BASIX assesses the energy used by the main heating and cooling systems for the living room and the bedrooms. Secondary heating (for example, a fireplace in addition to air-conditioning in a living room) is not considered.
BASIX recognises the following types of heating:
- gas fixed flued heater – with appropriate star rating
- gas hydronic system – gas-heated hot water piped to underfloor system and/or radiators
- 1-phase air conditioning – with appropriate star rating or range of energy efficiency ratio (EER)
- 3-phase air conditioning - with appropriate EER range
- heat pump hydronic system – hot water from heat pumps piped to underfloor system and/or radiators
- air-conditioning ducting only
- electric floor heating – electric underfloor heating
- wood heating (single dwellings only, not multi-dwelling developments)
- central heating systems – multi-dwelling developments only
- no active heating
BASIX recognises the following types of cooling:
- ceiling fans*
- evaporative cooling
- ceiling fans + air-conditioning*
- 1-phase air-conditioning – with appropriate star rating or range of energy efficiency ratio (EER)
- 3-phase air conditioning - with appropriate EER range
- air-conditioning ducting only
- central cooling systems – multi-dwelling developments only
- no active cooling
*Provided ceiling fans have not been included in the Simulation method thermal comfort assessment.
As well as the individual systems listed above, central heating systems and central cooling systems are also an option in multi-dwelling projects.
The estimated demand for active heating and cooling is calculated from the dwelling characteristics and climate zone entered in the BASIX Thermal Comfort section. If no active heating or cooling is selected where there is a heating or cooling requirement specified in the thermal comfort section, the dwelling is assumed to use some form of portable or retro-fitted heating or cooling systems.
The option of 'air-conditioning ducting only' is for those situations where, usually due to construction costs, the owner will not have the air-conditioning unit 'engine' installed by the time the Private Certifying Authority is due to issue the Occupation Certificate. This allows the home owner to reduce initial construction costs, but still recognize an advantage in BASIX from having an air-conditioning system that will be installed a short time after occupation.
When the option 'air-conditioning ducting only' is selected, the efficiency of the air-conditioning unit will default to the lowest value. When installed, the air-conditioning unit is likely to be rated higher than the default value.