loss and hot water capacity.
for example

A property measuring 200 m2 with 3 bathrooms aged around 40 years old that has been installed with double glazing cavity wall and lost insulation to a good standard may need a system sized at about 12Kw this is based on the property size and with a heat loss of 50 watts per m2. fairly normal really this would include all the domestic heating and hot water running on radiators offering an estimated efficiency of 332% COP 3.32 this system operating all year round should be costing about £1,100 per annum total based on 10 pence per unit. This is using a Danfoss system which is seen as one of the best on the market.

Depending on your property size depends on whether you need to use the LPG as back up if you wish to know more just let me know a little more about your propety and I can certainly let you know

Neil

lovesgshp

npreston1 wrote: »

Heat pumps can work as a boiler tie in but this is not always the most suitable method of use and it really comes down to what type of property you have and its heat loss and hot water capacity.
for example

A property measuring 200 m2 with 3 bathrooms aged around 40 years old that has been installed with double glazing cavity wall and lost insulation to a good standard may need a system sized at about 12Kw this is based on the property size and with a heat loss of 50 watts per m2. fairly normal really this would include all the domestic heating and hot water running on radiators offering an estimated efficiency of 332% COP 3.32 this system operating all year round should be costing about £1,100 per annum total based on 10 pence per unit. This is using a Danfoss system which is seen as one of the best on the market.

Depending on your property size depends on whether you need to use the LPG as back up if you wish to know more just let me know a little more about your propety and I can certainly let you know

Neil

Obviously I do not know which model you are quoting, but the COP on the 12Kw model DHP AL12 is 3.35. This is based on a temperature input of 7C, output 35C.
That would be too low for a radiator system
EN14511 has 2 standards. 1@ 7C input 35C out and the 2nd @ 7C input 55C out.
Their link attached (Danfoss)
http://www.airsource-heatpumps.co.uk/Air_Source_Heat_Pumps_DHP-AL_datasheet.pdf

Please correct me i I am wrong

lovesgshp

Heat pumps can work as a boiler tie in but this is not always the most suitable method of use and it really comes down to what type of property you have and its heat loss and hot water capacity.

There is nothing wrong with putting a ASHP as a retrofit installation. It means you can have your existing system boost the ASHP if there is a significant demand in heating supply. We fit many dual systems here in Italy.

NaffSlack

Hey Guys, me and my missis have had a quote for this system as we have an outdated boiler and crappy storage heaters. its a lot more money than i had earmarked for this but im wondering that if the long term benifits off set this cost than i may be willing to go ahead.

If theres people looking at this forum that have had it for a few winters how has the system coped with the cold weather? We live in a rather warm area of south london and even during the worst of it it never reached below -5.

Also as not many people have this system yet as its relitivly new here if you have had any maintenance on the system? and what have the costs of that been? my major concern is that as not many people know about this system that the people that do will then therefore charge what ever they like as they are the only ones that know about it.

We seem to have a good team doing this for us and very profectional but still its a lot of money so we need to know if this is really worth the investment.

zeupater

NaffSlack wrote: »

Hey Guys, me and my missis have had a quote for this system as we have an outdated boiler and crappy storage heaters. its a lot more money than i had earmarked for this but im wondering that if the long term benifits off set this cost than i may be willing to go ahead.

If theres people looking at this forum that have had it for a few winters how has the system coped with the cold weather? We live in a rather warm area of south london and even during the worst of it it never reached below -5.

Also as not many people have this system yet as its relitivly new here if you have had any maintenance on the system? and what have the costs of that been? my major concern is that as not many people know about this system that the people that do will then therefore charge what ever they like as they are the only ones that know about it.

We seem to have a good team doing this for us and very profectional but still its a lot of money so we need to know if this is really worth the investment.

Hi

Welcome to the forum ....

You mention you have a boiler & storage heaters .... is this a gas heating boiler, if so why do you have storage heaters too ??

If gas is available in the property it would generally be cheaper overall to stay with gas, both on an initial installation and ongoing fuel cost basis, but we could do with more information on what you have in place & what the ASHP installers propose to install and have quoted for in order to help ...

HTH
Z