On this page, you’ll find useful information about heating and cooling your home efficiently:
To combat those hot, humid days and nights, try first to reduce the need for cooling and select an appropriate mix of fans and air conditioners for each room.
The most efficient and cheapest way to cool your home is to need less cooling in the first place. The following small, low-cost changes can make a big difference to comfort and running costs:
If you are limited in what you can do, focus on shading west-facing windows from the low, intense afternoon sun.
External shading aims to block heat before it enters the house and is generally more effective than internal shading. Some options include:
Internal shading is typically easier and cheaper to retrofit compared to external devices but less effective since heat has already entered the house. Remember to close blinds/curtains facing west or north during the hottest part of the day when possible.
Before air conditioning became popular, most homes used ceiling fans. Fans can still help beat the heat on their own or when used with air conditioning.
Many modern fans now have a Direct Current (DC) motor which use about 70% less electricity than older-style AC fans, making them cheaper to run and better for the environment. They’re also quieter, sleeker, and usually come with more speed settings, so they are ideal for bedrooms, enabling you to get a good sleep even on those hot humid summer nights.
By using fans alongside air conditioning you can set the thermostat a couple of degrees warmer while feeling just as cool. In winter, reversing their direction recycles the warmer air that has risen to the ceiling.
Reverse-cycle (also called “heat pump”) air conditioners are the most efficient way to both cool and heat your home from a single system. An old, inefficient, or poorly-sized system can cost you hundreds of extra dollars a year.
When selecting a system, look for:
Good ventilation protects your home from mould and damp, which can be a particular problem in older homes. Ventilation and insulation should be considered together, not separately. Sealing up a home to make it more energy efficient, without also fixing exhaust ventilation, can trap moisture inside and make mould problems worse.
You will need controlled ventilation in the following areas:
Bathrooms: Exhaust fans should duct outside (not into the roof space) to clear steam properly.
Kitchens: A rangehood ducted to the outside removes cooking moisture and grease-laden air before it settles into cupboards, ceilings and walls.
Laundries: Vent dryers to the outdoors, and try to avoid drying clothes inside on wet days.
Subfloors: Poor subfloor ventilation is a major driver of mould and timber rot.
Roof cavities: Whirlybirds or ridge vents help older homes with minimal roof ventilation, reducing summer heat build-up and stopping condensation forming in the roof space over winter.
The cheapest heat is the heat you don’t lose in the first place. A few changes make a real difference to comfort and running costs:
Reverse cycle air conditioners move three to six units of heat into your home for every unit of electricity it uses, making it the most efficient of all heating options.
Even though they are more expensive to buy, they are the cheapest to run, while also providing summer cooling.
Burning gas releases CO₂ from the heating appliance and methane in extraction and distribution, another powerful greenhouse gas. Unlike electricity that lowers emissions as more renewables enter the system, gas emissions will not reduce significantly over time.
Unflued gas heaters also release nitrogen dioxide, carbon monoxide, and fine particulates within the home, all of which have health implications, and can lead to condensation and mould in poorly ventilated rooms.
Supply of bottled gas is expensive and often inconvenient. On top of this, all gas appliances require regular safety checks, adding to the overall running costs.
Most people enjoy the vibe of a fire; however, it is not an efficient way to heat your home and, unless you have a cheap source of wood, it can be expensive. The particulates emitted from burning wood also reduces the local air-quality and affect respiratory health within the community.
The same reverse-cycle (“heat pump”) system that cools your home in summer is also its most efficient heater in winter.
When choosing a system, look for:
See Grants, Rebates & Finance for heating and cooling equipment
The table below compares the efficiency, emissions, cost and comfort of the main heating types.
| Comparison of main heater types | |||
| Reverse-Cycle Electric (Heat Pump) | Gas Heating (Flued / Ducted) | Wood Heating (Closed Combustion) | |
| Efficiency | 300–600% moves 3–6 units of heat per unit of electricity used | 70–95% some heat is always lost up the flue | 60–80% for a modern closed heater as low as 10–20% for an open fireplace |
| How it works | Extracts heat from outside air rather than generating it directly | Burns natural gas directly to generate heat | Burns wood fuel directly; open fireplaces lose most heat up the chimney |
| Typical running cost | Lowest per unit of heat delivered, due to high efficiency | Often higher per unit of heat than electric heat pumps, plus maintenance and potential health costs | Highly variable — cheap or free if self-sourced, costly if buying seasoned wood; labour-intensive |
| Emissions (grid electricity) | Falls as the grid decarbonises; near-zero if run on rooftop solar | Direct fossil fuel combustion in the home — fixed at the point of use, doesn't improve over time | Significant particulate/smoke pollution; CO₂ impact debated (can be near-neutral if sustainably sourced) |
| Comfort | Even, thermostat-controlled; doubles as summer cooling | Fast, strong heat output; no cooling function | Strong radiant heat near the fire, uneven through the house |
| Convenience | Clean and easy to use | Supply of bottles can be difficult | Needs manual tending |
| Upfront costs | Moderate; higher for ducted whole-home systems | Moderate; plus ongoing gas connection fee, regardless of use | Moderate to high for a compliant closed heater and flue installation |
