By the Kila team · Last updated 6 November 2026
South African summers can be punishing, and this year electricity costs more than ever. Municipal tariffs rose by roughly 9% on 1 July 2026, so the question for many households isn’t just “how do I stay cool?” but “how do I stay cool without a shocking bill?” The good news is that the cheapest options are also among the most effective, and a few free habits can make a bigger difference than you might expect.
This guide compares fans, evaporative coolers and air conditioners using real running costs in rand, explains which option suits which part of the country, and shows how to keep the heat out of your home in the first place. It builds on our guide to reducing electricity use at home in South Africa.
Quick answers
- Cheapest way to cool a home: Keep the sun out, ventilate at night and use fans. A fan costs roughly R0.20 to R0.40 an hour to run.
- Evaporative (air) coolers cost roughly R0.30 to R0.90 an hour and work best in dry air. They are a poor choice in humid coastal areas.
- Air conditioners cool fastest but cost about R2 to R6 an hour to run, depending on whether they use inverter technology.
- Inverter air conditioners cost more to buy but are around 15% to 50% cheaper to run, according to a South African price comparison.
- Electricity price: Big-metro residential rates are roughly R3.40 to R4.40 per kWh, so we use R4.00 per kWh in the examples below.
Step one: stop the heat getting in
Cooling a hot house is far more expensive than keeping it from heating up. These steps cost little or nothing and make every cooling device work better.
- Block the sun at the window. Close curtains and blinds on sunny windows during the day, especially those facing north and west. Light-coloured or reflective-backed curtains help. See how to choose the right curtains. External shade covers, awnings and shrubs or trees outside windows are even better because they stop the heat before it reaches the glass.
- Ventilate at the right time. Open windows and doors in the evening, at night and early in the morning when the air outside is cooler, ideally on opposite sides of the house for a cross-breeze. Close up when the outdoor temperature rises above the indoor temperature.
- Cook without heating the house. Avoid using the oven in the hottest part of the day. A microwave, an air fryer, a slow cooker or a braai outside adds much less heat. If you do use the oven, our oven guide explains energy use, and a good kitchen extractor fan helps vent heat out of the kitchen.
- Switch off what you aren’t using. Lights and appliances give off heat. LED lighting produces far less heat than old incandescent bulbs.
- Dry washing outside rather than using a tumble dryer, which adds heat and moisture indoors.
What does it cost to run each option?
Every appliance’s running cost comes down to three numbers: how many watts it uses, how many hours you run it and what you pay per kilowatt-hour (kWh). The formula is simple: watts ÷ 1,000 × hours × your tariff. Check your own bill or prepaid token for your rate.
What electricity costs in 2026
| Municipality | Residential rate from 1 July 2026 (incl. VAT) |
|---|---|
| Johannesburg (City Power) | about R3.34 to R4.37 per kWh, depending on how much you use |
| Cape Town (first block) | about R3.43 per kWh |
| Durban (eThekwini) | about R4.17 per kWh, single rate |
Rates vary by block, connection type and supplier, and some bills also include fixed monthly charges. We have used R4.00 per kWh in the table below, so scale the figures up or down for your own tariff.
Running costs at R4.00 per kWh
| Cooling option | Typical power use | Cost per hour | 6 hours a day for a month |
|---|---|---|---|
| Stand or ceiling fan | 50–100 W | R0.20–R0.40 | R36–R72 |
| Evaporative air cooler | 70–230 W | R0.28–R0.92 | R50–R166 |
| Inverter split air conditioner (running) | 500–1,000 W | R2.00–R4.00 | R360–R720 |
| Portable or older non-inverter air conditioner | 1,200–1,500 W | R4.80–R6.00 | R864–R1,080 |
Power use depends on the model, the room and the weather. Air conditioners in particular can draw anywhere from about 500 W to 3,500 W depending on size and technology, so check the rating plate on any appliance you are considering.
