ASHP - how much space is needed in the house

elljay

I'm investigating aspects of changing from solid fuel to ASHP and while there's plenty of space on the outside wall for the unit I'm unclear how much space I need indoors.

Youtube videos of other domestic installations seem to show huge tanks, with masses of pipes, contained in what looks like a mini plant room or at least a utility room.  Neither of which I've got!  I have a through lounge/kitchen diner downstairs and the airing cupboard with the present immersion is upstairs.  Small house.  However ASHPs are put into flats so it must be possible.  Can anyone share their own experiences please?  I'm also interested in how much upheaval is involved in putting it in, it feels like a huge job but may not be.  I have radiators already from the present system and they will need to be replaced with larger ones.

Many thanks

Liz

matelodave

Different systems require different amounts of spac, so you really need to investigate what is available to suit your particular circumstance. Be aware that you will need larger radiators. probably around twice the size of the ones you've already got. You may need to uprate some of the plumbing and most of all you need to learn how to use it properly and that it suits your lifestyle.

Some monobloc units have most of the components in the external unit, so the refrigerant/water heat exchanger is outside but still need space indoors for a reasonably large tank. Some I've seen are festooned with pumps and other controls.

Yet again there are units where some of the heat exchanger and hot water tank are in one large indoor unit - the connection to the external unit conveys refrigerant rather than water.glycol from a monobloc

My Daikin 11kw has an external unit with an indoor hydrobox (looks like a wall mounted boiler) which houses the heat exchanger and pump and is therefore connected to the external unit via refrigerant pipework and there's a separate 200litre hot water tank much like any other. All of it would probably fit into a normal airing cupboard.

Although I've got an ASHP and I'm more than happy with it you do need to understand what they are, how they work and how to use them to get the best out of them.

Make sure that whoever you get to do the job is MCS registered and get at least three quotes to ensure that you get a good idea of what you are being offered. Going for a heatpump is not as straightforward as some like to make out, neither is it as cheap to run as mains gas or oil but probably a bit cheaper than LPG if you get it set up and run it properly.

Reed_Richards

All I have inside the house is a large cylinder in the airing cupboard.  The cylinder incorporates a buffer tank so it's larger than the one it replaced despite having  the same water storage capacity.  It is "festooned" with a pump for the central heating and three or four motorised valves.  There is also a pressure vessel as my cylinder is unvented.  You are likely to need new 28 mm pipes between the heat pump and the buffer tank.
 
In my case there was little upheaval.  My old cylinder was replaced by the new one.  My external oil boiler was replaced by the heat pump in the same location.  I live in a bungalow and all the necessary pipes were routed via the loft.  Although the radiators needed to be replaced with ones having a larger output they don't necessarily need to be physically larger if your existing radiators are old enough to be single or double panel with no fins.  I had to add two extra radiators to satisfy the calculated requirements.

I don't have anything like the "hydrobox" that @matelodave has.  I am yet to find out if my heat pump can compete with my old oil boiler on running costs but it doesn't look like it will be much different either way.   

elljay

Thank you so much both, lots more research to do obviously and your experiences and advice have been really helpful.

Liz

matelodave

This is what mine looks like - theres more plumbing than usual because we've got a water softener (the three pipes up are cold, soft cold and hot) and the underfloor heating manifold are all located in the utility room together with a feed to the outside tap and to a wash basin just under where the paint tins are. The Hydrobox is above the 200 litre cylinder (a monobloc system has all the hydrobox gubbins inside the external unit). The second piccy shows what it looks like now with all the cupboards in place. The cupboards to the right are all easily removable for access. The water softener is in the cupboard next to the washing machine It really does look worse than it really is.