How much room for air source heat pump?

[Clinkyclunk]

I'm planning a kitchen extention and I am thinking about future needs as we are likely to be in this home long term. A big chunck of the old kitchen will become a utility room, housing the boiler, washing machine etc. What I'm thinking is how much room does all the inside parts of the air source heat pump take up? If we do end up with one, I want all the gubbins to fit inside the utility room. It's a three bed detached house so I guess the water cylinder would be an average size, whatever that is.

If anyone has one installed, can you give me an estimate of the size so I can size my utility room adequately.

We are also, just in case, having the underfloor heating pipes laid whilst everything is being ripped out and new floor laid. It makes sense to do this now, rather than have to rip up floors again later on. I understand these need a whole manifold set up thing, so would be interested to see how much room these take up, as I want that in the utility too.

Floors and walls will be or already are insulated well, trying to make the house as efficient as possible, as I understand they only really work in super insulated houses.

Hiya our water tank for our ecodan is 1m X 1m and being moved to our new utility (currently building extension)

The hot water tank for mine is in a huge cupboard about 6ft by 3ft
before you buy one some things to bear in mind

1. Can you get it serviced by someone local no one near me will
2. Are you happy to have tepid water unless you use the immersion heater bit
3. are you ok with heating that isn’t flexible and costs a fortune

I’ve actually turned mine off for the summer so we are boiling water for washing and bathing on the gas cooker as it’s sooo much cheaper.

We had ours installed last summer. Large water cylinder in our internal garage, roughly where our boiler was, but standing on the floor instead of up high. It is big, admittedly, but the upstairs cupboard which did house the cylinder is now empty. I don't think there's anything else inside for the heat pump - the pump itself is outside, of course. Underfloor heating all "gathers" together in our under-stairs cupboard and doesn't take up a huge amount of space either. We have a pretty modern 4-bed house, so not huge.

We haven't had the problems the PP has and haven't used the immersion heater at all (4 people in the house). Our hot water is plenty hot enough and the heating works well at a constant temperature all the time. We also have solar PV panels and a storage battery and for a few months now have been making money on our electricity bills (no gas any more).

Oh, and we live in north central Scotland, not some balmy sunny southern coastal region.

I'd say go for it if you can!

We also don't have problems with hot water. We heat our water at night when it's cheap and it lasts all day for us (family of 4)

Thanks all. 1 metre square is actually less than I was expecting. I take it that the cylinders are very tall, taller than a person say. Having searched for pictures some look huge and have their own room, but I guess these are for very large houses.

@BeanMachine that's interesting about a storage battery. Solar is also on our list of things to do way down the line in the future. How much space does a storage battery take up. Could you mount this on a wall for example?

I'm trying to be smart and plan ahead, and hopefully save time and money in the future, not having to reconfigure any space in the house.

I have one (air source heat pump a Panasonic one). The new cylinder fitted where the old cylinder was in a small airing cupboard I had to have a special tall thin cylinder though as the standard one wouldn't fit. The main unit is outside. Cost wise it isn't cheap to run in the winter but summer use we see extraordinary good efficiency for hot water. I also have solar and am looking at a Tesla power wall battery. Most batteries now can be wall mounted however thermal considerations mean mine will probably go in the brick shed.

When I get home I’ll take a picture of ours. It’s all in a cupboard in the utility. Standard internal door width and to the ceiling. I think it’s about 70cm deep but will check.

Thanks @Oscarthedog. Is that because the battery prefers cooler termperatures? Or do they kick out a lot of heat? Putting a battery in a room with heat from a hot water cyclinder may not be the ideal place I guess then?

Thanks @Thursday37, that would be perfect to see your setup.

@Clinkyclunk our storage battery (a Tesla one) is on an outside wall. There is some kind of unit in our under-stairs cupboard too to connect it to the mains electricity. It's slim although relatively big - about the area of a kitchen cupboard door?

I was thinking about the heat pump servicing issue. Our installer said they will help with this (we haven't hit a year yet) and it is an area that will surely only get easier with time as more people switch to pumps away from gas. My parents in the north of Scotland have a ground source pump for 10+ years and haven't had any problems at all.

I would say ours is about 1x1m but must be over 6ft high. We went for a bigger size than recommended (300 litre) as we use a lot of hot water, especially teenagers having long showers! 🙄

I am delighted with how it works. We leave it on all the time and regulate temperature with thermostat and house is much warmer. Cost wise was about the same as our gas boiler at the moment but will be cheaper to run once we come off our fixed rate tariffs (because gas prices have increased more than electricity). Only issue we've had is when it's been very cold (-4c) and then we've had a lot of people trying to have bath/showers. Might have to wait 30 mins to get water hot again
It is a good idea to get a local installer so they are on hand for servicing.

Also, I don't think house has to be super insulated. Roof/loft is important but we got our floor insulation and cavity wall done after the pump install, and house was warm without the added insulation. Will be cheaper to run though if course if house is well insulated as you'll lose less heat

@Clinkyclunk the battery in shed was solely about optimum running yes a Tesla power wall can run outside but works best and most efficiently between 0 and 30 degrees Celsius.

Someone I know has one and reported that the outside unit was quite large and almost needed its own room to protect it from the elements.
It has to run all the time, 24/7, to work, and obviously it's powered by electricity.

It takes several days to warm the house up if it's been switched off.
It didn't make their house really warm, but kept it at a consistent temperature that they were able to adapt to.

This was in a fairly large older house.

My clients install these more and more often.

Admittedly, I do not involve myself in this side of the business and leave this to one of my colleague's.

Most of the newer systems have a 1m by 1m tank inside which is around 6ft high. The general rule is for every KW of energy you put in you get 3 out. But this is improving year on year.

They also advise all radiators are double fanned and are 50 percent larger than what you'd have with gas.

Our current heat pump specialist is of the opinion that if you are going to live in the property long term you should ideally pair it with solar panels to cover some of the cost of it running.

One thing that's recently cropped up is we were advised that some mistibishi units cannot have any planting within 1m of the heat pump are temperatures around can be extremely low. This is only one model we have been warned about but unsure if its something to consider with others.

Hope this helps

Sorry they are the right way up on my phone but this daft site switches them!

@Thursday37 I’m not into interested in ASHPs but also where your doors are from please 😊? Thanks

That was meant to be not only (not into) interested in ASHP!

Howdens ☺️

@Thursday37 thank you

@Thursday37 that really helps, thank you!

An ASHP is likely to need larger radiators and also larger diameter pipes, because in order for them to run at top efficiency, they need to deliver water to the radiators at a lower temperature than what a gas boiler can do efficiently. A gas boiler can give water at 60C quite easily where an ASHP might be running at 35-45C depending on outside temperature: when it is warmer outside, the house can be kept comfortable with a lower temperature of heating water.

An ASHP works best in a home that is well insulated and that is occupied year-round. I would not use one in a poorly insulated home, nor in a second home, since for the latter, it would be more efficient to let the house get colder when not occupied and then heat it to "comfort" temperatures only when it is occupied.