Airwater-heat-pumps

k123456

Hi We are looking at a house with

http://www.nibe.eu/Domestic-heatingcooling/Airwater-heat-pumps/

This supposedly heats the underfloor heating /and/or the hot water

Are these as efficent as the manafacturers claim

House is approx 1800 sqft , underfloor heating, timber frame , approx two years old

I've looked at the pdf's etc from Nibe, and still cant understand, how it all works

k123456

k123456 wrote: »

Hi We are looking at a house with

http://www.nibe.eu/Domestic-heatingcooling/Airwater-heat-pumps/

This supposedly heats the underfloor heating /and/or the hot water

Are these as efficent as the manafacturers claim

House is approx 1800 sqft , underfloor heating, timber frame , approx two years old

I've looked at the pdf's etc from Nibe, and still cant understand, how it all works

k

Outkast_IRE

If the house is really well insulated and good airtightness aswell it might work to an acceptable standard.

What i will point out though is if the house isnt exceptionally well insualted and airtight if its a freezing cold winter like the 2010/2011 winter and previous years the efficency seems to go to the dogs as the unit needs to run in DEFROST mode for a good while before it starts heating the house.
In the same vein i have seen people with electricity bills in the thousands from that exceptionally cold winter.

Im sure someone will disagree but personally i wouldnt touch them with a bargepole unless the house is really well insulated and really airtight.

k123456

Outkast_IRE wrote: »

If the house is really well insulated and good airtightness aswell it might work to an acceptable standard.

What i will point out though is if the house isnt exceptionally well insualted and airtight if its a freezing cold winter like the 2010/2011 winter and previous years the efficency seems to go to the dogs as the unit needs to run in DEFROST mode for a good while before it starts heating the house.
In the same vein i have seen people with electricity bills in the thousands from that exceptionally cold winter.

Im sure someone will disagree but personally i wouldnt touch them with a bargepole unless the house is really well insulated and really airtight.

I still don't understand the principle of how they get energy and heat from cold air outside, something to do with the condenser unit ?

engineermike

A simple explanation for heat pump action:

So how does the heat pump pull heat from the air or ground outside?

On the face of it you would think this can’t possibly work, taking heat from the air or ground outside! But in fact you already have a form of heat pump in your home and we take for granted that it continually works every day. Your fridge or refrigerator is a simplified heat pump, taking heat from inside your fridge through a series of coils fitted to the interior and transferring this heat to a panel of coils at the rear of the fridge unit. Quietly and efficiently this appliance performs the role of a heat pump day and night (and if you go to the electrical store you will see very high energy rating cert.’s on fridge’s, of the order of A or B rating).

For a more detail explanation:

Air source heat pump - how it works

Ground source heat pump - how it works

Both air and ground source (or ASHP - GSHP) pumps work in a similar fashion, with the refrigerant - or anti freeze in the energy loop either taking its energy from the air or ground outside your home and expelling its heat into the homes space heating and or hot water.
An air conditioning unit is the exact same principal and working equipment as a heat pump, only in reverse.
The physics of the heat pump can be explained in the following manor:

When something evaporates, heat is taken in e.g.
• You feel cold when you get out of a swimming pool. The water evaporating off your skin takes extra heat from your body and makes you feel cold even though the
pool hall is hotter than a normal room.
When something condenses, heat is given out e.g.
• When you get steam from a kettle on your hand, it burns so badly. The steam condenses on your hand and gives out extra heat.
These two processes are the foundation of refrigeration and heat pump technologies.

Mike

engineermike

k123456 wrote: »

Hi We are looking at a house with

http://www.nibe.eu/Domestic-heatingcooling/Airwater-heat-pumps/

This supposedly heats the underfloor heating /and/or the hot water

Are these as efficent as the manafacturers claim

House is approx 1800 sqft , underfloor heating, timber frame , approx two years old

I've looked at the pdf's etc from Nibe, and still cant understand, how it all works

Nibe pumps are quite a good machine, generally the faults lie with incorrect installation, as the other poster mentioned the correct insulation in the fabric of the building is essential.
Secondly the correct heat distribution system is essential for efficient running - I.e. rads and hotwater system, low temp rads or underfloor heating is the norm for heat pumps.
Finally service for a pump is required every couple of years, the anti freeze in the energy loop may need replacement and also to ensure your system is running at maximum effciency etc. F Class heating engineers are required to service any system - such as a heat pump.
Mike

k123456

engineermike wrote: »

k123456 wrote: »

Hi We are looking at a house with

http://www.nibe.eu/Domestic-heatingcooling/Airwater-heat-pumps/

This supposedly heats the underfloor heating /and/or the hot water

Are these as efficent as the manafacturers claim

House is approx 1800 sqft , underfloor heating, timber frame , approx two years old

I've looked at the pdf's etc from Nibe, and still cant understand, how it all works

Nibe pumps are quite a good machine, generally the faults lie with incorrect installation, as the other poster mentioned the correct insulation in the fabric of the building is essential.
Secondly the correct heat distribution system is essential for efficient running - I.e. rads and hotwater system, low temp rads or underfloor heating is the norm for heat pumps.
Finally service for a pump is required every couple of years, the anti freeze in the energy loop may need replacement and also to ensure your system is running at maximum effciency etc. F Class heating engineers are required to service any system - such as a heat pump.
Mike

thanks for all the replies. house is a newly built timber frame hi insulation ber b, underfloor heating throughout

Outkast_IRE

k123456 wrote: »

thanks for all the replies. house is a newly built timber frame hi insulation ber b, underfloor heating throughout

If you do go for the heat pump i would reccomend a very good solar installation to help heat the hot water, the aim being to help reduce the workload on the pump in the winter so it can concentrate on heating the home moreso that the hot water.