Just when you thought being in home isolation would save you time and money, the first winter bill arrives.
COVID-19 restrictions have been necessary, but they may leave us out in the cold. Now you're spending more time at home you might also be noticing your house is draughty.
CSIRO's Senior Experimental Scientist Michael Ambrose explains why some Australian homes are so cold.
"Some houses in Australia are designed to be leaky. In northern Australia, 'troppo architecture' houses are designed to be open to breezes, to keep the house cooler in summer," Mr Ambrose said.
"But unintentional draughts are an issue in southern Australia where they can add up to 20 per cent to your energy bill."
Home truths
"Leaky houses tend to go with age. The older the home, the leakier it is. Old weatherboard houses from the 1950s are very leaky, especially if they're on stumps. You don't get leakage through concrete slabs," he said.
Mr Ambrose, along with CSIRO former Senior Research Engineer Mike Syme, collaborated on one of the only studies on how airtight Australian homes are. The study found Australian homes are 'leaky' by international standards and older buildings are generally much draughtier.
During the recent bushfires, Australians were encouraged to close their doors and windows to minimise exposure to fine smoke particles. But in many homes, this smoke simply seeped in through the cracks and gaps.
In Australia, there is currently no specific level of air tightness for new homes to achieve. The building code states "sealing of the building envelope against air leakage" is required for compliance. But there is no measure as to what is an appropriate level of sealing.
Mr Ambrose and Mr Syme tested homes using a 'blower door test'. The equipment sucks air into the house, before reversing it and blowing the air out. It calculates how many air changes per hour are occurring. Blower door tests find where there are gaps, where draughts form, where cold air can seep in and warm air can seep out. These gaps need to be sealed up.
Tips to draught-proof your house
Michael has some tips and tricks to make your home a little warmer, and to save you some money, this winter.
1. Windows
Uncovered windows account for up to 40 per cent of heat loss in the winter.
- Use heavy, lined curtains that fall below the window to keep warmth in
- Check your windows for cracks
- Consider sealing gaps with insulation strips or caulk (a waterproof filler)
- Install pelmets above your windows/curtains to stop warm air escaping
- You can also hang a heavy blanket or towel off the curtain rod.
2. Doors
Sealing gaps around doors can help draught proof your house.
- If you feel a draught, make a 'door snake' for internal doors
- For external doors, use a plastic or metal door seal with wipers
- For draughts around the edges of the door, use adhesive weather stripping.
3. Old heaters, fireplaces and hot water systems
Sometimes when services are removed the hole isn't sealed. To draught proof the house you'll need to seal it up.
- Look for gaps around built-in appliances, at the back of cupboards and under the kitchen sink
- You can fill gaps with expanding foam
- If you have an old fireplace, use fireplace dampers to block airflow.
4. Fixed vents and exhaust fans
Some old brick homes have fixed ceiling and wall vents. Block these to stop air leakage
- For old exhaust fans, use a ventilation cover to block the vents over winter.
5. Evaporative cooling units
These are meant to have winter covers or dampers but they're not always effective.
- You can draught-proof them by using magnetic strips around the vent receiver in your ceiling
- Clip the covers on in winter and peel them off in summer.
6. Other gaps
Listen for rattles or whistling and feel for moving air
- Kitchen cabinets are often leaky, there may be gaps around the pipes and joints in the cabinets
- Other areas include where skirting meets the wall, and where bricks meet the wood trim
- Fill small gaps with silicone sealant
- Fill bigger gaps with expanding spray foam
- Be careful around internal gas appliances as they need fixed ventilation.
7. Rugs and carpets
Cold air can roar up through gaps in the floorboards, especially in timber homes raised above the ground.
- Use rugs and carpets to act as a layer of insulation.
8. Let the sunshine in
- Keep your blinds or curtains open during the day to warm your home, especially north and west-facing rooms.
- Let the sunshine in to warm your home
For more ideas, look to the CSIRO's tips on giving power bills the cold shoulder. Or on the government's heating and cooling site. Some states offer rebates for professionally installed draught-proofing. And if you're a concession card holder you may get free materials. Visit the Australian Government's Your Energy Savings website.
Kate Cranny writes for the CSIRO. Click HERE for more tips from CSIRO to save energy in your home
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