Feature

Keep warm this winter

Green Lifestyle Magazine

Want to save up to 70 per cent on winter heating costs? Before you pump up the high-powered heater, there’s some simple measures to ensure you won’t suffer blow-out bills or icy toes.

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When the average person thinks about making their home warmer in winter they tend to think of what building designers call ‘heat gain’. They buy a bigger heater, or more of them, believing that the more heating they have the warmer they will be. While that is true, it’s actually a remarkably inefficient and costly approach to thermal comfort. The secret to effective heating is more about preventing heat loss than achieving heat gain.

Picture this: you’re snuggled in bed on a wintery night, covered by a quilt. How cosy. But what happens if you lift up the quilt? Whoosh! Out goes the hot air. You start to shiver, because your body has to work overtime to keep you warm. Insulating and gap sealing your home is like putting on a doona. Once it’s done, getting and staying warm is a cinch.

Benefits of Insulation

Insulation is a heat barrier: in winter it keeps heat in, in summer it keeps it out. Ideally, walls, floors, roofs and ceilings all should be insulated, but in many older homes it’s only practical to insulate the roof and ceilings. Retrofitting insulation to your roof and ceiling is the single best thing you can do to prevent heat loss, and will save up to 45 per cent on your heating and cooling bills.

Every type of insulation has an R-value, a measure of its performance. The higher the R-value, the better it is at doing its job, though walls don’t require insulation with as high an R-value as would be used in ceilings.
If you live in Hobart, your main concern is to keep heat in. In Brisbane, you’ll mainly want to keep heat out, although at night the situation may be reversed. The excellent Your Home Technical Manual has recommended insulation R-values for each Australian climate zone.

A sufficient quantity of ceiling insulation batts will usually cost $700 to $2,700, excluding installation. Lyn Beinat from ecoMaster in Victoria recommends combining these with reflective foil in the roof. “If you include a layer of reflective insulation, you would be looking at an additional $1200 or thereabouts,” she says. “But you would also be increasing the effectiveness from R3.5 to R5.2 in winter and R5.9 in summer.”

If you can’t install floor insulation, you can still guard against heat loss by putting rugs down over winter. Five per cent of a home’s heat loss occurs through floors, so rugs will make a noticeable difference.

Seal cracks and gaps

According to John Knox of the Alternative Technology Association, if you added up all the areas where air leaks occur in your home, you would have “the equivalent of a square metre hole in your wall”.

“If you had a square metre hole in your wall would you fix it? Of course you would!” Knox states, He says fixing gaps that cause draughts can save up to 25 per cent of your home’s heating and cooling costs.
Air leaks are commonly found around doors and windows, skirting boards, chimney vents, wall vents, exhaust fans and light fittings. Sealing these gaps to prevent cold air getting in is something you can easily tackle yourself.

Start with exterior doors, at both the front and back of the house. Seal the bottom of the door with a screw-on brush sealer, which you can buy at a hardware store for $15 to $20. Then seal around the door frame with weatherproof foam tape (also available at hardware stores). The tape can make the door a little tricky to close, but you can remove it when the weather warms up if you need to.

Internal doors can be sealed with brush sealers too. This will help to keep heat in certain parts of the house.
For cracks and gaps between the walls and skirting boards use a standard gap sealant such as silicone.
A good hardware store will have a range of draught seals for all types of windows, including older-style double-hung sash varieties and modern hinged styles. Really difficult windows can be sealed shut over winter, and the seal removed when the weather improves. Cost per window is $6 to $8 – which is small change compared with the energy savings.

Ceiling exhaust fans can be another source of heat loss, as you’d know if you’ve ever stood under one after a warm shower in winter. Many new models are designed to seal after use, but older models are terribly gappy. Consider installing a product such as a DraftStoppa, a self-sealing cover that can be fitted over existing ceiling exhaust fans to stop ceiling leaks.

Stop heat loss through windows

Up to 40 per cent of heat loss in a home is through window glass. One of the most effective and easiest options to mitigate this problem is to use curtains. Choose thick, preferably multi-layered styles to create an insulating layer of still air between them and the windowpane. Pelmets are also of great benefit, and for a little extra effort you can even add a little Velcro to the window frames and around the edges of the curtains to ensure they sit tight to the frames to stop cold air getting in.

Double glazing is highly effective at insulating windows but if your budget doesn’t stretch that far you could consider retrofitting secondary glazing panels such as ecoGlaze or Magnetite. “Some systems require you to remove the panel before you can open the window,” Lyn Beinat notes. “Other systems do not impact on the operation of your windows or doors.”

If you’re renting, a cheaper option is a stick-on glazing product such as Clear Comfort.

With your roof and windows insulated and your gaps sealed, your heater will be twice as effective for half the effort, keeping you warm and saving big bucks on your power bills.

More things you can do

Once you’ve ticked off all the easy-to-achieve heat-saving measures there’s still plenty more you can do. Consider the following:

- Next time you repaint your home, add an insulating paint additive such as Thermalite or Insuladd. These products reduce heat loss through walls and ceilings by up to 25 per cent.
- If you’re upgrading your heating consider installing a split system air conditioner. These are highly efficient space heaters and if you use renewable power they’re as green as it gets.
- Heat shifters are another good idea. These work by moving the heat from one room in the house to another through the ceiling cavity via a duct with a fan. They’re good if you only heat the living room in the evening, but want to pump that heat into the bedrooms at night’s end.
- Make the most of the sun. Let winter sunlight through the windows during the day, then seal them up tight at night.