Ditching our ancient boiler for split A/C & heating.

Iamzod

Iamzod

Iamzod

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We're looking at ditching our near 40 year old back boiler for a nice shiny new combi boiler, due to all the pipework issues & the need to move it from inside the chimney breast to the bathroom the quotes are all coming in at £5-6k.

A thought occurred to me, AC systems with heatpumps have heating capabilities & we could get a split system in the living areas for less than £6k. I do have a portable AC unit already which I use in summer however it's not exactly efficient at 2kw, when it's 30c outside it has to run at full tilt continuously.

Has anyone got a split AC system, what are they like cost wise to run and are they a viable alternative to using a boiler & gas fired central heating?

I work from home & having split AC in my office instead of the 2kw monster would be rather nice in the summer.
 
Iamzod said:
We're looking at ditching our near 40 year old back boiler for a nice shiny new combi boiler, due to all the pipework issues & the need to move it from inside the chimney breast to the bathroom the quotes are all coming in at £5-6k.

A thought occurred to me, AC systems with heatpumps have heating capabilities & we could get a split system in the living areas for less than £6k. I do have a portable AC unit already which I use in summer however it's not exactly efficient at 2kw, when it's 30c outside it has to run at full tilt continuously.

Has anyone got a split AC system, what are they like cost wise to run and are they a viable alternative to using a boiler & gas fired central heating?

I work from home & having split AC in my office instead of the 2kw monster would be rather nice in the summer.
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Well, yes they are, because there isn't much difference between an AC system and one of these heat-pumps everyone is installing these days. Well, in performance. But in cost there is a significant difference, thanks to various government incentives to install the latter. If I were you, and facing that sort of cost, I would certainly consider a heat-pump.
For changing over to a newer (sealed system) boiler they usually charge you enough to deal with leaks. That's what makes it so expensive. Cheaply they will just move it to wherever it is convenient to them, not you, by the way. Thing is, they are getting close to the subsidised installation costs of a heat-pump, so I would definitely consider that.
If you can tolerate AC then you can tolerate a heat-pump.
 
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SpellowHouse said:
Well, yes they are, because there isn't much difference between an AC system and one of these heat-pumps everyone is installing these days. Well, in performance. But in cost there is a significant difference, thanks to various government incentives to install the latter.
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Don't think i'm eligable for any incentives unfortunately.

The boiler would be going in the loft if we go down that route, there is nowhere else it could go.
 
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Iamzod said:
Don't think i'm eligable for any incentives unfortunately.

The boiler would be going in the loft if we go down that route, there is nowhere else it could go.
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You can get £7500 towards the install of a heat pump.

However when he says there is a significant difference in cost because of that between AC and water heat pump that may not actually be true depending on your property.
 
Iamzod said:
Don't think i'm eligable for any incentives unfortunately.

The boiler would be going in the loft if we go down that route, there is nowhere else it could go.
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You can get the MCS certified grant for an ASHP/GSHP but in order to meet the 2.8 SCOP (efficiency target) I believe UK HP units have the cooling circuit limited to the defrost function in winter.

My ASHP HWC is going in the loft as it's big and my house is quite small. I had to get a structual survey before the instaler would go ahead in that location.
 
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There are changes due to the grants for ASHP to allow air-air with cooling functions, so may be worth waiting around a bit for.

I think there are a number of things you're missing that need to be taken into account, such as hot water, i'm guessing you have a sink in a bathroom or separate toilet(s). Also you'd need a unit or feed in each room. I have a ducted split system upstairs covering the 4 bedrooms and it's generally left ticking over over all winter and summer either heating or cooling, but not in the bathroom and this room is notably colder than the rest of upstairs. We have an ensuite so don't really use this bathroom, so a small sacrifice, but if I did I'd need that to be fed too.
 
SoliD said:
There are changes due to the grants for ASHP to allow air-air with cooling functions, so may be worth waiting around a bit for.

I think there are a number of things you're missing that need to be taken into account, such as hot water, i'm guessing you have a sink in a bathroom or separate toilet(s). Also you'd need a unit or feed in each room. I have a ducted split system upstairs covering the 4 bedrooms and it's generally left ticking over over all winter and summer either heating or cooling, but not in the bathroom and this room is notably colder than the rest of upstairs. We have an ensuite so don't really use this bathroom, so a small sacrifice, but if I did I'd need that to be fed too.
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I called a few places today & they said we'd be eligable which surprised me, it would be handy as it effectively doubles my budget from £6k to £13.5k.

I asked about air-air with cooling as that's definately what i'd want & they seemed to think it do-able.

As for hot water from the tap, it looks like you can get electric water heaters, i'm sure we used to have one in the office at work under the sink. Our shower is elecrtic already.
 
We have the hot water tanks at work which are not too bad, but looking around you can get a hot water tap which heats direct during use which might look more pleasant in a bathroom than a tank above/below the sink, in the kitchen there are plenty of options for boiling water taps.
 
Proper correctly sized air to air heat pumps offer similar performance to air to water heat pumps which are slightly cheaper to run than gas at price cap prices.

If you are seriously considering air to air, check out this channel below.

Just a word of caution, the final hot water solution they went with is very expensive and you can now get combined air to air systems what will also heat a hot water cylinder which are much cheaper.

You can also get loft mounted air con units which can be ducted into multiple rooms so they will cover small rooms like bathrooms without dedicated units for those rooms.

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As you already have a wet heating system, I would focus on going down the air to water route. Check out some of the big box installers like Octopus for a quote.

You will need somewhere for a hot water cylinder but that can be in an attached garage or loft.

If you do get a heat pump, seriously consider solar and batteries, it will reduce your energy costs considerably.
 
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Iamzod said:
In what way?

That's why i'm asking about the running costs and already got A/C but it's one of the massive portable units where you stick the pipe out of the window.
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I'd be concerned that going all-electric would be costly, particularly when you're generating domestic hot water with a COP of 1 at 28 p/kWh or something like that, bearing in mind gas is say 8 p/kWh and a gas boiler is maybe 85% efficient. Having said that, you've got an electric shower already so I could be very wrong.
 
It’s you’ve got an electric shower already, the cost difference would be negligible. Hot water is also a relatively small proportion of your heat demand.
 
dirtychinchilla said:
I'd be concerned that going all-electric would be costly, particularly when you're generating domestic hot water with a COP of 1 at 28 p/kWh or something like that, bearing in mind gas is say 8 p/kWh and a gas boiler is maybe 85% efficient. Having said that, you've got an electric shower already so I could be very wrong.
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We barely use the hot water in reality, it doesn't even work currently as the boiler has an issue so we have to put the heating on to get hot water and it's now too warm for heating.

It's only used in the bathroom for washing hands and a shave. We don't have a bath & exclusively use the dishwasher.

Even with my gaming pc, 2 heated aquariums, my 2 hot showers a day and an AC unit in use over the summer our combined DD is only £210.

The heating makes up a massive amount of that, it can cost £7-£12 per day over winter for heating.

I do the odd silly thing too, like last summer i filled a 7000 litre garden pool using a hose adapter connected to the shower. That was expensive but the pool was lovely & warm!
 
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