How Much Does It Cost To Run A Portable Air Conditioner? (UK prices)

With Summer temperatures set to soar this year, many of us are looking at ways to keep cool. One solution could be a portable air conditioner. 

The thing is, A/C units are expensive to run, aren’t they? The reality is we make assumptions based on the way we look at life. In other words, what value do you put on keeping cool?

We’ve looked at the most popular portable aircon units here in the UK and calculated just how much they actually cost to run. Keep reading for the results.

How We Calculated The Running Costs Of A Portable A/C

To calculate how much a portable A/C unit or any other electrical item costs to run you first need to find out the power rating in kilowatts. 

To do this just divide the wattage of the item by 1000 the answer is the power rating in kilowatts.

So using the example of the average portable AC which is 1200 watts, this unit will have a power rating of 1.2 Kw because; 

1200 ÷ 1000 = 1.2.

Once we know the power rating in kilowatts we can times this by how many hours the unit is running for to find the amount of energy the appliance is using.

So let’s say we run our 1200 watt portable A/C unit for 4 hours per day. This would give us a calculation that looks like this; 

1200 ÷ 1000 = 1.2 x 4 = 4.8

Which means our 1200 watt portable A/C unit uses 4.8 units of energy over 4 hours.

We can then calculate how much it costs to run the unit per hour by multiplying the amount of energy used per day by the price of your electricity per unit (which can be found on your utility bill).

The current price for a unit of electricity in the UK is around 34p so our 1200 watt portable A/C unit will cost us £1.63 to run for 4 hours per day or around 41p per hour. 

We calculated this in the following way;

1200 ÷ 1000 = 1.2

1.2 x 4 = 1.632

1.632 x .34 = 40.8

This calculation can be used for any electrical appliance including portable aircon units.

Average Running Costs Of Portable A/C Units

Portable A/C Wattage	Average Cost Per Hour
1000	34p
1200	41p
1500	51p
2000	68p
2500	85p

The above costings are based on electricity costs of 34p per unit.

So given that the average portable air conditioner uses 1200 watts, that means that they roughly cost around 41p per hour to run. Running the portable AC for 8 hours per day would cost around £3.28.

Why You Should Pay Attention To The BTU When Buying Portable Aircons

Portable A/C units are graded in BTUs (British Thermal Units). The BTU measures how much heat an aircon can remove per hour. 

This means that the higher the BTU rating, the more heat can be removed from the room each hour the unit is running. 

The higher the BTU rating also usually means the higher the wattage and therefore the more it will cost to run.

Automatic Cut Off

Once your portable aircon unit reaches the preset temperature it will cut off automatically. Which means it might not run for as long as you have it switched on.

However, it will cut back in as soon as the temperature of the room increases above the preset level.

How Fast Does A Portable A/C Unit Cool A Room?

The amount of time needed to cool a room will be dependent on a number of factors. Which include;

• The difference in temperature between the desired temperature and the current temperature
• The size of the room
• The BTU rating of the portable A/C unit

We tested a portable A/C unit with a BTU rating of 12000 in a room with the following dimensions, 4m x 4m x 2.5m which is around 40m³. 

In 2 ¼ hours it lowered the temperature of the room from 29 C to 22 C and used 2.5 kW of energy. In fairness the room felt cooler than 22 C due to the circulation of the air.

The Cost Of Running A Portable AC Unit in the UK

As you can see from the above text, the cost of running a portable A/C unit in the UK can vary considerably depending on several factors. Things like;

• The BTU rating
• The Wattage
• The size of the room
• The ambient air temperature
• The cost of electricity per unit

Window Kit

Another factor that we haven’t touched on as yet is the vent window kits. These are supposed to be designed to fit in the gap of your open window to create a tight seal to prevent warm air re-entering your home.

These kits are often inadequate which means the A/C has to work far harder and for much longer than they would need to if the kit sealed the window space properly.

You can make your own using plywood or polystyrene which are often far more effective than those supplied with many portable A/Cs or purchased online.

Energy Costs UK

Most of the power suppliers in the UK seem to be following a set price so there’s not much (if any) difference in the price.

The main questions you need to ask yourself are; 

1. Can you afford to buy a portable aircon unit?
2. Can you afford to run a portable aircon unit?
3. Do you have space for a portable A/C unit?
4. Can you seal the window adequately?

Do You Have Any Questions?

Hopefully we have answered all of your questions concerning the running costs of a portable air conditioner. If there’s something we’ve missed, or you have any more questions concerning portable A/C running costs feel free to ask in the comments section below.

Frequently Asked Questions