Tucking up downlights

By - , Build 96

Manufacturers, suppliers, designers, electricians and insulation installers should all know how to maintain the thermal envelope around downlights. Do you?

Figure 2: The clearances specified in NZECP 54 for untested light fittings in confined spaces. Insulation may be compromised in this installation.
Figure 1: Optimum layout to ensure NZBC Clause H1 compliance.

Insulation is often installed with a clearance distance around recessed downlights. The effect of heat loss from warm air rising into concealed ceiling spaces is often seen as far less important than possibly causing a deadly fire from insulation abutting a light fitting.

What the requirements say

This thinking goes against the requirements of the New Zealand Electrical Code of Practice (NZECP) 54: 2001 which states under 2.6 Thermal Insulation: ‘Recessed luminaires and any auxiliary equipment shall be constructed and installed so as not to compromise the thermal efficiency of buildings’.

It also isn’t supported in that, historically, insulation products used in New Zealand have not typically supported combustion.

The problem is further compounded because:

  • insulation is usually installed at a different time (by a different person) to the light fittings
  • the relationship between the New Zealand Building Code (NZBC) Clause E9 Electricity and NZECP 54: 2001 is clearly defined, but misunderstood
  • light fitting types have historically not been required to be specified at the time of building consent approval by the Territorial Authority
  • a wide variety of specialist and/or budget lights (both bulbs and fittings) are now available on the market and not all light fittings have been tested to NZECP 54
  • lights are often selected by the owners and sometimes specified relatively late in the construction process
  • there is a lack of detail about lighting provided by manufacturers and designers
  • if specified, fittings are sometimes substituted for a similar looking fitting during the supply/installation process.
Figure 1: Optimum layout to ensure NZBC Clause H1 compliance.

Electricians must ensure compliance

An electrician is bound under the requirements of their registration and self-certification authorisation to ensure that NZECP 54 is complied with. For details refer to the Energy Safety Service website www.ess.govt.nz under ‘Rules and reports’, ‘Acts and regulations’, ‘Electricity Regulations 1997 and amendments’, and then specifically to ‘Regulations 69 Electrical safety and 69A Electrical installations’.

Specify at consent stage

Downlights should be specified at the time of building consent. The NZEPC 54 fitting rating needs to be indicated to ensure that the NZBC Clause H1 Energy efficiency is not compromised when downlights are installed in a ceiling.

NZECP 54 gives guidance on ‘the selection of recessed luminaires and their installation requirements to ensure that the integrity of the building is maintained. This integrity includes building elements, thermal, acoustic, fire and moisture’.

If you see a gap between the insulation and the fitting, and want to improve your thermal efficiency, BRANZ recommends using the correct fitting type. To allow close-butted insulation, the light fitting must be rated as either category Closed and Abutted (CA) or Restricted and Abutted (RA) – refer to the manufacturer’s installation instruction sheet.

Typically use only CA fittings above moist areas like kitchens, laundries and bathrooms.

Figure 2: The clearances specified in NZECP 54 for untested light fittings in confined spaces. Insulation may be compromised in this installation.

Some DIY allowed

The Acceptable Solution G9/AS1 allows members of the public to carry out some of their own electrical work. The Electricity Act, Regulations and relevant Codes of Practice are available on the Energy Safety Service’s website www.ess.govt.nz. A good first reference for those considering altering wiring, A guide to doing your own electrical work safely and legally, is available on the website under ‘Safety information’ then ‘Electrical safety’.

But remember, don’t remove the cover or do any wiring work behind the meter board.

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More articles about these topics

Articles are correct at the time of publication but may have since become outdated.

Figure 2: The clearances specified in NZECP 54 for untested light fittings in confined spaces. Insulation may be compromised in this installation.
Figure 1: Optimum layout to ensure NZBC Clause H1 compliance.

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