UPDATED: Air Source Heat Pumps/Air Con - Full Info & Guide, is it cheaper to run than mains gas?

Swipe

Do you all have your heat pumps connected to outside isolator switches? I hear this is commonplace for standard AC cooling units. An AC engineer came to survey yesterday and said there's no way he would connect to the internal wall socket as per steveheads set up.

richardc1983

Swipe wrote: »

Do you all have your heat pumps connected to outside isolator switches? I hear this is commonplace for standard AC cooling units. An AC engineer came to survey yesterday and said there's no way he would connect to the internal wall socket as per steveheads set up.

I personally have my multisplit unit originally setup into the back of the ring main socket inside, unfortunatly at that time there was no way to isolate it other than shut the power sockets power.

WHen i had the system serviced I paid for it to have a 13Amp fused plug on so I could isolate it should I need to.

The point is that non inverter units used to draw a surge of power when starting up and would trip consumer units. Inverters start up very softly and run at about 5amps meaning it is perfectly safe to run off a plug socket with appropriate fuse.

My 8kw multisplit unit has a 13amp fuse fitted in the plug and draws 12amp when running flat out and has run fine since.

I am changing the system to Mitsi soon and having separate splits installed and due to 3 systems running at 5amps each this will be too much for my consumer unit so they are upgrading the consumer unit and I will have a dedicated circuit for the a/c.

It depends on what your installer wants to do. But they are perfectly safe to run on 13amp fuses.

Theres a topic on re in discussion: Some mixed opinions but generally its safe.

http://www.refrigeration-engineer.com/forums/showthread.php?t=8493&highlight=running+plug

samtheman1k

richardc1983 wrote: »

It depends on what your installer wants to do. But they are perfectly safe to run on 13amp fuses.

Err..that is really bad advice. If it is a permanent installation, it needs to comply with Part P regulations, and as the inverter is outside, it needs to have an RCD attached, which, all but the latest wired internal ring mains don't.

richardc1983

samtheman1k wrote: »

Err..that is really bad advice. If it is a permanent installation, it needs to comply with Part P regulations, and as the inverter is outside, it needs to have an RCD attached, which, all but the latest wired internal ring mains don't.

Sam

Read the following post off another forum from people in the trade, loads of engineers do it, its not illegal to do it. As long as there some way of isolating it.

http://www.refrigeration-engineer.com/forums/showthread.php?p=143717#post143717

samtheman1k

richardc1983 wrote: »

Sam

Read the following post off another forum from people in the trade, loads of engineers do it, its not illegal to do it. As long as there some way of isolating it.

http://www.refrigeration-engineer.com/forums/showthread.php?p=143717#post143717

An isolator won't stop you getting shock if the wiring develops a fault! (unless you know about it beforehand of course :rolleyes:).

richardc1983

samtheman1k wrote: »

An isolator won't stop you getting shock if the wiring develops a fault! (unless you know about it beforehand of course :rolleyes:).

Fair enough but what im saiyng is its not illegal as confirmed on the other forum, and is no more unsafe than having a tv with faulty wiring.

samtheman1k

richardc1983 wrote: »

Fair enough but what im saiyng is its not illegal as confirmed on the other forum, and is no more unsafe than having a tv with faulty wiring.

Yes it is, as a TV isn't outside where there is a high chance of water ingress....

At the very least, it should be plugged into a circuit that is protected by a MCB, which it won't be if the wiring is old, may be if recent, or definitely if brand new and the installer was anticipating the 18th edition of part P. You mentioned you had a split load system, so you should have some circuits that have MCDs on.

It's a bit of a grey area to be honest, whether a RCD/MCD is required on outside equipment. Our electrician installed one on everything that went outside, and I always use one on any tools that are outside. They are cheap, and given the extra risks, are worth it...so why not?

richardc1983

On the end of the plug I have just checked is an RCD protector. Like you would have for mowing the lawn.

StevieArgyll

Hi
Could someone give me an idea how noisy these are.

I recently moved out of the city and live in a small village near the sea. It is exceptionally quiet I maybe hear about 20 cars in a day. Its so quiet that I can hear my stockli food dehydrator or my fridge freezer while on cooling, from a seating area in back garden 30 feet from the house if the back door is open. So basically what i am saying is that the only real background noise is birds. Would an ASHP ruin the tranquility?

paceinternet

Well some are more noisy than others as shown by their db ratings, but you can see many in operation in retail or commercial properties, so stop by and listen. The noise is mostly of air movement through the fan (outside and inside).
Older outdoor units may start to rattle a bit, and the same can happen to the indoor units.
So depends what noise level bothers you, but generally, they are probably quieter than a gas or oil fired boiler.