Alice Springs experiences both extremes of climate – from subzero temperatures in winter, to over 40 degrees in summer.

Whist the use of some heating and cooling devices may be inevitable, there are many steps that householders can take to maintain a comfortable home. These will help reduce the need for use air conditioners and heaters and keep energy bills down – in many cases you can save hundreds of dollars / year.

The building...

Maintaining a comfortable home in the Alice Springs climate is about keeping heat out in summer, and keeping warmth inside during winters. If you live in an energy efficient house, you are less likely to need or want an air conditioner.

The building envelope (which includes the roof, walls, windows and floors of a home) has a significant impact on the amount of heat gain in summer and heat loss in winter. Ensuring the building envelope is appropriate for the harsh Alice Springs climate is one of the most important factors:

Roof

Your roof receives more direct sunlight than your walls and windows. A dark coloured roof absorbs a large amount of this heat, which can easily pass through to your living areas. To cut down this heat flow, paint your roof a light or preferably white coloured roof. Evidence from local trials showed that you can reduce the temperature in your living areas by around 3 degrees.  Installing a roof ventilator (ie whirlybird) helps exhaust hot, stale air in your roof cavity, thus help to reduce the heat transferring to your living areas.

Insulation

Ceiling and wall insulation is critical to keep your home comfortable naturally and reducing the need for air conditioning. Insulation acts as a barrier to heat flow (in and out) and is essential to keep your home warm in winter and cool in summer. Insulation not only keeps your home comfortable, but will ensure that when you do use air-conditioning, it works efficiently. See here.

Windows and walls

A large amount of heat can be gained or lost through windows. It’s important to ensure adequate ‘protection’ of walls and windows in summer; heating benefits can be achieved by allowing sunlight in winter. Sun protection can be in the form of one or more of the following:

• Appropriately sized eaves;
• Permanent shading such as verandas or awnings, especailly on east, west and south west side of your house;
• Fitting a 'skin wall' to walls or painting them a light colour
• External horizonal and vertical shading devices;
• Landscaping (ie planting shade trees or shrubs);
• Tinting windows or double-glazing.

In winter, warmth can be retained by:

• Installing internal curtains, blinds and pelmets;
• Installing double glazing.

Using appliances effectively

The need to use air conditioners can be minimised by using the techniques outlined above. When air conditioners are used, the following techniques will help cut energy consumptions and running costs.

Keep the heat out

On mornings of hot days, close up the house and shade all windows to block out the summer heat.  Be mindfull to allow some fresh to enter the house, preferrably from the shaded (and therefore cooler) side of your house

Use fans first

If you’ve followed the advice above, you will find that fans will keep you comfortable for much of the time.   Fans cost a fraction of the cost of running other cooling systems (well under 1 cent/hour) for most units.

Cooling with an evaporative system ("Swampy")

The most common type of air conditioners in Alice Springs are evaporative systems, otherwise known as 'swampies'. This technology uses a large fan which blows air over filters which are kept damp with water from a plumbed connection. This in turn provides cooling for occupants by moving, cool moist air. To ensure maximise efficiency, ensure that:

• the fan is set at the appropriate speed, rather than on full (when not needed);
• ensure that some windows / doors to be left open, to allow for the air movement to be maintained.

An evaporative system costs around 5-8 cents/hour to run, depending on the fan speed.

Using a refridgerative system

Refrigerative systems, whether they be room systems (known as ‘splits’) or whole house systems ( ie ducted) use a different principle to provide cooling that evaporative systems. They work by providing cold, dry air to lower the air temperature and lower the humidity, which in turn keeps you cool. For optimal efficiency and comfort and reduced running costs:

• ensure that the unit is set at either 26°C or 10° below the outside temperature, which ever is warmer. Remember, every 1 degree cooler in summer, increases the running costs by as much as 10%.doors should be kept closed.
• Close external doors and windows that are being cooled to reduce cool air escaping;
• Close internal doors to areas being cooled to minimise wasting being energy by cooling un-occupied rooms;
• Use in conjunction with fan - you can have the thermostat on the air conditioner set a few degrees higher and still be comfortable if you have a fan operating (fans cost a lot less to run than air conditioners).

Refrigerative systems are the most expensive to run – efficient models cost around 30 cents/ hour; larger or less efficient models (such as those common in ex-Defence houss in Alice Springs) can cost around 40-50 cents / hour or more (for each unit).

Remember – evaporative and refrigerative systems work on different principles so to save energy and money, make sure you use each system appropriately.

Maintenance is important

No matter what system you have though, ensure that you maintain the system according to manufacturers instructions. This will help reduce running costs and extend the life of the system.

Evaporative systems should be serviced on an annual basisRefer to manufactures instructions for appropriate maintenance instructions for refrigerative systems (cleaning the filters regularly will help keep them running as efficiently as possible).