Home air conditioning in the UK

[steve30]

I'm wondering if anyone can advise me on air conditioning.

I have a two bedroom end-terrace house. My bedroom-cum-electronics-lab gets ridiculously hot in summer and I'd really like air conditioning for it. I have solar power so I'm not too concerned about summer time running costs.

Our kitchen doesn't have any heating, and the downstairs is always cold in winter. So I keep pondering air conditioning for the kitchen, primarily for heating in winter. I expect it will be cheaper to run than the 3kW resistive heater we use now (which is only barely adequate). Of course the free cooling in summer will be useful; otherwise I'd just see about adding another radiator to the central heating.

Now, to complicate it a bit more, my Mum has decided she'd like AC in her bedroom. I expect this won't see that much use as that room doesn't get stupidly hot.

I intend to get someone out to have a look and give me a quotation in the near future, but in the mean time, does anyone here have any recommendations on what kind of equipment or setup might suit us?

Thanks
steve30

[Ice-Tea]

Afaik, not terribly difficult to install. I think most units these days come prefilled with a fast-connect, as long as you don't exceed predefined lenghts of tubing. There are a gazillion online outlets offering packages. Like:

https://zet-shop.be/airco#/samenstelling-buitenunit_met_3_binnenunits

[jc101]

I have two AC systems, one in the house and one in the office (which is in the garden).

The office is a small split Daikin system, cools in the summer, heats in the winter.  I put it in after the electric bill for using a fan heater over the first winter.  Costs a fraction of the cost to run and gives cooling in the summer, which is great.

The house is a 3 way split unit (conservatory, living room, and master bed upstairs) .  Daikin fan/compressor outside and the three split units inside, one per room.  This one is rated at 9kW heating/cooling and draws a max of around 2.8kW of electric when working hard.  Based on the monitoring I have on the solar and house electric use, not put a clamp meter on it's feed.

We also have solar, so in the summer the AC side is free.  In the winter, on a sunny day we run the units for heating as it's cheaper than turning on the boiler.

All professionally installed by a local company, been in for around 7 years now without missing a beat.  They are serviced/cleaned twice a year.

I went for Daikin systems, after much research.  My prime concern was to keep the noise of the outdoor units as low as possible, plus good efficiency and warranty.
I think there is still only 5% VAT on heat pumps (air or ground, inc installation) in the UK, providing a suitable installer is used.

If you are in the Cambridge / Huntingdon / Peterborough area send me a DM and I'll happily pass on the company details.

[coppice]

Its really easy to install air cons. If you haven't done so you might worry about getting the coolant circuit of a split air con charged, but its actually trivial. Chose Daikin, or perhaps Mitsubishi, and you'll be unlucky if you have reliability issues for a number of years. Not all makes are created equal.

You say you have solar panels. If these are grid tied, so the air con has guaranteed power, things should be fine. If they are isolated you may need to look at specialist (more expensive) air cons which are tolerant of the power being erratic when the sky isn't blue. Heat pumps and frequent short power interruptions do not go together well. Older heat pumps take a huge surge of power at startup, which can be a problem with a solar system that cannot briefly source the surge power, but most modern designs soft start.

[steve30]

jc101: Sounds like you have a nice system. How much did it cost for the 3 way system in the house? That will be similar to what I'm wanting to do.
I'm nowhere near Cambridge, so I'll go with someone local.

coppice: Yes, the solar system is grid tied, so no issue with a lack of power.

[AndyC_772]

I had a Daikin sytem installed about 18 months ago, one outdoor unit and two indoor.

In winter I'm normally in one of the rooms that has a/c, so I use the system to heat that room instead of using the gas central heating to heat the whole house. The saving pays to run the system for cooling in summer, so I'm more or less cost neutral over the whole year.

The system is quiet and effective, and reliable so far. Total installed cost was about £5k IIRC.

[Marco]

Afaik, not terribly difficult to install. I think most units these days come prefilled with a fast-connect, as long as you don't exceed predefined lenghts of tubing. There are a gazillion online outlets offering packages.

Isn't it illegal to sell to private customers unless they have already contracted for professional installation nowadays? (In the EU.)

[coppice]

Afaik, not terribly difficult to install. I think most units these days come prefilled with a fast-connect, as long as you don't exceed predefined lenghts of tubing. There are a gazillion online outlets offering packages.

Isn't it illegal to sell to private customers unless they have already contracted for professional installation nowadays? (In the EU.)

