Air heat source pumps

[driverman]

Hi Guys, soon be wiring for an air heat source pump which is to be sited outside a detached double garage with a studio flat above. I need to determine the overall load that will be required to determine size of sub main to be installed. At this point in time I've no info from the owner about the heat source pump apart from that it may be a 12 kW model. I know nothing about these pumps...Would 12kW be the output? It is a large house. Scrolling through some older threads, it would appear that a 40amp MCB required.
Seems a very high requirement if pulling that amount of load. Thought it was to make running cost a great deal lower.
Your thoughts appreciated

 

[Rockingit]

Typically with ASHP you'll have a feed to the compressor and then one or two 3kw feeds to the heaters in the tank, plus some control wiring etc. You need to get the installation spec before proceeding.

 

[driverman]

Typically with ASHP you'll have a feed to the compressor and then one or two 3kw feeds to the heaters in the tank, plus some control wiring etc. You need to get the installation spec before proceeding.

Yes agree with you....family member job, he is a plumber (sorry). The actual model etc still to be decided which was discussed this weekend. I'm under the impression though that the hot water will be done by solar panels only.
I'm only doing the basic wiring for it, but need to know the loading. I'm starting to lean on him as I dont want a last minute panick

 

[a1colly]

You'll also need to notify DNO of intentions of installation

 

[driverman]

You'll also need to notify DNO of intentions of installation

all taken off a1colly when building regs applied for. But a very good point as I know many are installed without the DNO being informed either by the installer and or the customer.

 

[rapparee]

The dimplex heat pimps have immersion heaters on reserve because when the temp drops below -10°C they become ineffective, will you be installing smart rads through the house they need a seperate supply at each radiator to power 30w fan inside radiator

 

[Rockingit]

all taken off a1colly when building regs applied for. But a very good point as I know many are installed without the DNO being informed either by the installer and or the customer.

Eh? DNO have nothing to do with this. It's just a heat source, nothing else.

 

[a1colly]

ASHP requires pre approval from DNO

 

[Rockingit]

ASHP requires pre approval from DNO

Well I've done 8 so far this year, across two different DNO's, and no they don't. Why would they?? There are some GSHP's that do, due to the compressors in them, but not ASHP fans - they're little more than AC units wired backwards!!

 

[atm84]

DNO may want to know if you were applying for an upgrade or new supply. Even then they aren't too interested. The load will be minimal and it will be a soft start so it will have little or no affect for the DNO.

 

[Rockingit]

DNO may want to know if you were applying for an upgrade or new supply. Even then they aren't too interested. The load will be minimal and it will be a soft start so it will have little or no affect for the DNO.

FFS, what is it with people?! The installation of ANY new load needs to be evaluated and may give rise to the need to upgrade the existing supply or form part of the requisition of a new one. However, in the vast majority of cases, especially domestic, this is highly unlikely.

And the issue(s) to do with heat pumps is mainly harmonics, not load.

 

[driverman]

Ok DNO debate over.....What is a typical load requirement for a ASHP? I've still no info from home owner.

 

[rapparee]

Ok DNO debate over.....What is a typical load requirement for a ASHP? I've still no info from home owner.

You would need to talk to customer a heat pump can be up to 65kw output. We installed one to heat an pffice block with smart rads it takes a 32a supply

 

[driverman]

You would need to talk to customer a heat pump can be up to 65kw output. We installed one to heat an pffice block with smart rads it takes a 32a supply

Yes i'm trying to get exact info,,,,,he thought from memory that 12kW was mentioned. Large-ish house 15m x 9m

 

[plugsandsparks]

you cannot guess this, it could be 3P even that turns up. They are so many different ones. I would wait until the client has got written specs from the installer and has ordered against a specification before considering a supply. But if he only has Sp at the property you may want to at least steer him in that direction.