Keep cool without blowing your energy bill
You can keep your home cool without blowing your energy bill, according to EECA ENERGYWISE.
Technical expert Allen Davison says more New Zealanders are using their heat pumps as air conditioners in summer and there are tactics to avoid big energy bills. For example using the fan only setting helps you feel cooler by creating a breeze, he says.
“This setting uses a lot less electricity than the full cooling mode. Keep your windows open while using the fan only mode.”
Selecting the dehumidifying mode also uses less electricity than the full cooling mode, Mr Davison says.
“This works well if it’s humidity rather than the temperature that’s the problem. Shut your doors and windows in the rooms you're dehumidifying.”
Mr Davison suggests only using 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 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 over-cooling.”
Avoid using auto settings because if you forget to switch the unit off, it will start heating if the temperature drops below the thermostat setting, he says.
“It’s also important to clean the filter of your air conditioner regularly because clogged filters stop the appliance running efficiently.”
Floor and desktop fans are relatively cheap to buy and install, and are much cheaper to run than air conditioning, Mr Davison says.
“They're especially good if you only get a week or two of extremely hot weather during the year.”
Close blinds and curtains
Closing blinds and curtains at windows that receive direct sun provides shade from the hot sun.
Longer term solutions
- Plant deciduous trees on the north and west sides of your home - they 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.
- Install external window shades - such as blinds, awnings or louvres. They 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.
- When building, design eaves (or roof overhangs) above north-facing windows - to stop direct sunlight entering rooms at the height of summer, but allowing 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.