Aren't the controls only on the harmful refrigerants?

[steve30]

Afaik, not terribly difficult to install. I think most units these days come prefilled with a fast-connect, as long as you don't exceed predefined lenghts of tubing. There are a gazillion online outlets offering packages.

Isn't it illegal to sell to private customers unless they have already contracted for professional installation nowadays? (In the EU.)

I know some suppliers won't sell to end users, but I don't know if that is a legal matter or not.

I'd rather get it installed professionally anyway. I've never worked with refrigeration before and this would be a rather big/expensive project to start on  .

[Ice-Tea]

Illegal? Why would it be? 

Again, as far as I know, at least some units are prefilled and only require to "clikc" the tubing in place.

[Marco]

Illegal? Why would it be? 

https://eur-lex.europa.eu/legal-content/EN/TXT/?uri=CELEX%3A32014R0517

"Non-hermetically sealed equipment charged with fluorinated greenhouse gases shall only be sold to the end user where evidence is provided that the installation is to be carried out by an undertaking certified in accordance with Article 10."

I guess in theory quick connectors on prefilled lines which break a hermetic seal during installation qualify, but it's skirting the law. Still looking around I do see shops still selling minisplits with prefilled lines, so I guess government hasn't cracked down yet.

[Halcyon]

Steve, check out "multi split systems". Essentially they are a split system but with multiple indoor units connected to the same outdoor unit.

I know most of the big brands sell/install them including Daikin, Mitsubishi and Fujitsu.

Obviously you can't heat and cool at the same time, but it could be a good option for you, particularly if one unit won't be used very often.

[Psi]

Multi split systems are usually only desirable to avoid the unsightly 'look' of having an outdoor unit for each indoor unit.
Or if you only have space for one outdoor unit.

For 2-3 indoor units a multi-spit system typically costs around the same as 2-3 separate mini-split systems.
(If you have like 5 indoor units then multi split hardware will be cheaper but the install is more complex and costly)

Multi-split has some disadvantages:
- You only have 1 outdoor unit, if that unit fails then all your indoor units stop working.
- As Halcyon said, you cannot have one room cooling and another room heating. (Sometimes one person is cold while others are hot so this can be an issue)

So I would recommend multiple mini-split system if you have room for them.

[NiHaoMike]

In the US, buying A/Cs, heat pumps, and refrigeration equipment other than self contained units (e.g. window, wall, or portable) require an EPA 608 license, which is pretty easy to get. Apparently, the equivalent in some other countries is more difficult.

- As Halcyon said, you cannot have one room cooling and another room heating. (Sometimes one person is cold while others are hot so this can be an issue)

True of most residential systems (there's generally little reason to run both active cooling and heating at the same time), but for commercial systems, it's common to use a more elaborate design to accommodate a server room (cooling needed year round) along with some office spaces (heating or cooling as needed).

If for some reason you do often run into a situation where you need to cool one room while heating another, a cheap, efficient solution is to put a portable A/C in the room to be cooled and duct the hot air to the room to be heated.

[steve30]

Thanks for the replies.

A Multi-split will be the way to go I think, as I don't really have room outside for several outdoor units. There will be no need for heating and cooling at the same time.

I think I'll get a professional in next week to have a look and give me some prices.

[pcmad]

is the room sun facing if so when the sun hit it close the windows and put cardboard on the window or even a space blanket this work quite well for me

[Circlotron]

Afaik, not terribly difficult to install. I think most units these days come prefilled with a fast-connect, as long as you don't exceed predefined lenghts of tubing.

Aren't you also meant to evacuate the pipes with a vacuum pump to remove any traces of moisture? I know the crowd that installed our Daikin split system didn't... 

[coppice]

Afaik, not terribly difficult to install. I think most units these days come prefilled with a fast-connect, as long as you don't exceed predefined lenghts of tubing.

Aren't you also meant to evacuate the pipes with a vacuum pump to remove any traces of moisture? I know the crowd that installed our Daikin split system didn't... 

That's not part of the installation procedure for the Daikin systems I've owned. If there were condensation on the pipes I hope an installer would warm them to dry them out, but I've never seen people taking any special precautions.

[Monkeh]

Some systems do have pre-purged pipe sets with special connectors with integrated valves. For everything else, purging is required.

[Photon939]

I've seen a few systems configured for DIY where the lines come with special quick-connects and both indoor and outdoor units come pre-charged with refrigerant so you probably just get a small psst when connecting and doesn't need a vacuum pump.

