How much does it cost to run a portable air conditioner, and how quickly does it cool a room?

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With the temperatures continuing to soar and the Met Office issuing an extreme heat warning, many of us have been looking to buy a portable air conditioning unit.

If, like me, you are vaguely aware of these, you will know they cost a lot to run, they are loud, they are big and awkward to use with UK based windows.

This year, I finally caved and bought an Inventor Magic 12000BTU Portable Air Conditioner from Amazon, which is now out of stock.

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How much does a portable air conditioner cost to run?

The main concern with air conditioning is the cost to run it. The power consumption will vary depending on the cooling capacity of the unit. This typically ranges from 1Kw to 1.3kW for air-con units rated from 9000 to 12000 BTU.

My Inventor Magic is rated at 1350W per hour for cooling. Actual usage appears to vary between 1100W and 1300W, and this seems to average out at 1200W while it is running full blast.

I am currently with SO Energy which has a unit rate of 13.6476p/kWh (I chose them because of the cheap electricity due to me running a lot of computers). You can sign up for SO Energy here.

This then works out at 16.38p per hour to run, which seems quite cheap, really.

However, this will quickly add up. Looking at my electricity bill, it is almost as much per hour as the rest of my house when averaged out across the month (last month was 800kW so 26.6kW per day).

Running it for a few hours in your home office in the afternoon and/or in your bedroom before bedtime probably won’t cost that much in the grand scheme of things. Falling into the habit of running it several hours per day when it is mildly warm will add a significant amount to your electricity bill.

Of course, the air con will switch off when it reaches the desired temperature (and back on) so your results will vary.

How quickly does an air-con cool a room?

I am still testing it and have only just started keeping an eye on temps and times. Considering the current heatwave, I thought I’d get some content out sooner and add more accurate numbers over time.

In 2 hours 15 minutes, it has used 2.5kW of energy and cooled my office from 27-degrees to 21-degrees. Subjectively it feels cooler, I think the cool air moving around the room makes it seem colder than it is. My office is 4.5m x 3.5m and is 2.5m high, so just shy of 30m3.

How loud are portable air conditioners?

Really quite loud. I don’t have an accurate sound meter, but using my phone, it reads 40-50db with the air-con just off to the side of me. The sound profile isn’t too bad, it is not high pitched and just sounds like a fan on high speed. I can cope with it switched on in the office, but there is not a chance in the world could I fall asleep with it on. I plan to cool my bedroom to something more pleasant then switch it off when I go to sleep. I will resort to a quiet pedestal fan if it gets too hot in the night.

How large are air conditioning units?

They obviously vary a lot depending on their rating. The Inventor Magic 12000BTU is one of the higher-rated models out there and, therefore, physically large.

It is probably about as tall and wide as an under-counter fridge but less deep. It weighs 35KG, so it wasn’t all that fun carrying it up the stairs by myself. If you keep it on the same floor, it is not too bad as it is roller wheels on it.

How easy is it to fit a portable air conditioner hose through a UK uPVC window?

The Inventor Magic 12000BTU comes with a windows kit, but this appears to be for sash windows (the traditional windows that slide up).

I have uPVC windows that are top hung, which is therefore not compatible. There are various kits you can buy on Amazon, which are basically bits of cloth with zip and velcro that stick around the gaps in the window. From my brief experience with them, they are a bit rubbish, and I am very sceptical of the large number of Amazon reviews some of them have. Unfortunately, this seems about the best solution, certainly for temporary use.  It is far from ideal, and they are quite ugly, but it is what it is.

Last update on 2021-09-19 / Affiliate links / Images from Amazon Product Advertising API

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