Think of it this way, if you have worked in either field, but have used specifier’s documentation, you will have complied because the specifier must comply with the requirements of the Building Code of Australia (BCA).
If you are doing any work where you, as the contractor, are designing the lighting aspects of a commercial or residential installation then you must comply with the BCA. You have a responsibility to your client for the mandatory compliance to the BCA. No more placing lights ”willy-nilly” in an installation as there are now a number of energy efficiency requirements to which must be adhered.
Simply put, these are to provide a 6-star energy rating for new residential buildings, improved energy efficiency requirements for hot water systems and lighting in new residential buildings and increased energy efficiency requirements for all new commercial buildings
Incidentally these provisions have been in effect since May 2010 in South Australia and ACT. Queensland, Victoria, New South Wales, Western Australia and Northern Territory have adopted them from May 2011. Where a planning permit is required for a construction of a new home or major renovation, the customer will require a Certificate of Occupancy. This certification will be determined at the commissioning phase by the local council Building Inspector, usually from the house lighting plans that are submitted.
The provisions are mainly to affect hard-wired lighting as such, but do extend to a number of other areas where electrical power is used. Free-standing lighting connected by the usual plug into a wall socket, bathroom heater and light units and any fans, exhaust or ceiling, without lamps are exempt. As are decorative or display lighting which is switched and controlled separately from normal lighting.
Following are a number of points providing a “heads-up” on just what is affected by these energy efficiency provisions.
Roof and ceiling construction
Where downlights are installed, there is usually a loss of insulation in those areas. The electrician must realise that this will limit the number of these devices allowed to be installed and he must be aware of the appropriate R-value in insulation for compensation. The more downlights, the higher the rating of insulation required.
Insulation is not permitted to interfere with the safe and effective operation of a domestic service or fitting. Necessary clearances per the Wiring Rules or manufacturer’s instructions are to be followed when installing any devices within the ceiling.
Artificial Lighting and Power
Specifications have been set for Illumination Power Density (IPD) of artificial lighting, excluding heaters that emit light. This allowance is based on the power drawn by the system not just on the capacity of the lamps. Tables are provided in the BCA to enable correct calculation of the IPD.
The IPD must not exceed:
- 5W/m2 in the interior of a house (Class 1 building)
- 4W/m2 on a verandah or balcony of a house (attached to a Class 1 building)
- 3W/m2 in the interior of a garage (Class 10 building)
These values can be exceeded if control devices, such as dimmers and lighting control systems, are used.
Allowances for Lighting Control
This allowance is based on various adjustment factors and the ratings defined above are divided by that factor based on type of control device and the percentage of area being controlled. Sorry about the calculations below but it is important that you understand that lighting controls from the most basic to fully automated enable a far greater allowance as to the wattage per square metre than the three IPD values above.
1. The very simplest being for a lighting timer in a corridor where the factor is 0.7 (eg. 5/0.7 = 7.14W/m2).
2. By moving to a motion detector (forgive the pun) there are various factors used depending on:
a) At least 75% of the area or the area being switched in one block is less than 200m2 is controlled by one motion detector, at a minimum – allowance factor 0.9 (eg. 5/0.9 = 5.56W/m2).
b) Up to 6 lights are switched as one block by one motion detector, at a minimum – allowance 0.7 (eg. 5/0.7 = 7.14W/m2).
c) Up to 2 lights are switched as one block by one motion detector, at a minimum – allowance 0.55 (eg 5/0.55 = 9.1W/m2).
3. A manual dimming system where lights are controlled by a rotary knob or a slider and where not less than 75% of the area is controlled by such – allowance 0.95 (eg 5/0.95 = 5.26W/m2).
4. A programmable dimming system where pre-selected scenes or levels are automatically selected by the time of day, a photo-electric cell or occupancy sensor and where not less than 75% of the area is controlled by such – allowance 0.85 (eg. 5/0.85 = 5.88W/m2).
5. A dynamic dimming system where the lighting level is varied automatically by a photo-electric cell to either proportionally compensate for daylight availability or lumen depreciation of the lamps - allowance 0.9 minimum for fluorescent lamps (eg. 5/0.9 = 5.56W/m2) or 0.8 for high pressure discharge lights (eg. 5/0.8 = 6.25W/m2).
6. A fixed dimming system where lights are controlled to a level and that level cannot be adjusted by the user and 75% minimum of the area is controlled by such to reduce overall lighting level and power consumption of the building – allowance is that percentage of full power to which the dimmer is set divided by 0.95 (an example depends on that set power figure)
7. A “combined” daylight sensor and dynamic control device where:
a) Lights within the space adjacent to windows, where the distance from the window equals the depth of the floor to window head height – allowance 0.5 (eg. 5/0.5 = 10W/m2).
b) Lights within the space adjacent to roof lights – allowance 0.6 (eg. 5/0.6 = 8.33W/m2).
But bear in mind that these allowances in the “combined” scenario are not available for tungsten halogen or other incandescent sources.
All ballasts for lamps must now be of the electronic type, with halogen and fluorescent lamps being required to be switched separately. This will incur limitations on the use of inefficient fluorescent and halogen lamps.
Switch locations and the areas of control are to be taken into consideration when designing an installation. This requirement will effectively ensure that where a space is not occupied or the service is not needed, there will be an energy saving in regard to light and power usage. Any switching is not to activate larger areas where only small areas need lighting.
Building Perimeter Lighting
Lighting around the perimeter of a building needs to be controlled by a daylight sensor, timer or motion detector.
Facilities for Energy Monitoring
Most commercial buildings, depending on their size, will be required to have a facility to record and monitor energy consumption.
Summary
I can hear “You need to be Einstein!” comments on the calculations and other comments as to the usual over-governing by our government bodies, but it is important that all installers take this as an opportunity to provide more value to your customer and to the cleaner and greener strategies that should now be our focus.
Inefficient systems will be a thing of the past with the provisions now mandated. The use of control systems will limit the unnecessary wastage of energy and ensure that only the areas to be serviced by electrical lighting are in use only when occupied. No matter what the job you get asked to quote on, all electricians will need to be aware of these provisions as the use of lighting controls will substantially increase the value to the customer. A grand opportunity indeed!
The comments above are certainly not detailed and further information can be found at the website of the Australian Building Codes Board (ABCB) and in the BCA 2011 Building Code.