Any of the regular systems that just come with flare connections and a pre-flared lineset will need evacuation and leak testing with a vacuum pump and nitrogen before letting the refrigerant out of the outdoor unit.

edit - monkeh beat me to it

[steve30]

Time for an update. Someone finally got back to me with a quotation.

For a 3 room multi split he's quoted about £4700, for either a Fujitsu or Mitsubishi. He also suggested three single splits, which is about £4000. TBH I'm surprised that the single splits are so much cheaper. The trouble with single splits is that I think it would be quite cumbersome having three outdoor units on a small house.

Would anyone say those prices are in the right ballpark? I gather air conditioning is rather expensive in England.

[james_s]

In the US, buying A/Cs, heat pumps, and refrigeration equipment other than self contained units (e.g. window, wall, or portable) require an EPA 608 license, which is pretty easy to get. Apparently, the equivalent in some other countries is more difficult.

It's ridiculously easy to get, at least it was about 15 years ago when I got licensed. I did it thinking I'd need it to buy the equipment and supplies but at this point I've installed four different split system heat pumps and got a 30lb jug of R22 and nobody actually asked to see my license when I bought any of it.

As for prices, I think it's expensive anywhere. A friend of mine paid $10k to have a 3 ton split system heat pump installed in his house. Meanwhile I spent $1500 for a similar 3 ton system of the same efficiency rating *and* a new condensing gas furnace/air handler and all the lines, fittings and other bits. I bought new scratch & dent equipment despite HVAC guys telling me it wasn't going to work, that was 15 years ago and it's still going strong.

[Marco]

For that kind of money couldn't you get a reversible heat pump installed and pull some water lines for chilled water air conditioning units?

Saves you money on your heating bill too.

[coppice]

Time for an update. Someone finally got back to me with a quotation.

For a 3 room multi split he's quoted about £4700, for either a Fujitsu or Mitsubishi. He also suggested three single splits, which is about £4000. TBH I'm surprised that the single splits are so much cheaper. The trouble with single splits is that I think it would be quite cumbersome having three outdoor units on a small house.

Would anyone say those prices are in the right ballpark? I gather air conditioning is rather expensive in England.

The single room air cons seem to be cheaper because they are made in huge volumes compared to the larger and more complex designs. Also, the single room kind is a quick and easy install these days, because they are pre-charged. The mullti-room ones usually need longer runs, so they need to be charged with additional coolant, making the installation more complex.

As you said, a stack of external units, with enough space around them for the air to flow freely, takes quite a lot of space. However, its often easier to find 3 small spaces around a house than one large one. A spacious location is important, for free air circulation. These things can work very inefficiently if they are placed where their output air keeps recirculating to their input.

The installation cost will vary a lot with how they are installed. If the locations work out nicely there might be an external unit just the other side of the wall from its internal unit. However, if there is a pipe run needed along the walls, channelling them out can be time consuming, costly, and require some serious redecoration to tidy up afterwards. Remember than these pipe runs need to slope down gently from the interior unit to the outside world, as the run usually includes a condensation drain tube, alongside the coolant send and return pipes. Make sure when the units are installed that you can get to that drain tube easily. You probably have to rod it through every year or two, to clear out accumulated crud. If you don't, you will find the decoration on your wall ruined one day when it finally clogs up (been there, done that).

I'd go for Mitsubishi over Fujitsu General, unless Fujitsu have improved their noise levels in recent years. Daikin and Mitsubishi are usually the safest bets.

[Lord of nothing]

My personal opinion on such device is it depend how cold it get in Winter and how long it be and how thermally isolated your House is.
Here is a good TV Show with a quite serious Guy (not that German idiots who show up normally  ) who show what Construction Company did wrong.
OMG its often horrific to see what "one men show" did with there Eastern European Guys who no clue about anything on a construction site.
Well when that is only the Tip of the Ice Block how bad must the "average" House be.
I would say such Head, Cooling thinks could work in a Area who have low min Temp in Winter. In middle and northern Europe (away from the Cost) who often Winter mean Winter I highly would stay away from such a think as Central Heating.

We Installed an "Emergency Wood Burning Oven" as an alternative Head source in the Case the Main Gas one fail some day. 

[steve30]

I keep umming and arring and this and now I'm wondering if the three separate units might be feasible. The one for the front bedroom can be mounted on the side of the house somewhere, either high up on the wall or low down on the path, and the two units for the two rear rooms could be mounted low down on the wall round the back. It would still be more cumbersome than one unit, but it might work OK.

