Reducing the cooling load of a room

Where windows allow direct sunlight into the room during summer, the solar energy will significantly increase the cooling load. Shading can reduce this load. Permanent purpose-designed external shading such as roof overhangs and awnings work best. Internal shades will still allow a large proportion of the heat to enter the room. Shading can be designed to simultaneously allow beneficial winter sun while excluding summer sun.

Thermal insulation can be retro-fitted to some construction types using ceiling and underfloor insulation, and wall cavity insulation. The higher the R value the higher the thermal performance.

Air leaking into and out of a room can significantly increase cooling loads and reduce local comfort. Gaps around windows and doors, old vents and disused chimneys, leaking floors and construction joints can all be sources of air infiltration.

Some of the gaps in the room may have been purpose-designed for natural ventilation, providing outdoor air for occupant comfort and health. Often, occupants control natural ventilation by opening windows and doors. In an air conditioned room, the ventilation should be mechanically provided because of the tendency for occupants to close all windows and doors on hot and cold days. Whole-of-house heat recovery ventilation systems are ideal for periods when air conditioning or heating is in use.

Temperature control can have the highest energy impact, for example running the system too cold or running the system when the room is unoccupied and cooling is not needed. Modern units have sophisticated controls and may be IoT (Internet of Things) enabled to provide energy-efficient operational monitoring and reporting.

Ongoing inspection and maintenance is essential to ensure the unit operates properly.