NCC 2016 Volume One
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Specification J5.2d Space Heating

Specification J5.2d Space Heating

1. Scope

This Specification contains the requirements for heaters used for air-conditioning or as part of an air-conditioning system.

Intent

To clarify that provides the requirements for stand-alone heaters used for air-conditioning, as well as heaters used as part of an air-conditioning system.

2. Heaters

(a)

A heater used for air-conditioning must be—

(i)

a solar heater; or

(ii)

a gas heater; or

(iii)

an oil heater, but only if reticulated gas is not available at the allotment boundary; or

(iv)

a heat pump heater; or

(v)

a solid-fuel burning heater; or

(vi)

a heater using reclaimed heat from another process such as reject heat from a refrigeration plant; or

(vii)

an electric heater if—

(A)

the heating capacity is not more than—

(aa)

10 W/m2 of the floor area of the conditioned space in climate zone 1; or

(bb)

40 W/m2 of the floor area of the conditioned space in climate zone 2; or

(cc)

the value specified in Table 2a where reticulated gas is not available at the allotment boundary; or

(B)

the annual energy consumption for heating is not more than 15 kWh/m2 of the floor area of the conditioned space in climate zones 1 to 5; or

(C)

the in-duct heater complies with J5.2(a)(i)(B)(cc); or

(viii)

any combination of (i) to (vii).

(b)

An electric heater may be used for heating a bathroom in a Class 3 building or Class 9c building if the heating capacity is not more than 1.2 kW.

(c)

A fixed space heating appliance installed outdoors must be capable of automatic shutdown.

(d)

A water heater, such as a boiler, that is used as part of an air-conditioning system must—

(i)

achieve a thermal efficiency complying with Table 2b when tested in accordance with BS 7190; and

(ii)

use reticulated gas where it is available at the allotment boundary.

Table 2a MAXIMUM ELECTRIC HEATING CAPACITY

Floor area of the conditioned space Climate zone
3 4 5 6 7
W/m2 of floor area
Not more than 500 m2 50 60 55 65 70
More than 500 m2 40 50 45 55 60

Table 2b MINIMUM THERMAL EFFICIENCY OF A WATER HEATER

Fuel type Rated capacity (kWheating) Minimum gross thermal efficiency (%)
Gas Not more than 750 80
More than 750 83
Oil All capacities 80
Intent

To constrain the use of high greenhouse gas intensity heating sources used for air-conditioning.

The energy sources that may be used for heating a space directly are listed in which also specifies that all forms of heating described in to can be used in combination so as not to restrict heating to only one type. This clause recognises a combination of heating options may be the most appropriate and cost effective heating solution and may include a limited amount of electric resistance heating.

permits reclaimed heat from another process such as from a refrigeration plant, a co-generation plant, and bio-fuels to be used and this reclaimed energy can be used in conjunction with one or more heaters allowed under .

Electric heating can be used in specific circumstances only as outlined in which allows a small amount of electric resistance heating, up to 10 W/m2 for climate zone 1 and 40 W/m2 for climate zone 2, for the floor area of the conditioned space. The small allowances recognise the likely limited heating required for these mild climates.

permits larger electric heating allowances in situations where reticulated gas is not available at the allotment boundary, recognising the likely limited heating options in areas where natural gas is not readily available. The maximum values are specified in and are again climate zone based to recognise the limited heating required in temperate climates, compared to cool climates.

allows a further exemption for relatively small electric heaters in climate zones 1 to 5 if the annual energy consumption for this heating is not more than 15 kWh/m2 of the floor area of the conditioned space.

places limits on the amount of reheat allowed for an in-duct heater.

permits a small 1.2kW electric heater in a bathroom of a Class 3 or Class 9c aged care building. Typically this would include small electric heaters such as a 3-in-1 heater, exhaust fan and light system.

is specifically for fixed outdoor heaters and requires that the heater must be capable of automatic shutdown, which may be achieved by an outdoor temperature sensor, timer, motion detector or the like. This requirement aims to limit energy consumption when the service is not needed.

specifies the efficiencies required for gas and oil fired heaters that heat a space via water, such as boilers. The minimum thermal efficiencies located in are based on fuel type and rated capacity of the boiler in kW. The performance of the water heater must be tested in accordance with British Standard BS 7190 which covers the assessment of low temperature hot water boilers using a test rig. Note that by using a performance based solution, alternative testing standards may be utilised.

also requires gas to be the energy source where it is available at the allotment boundary.