Australian houses are not built to be energy efficient. They have been described as "glorified tents" and because of this they are hot in summer and cold in winter requiring expensive energy to heat and cool. This costs lives and produces expensive energy bills and high carbon emissions. In Europe new houses are required to be near zero energy by the end of 2020, whereas in Australia we have only required new buildings to be 6 star on the NatHERS rating since 2003 and most older building are 1 star.
So unless you have deliberately built your house to a high energy efficiency you probably are interested in learning how to decrease you winter energy bills and carbon emissions.
If you are in the fortunate position of building a new house then you should make sure it is built to 8 star NatHERS standard. Heating and cooling is responsible for about 40% of the average household energy use so you will make your house cheaper and more comfortable to live in.
Retrofitting an existing house is the next best option with some of the these only possible if you own the house. Houses lose their heat through windows, draughts and gaps and through uninsulated roofs, walls and floors.
Insulation
Walls and ceilings require insulation to stop the heat getting out in winter and getting in in summer. In Queanbeyan the recommended R Value is R5 in the roof and R2 in the walls and floor. Start with the roof first as you can lose up to 40% of the heat in your home through the roof; 20% through walls and up to 15% through the floor. It costs about $1300 for the R5 insulation for 100m2 ceiling and installation about $80 per hour. Get a quote for insulation you may be pleasantly surprised that it is not much more than your normal winter energy bill.
Windows
If you can afford it changing your windows to double glazed ones can reduce your heat loss through the windows by 40-60%.
However otherwise you can work on using window coverings. Lined curtains and properly fitted blinds with box pelmets can seal in the warmth in winter and keep the heat out in summer. Curtains should reach to the floor and cover the sides of the windows to trap the cold air against the window. In winter, open them during the day and close them at night to cut your heating bill by up to 10%. In summer, close curtains, blinds, windows and doors during the day and open them in the evening when temperatures fall to let evening breezes cool your home naturally.
If you are on a budget you could sew second hand woollen blankets to the back of other curtains.
On windows that you don't need to be able to see through taping bubble wrap to the window gives you an improvised double glazing and is surprisingly effective.
Draughts
Your average house is full of draughts from around doors and windows, up chimneys, where cables and pipes leave the house and fixed wall and ceiling vents. Use door strips and weather stripping from your local hardware to fix the draughts from doors and windows. Caulk up other gaps. Wall and ceiling vents can be removed or a low cost solution is to cut a pice of bubble wrap to the same size and tape it to the vent.
Heating
The cheapest form of heating is a reverse cycle air conditioner. Try turning it off at night and setting it to turn on again an hour before you get up. Instead of running it at 25 degrees Celsius run it at 19 degrees and put on thermals or another layer of clothing. Close off rooms that don't need to be heated. Warm you bed with a hot water bottle or electric blanket rather than the whole bedroom.
Fixing these sources of heat loss and modifying your heating behaviour not only saves you money but reduces your carbon emissions as well.
So unless you have deliberately built your house to a high energy efficiency you probably are interested in learning how to decrease you winter energy bills and carbon emissions.
If you are in the fortunate position of building a new house then you should make sure it is built to 8 star NatHERS standard. Heating and cooling is responsible for about 40% of the average household energy use so you will make your house cheaper and more comfortable to live in.
Retrofitting an existing house is the next best option with some of the these only possible if you own the house. Houses lose their heat through windows, draughts and gaps and through uninsulated roofs, walls and floors.
Insulation
Walls and ceilings require insulation to stop the heat getting out in winter and getting in in summer. In Queanbeyan the recommended R Value is R5 in the roof and R2 in the walls and floor. Start with the roof first as you can lose up to 40% of the heat in your home through the roof; 20% through walls and up to 15% through the floor. It costs about $1300 for the R5 insulation for 100m2 ceiling and installation about $80 per hour. Get a quote for insulation you may be pleasantly surprised that it is not much more than your normal winter energy bill.
Windows
If you can afford it changing your windows to double glazed ones can reduce your heat loss through the windows by 40-60%.
However otherwise you can work on using window coverings. Lined curtains and properly fitted blinds with box pelmets can seal in the warmth in winter and keep the heat out in summer. Curtains should reach to the floor and cover the sides of the windows to trap the cold air against the window. In winter, open them during the day and close them at night to cut your heating bill by up to 10%. In summer, close curtains, blinds, windows and doors during the day and open them in the evening when temperatures fall to let evening breezes cool your home naturally.
If you are on a budget you could sew second hand woollen blankets to the back of other curtains.
On windows that you don't need to be able to see through taping bubble wrap to the window gives you an improvised double glazing and is surprisingly effective.
Draughts
Your average house is full of draughts from around doors and windows, up chimneys, where cables and pipes leave the house and fixed wall and ceiling vents. Use door strips and weather stripping from your local hardware to fix the draughts from doors and windows. Caulk up other gaps. Wall and ceiling vents can be removed or a low cost solution is to cut a pice of bubble wrap to the same size and tape it to the vent.
Heating
The cheapest form of heating is a reverse cycle air conditioner. Try turning it off at night and setting it to turn on again an hour before you get up. Instead of running it at 25 degrees Celsius run it at 19 degrees and put on thermals or another layer of clothing. Close off rooms that don't need to be heated. Warm you bed with a hot water bottle or electric blanket rather than the whole bedroom.
Fixing these sources of heat loss and modifying your heating behaviour not only saves you money but reduces your carbon emissions as well.
It isn't too hard to slowly get used to warming your house to a lower temperature.
ReplyDeleteWe don't heat overnight and things cool down quite a bit. It was -7C outside last night, but 11C in the house when I got up this morning. We are very lucky that the owners before us put in a lot of insulation and also left a number of bags in the roof for the job to be finished. And luckily under our house is easy to access, so insulating the under floors wasn't hard.
We've had the fire going slowly for about 90 mins now today and things have warmed up to 12.8C (just cracked zero outside). My hands feel quite cool sitting here typing, but my body feels warm even without too many layers. My ugg boots are probably helping!
The house will slowly get up to 17C as the day goes on. We've gotten so used to the cooler temps (and I make sure anyone complaining of the cold is properly dressed), that anything over 17C feels too hot. Early in the season it takes a little bit of getting used to, so I will sometimes heat the house to 19C at the beginning of the season, then drop it down as we acclimatise.
My job for today is to order a blind for the kitchen window. It is in the part of the house that we heat, but sits bare. The next step after that would be to replace the windows with double glazing. If we are still living here when they reach the end of their life we will, but I'm reluctant to replace them while they are still usable.
Thanks for your comment Jamie. You are quite right we can acclimatise to lower temperatures and the regular practise of putting the air conditioner on 25 degrees in winter and 18 degrees in summer is ridiculous . WHO recommends a room temperature of 18 degrees C to reduce cardiac deaths in winter but if you rug up and move around you can let the house warm up itself during the day, particularly if you have insulated the house well like you have.
ReplyDelete