Its difficult to make my mind up.

[jc101]

I keep umming and arring and this and now I'm wondering if the three separate units might be feasible. The one for the front bedroom can be mounted on the side of the house somewhere, either high up on the wall or low down on the path, and the two units for the two rear rooms could be mounted low down on the wall round the back. It would still be more cumbersome than one unit, but it might work OK.

Its difficult to make my mind up.

The pics attached show our two outdoor units.  The larger against the brick wall is the 3 way unit, which does a conservatory, downstairs living room, and master bedroom.  They must all be either heating or cooling.  Initially this just ran 2, but we added the 3rd last summer.  To do that they pumped the system down into the outdoor unit, added the extra pipework, then pressure tested the whole system.  Once complete, it was vacuumed out again then the outdoor valves opened and the system tested.  No additional gas was needed.  The upstairs unit piping etc. goes up into the loft, then from the front of the house to the back, and down out the outside rear wall on a tray tucked behind the soil pipe once it gets above the door.

The smaller unit just does my office/lab/workshop in the garden, again heating or cooling.  Being newer, the office one can also be controlled via an app - which I've found handy from time to time.

Noise wise, the large unit is actually not too noisy - I ran it flat out in heating mode when it went in and out neighbour didn't notice it, their back door is just over the wall to the left.  We can't hear it, even stood in the kitchen, unless the window is open.

A friend also added a couple of units to their house last summer, they went with two single systems.  They have both outdoor units above a flat roofed garage side by side, where they cannot be easily seen.  If they went with 3 indoor units they would have gone with a 3 way unit, but the installer thought (correctly) they would only need the 2 indoor units for what they wanted.

I would check the power usage of running three separate systems against one larger one.  If we have a unit on in the house, to turn on another doesn't really make a big difference in consumption (based on the monitoring we have for the solar PC system).  I guess running three separate systems may be slightly more inefficient?

Bottom line is the 3 way outdoor unit doesn't take up the same space as 3 separate units, by quite a margin.  Plus it's easer to service (only 1 unit to clean rather than 3).  It did need a separate 20amp supply though from the consumer unit, all the indoor units are powered from the outdoor unit.  The outdoor units can also generate quite a bit of water in winter when they defrost, ours is sitting above a gravel patch which lets it soak away.

Price wise, I has been in 6 or 7 years now, and with the additional indoor unit last summer the whole 3 way system would have been around £4.5k all in.

[coppice]

The one for the front bedroom can be mounted on the side of the house somewhere

If you mount something like that high up, are you going to run into planning permission issues, as its very visible? They work more efficiently well away from the ground, as the air flow around them is better, so its a technically superior location. However, even minor complaints about what you do can get quite costly.

[coppice]

I would check the power usage of running three separate systems against one larger one.  If we have a unit on in the house, to turn on another doesn't really make a big difference in consumption (based on the monitoring we have for the solar PC system).  I guess running three separate systems may be slightly more inefficient?

If you look at the efficiency ratings though the Daikin range, as an example, you'll find that density rather than capacity is the big factor. For example, their smallest and next to smallest capacity units are the same size, but the smaller capacity one is more efficient by some margin. Move to the next physically larger model and the efficiency goes up again.

If you are worried about space, you might want to consider why you are installing the system. If cooling only serves most of your needs the exterior unit for the cooling only models is a lot smaller than the external unit for the heat and cool models.

[jc101]

I would check the power usage of running three separate systems against one larger one.  If we have a unit on in the house, to turn on another doesn't really make a big difference in consumption (based on the monitoring we have for the solar PC system).  I guess running three separate systems may be slightly more inefficient?

If you look at the efficiency ratings though the Daikin range, as an example, you'll find that density rather than capacity is the big factor. For example, their smallest and next to smallest capacity units are the same size, but the smaller capacity one is more efficient by some margin. Move to the next physically larger model and the efficiency goes up again.

If you are worried about space, you might want to consider why you are installing the system. If cooling only serves most of your needs the exterior unit for the cooling only models is a lot smaller than the external unit for the heat and cool models.

I think the 5% VAT applies if it's a heat pump, for plain cooling I think the VAT would be 20%.  The rules may have changed over the years since we had the systems installed.  For us, the Solar PV covers the cost of running the system when needed, even on some winter days - so it's way cheaper than turning on the central heating.