Fans, evaporative coolers and air conditioners compared
| Option | Indicative price | Running cost | Best for | Watch out for |
|---|---|---|---|---|
| Fans (stand, wall, ceiling) | Stand fans from about R300. Ceiling fans from about R650 and may need an electrician | Lowest | Everyday relief in most rooms, with the lowest running costs | Cools people, not the air. Switch off when you leave the room |
| Evaporative air cooler | From about R800 | Low | Dry heat, such as the Highveld and drier inland areas | Adds moisture and works poorly in humid places. Needs water and can be noisy |
| Portable air conditioner | Varies. Check current retailers | High | Renters and single rooms where installation isn’t possible | Typically uses around 1,200 W for a 12,000 BTU unit |
| Split air conditioner (inverter) | From about R4,500. A mid-range inverter for a 25 m² room was around R10,000–R14,000 installed | Medium to high | Bedrooms, home offices and very hot or humid areas | Needs professional installation and an annual service |
The purchase prices above come from a South African price comparison published in 2021, so treat them as a floor. Prices today are likely to be higher, so compare current offers at several retailers.
Which option suits where you live?
South Africa’s climate varies enormously, so the best choice depends on whether your heat is dry or humid. This is a general guide, and your own home’s orientation, roof and insulation matter too.
| Region | Typical summer conditions | Good starting point |
|---|---|---|
| Highveld (Johannesburg, Pretoria) | Hot days, cooler nights, relatively dry air | Shading, night ventilation and fans. Evaporative coolers can work well on dry days |
| Humid coast (Durban and the KwaZulu-Natal coast) | Hot and humid, including at night | Fans and an air conditioner, which also removes moisture. Avoid evaporative coolers |
| Cape Town and the Western Cape | Dry summers, often with wind | Shading and ventilation first. Fans for the hottest days |
| Hot interior (Limpopo, Northern Cape, Karoo) | Very hot and dry | An air conditioner in main living areas or an evaporative cooler in dry heat |
How to choose the right cooling device
Choosing a fan
- Match the fan to the room. Ceiling fans suit most bedrooms and living rooms with standard ceilings, while stand fans can move between rooms.
- Check the wattage. Most fans use 50 to 100 W, and lower is better.
- Look for adjustable speeds and a timer.
- Use it wisely. In summer, set ceiling fans to turn counter-clockwise so they push air down. A bowl of ice in front of a stand fan gives an extra cooling effect.
Choosing an evaporative cooler
- It works by evaporating water, so it suits dry air and does little in humid conditions.
- Keep a window slightly open so the added moisture can escape.
- Check the tank size, noise level and how often it needs filling.
Choosing an air conditioner
- Choose inverter technology. Inverter models cost more upfront but are about 15% to 50% cheaper to run. At six hours a day, the gap between an inverter and a non-inverter unit can amount to a few hundred rand a month.
- Get the size right. As a rough guide, about 9,000 BTU suits rooms up to roughly 20 m², and about 12,000 BTU suits rooms of roughly 20 to 30 m². Sun-baked rooms, high ceilings and big windows need more capacity. An undersized unit runs constantly. An oversized unit costs more to buy and run.
- Plan for installation and servicing. Split units need professional installation, and regular servicing keeps running costs down. One survey put an annual service at around R600.
- Check the energy efficiency rating on the label, as well as the noise level and warranty.
For more on cutting your bill, see our electricity-saving guide. The Department of Electricity and Energy also has a helpful guide to air conditioners and an appliance cost calculator.
How to use cooling without wasting power
- Cool only the room you’re using. Close doors and windows when an air conditioner is on.
- Set a sensible temperature. Around 24 to 26°C is comfortable for most people. Setting it much lower raises your bill without making you much more comfortable.
- Use the timer or sleep mode in bedrooms.
- Combine a fan with an air conditioner. Moving air lets you set the air conditioner a little higher.
- Clean the filters regularly on air conditioners and coolers.
- Turn fans off when you leave the room. They cool you, not the room.
Sleeping cool
Hot nights can wreck your sleep. Open windows once the air outside is cooler, use a fan on a low setting and keep bedding light. Your mattress and pillows matter too. See our guide to choosing the right bed and mattress. Cooling pillows (around R600 in a 2021 comparison) and gel mattresses are other options, but fans and ventilation should come first.
