Lighting

Lighting accounts for around 10% of the energy consumed in a typical home. This is often easily reduced by replacing inefficient globes with more efficient options (eg. compact fluor escent CFL or LED globes). While standard CFL globes have been readily available for years, we are starting to see LED globes available for direct replacement into standard light fittings. Some miscellaneous energy efficient globes for general use are inclded in the globes page, for interest.




















This page deals predominantly with improvements for the ubiquitous 12 volt halogen recessed downlights.
The home fitted with multitudes of recessed downlights is problematic because:
  1. Very high lighting energy requirements and cost
  2. Increase in heating requirements due to heat escaping through gaps around downlights
  3. Increase in heating costs because of disrupted insulation
  4. Overheating in warmer months, increasing cooling demands in summer
  5. Potential fire risk due to high operating temperature of halogen globes

The flaws associated with downlights are as follows

 Flaw    Problem
 Solution Considerations
Halogen globes are  inefficient (95 - 98% energy is converted to heat)
High lighting costs and
Change globes to more efficient type (eg CFL or LED)
Easy for 240 volt fittings. Depends on type of transformer for 12 volt fittings  
 High temperatures (up to 300°C)



Protect insulation by using a downlight cover
 
Gaps around light fitting
The gap around the fitting draws heated air into ceiling cavity and replaces it with unheateed air pulled in through vents and gaps
Seal fitting with a downlight cover
 
Halogen globes generate a lot of heat (up to 300 degrees celcius)   
 Fire risk
Protect ceiling cavity contects with a downlight cover
 
 Insulation must be pulled back from the halogen globe
  
12 volt downlights have a transformer to step the voltage down from 240V to 12 voltsMost standard transformers requires a certain current to operate smoothly. Simply replacing the globe to a compact flurioescent globe or LED globe often results in the light flickering.Revert to 240 Volt downlight fittings
Requires an electrician to install
  Replace transformer with a new low load transformer
Requires an electrician to install
 Traditional transformers use considerable energy in the process of stepping down the voltage to 12 volts. The power used does not generate light and adds to the inefficiency of this style of lighting 
Replace transformers with low powered transformers
Requires an electrician to install
Narrow beam widthSix to eight globes and fittings requried for equivalent light distribution from single surface mounted fitting
Choose wide beam globes
 
  Replace recessed fittings or spot lights with alternative surface mounted or pendant fittings
Requires an electrician and some repair work on plaster


Given the flaws described above, there is no single complete solution and finding the best solution depends on the situation and preferences! From an energy efficiency standpoint, the best solution of all is to remove all downlights, repair the holes and replace with well designed modern surface mounted or pendant light fittings. This solution resolves all problems once holes in the ceiling and insulation are restored.

The first step is to determine whether light fittings are 12 or 240 volt fittings. Some recessed fittings and track lights do not use a transformer, simply using 240 volts. This situation is more straight forward to deal with.