[Messtechniker]

If it is your house, you'd better get to to root cause of "hot in summer - cold in winter -
i.e. hire an expert on thermal house insulation. DIY is not suitable here because of the
massive change to the thermal physics of the entire house. When getting it wrong you
will probably be suffering from an incorrectible mould problem quite quckly. So beware!

[Monkeh]

If it is your house, you'd better get to to root cause of "hot in summer - cold in winter

Could it perhaps be that it's hot in summer, and cold in winter? Insulation alone doesn't do much.

There's nothing wrong with the insulation in this house - but, amazingly, with an outdoor temperature of 18C right now and the sun aimed right into the window, it's bloody hot in here compared to a few weeks ago, when it was 4C outside and cloudy..

[mikeselectricstuff]

I installed a Mitsubishi split system myself a couple of years ago in the house, as I already had a Mitsubishi in the workshop that's worked flawlessly for >15 years.

Don't recall the supplier, but bought everything online from them - they did pipe sets that are already insulated with flared ends, so the only gear you need is a vacuum pump and manifold gauge ( rent these from Ebay if needed!), though due to length I needed to cut & flare the pipes - beware the cheap flaring tools - just managed to do the 4 flares I needed before it fell apart!

I have a feeling that there are some regs involved, but like the Part P bullshit, who's gonna find out ?
Definitely wasn't an issue buying everything - make up a company name if needed!

[Messtechniker]

 and the sun aimed right into the window, it's bloody hot in here compared to a few weeks ago, when it was 4C outside and cloudy..

So the window might be the problem. First measure would then be reflective window blinds. The second measure, provided the windows are older that 5 years or so, would be to replace them with modern up-to-date double-glazing or triple-glazing with an U-value no greater than 0.8 m2 K. In the case of such windows and inadequate wall insulation the condensation now collets on the walls now giving rise to a mould problem especially when you have wallpaper on the walls.

If sometimes in winter the condensation is occasionally on the outside with a small bit of inside condensation at the bottom then you already have well thermally insulated windows. In the case of older so good windows the condensation usually collects on the full inside surface.

Just my experience and when talking to some real experts on this.

[james_s]

If you look at the efficiency ratings though the Daikin range, as an example, you'll find that density rather than capacity is the big factor. For example, their smallest and next to smallest capacity units are the same size, but the smaller capacity one is more efficient by some margin. Move to the next physically larger model and the efficiency goes up again.

If you are worried about space, you might want to consider why you are installing the system. If cooling only serves most of your needs the exterior unit for the cooling only models is a lot smaller than the external unit for the heat and cool models.

That is precisely how they get the higher efficiency ratings, the cooling capacity is based on the horsepower of the compressor, the efficiency is based on the ratio of coil size to cooling capacity. My 14 SEER 3 ton heat pump is the same physical size as a 12 SEER 4 ton unit and the indoor coil is rated for 4 ton (48k BTU/h). For even higher efficiency some systems use fancy variable speed compressors and fans but the biggest gain is by upsizing the coils.

[james_s]

Aren't you also meant to evacuate the pipes with a vacuum pump to remove any traces of moisture? I know the crowd that installed our Daikin split system didn't... 

Generally yes, although I've heard of systems that came with pre-charged lines with special fittings. The issue with this of course is that you're stuck with whatever length the lines are so you can end up with an unsightly coil of excess line. If you have a situation where you need to have a sharp bend and kink the line you're SOL. It's better IMO to just get a vacuum pump and do it the old fashioned way. I usually pump the lines down for about an hour with a good vacuum pump to make sure any moisture evaporates out.

[coppice]

If you look at the efficiency ratings though the Daikin range, as an example, you'll find that density rather than capacity is the big factor. For example, their smallest and next to smallest capacity units are the same size, but the smaller capacity one is more efficient by some margin. Move to the next physically larger model and the efficiency goes up again.

If you are worried about space, you might want to consider why you are installing the system. If cooling only serves most of your needs the exterior unit for the cooling only models is a lot smaller than the external unit for the heat and cool models.

That is precisely how they get the higher efficiency ratings, the cooling capacity is based on the horsepower of the compressor, the efficiency is based on the ratio of coil size to cooling capacity. My 14 SEER 3 ton heat pump is the same physical size as a 12 SEER 4 ton unit and the indoor coil is rated for 4 ton (48k BTU/h). For even higher efficiency some systems use fancy variable speed compressors and fans but the biggest gain is by upsizing the coils.

