Calling all aircon experts

[ban-all-sheds]

I want to put A/C into the 3 bedrooms of my house. Don't have details of room sizes etc, as I'm not at this stage looking for the exact spec of the unit(s), but it's your typical 3-bed semi, 2 double bedrooms + 1 small single. One double is at the rear, west facing, the other double and the small single at the front, east facing.

In terms of each of the following

• Purchase and installation costs
• Running costs
• Effectiveness/flexibility

what's best - 3 individual units or a central system in the loft?

 

[2scoops0406]

Purchase and installation costs

See rule 9

Shame you haven't considered your carbon footprint

 

[electronicsuk]

In terms of each of the following

• Purchase and installation costs
• Running costs
• Effectiveness/flexibility

what's best - 3 individual units or a central system in the loft?

I have installed a few air conditioning units before, it hardly qualifies me as an expert but nobody else seems to want to provide a worthwhile answer to your questions.

In terms of purchase and installation costs, I would expect a central system to be cheaper. You would only have one outdoor condenser unit to install on the outside of the house, not only will this look nicer but it will also mean less cable and refrigerant lines to run.

Running costs depend on how you use the system. If you only plan to use it in one room for the majority of the time and the other rooms when guests stay over, individual systems will probably provide the best electrical economy. If you want to cool all rooms the majority of the time then a central system should perform better.

Neither solution should be any less effective, although I would say individual units are more flexible. If you plan on installing individual heat pump units then each room can be cooled or heated individually, a central system will no doubt only be able to operate in one mode at a time, i.e. all rooms cooling or all rooms heating. Don't quote me on that, though.

These are probably all questions to be asking your installer...

 

[breezer]

but nobody else seems to want to provide a worthwhile answer to your questions.

Its not that, B-A-S did say "Post Subject: Calling all aircon experts"

there are none

and as you said

These are probably all questions to be asking your installer...

also B-A-S left the forum some time ago of his own accord, (you figure it out)

and for what its worth, i would have thought the answer is 3 single units.

 

[Adam_151]

also B-A-S left the forum some time ago of his own accord, (you figure it out)

Posted: Wed Jun 13, 2007 3:05 pm

It would seem that he is not that far away

 

[breezer]

I never said he wasnt, he left, (of his own accord) and has been back once before, but he said somethin like he isnt coming back

back in april he posted

No, I'm not back, but my ID still works, and this is a one-off important post.

 

[JohnD]

bygones?

 

[securespark]

FWIW, welcome back, fellow sporter of facial hursuite-ness!

 

[Steve]

Nice to hear from you ban-all-sheds. Hows things? Do you like what we've done with the place?

Single room air con units, having 3 smaller compressors are going to be more expensive to run and probably more expensive to install. However, there is a type of outdoor compressor that can be pipe and controlled to three indoor units. Thus each room still has individual control. The only downside is you cant have one room cooling and one room heating, but this is always going to be very unlikely.

Personally i'd choose the ducted option, with a central loft distributor. One downside of this one is you'll need an air return, but for this to work you'll either need another hole in each ceiling, or vents in all the bedroom doors.

Are you thinking ebay units or pro supply / installed?

 

[electronicsuk]

also B-A-S left the forum some time ago of his own accord, (you figure it out)

and for what its worth, i would have thought the answer is 3 single units.

Before my time I'm afraid! Oh well, seems the question has been answered anyway.

 

[solo]

Huzzah. All hail the mighty Ban. He has returned from his travels across the mighty screwfix forum. We are forgiven. Ah the crops will be plentiful this year and the women fertile once more. Let us drink and be merry. Huzzah, huzzah.

 

[Pensdown]

Personally i'd choose the ducted option, with a central loft distributor. One downside of this one is you'll need an air return, but for this to work you'll either need another hole in each ceiling, or vents in all the bedroom doors.

For an office installation in a false ceiling yes, as a retro fit in a domestic loft no. When you're trying to get to sleep the vibration noise would drive you insane and lets be honest, BAS needs his beauty sleep

IMO for a domestic install you can't beat a multi inverter system. You only need one very quiet condenser with a low starting current and you can get nice slim unobtrusive air handling units which again are also almost silent. Full remote control, individual time switch control and the system wont cost you much more to run than the average heating system in the winter.

As for purchase and install costs.... you pay for what you get and I would budget around 2-3k per room but you may do better.