Staying safe in the heat
Heat can be dangerous, especially for babies, older people, people with health conditions and pets. Keep them in the coolest part of the home, offer plenty of water, and never leave children or animals in a parked car. If you go outdoors, protect your skin with the right sunscreen. See how to choose sunscreen in South Africa.
Longer-term ways to keep a home cooler
- Insulate the ceiling or roof. This keeps heat out in summer and in during winter.
- Paint the roof a light colour or add reflective coatings if the structure allows it.
- Add external shading such as awnings, shade covers, pergolas or deciduous trees on the sunny side.
- Upgrade the windows or add reflective film where heat gain is a big problem.
Cooling checklist
- Sun-facing windows covered during the day
- Windows opened for cross-ventilation at night and early morning
- Oven use kept to cooler hours
- Unused appliances and lights switched off
- Fans ready in the rooms you use most
- Your electricity rate checked and running costs worked out before you buy
- An inverter air conditioner considered for bedrooms or an office, if you need one
- Filters cleaned and units serviced
Frequently asked questions
What is the cheapest way to cool a house in South Africa?
Keep the sun out with curtains and shading, ventilate at night and use fans. This combination costs the least to buy and run and works in most parts of the country.
How much does it cost to run a fan in South Africa?
A typical fan uses 50 to 100 watts, which costs about R0.20 to R0.40 an hour at R4.00 per kWh. Running it six hours a day costs roughly R36 to R72 a month.
How much does it cost to run an air conditioner per hour?
At R4.00 per kWh, an inverter split unit running at 500 to 1,000 watts costs about R2 to R4 an hour. A portable or older non-inverter unit using 1,200 to 1,500 watts costs roughly R4.80 to R6 an hour.
Do evaporative coolers work in humid areas?
Not well. They cool by evaporating water, so they work best in dry air, such as on the Highveld, and add unwanted moisture in humid places like Durban.
Is an inverter air conditioner worth the extra cost?
Usually, if you will use it often. Inverter models cost more upfront but are about 15% to 50% cheaper to run, so the saving builds quickly with regular use.
What size air conditioner do I need?
As a rough guide, about 9,000 BTU for rooms up to roughly 20 m² and about 12,000 BTU for roughly 20 to 30 m². Sun exposure, ceiling height and window size change the answer, so ask a supplier to assess your room.
What temperature should I set my air conditioner to?
About 24 to 26°C is comfortable for most people. Setting it much lower raises the bill without much extra comfort.
Can I run a fan or air conditioner on backup power?
Fans and evaporative coolers use little power, so a small inverter or battery can usually run them. Most air conditioners need a much larger system, so check the wattage before you plan around one.
Do ceiling fans actually lower the temperature?
They don’t cool the air, but the moving air makes you feel cooler. Turn them off when you leave the room.
Final thoughts
You don’t need an expensive air conditioner to survive a South African summer. Start with shading, night ventilation and fans, add an evaporative cooler if you live in a dry area, and buy an inverter air conditioner only for the rooms that really need one. Work out the running cost before you buy, and use the formula in this guide to compare any appliance.
Electricity tariffs, appliance prices and local conditions change, so check your own rate and current retailer prices before you decide.
More Kila home and living guides
- How to Reduce Electricity Use at Home in South Africa
- How to Choose the Right Curtains for Your Home
- How to Choose the Right Lighting for Your Home
- How to Choose the Right Bed and Mattress for Your Home
- How to Choose the Right Air Fryer for Your Home
- All Kila Home & Living guides
Sources and further reading
- OurPower: Electricity price increases, July 2026
- Gauteng Tourism: City Power tariffs from 1 July 2026
- BizNews: South Africa’s biggest cities raise electricity tariffs from July 2026
- 1Life: What’s the cheapest way to cool your home?
- Jacaranda FM: How much electricity it costs to use your fan
- Defy: How much energy does a portable aircon use?
- OurPower: Appliance running-cost calculators
- Department of Electricity and Energy: Air conditioners
Running costs are estimates based on typical appliance wattages and an electricity rate of R4.00 per kWh. Your costs will differ. Purchase prices are indicative. Kila may earn a commission if you buy through some links on our site. See our disclosure policy.