Cooling your home

There are a range of things you can do to make your home cooler without adding to your electricity bill.

Opening doors and windows

Good cross-ventilation can help l cool your house down in summer. Create cross-draughts by opening doors and windows in different rooms, allowing the breeze to move through your home. Fit security latches so your windows can be left partially open during the day. 

Reducing heat from direct sun

  • Adjustable external window shades - such as blinds, awnings or louvres allow you to shade rooms in summer, but let light and heat in at other times of the year. External shading is much more effective than internal shading as it blocks the sun's heat before it gets inside your home.
  • Eaves (or roof overhangs) above north-facing windows - can be designed to stop direct sunlight entering rooms at the height of summer, but allow direct light in the rest of the year. They won’t help you with low-angled morning and afternoon sun from the east and west.
  • Deciduous trees planted on north and west sides of your home - provide shade in summer, but lose their leaves in winter and allow sunlight through. You can also use trellises for growing plants to shade your windows in summer.


A well-insulated house doesn't just stay warmer in winter, but is cooler in the summer months too. Start by insulating your ceilings and floors. 


Passive cooling


Ceiling and roof vents or chimneys use the sun’s heat to draw hot air out of your house. They’re more common in countries like Australia where cooling is more of a concern. Windows with trickle vents (small openings to allow ventilation) can help to reduce heat build-up in areas prone to overheating.


Ceiling and floor standing fans are relatively cheap to buy and install, and are cheaper to run than air conditioning. They're especially good if you only get a week or two of extremely hot days during the year.

Active cooling

Air conditioners and heat pumps

There are a number of ways to make sure your air conditioner or heat pump will cool as effectively and as cheaply as possible.

  • Try using just the fan - most heat pumps or air conditioners have a fan only setting which can help create cross-draughts in your home. Keep your windows open while using the fan only mode.
  • Use the dehumidifying mode - if it’s the humidity rather than the temperature that’s the problem. This mode uses less electricity than the full cooling mode. Shut your doors and windows in the rooms you're dehumidifying.
  • Only use cooling mode on really hot days - when the other methods aren't enough. Shut all your doors and windows in the rooms you're cooling. It's best to just cool one room as this is what most heat pumps/air conditioners are sized for. Set the thermostat to around 22˚C. The room won't cool down any quicker if you set it lower, but you are likely to use more electricity by overcooling.
  • Avoid using auto settings - if you forget to switch the unit off it will start heating if the temperature drops below the thermostat setting.
  • Use the right size heat pump - it will cool your house properly without having to work too hard. The same rules apply for cooling as for heating.

Options for staying cool in summer - Smarter homes website