 

[stem]

I saw one of these demonstrated at an exhibition and it didn't seem too noisy, although it's difficult to tell when it's not in real life home environment. They look ideal for DIY installation though as they come in sections but are gassed up and ready to go. Power consumption details included.

http://www.elliotts.co.uk/aircon/lofty_temp.htm

 

[r.bartlett]

Efficiency wise check out the ECA website to check if the manufacturer you've been quoted is listed. The ducted system is a good option and provided the right make is chosen - as near silent as is possible. Hence pretty much all hotels and posh house are using these ducted units. Usually individual 2 or 3.5 kw units but the larger ones 5,6 &7 Kw c/w decent ductwork will be similar.

The downside is loss of Attic space, high install costs due to extra parts & labour. no individual room temp control. If the unit goes down you lose all the rooms. Can only heat or cool so if granny likes it warm -tough.+ part P may become involved..

Wall mounts splits are ugly. LG have their 'artcool' range but you're lumbered with LG relibility..You take your choice.

We estimate a bedroom with a 2kw wall mount single split(Daikin) will be around 1.2-1.5k + Vat (which is 5% on these)

A multi is actually dearer due to the cost of the outdoor unit. Personally I much prefer single splits as they give you far more flexibility of operation

Cheers

Richard

 

[ban-all-sheds]

OK - thanks to all contributors. Technical responses first...

. . . . .

See rule 9

Comparative figures or %ges/ratios will be OK.

Shame you haven't considered your carbon footprint

I have.

I rather like what using a high-COP heat pump in winter instead of burning gas will do to it.

. . . . .

Running costs depend on how you use the system. If you only plan to use it in one room for the majority of the time and the other rooms when guests stay over, individual systems will probably provide the best electrical economy. If you want to cool all rooms the majority of the time then a central system should perform better.

It would be essentially all rooms at once.

Neither solution should be any less effective, although I would say individual units are more flexible. If you plan on installing individual heat pump units then each room can be cooled or heated individually, a central system will no doubt only be able to operate in one mode at a time, i.e. all rooms cooling or all rooms heating. Don't quote me on that, though.

Would want either all cooling or all heating.

These are probably all questions to be asking your installer...

Indeed, and I shall be.

. . . . .

Are you thinking ebay units or pro supply / installed?

Almost certainly the latter. Partly for installation reasons (I don't want to be up a ladder with the external unit on one shoulder) and partly because I'm dubious about the quality of the hardware itself.

. . . . .

IMO for a domestic install you can't beat a multi inverter system. You only need one very quiet condenser with a low starting current and you can get nice slim unobtrusive air handling units which again are also almost silent. Full remote control, individual time switch control and the system wont cost you much more to run than the average heating system in the winter.

Only snag is all that plumbing running from one side of the house to the other...

. . . . .

I saw one of these demonstrated at an exhibition and it didn't seem too noisy, although it's difficult to tell when it's not in real life home environment. They look ideal for DIY installation though as they come in sections but are gassed up and ready to go. Power consumption details included.

http://www.elliotts.co.uk/aircon/lofty_temp.htm[/QUOTE]
That looks like the one that Wickes sell. Seems a bit cheap?

. . . . .

Efficiency wise check out the ECA website to check if the manufacturer you've been quoted is listed.

Will do.

The downside is loss of Attic space,

Yes - I know. Makes me worry where I'll put all those undated accessories and red/black cable reels...

high install costs due to extra parts & labour.

OK. I would have expected the overall cost to be less than the sum of 3 individual installs.

no individual room temp control.

Now that does surprise me - I really would have expected that each room user could control how often, and how much, air was blown in, and thus the temperature of his room.

Can only heat or cool so if granny likes it warm -tough.

That won't be a problem - I can't see how we'd want some rooms heated and some cooled at the same time.

part P may become involved..

I can cope with that.

Wall mounts splits are ugly.

In the eye of etc - I have to say that most don't seen too bad to me, and some wouldn't worry me at all (e.g. Mitsubishi Mr Slim).

We estimate a bedroom with a 2kw wall mount single split(Daikin) will be around 1.2-1.5k + Vat (which is 5% on these)

Interesting that that's half of Pensdown's estimate. What matters ultimately is what the quotes are from the installers I eventually go to - at the moment I'm just gathering info.

A multi is actually dearer due to the cost of the outdoor unit. Personally I much prefer single splits as they give you far more flexibility of operation

I'm starting to think that 2 units, a 2-way split at the front and 1 single at the back for the might be the best combination.

Still - we shall see - I really am just trying to learn and get a range of opinions for when I start talking to installers - if I were seeking to DIY it I'd say so.