EFFICIENT HEATING/COOLING + APPLIANCES - ALTERNATIVES TO GAS

Heating and Cooling 

Ceiling fans - For a dwelling that uses passive design principles well, to keep a space not too hot or too cold, good cross ventilation and ceiling fans should be sufficient in bedrooms for keeping comfortable during the hotest night. It is also nice sleeping under the breeze from ceiling fans - more comfortable than sleeping in a room with an air-conditioner. 

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Reverse cycle split system heating and cooling units. Purchase units within one star of the best available for that required capacity unit. Refer to https://reg.energyrating.gov.au/comparator/product_types/64/search/ to determine most efficient units within each capacity range. If you are looking to cool and heat a moderate sized whole house 7-10kW capacity multi-head reverse cycle split system units might typically be required.  For larger townhouses multi-head units of 10-19kW capacity might be required.

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Where a roof space allows, a concealed reverse cycle heating/cooling unit may be installed with ducts supplying air to each duct outlet. Systems should be zoned to allow for different heating or cooling demands depending on the location of the room and its access to winter or summer sun. 

Alternatively 5kW for the open plan area. Smaller 2.5kW reverse cycle units might be an option if required for heating and cooling in bedrooms. 

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Some people like access to a central point of heat to stand or site beside, as may be provided by a gas heater. When this is required, a single electric panel heater in a specific location can augment the split system or ducted unit approach.  

Top line suppliers such as Daiken now offer reverse cycle heating and cooling units that include ventilation and also heat recovery on ventilated air. This allows running on ventilation only mode, and is critical for ensuring sufficient fresh air, for better sealed more energy efficient homes. 

Heat pump and hydronic (water pipe) in-slab heating where the water (in a tank) is heated by a heat pump with energy supplied by PV panels, is another way to optimise the use of electricity generated by PV panels. The system is useful where it is difficult to get direct sunlight on the concrete slab and when the house is built to typical insulation and sealing performance levels. However a number of distributed reverse cycle heating and cooling units (heat pumps) and a well sealed home might prove more useful as experienced in this excellent Renew article. 

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Hot water

• Heat pump storage hot water units connected to PV panels. The small amount of electricity that is required to heat these hot water units can be generated during the day by electricity generating solar PV (Photo Voltaic) panels. Currently these units are more expensive than traditional storage electric hot water units
  
  

• Electric storage hot water units connected to PV panels to reduce their energy consumption.
  
  

• Electric storage units connected to solar thermal panels (Solar boosted electric hot water units) - the water is pre-heated by the sun to reduce the electricity load required to get to the desired temperature.  
  
  

• Instantaneous electric hot water units - these units are demanding on power use and require three phase power if to be used to supply sufficient hot water for showers. Three phase power is available to most apartment developments and many commercial developments, but generally not installed to individual dwellings. These are only environmentally friendly when the power supply is from an onsite or offsite purchased renewable source (eg mains accredited green power or South Australian mains power not standard current predominantly fossil fuel Victorian, NSW or Qld mains power). 
  
  

Cooking - electric induction cooktops. Safe, energy efficient, and a low simmer can be maintained better than gas.

Induction cooktops are more efficient because food being cooked with induction will receive 90% of the heat generated (and hence will cook faster) as opposed to only 40-55% for gas. Induction cooking uses the magnetic property of cookware to directly heat it only and nothing else, unlike gas cooktop.

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Induction cooking requires that the cookware is magnetic. If a magnet sticks you can use the cookware for induction cooking.

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Induction coocktops range from 200W - 3700W. Stovetops with 7-inch burners generally span from 1,200 to 1,800 Watts, while 9-inch ones generally start from 2,200 and can rise to 3,300 Watts.

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For more details read