I got Air Conditioning Installed at Home and Here’s What I Learned… (UK)
It’s getting hotter and hotter in Britain. With a record high May ALREADY, I made the apparently prophetic decision to get a dual head mini split air conditioning system installed. Here’s what I’ve learned in the month or so that I’ve had it installed. First, let me explain what I had installed, how much it cost, how it works, and then we’ll go through some options you might want to consider.
My system is a two way multi-split, which means I have one outdoor unit and two indoor units. The outdoor unit is the compressor – the noisy bit (although we’ll come back to that in a minute) – while the indoor units are basically just a radiator and a fan. This split means the experience in the room you are cooling is near silent, especially compared to noisy and naff portable units you might have experienced before. I went with Midea, in part because they are generally the cheapest units around, and in part because they are the original equipment manufacturer for parts like the compressor for basically all AC options anyway. Because my rooms are small enough, I have the smallest indoor units available, 2.5kW specifically, and the outdoor unit is 4kW. We’ll come back to those power ratings soon too. The outdoor unit is standard, but the indoor units are a little fancier, being their Breezeless E model, which I’m very happy with.
The installation process is pretty simple. Two lads came round for the day, bored two 40mm holes all the way through the wall, then stuck the indoor units up on the walls. They are both on the same external wall which helps a lot. The outdoor unit is mounted on its brackets – with some anti-vibration rubber pucks – then they run the lines. These are copper hardlines, with the units pre-charged with gas for somewhere between 10 and 15 metre pipe runs, and they’ll also run condensate drain lines for each indoor unit and the outdoor one. You’ll need a rotary isolator for the power input, they’ll hook it all up, and then vacuum the lines, let it sit for half an hour to make sure there’s no leaks, then they let the gas out, test it, and that’s pretty much it installed.
The power element is possibly the most interesting part here, so let’s talk about those ratings. 2.5kW is a lot of power, and 4kW is even higher, but that is the amount of heat the system can move, not the electrical power required. Because heat pumps are generally between three and four times more efficient than the electricity required. That means this 4kW unit only draws a maximum of 1 to 1.3 kW from the wall – that’s not even a third that a single plug socket can provide! That means most installations can be run with a three pin plug if you want, although I’ve run it on the same dedicated 16 amp circuit my boiler is on as my plug circuit isn’t exactly bursting with capacity. What’s more, the 4kW figure isn’t even what it runs at. While yes, with both units on, at full blast, it will draw a bit over a kilowatt, with just one unit maintaining temperature, you’re looking at more like 300-400 watts, or about 700 watts for one unit at full blast. That’s the power for the compressor, AND the indoor unit fans. That’s really cool, literally! For context, portable AC units generally run at 800-1200 watts, PER UNIT, and suck by comparison. We’ll come back to that.
Next callback, noise. Having used multiple portable units for the last couple years, I was afraid that this would be just as noisy. Sure, noisy outside, but noisy nonetheless. Happily, this thing is whisper quiet. Even at full chat, a car driving by is louder even right next to the outdoor unit! I was afraid of vibrations making it into our bedroom wall – it is bolted to the outside of our bedroom after all – but there’s nothing. It’s silent. As for the indoor units? Well a desktop fan is louder. A lot louder, by comparison. These things are insanely silent – enough that I often forget they are even on – and with the ability to put these in ‘Breezeless’ mode (which shuts the louvres) and to turn the LED screen off, you wouldn’t know it was still blowing cool air unless you stood right under it and felt the air. It’s amazing. Oh, and these also have a UV lamp inside meant to clean the air nicely – a nice value add. Oh, and you know I’ve hooked these up to Home Assistant (while blocking their internet access) right? Yeah I can control both from my phone, or from the remotes. It’s amazing.
As for the effectiveness, well hot damn it’s good. Or should I say cold-damn. Nah that doesn’t work. Anyway, it’s insane how big a difference it makes. Even in a 150 year old British house, it’s so incredibly effective at pulling heat from the room and keeping it out. So far we’ve had to keep turning it off or up so it doesn’t freeze us, it’s that effective. Coming from a portable AC unit with the same theoretical heat moving capability, I can say that this is night and day different. The portable AC does work, but it gets less effective as the compressor heats up, and is only really useful when blowing right at you, whereas this will cool my entire downstairs if you leave the door open, and it’ll use less power doing it. Amazing. Oh, and this system is also reversible, so in winter this can be our heating too, and it’s actually a little more efficient going that way too, so that’s handy. The joys of having a heat pump strapped to your house.
Of course the big question is the cost. Yeah, it isn’t cheap. I paid £2600 for this, fully installed, and with a 10 year warranty. I did do the initial electrical work myself so I saved a couple quid there for my specific install, but most installers will do it for free assuming you have a plug socket nearby to the outdoor unit’s mounting location. That is, of course, about an order of magnitude more expensive than a portable unit, and not something renters can easily get installed, so I understand this won’t be for everyone, but if you own your house, and especially if you work from home, you might want to consider getting AC installed. Multi-splits like mine can actually be four or sometimes five way splits, meaning a single outdoor unit and up to four or five indoor units, which I think is really cool. I definitely prefer a single outdoor unit, although there just wasn’t much space I could fit another even if I wanted to. There are a few other styles of AC units, including ones where you basically just drill two big holes in the wall, mount one indoor unit, and then you get essentially a wall-mounted portable unit (so no noise benefit, but a lot more efficient and cheaper because you don’t need to work with refrigerant gases), or you can get portable units. They are ok, but as I’ve said I’m mighty glad I went with the proper stuff. I’d also argue that your home’s value would go up by a couple grand for having AC installed, but maybe that’s copium.
Overall, I’ve been blown away by just how effective, efficient and quiet this system is, and I’m already more than happy with my purchase. I struggle in warmer temperatures, and with more hotter and hotter days coming, I’m glad I can stay comfortable as I live and work at home. Funnily enough, thanks to how efficient this thing is compared to our two previous portable AC units, this is sort of paying for itself over the years too, plus as the price of gas rises, being able to heat at least parts of our house with electricity (some even from my solar installation) is pretty handy. I’m pleased with this thing.