Only the bargain basement air cons lack variable frequency drive, but that is only one of the efficiency improvements that have been introduced in recent years. The efficiency difference between a cheap air con and a high quality one of the same size and power is now quite large.

[james_s]

Only the bargain basement air cons lack variable frequency drive, but that is only one of the efficiency improvements that have been introduced in recent years. The efficiency difference between a cheap air con and a high quality one of the same size and power is now quite large.

Well I'm speaking of the fullsized split systems that are common in the US, AFAIK most of them are still of a conventional design although the last one I installed was about 10 years ago so things may have changed. Since the forced air central heating is virtually ubiquitous in the US is very rare in the UK if it exists at all, I'm not even sure if you can get the sort of split system AC/heat pumps that are common here. They consist of an outdoor unit with the compressor in it and an indoor unit that is either an air handler or an evaporator coil that is installed between the outlet of a furnace and the ducting.

[Monkeh]

You can, but they're mostly seen in commercial installations and the overpriced dwellings of the unacceptably rich.

There's a big push on heat pumps coming over here, so we may see them domestically eventually.

[Marco]

I doubt it, why would we want ducts with all the architectural problems, filtering, mold etc? Phase change refrigerant loops have their own issues ... but pumping water around the house is relatively easy and the most common solution in Europe already for heating. So just insulate the pipes and use them for chilled water too, problem solved. A wall fan coil unit for chilled water is a lot less complex and cheaper than a wall unit for a multisplit too.

[Monkeh]

I doubt it, why would we want ducts with all the architectural problems, filtering, mold etc? Phase change refrigerant loops have their own issues ... but pumping water around the house is relatively easy and the most common solution in Europe already for heating. So just insulate the pipes and use them for chilled water too, problem solved. A wall fan coil unit for chilled water is a lot less complex and cheaper than a wall unit for a multisplit too.

And now you need to bring big awkward pipes into every room, along with AC power, thermostat, fan, filter.. you get the distinct joy of having to deal with pump replacement, air locks, bubbling, cavitation, water hammer..

I'm so sick of wet systems it's not funny.

Oh, and you'll still need condensate drains on each of those units, if you've any plans on controlling humidity..

[Marco]

I'm so sick of wet systems it's not funny.

Have you considered emigration? Regardless of your personal feelings I think you'll agree that hydronic systems will likely stay dominant in Europe.

Duct based solutions will almost certainly remain extremely expensive niche solutions ... unless you import the equipment from the US and DIY everything.

[Monkeh]

I'm so sick of wet systems it's not funny.

Have you considered emigration? Regardless of your personal feelings I think you'll agree that hydronic systems will likely stay dominant in Europe.

Due to old buildings (Which actually means old - I'm looking at you, USA, I've lived in houses older than you), yes, there will be a lot of wet systems, especially for heating.

Duct based solutions will almost certainly remain extremely expensive niche solutions ... unless you import the equipment from the US and DIY everything.

One can hope a ducted system in newer construction using more modern methods may have some impact. Far preferable in my opinion - central filtering, single fan, low noise, easily balanced, easily zoned.. Ductwork is cheap, less electrical work required, fewer expensive components.

[coppice]

One can hope a ducted system in newer construction using more modern methods may have some impact. Far preferable in my opinion - central filtering, single fan, low noise, easily balanced, easily zoned.. Ductwork is cheap, less electrical work required, fewer expensive components.

I've used water based systems. I've used heat pump systems that circulate the refrigerant. I've used ducted air systems. The only one I never want to use again is a ducted system. They are a nightmare to keep clean and hygenic.

[Messtechniker]

Just look around in any hotel (with ducts) irrespective of the number of stars
of your choice. They never clean the ducts. Just my experience.

[james_s]

I didn't mean to start a debate over which system is better, they both have advantages and disadvantages, my point was only that central forced air is extremely dominant in the US compared to a boiler with radiators in Europe/UK. Since forced air is the standard over here when I hear "heat pump" I automatically think of the sort that are the most common here.

We do have mini-splits as well, they're commonly installed in mobile homes and houses that were built with individual electric resistance heaters.

[steve30]

Forced air heating is pretty much unheard of here in England (in houses at least). I know some houses do have it, but I don't think I've seen one myself. I've no idea if it'll take off in the future, what with heat pumps becoming more common, but the common way of doing heat pumps in houses here at the moment is to connect them to the existing hot water based radiators.

jc101: Thanks for the pictures and information. The VAT is indeed 5% if you have it supplied and installed by someone qualified.

mikeselectricstuff: Well done for doing it yourself . To be honest, I'd still like to try and do it myself, but at the moment, this would be too big/expensive to screw up, so I think its safer to have a professional do it.

