Installing supplementary air to air heatpumps

Pat38493

Hi - OH wants to install air conditioning in a couple of rooms in our house and is being tempted by a special offer from our local electricians for air conditioning units. They are offering air conditioning units fully installed for £1795 each.

However, I am thinking - wouldn’t it make more sense long term to install air to air heat pumps in those rooms which can also act as air conditioning?

We have a 5 bedroom house but somewhat unexpectedly all 3 of our kids are pretty much moved out earlier than expected so there is only 2 of us in the house about 90% of the time. There is really only a downstairs large lounge which has an open plan to the kitchen, and the main bedroom which is on the 2nd floor partially in the roof space (sloping walls) where we spend most of our time.

I don’t’ really want to replace the entire system yet as we only bought the house last year and the boiler is less than 2 years old, but I’m wondering if 2x A2A heat pump / air conditioners might be a reasonable investment? Would that cost a lot more than the £1795 per unit being marketed for aircon?

QrizB

Would that cost a lot more than the £1795 per unit being marketed for aircon?

You'll probably find that the £1795 "aircon" is actually an A2A heat pump.

Do you know the make and model of the units that the electricians are offering at that price?

Reed_Richards

Not all air conditioners can be set to heat as well as cool but I think the vast majority can, so it would be surprising if the ones in the offer cannot do both cooling and heating.

Pat38493

https://forums.moneysavingexpert.com/discussion/comment/82105356#Comment_82105356

It’s described as a “Hitachi Single split air conditioning unit” and it does say in the advert that it heats in winter as well. I have written to them for more details about the exact model and to specifically ask if it acts as an A2A heat pump in winter and not a traditional electric heater.

I know very little about this but I was guessing that an aircon that also does heating might not be an A2A heat pump but might just act as a kind of old fashioned electric bar heater in winter which would be very expensive.

Pat38493

https://forums.moneysavingexpert.com/discussion/comment/82105373#Comment_82105373

Yes - it can definitely do heating in winter but does that definitely mean it’s an A2A heat pump or might it be just directly heating the interior unit like an old fashioned electric heater which would be very expensive presumably.

Rodders53

I've never heard of 'aircon' indoor units with a resistive heating element.

You are over-thinking…. and possibly over-paying at that price. Check that it applies for a 2nd floor room install — they'll likely need scaffolding for that height!

Do get alternative quotes from other F-gas registered installers. They are F-gas registered I trust!

NB zero rated for VAT, still, I believe.
NB2 You'll officially need Planning Permission for multiple outdoor units. One may be permitted development. Many don't bother getting PP though.

Pat38493

https://forums.moneysavingexpert.com/discussion/comment/82105416#Comment_82105416

Thanks I will check all that before proceeding. Also according to AI (which may be wrong) I would also look at getting a multi split system where there is one outdoor unit at ground level and 2 indoor units with just pipes running to the upstairs unit?

Reed_Richards

My understanding is that to allow an air conditioner to both heat and cool it needs a "reversing valve". It's inconceivable that a more complicated direct-heating capability would be installed but you can check the specifications for Coefficient of Performance (or similar), how many kW of heat you get per kW of electricity. This will be specified for particular temperature differences between the inside and outside air. There will be a similar specification for cooling.

"split air conditioning" means that there will be a fan outside and a wall-mounted unit inside.

NedS

@Rodders53 wrote:

NB2 You'll officially need Planning Permission for multiple outdoor units. One may be permitted development. Many don't bother getting PP though.

There have been reports in the press this summer of LA's taking enforcement action to get AC units removed where people have not engaged with the planning process.

JKenH

I think the current regulations allow 2 outdoor units on a detached house, which being 5bed I assume it is. Depending on location of the rooms you may be able to install a multi split system with one outdoor unit and 2(or more) indoor units. Might e worth oversizing the outdoor unit with one that allows for later addition of more internal units.

I don’t think £1795 is out of the way,price wise. I had 2 separate units installed in 2019 and they cost around £1,000 each but prices have risen since then. I wanted to add more units this year but because of planning regs, I had to replace one of the existing units with a 3 way multi split (6kW outdoor unit with one 2.5kW and two 2.2.0kW indoor units). That cost me approximately £4k.

The units are really unobtrusive in operation but we opted against putting one in the bedroom we sleep in as my plan, in winter, is to use cheap off peak electricity to heat the house overnight and I didn’t particularly want to go to sleep in a cool bedroom and the room heat up while sleeping to uncomfortable levels. We are quite surprised what good job a 2kW unit on the landing did of cooling 3 good sized bedrooms. There is a separate aircon unit in what is officially the main bedroom which in practice is used as a guest room.

We still have oil central heating and intend to keep this as back up for really cold weather or when electricity is expensive.

The original 2 ASHPs were the best home investment we have made as they are very effective in just heating the space you want to use very quickly. On a spring or autumn evening when the temperature drops you can just pit the ASHP on and in less than five minutes the room is warm. Similarly at breakfast time.

michaels

https://forums.moneysavingexpert.com/discussion/comment/82105423#Comment_82105423

There are definitely multi split systems and that is likely to be the best way to go for up to 4 rooms unless for some reason they are a long way apart in terms of pipe runs as it should be cheaper and will require only one outside unit so no planning issues