Portable Air Con Running Costs

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2023 UPDATE: This was originally written back in 2021, back when electricity was cheap (I was paying less than 14p/kWh). Times have changed, lockdowns lifted, and a war started. I then updated the article in May 2022, I was lucky enough (and still am) to be in a fixed at 18.36p/kWh, but the variable rates had jumped to 28p/kWh.

Things got worse, by October, it was predicted that prices would jump another 80%, and the government had to intervene with the Energy Price Guarantee (EPG).

The Energy Price Guarantee regional rates from October to December 2022 had an average price of £0.3242 per kWh. The typical dual-fuel household direct debit bill under the Price Cap should have been £3,549/year, but the EPG reduced this to £2,500/year.

From January through to March 2023, the typical annual fee should have jumped to £4,279/year but remained locked at £2,500/year.

The April to June 2023 Energy Price Guarantee rates saw an average rate of £0.3162 per KWh for direct debit. The annual fee for this period had a significant reduction down to £3,280/year (which is still ridiculously expensive).

From July 2023, the EPG will end for most people the price cap of £2,074/year will fall below the new EPG rate of £3,000/year.

From July 2023, the Energy unit price for Price Cap will be £0.30 per kWh with a daily standing charge: £0.53.

Original Post (with 2023 prices)

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.

Recommended Portable Air Conditioners

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.

The Inventor Magic I used was 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.

Cost to run an air conditioner in 2023

Various tariff examples:

  • 2021:
    • SO Energy: 13.6476p/kWh
  • 2022 (May, Variable Tariffs)
    • Bulb: 28.0203p per kWh
    • British Gas Standard Variable: 28.021p per kWh
  • 2022 Energy Price Guarantee (EPG): average price of £0.3242 per KWh
  • From July 2023
    • EPG is £3,000/year
    • Price Cap is lower at £2,074/year
    • Electricity Unit Rate should be £0.30 per kWh
    • Daily standing charge: £0.53.

Based on the above prices, in 2021 it was costing me 16.38p per hour to run, and in May 2022, it would cost 33.60p or a 105% price increase.

For 2023, the July price cap will mean it costs 36p per hour to run, which is 7% higher than last year.

At this point, I am just grateful that the prices have temporarily stopped shooting up.

While the per-hour running costs don’t look that bad, this uses about the same electricity by itself as the rest of my house (apart from when I cook), and the costs will add up quickly.

My overall opinion hasn’t changed about them. If you plan to leave one of these on all day, then you are in for a bad time when you get your energy statement. Of course, the air con will switch off when it reaches the desired temperature (and back on), so you may not be running it all the time.

Air conditioners were always expensive to run, and being a tight-fisted northerner, I would never run one all day. However, when it is painfully hot outside, and my office is touching 30 degrees, or my bedroom is 23+ degrees, I think spending £1.08 running an air-con for three hours is still worth it. They are very noisy anyway, so I’d prefer to have them running as little as possible.

How quickly does an air-con cool a room?

This will depend on the cooling capacity of the air con.

When I used the Inventor Magic with a 12000 BTU cooling capacity it was able to reduce the temperature in my office from 27 degrees to 21 degrees in 2 hours 15 minutes, and it used 2.5kW of electricity.

My office is 4.5m x 3.5m and is 2.5m high, so just shy of 30m3.

I ended up sending that air con back, as it was too large for me to store anywhere and my windows open from the bottom which makes creating a seal difficult.

This past week I have been using the Ecoflow Wave 2, which is only small with a 5100 BTU cooling capacity. This is not designed for home use but for off-grid living like caravans, boats and vans. However, the 5100 BTU cooling capacity is just enough for the spare bedroom I sleep in when I struggle to get to sleep. This is 2.5m wide, 4.5m long, and 2.5m high and I had to create a makeshift window seal and vent using some cardboard.

EcoFlow Wave 2 Portable AC Review Battery Attached
Ecoflow Wave 2

With this air con, I am able to cool my small room from 25 degrees to 19 degrees in about 3 hours or so. Due to the lower cooling capacity, it only draws about 400W (it is rated up to 500W).

How loud are portable air conditioners?

Really quite loud. When I reviewed the Inventor Magic, I didn’t have an accurate sound meter, but using my phone, it read 40-50db with the air-con just off to the side of me. It is officially rated at 54 / 54.3 / 54.5 dB(A) for low, medium and high.

The sound profile isn’t too bad. It is not high-pitched and just sounds like a fan at high speed. I can cope with it being switched on in the office, but there is not a chance in the world I could fall asleep with it on.

The Ecoflow Wave 2 is rated at 48dB for eco, 52dB for sleeping mode and 58dB. Subjectively but confidently, I would say it is significantly quieter than the Inventor Magic. I think some companies are a bit generous regarding noise level readings.

With the Ecoflow Wave 2, it is still too loud to sleep with, and the Eco mode isn’t powerful enough to keep the room cool throughout the night.

I, therefore, cool my bedroom to make it easy to get to sleep, then use a fan for the rest of 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 35 kg, 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.

The Ecoflow Wave 2 isn’t small, but it is a much more convenient size and weight (14.5 Kg)

How easy is fitting a portable air conditioner hose through a UK uPVC window?

EcoFlow Wave 2 Portable AC Review Venting
It’s not pretty but it works, just about.

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 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 like the best solution, certainly for temporary use.  It is far from ideal, and they are quite ugly, but it is what it is.

For me, I resorted to a makeshift solution with a large piece of cardboard to cover the entire window then holes cut to fit the air vents. I am considering getting someone else to redo this in either wood or an acrylic sheet.

  • [Original Post] 20th July 2021
  • [Updated] 20th May 2022 – Reflecting increased energy prices.
  • [Updated] 15th June 2023 – Reflecting the energy price cap that starts from July 2023.

Last update on 2024-06-19 / Affiliate links / Images from Amazon Product Advertising API

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  1. I have bought a DeLonghi EM82 portable a/c for my static caravan which is like an oven on hot sunny days. It is vented out of the side of the caravan and the hose wrapped in insulating material. With all windows and curtains closed the unit can cool the interior at the rate of about 4 deg C per hour down to 18 C but it feels cooler as soon as it switched on.
    I don’t find it particularly noisy when in max cooling mode but I am not sure I could sleep with it on.

  2. I have a similar model. I cant believe I didn’t know how to work out the cost before.
    Mines 1114w, Bulb is now 27.1p/kwh
    1114 ÷ 1000 x 27.1 = 30.19p I had mine on way more than I needed, I’ll certainly be more conscious next summer now knowing the price!

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