If you are worried about space, you might want to consider why you are installing the system. If cooling only serves most of your needs the exterior unit for the cooling only models is a lot smaller than the external unit for the heat and cool models.

coppice: Can you even get cooling-only models now? All the manufacturers I've looked at only do ones that have both heating and cooling, even the cheap no-name ones. The only cooling-only ones are the portables/window units.

Generally yes, although I've heard of systems that came with pre-charged lines with special fittings. The issue with this of course is that you're stuck with whatever length the lines are so you can end up with an unsightly coil of excess line.

These sorts of things used to be available here. B&Q sold some in the mid 2000s; I remember them advertising them. Don't think they'd be allowed to sell them here now though. Can't speak for other countries.

[Monkeh]

Generally yes, although I've heard of systems that came with pre-charged lines with special fittings. The issue with this of course is that you're stuck with whatever length the lines are so you can end up with an unsightly coil of excess line.

These sorts of things used to be available here. B&Q sold some in the mid 2000s; I remember them advertising them. Don't think they'd be allowed to sell them here now though. Can't speak for other countries.

They were definitely available last year - can't seem to find them now though.

[coppice]

Generally yes, although I've heard of systems that came with pre-charged lines with special fittings. The issue with this of course is that you're stuck with whatever length the lines are so you can end up with an unsightly coil of excess line.

These sorts of things used to be available here. B&Q sold some in the mid 2000s; I remember them advertising them. Don't think they'd be allowed to sell them here now though. Can't speak for other countries.

They were definitely available last year - can't seem to find them now though.

The B&Q stores here in York have not stocked any air-ons in the 3 years I've lived here. A few years ago the London stores certainly offered quite a range of air-cons.

[coppice]

Can you even get cooling-only models now? All the manufacturers I've looked at only do ones that have both heating and cooling, even the cheap no-name ones. The only cooling-only ones are the portables/window units.

Good question. Globally most air-cons, both the window and splits types, only cool. However, the ones imported to the UK might well be only of the heat+cool type.

[mikeselectricstuff]

mikeselectricstuff: Well done for doing it yourself . To be honest, I'd still like to try and do it myself, but at the moment, this would be too big/expensive to screw up, so I think its safer to have a professional do it.

There's really very little to screw up. If you use a pre-flared pipe set, it's literally just a case of screwing everything together, some wiring, vacuuming and opening the valves in the right order.
May be different now but last time I had any dealings with professional AC installers, they were somewhat of a "closed shop" and charged a lot - as domestic AC is fairly rare in the UK they mostly do business installs with fat budgets.

Maybe an option would to be to mount the units and run the pipework yourself and get someone in to commission it.

The only "rookie error" I made was to not have a steep enough fall in the condensate drain pipe immediately where it comes out of the indoor unit, and continuous fall all the way to the drain so the water  backed up and leaked.
   

[SeanB]

Split units heating and cooling is pretty much standard, it is rare to find cooling only, as the extra cost of adding in the valve and the extra wire is minimal, especially as almost all of the units will be expected to do heat pump duty at least part of the time, so having 2 separate but near identical models is silly. Only difference will be the programming of the controller, and the valve, along with the 2 direction cap tube needed to allow the switching. After all, if you want cooling only it is easy to simply select that on the remote, instead of leaving it in auto mode, where it will cool or heat as appropriate.

[coppice]

Split units heating and cooling is pretty much standard, it is rare to find cooling only, as the extra cost of adding in the valve and the extra wire is minimal, especially as almost all of the units will be expected to do heat pump duty at least part of the time, so having 2 separate but near identical models is silly. Only difference will be the programming of the controller, and the valve, along with the 2 direction cap tube needed to allow the switching. After all, if you want cooling only it is easy to simply select that on the remote, instead of leaving it in auto mode, where it will cool or heat as appropriate.

You need to get out more. Globally cooling only air cons outsell heat and cool by orders of magnitude. Heat and cool adds about 50% to the cost of a cool only model from the same manufacturer, and the external unit is considerably larger.

[NiHaoMike]

You need to get out more. Globally cooling only air cons outsell heat and cool by orders of magnitude. Heat and cool adds about 50% to the cost of a cool only model from the same manufacturer, and the external unit is considerably larger.

