LED company Brightgreen has released a comparative study on the effect recessed and surface-mounted LEDs have on home thermal efficiency.

Modelled on government and academic research, the study outlines how choosing surface-mounted LEDs instead of recessed equivalents can save homeowners so much in temperature control, that it covers the cost of lighting up an average-sized Australian home. Because they eliminate air leakage and gaps in insulation, surface-mounted LEDs require only half the total energy used by recessed equivalents.

With heating and cooling accounting for an average of 40% of Australian home energy usage, sustainable architects, builders and homeowners alike are increasingly concerned with boosting home energy ratings by combating air leakage and maximising insulation R-values.

Because warm air is more buoyant than cool air and will inevitably float upwards, having an airtight and well insulated ceiling is particularly important during these cooler months. Lighting plays a key role in overall home efficiency, with the right lights standing to reduce both lighting and temperature control energy usage.

By shining a light on the extra load recessed LEDs put on temperature control systems, Brightgreen presents a whole new way of thinking about LED efficiency. The study outlines the following three factors as primary considerations when assessing the overall efficiency of a luminaire:

Air leakage

Air leakage energy losses are caused by conditioned air leaving the home through cracks and openings. Because they require cut-outs in the ceiling, standard recessed downlights prevent homeowners from having a totally sealed ceiling. Air leakage as a direct result of recessed lighting cut-outs contributes to approximately 197.58kWhs per year of excess heating and cooling energy for an average-sized Australian home.

Insulation

A well-insulated ceiling is one of the easiest and most effective ways to boost home thermal efficiency. Unlike surface-mounted lights, recessed downlights require a safe clearance around each installation to prevent fire hazards. This clearance reduces insulation R-values by up to 0.5, resulting in an increase of heat conduction. For an average-sized Australian home this amounts to approximately 194 kWh of additional temperature control energy usage per year.

Energy usage

Energy usage and product lifetime should be taken into consideration when considering the sustainability of any lighting product. LEDs feature exceptionally long product lifetimes and generally emit a higher amount of lumens per watt than other light sources.