Budgeting: Air conditioning running cost, and cheaper ways to stay cool
An air conditioning running cost depends on the type of unit, how long it runs and how hot it is, and it can be one of the biggest summer energy costs. In a worked example, a portable unit used six hours a day costs about 45 a month.
By Wealtie Team · 3 min read
Key takeaways
- Air conditioning running cost depends on the unit, the hours and the heat.
- In a worked example, a portable unit used six hours a day costs about 45 a month.
- Fixed split units are usually cheaper to run than portable ones.
- Fans, shading and ventilation are far cheaper ways to stay cool.
What is the air conditioning running cost?
Air conditioning uses a lot of electricity, so in hot weather it can become one of the biggest items on your energy bill. The cost depends on the type of unit, its size, how many hours a day it runs, how hot it is outside and how well your home keeps heat out. Portable units are convenient but usually less efficient. Fixed split units, with a part inside and a part outside, cost more to install but usually less to run. In a worked example, a portable air conditioner used six hours a day costs about 45 a month.
In many homes, air conditioning is only needed for a few weeks each summer. Cheaper ways of keeping cool, like fans, shading and ventilating at night, can handle much of that time for a fraction of the cost.
The heat in your home comes mainly through windows, roofs and walls in the sun, plus heat from appliances and people. Stopping it getting in is far cheaper than removing it afterwards. External shades, closed curtains on the sunny side, and opening windows only when it's cooler outside than in can make a big difference before you switch anything on. Every degree of heat you keep out is a degree the air conditioner doesn't have to remove.
If you're thinking about buying a unit, it's worth trying the cheaper options first for a summer. You may find that blinds, fans and better ventilation keep you comfortable on all but the hottest days, and save both the purchase price and the running costs.
What does it cost to keep a room cool?
Here's a worked example of keeping one room cool for a summer month, in round numbers that work in any currency:
| Option | A month |
|---|---|
| Portable air conditioner | 45 |
| Fixed split unit | 25 |
| Electric fan | 3 |
The figures assume six hours a day for a month. Your own costs depend on your electricity price and the power rating of your unit, shown on its label. How to save money on your electric bill explains how to work out what appliances cost to run.
How do you lower air conditioning costs?
Set a sensible temperature
Every degree cooler takes more energy. Setting the thermostat a little higher still keeps you comfortable and cuts the cost. Using a fan alongside the air conditioner lets you set a higher temperature while feeling just as cool.
Cool only the rooms you use
Close doors and cool the room you're in, rather than the whole home.
Keep heat out
Close blinds and curtains on sunny windows during the day. Shading windows from outside is even more effective. Light-coloured or reflective blinds bounce more heat back out than dark ones.
Use a timer
Switch it on shortly before you need it, rather than leaving it running all day while you're out. Many units have smart controls that let you start them from your phone on the way home.
Maintain the unit
Clean filters regularly so the unit works efficiently. For portable units, seal the window kit around the exhaust hose to stop hot air coming back in.
What are the cheaper ways to stay cool?
Electric fans cost very little to run and can make a room feel cooler by moving air over your skin. Opening windows at night and closing them during the day keeps cooler air inside. Shading windows, using light-coloured blinds and switching off heat-producing appliances all help. Sleeping with lighter bedding and drinking cold water keep you comfortable without any energy cost. The summer budget covers other summer costs to plan for.
Is buying an air conditioner worth it?
If you live somewhere with long, hot summers, or someone in your home struggles with heat for health reasons, it can be. If hot spells are short, fans and shading may be enough. Work out the cost per use: a unit used for a few days a year costs a lot per use once you include the price.
Plan for higher summer bills
If you do use air conditioning, set aside a little extra in your budget for summer energy bills, just as you might for heating in winter. How to save money on heating covers the winter side.
How do you track energy costs in Wealtie?
Add energy bills as recurring transactions, so they log themselves on their date. Keep them in their own expense category and set a budget that allows for higher bills in the hottest months.
Questions people ask
In a worked example, a portable unit used six hours a day costs about 45 a month. Fixed split units usually cost less to run.
Usually more than a fixed split unit, because portable units are less efficient.
Set a slightly higher temperature, cool only the rooms you use, keep blinds closed on sunny windows and use a timer.
Fans, shading windows, ventilating at night and switching off heat-producing appliances.
This article is general information, not financial, tax or legal advice. Your situation is your own; check the numbers that apply to you before you act on them.