That's likely to be true in areas where gas heating is common. In areas where it is not but heating is needed a significant part of the year, heat pumps are very common.

[coppice]

You need to get out more. Globally cooling only air cons outsell heat and cool by orders of magnitude. Heat and cool adds about 50% to the cost of a cool only model from the same manufacturer, and the external unit is considerably larger.

That's likely to be true in areas where gas heating is common. In areas where it is not but heating is needed a significant part of the year, heat pumps are very common.

Its obviously market based. Remember that hot places are also the hot markets for air cons, and many of those places never really get cold enough for people to worry about heating.

[steve30]

We've done a load more umming and arring, and decided that the 3x single splits might be best, especially since it is considerably cheaper than the multi-split.

I've added a couple of pictures of the proposed locations for the outdoor units. The one for the front bedroom can go up on the wall in the first photo, and the two units for the rear bedroom and kitchen can be hidden behind the gate in the second photo (where the barbecue is).

[james_s]

I'm surprised that three separate singles are cheaper than one multi system, I guess there must be that much more volume of singles sold? The multi ought to get by with two fewer compressors and outdoor fans, less control gear, less sheetmetal, etc.

[steve30]

I'm surprised that three separate singles are cheaper than one multi system, I guess there must be that much more volume of singles sold? The multi ought to get by with two fewer compressors and outdoor fans, less control gear, less sheetmetal, etc.

I'd have thought that too. If you look at Fujitsu's price list, the high end 3x singles and the 3-way multi are about the same price. I'd guess the installation is more complex.

[james_s]

They do require copper lines to be run from each air handler back to the outdoor unit, that could get expensive. Do check on the energy cost though, I don't know if the multi-unit is more efficient than multiple singles or not but if it is that long term cost should not be overlooked.

[steve30]

Time for an update. I eventually got an AC system installed! We went for the three separate systems. My bedroom and the kitchen have the more 'standard' type, and my Mum's bedroom has a fancy silver model.

Here's a picture of the three outdoor units. The two for the rear of the house fit in nicely behind the gate, so are really only visible from our garden. The one for the front bedroom is mounted up on the wall. It is noticeable, but not too noticeable.

Its only been in a couple of days, but so far, the performance has been very good. The outdoor units are audible, but the noise is mostly that of the airflow. You can hardly hear the compressor or fan motor.

Total cost came to about £4300 including 5% VAT.

I'll post some more pictures later.

[steve30]

Here's some more pictures. In order: The fancy silver unit in my mother's bedroom, the silver one's corresponding outdoor unit mounted up on the wall, the unit in my lab-cum-bedroom, and the unit in the kitchen.

[tkamiya]

I'm glad they are working for you so well!

Just a reminder for US folks.  I spoke with an owner of A/C guys that I use about self-installs few months ago.  I was considering doing one myself for lab.  It gets awfully hot in there.  Amazon is full of self-install kits.  I am strictly speaking about split systems where piping is involved, and US only.

One gotcha for self-installing a split system is, if something should go wrong at install time or future, you have very little recourse.  Reputable service companies do not even come near customer self-installed systems.  So you are all on your own or rely on questionable sources.  If you look at review on Amazon, it shows many good stories and few bad ones, and bad ones are usually about getting it serviced.  I never had an A/C system that didn't lose coolant gas at one time or another.  So take that into consideration.

He couldn't tell me about legality of self-installs as his company never get themselves involved.

As technical and meticulous as most users on this forum is, I have no doubt it is possible to get it done.  But I wouldn't personally do that for above reasons.  I have a bad experience with "hacks" (they call fly by night installers hacks in A/C industry).  I do not want them involved either.  (for servicing later) 

[SeanB]

You get better airflow having those outdoor units further away from the walls, as indicated in all the installation paperwork, but most are installed practically on the wall, so lose out on airflow efficiency there. Just remember to wash down the outdoor coils every few months with a regular garden hose, not a high pressure jet, just a heavy fine spray, to get the dirt out.

Just did mine last month, and while I was there the other 2 units as well, they were running out black sludge for a few minutes just from dust accumulated in those coils. Not that those are mine, but only an extra 2 minutes of work.

[Marco]

He couldn't tell me about legality of self-installs as his company never get themselves involved.

You'll need to get section 608 type 1 certification, unless you use something like Panasonic Aquarea or Chilltrix (hydronic systems). Of course screwing up plumbing has bigger direct risks than screwing up with refrigerant.