Energy

Designing homes to conserve energy and use it efficiently, from sources that cause least environmental harm.

Heating options

The most sustainable heating approach is to maximise use of passive heating first, then select an active heating system to meet the remaining heating needs. Always start with the simplest and cheapest option for the circumstances.
There are different factors to consider for:

  • living or dining rooms
  • bedrooms
  • bathrooms
  • kitchens
  • open plan spaces
  • two-level spaces
  • indoor-outdoor flow spaces.

The different space heating options available can be categorised according to their efficiency or Coefficient of Performance (COP).

Best efficiency
(COP >1)		 Good efficiency
(COP about 1)		 Average efficiency
(COP <1)
• Solar energy (good passive design, appropriate glazing etc.) for entire space heating needs.
• Air-to-air heat pumps (convective heat).		 • Electric heating – radiant or convective.
• Hot water heating – radiators connected to an electric boiler.
• Underfloor (electric cable) radiant electric heating.		 • Flued natural gas, or LPG – convective or radiant.
• Underfloor hydronic (hot water) radiant heating – gas, electric or heat exchange.
• Hot water heating (radiator) – gas or oil.
• Ducted hot air from electric, oil, gas or LPG.
• Solid fuel burner.

Living room or dining room heating

For living and dining rooms, the space heating system generally needs to provide for:

  • heating of larger spaces
  • longer periods of use
  • variable occupancy levels.

Occupants should be able to control the heating, and it should have a relatively quick response time so both the occupants and the space can be quickly warmed when temperatures fall.

As activity within this space is often sedentary, it is important that natural air movements should not make the occupant feel cold.

Bedroom heating

The space heating system for bedrooms needs to allow for:

  • long periods of occupancy with low activity levels
  • gentle heating of the air in the room
  • low noise levels.

This is best achieved using convection heating. In a well insulated, passively warmed house, an oil-column heater or nightstore may be sufficient.

Bathroom heating

The space heating system for a bathroom needs to:

  • provide for short periods of use
  • have a very quick response (to warm the occupant when the bathroom is in use)
  • be effective and safe for use in a moist environment.

To minimise the risk of condensation forming, ventilation should be addressed first. After that, a low level of background heat is recommended, such as a hot water radiator or underfloor heating system.

Other options are:
•    ceiling-mounted heat lamps (with exhaust air duct)
•    electric radiant heaters
•    electric wall-mounted fan heaters.

Kitchen heating

The space heating system for a kitchen needs to allow for short or medium periods of use, depending on when the room is occupied and whether other sources of heat such as the oven are being used. The system also needs to allow for raised levels of moist air, which will require ventilation.

In general, heating is not required or installed in kitchens. If it is needed, the best heating option is an electric radiant heater.

Open plan spaces

Open plan areas generally include kitchen-dining, living-dining or a combination of both. The space heating system for an open plan space needs to allow for movement of air between areas and for loss of heat from the immediate area around the heater.

An even, level heat without draughts will be achieved with underfloor heating. Even heating can also be achieved with heat pumps, ducted central heating or hot water radiators throughout the area.

Additional heating for specific areas, such as the area where lounge seating is located, may be provided by gas or electric radiant heaters.

Two-level spaces

The heating system for a two-level space should allow for convection currents causing warm air to rise from the heated lower level to the upper level.

In a well insulated home, there may be sufficient heat flow from the lower-level heating system so that the upper level only needs a low output radiant or convective heater for boost heating. Alternatively, a ceiling fan can be used to redistribute heat, within a space and heat transfer systems can redistribute heat into adjacent hallways or bedrooms.

Indoor-outdoor flow spaces

The space heating system for a room with doors that are regularly opened to outside needs to allow for high air movement in and out and for rapid fluctuations in internal temperatures.

More information