As with lighting requirements, demand for artificial HVAC services can be minimised through the following:
- Reducing heat generation from lighting and equipment through upgrading to more efficient lighting and energy efficient equipment. The reduction in cooling loads from this strategy can be as much as 5–20%.
- Utilising cool roofs (painting roofs white) can reduce air-conditioning loads.
- Designing spaces which can be closed off to minimise the space required to be heated and cooled.
- Avoiding losses and leaks through windows. As much as 40% of the heat lost during winter, and up to 50% of unwanted heat gain during summer, is through windows. The use of appropriate shading devices, combined with double-glazing or low-emissivity windows can reduce heat loss during winter and the amount of incoming heat during summer.
- Improving the air-tightness of a building by sealing areas of potential air leakage, weather stripping doors and using external shading (such as overhangs, shading devices and light-coloured exteriors), or standard sealants or caulking.
- Using appropriate levels of insulation and optimising glazing areas to minimise heating requirements. If internal heat loads are high, insulation can increase annual HVAC energy use by increasing the need for cooling. This can be managed with economy cycles and natural ventilation.1
- Minimising energy waste by managing air leakage and ventilation while ensuring good indoor environmental quality.
- Expanding the temperature gap to at least 19–25ºC, depending on the seasons, to create a comfortable environment where no heating or cooling is operating. Cooling requirements can be minimised through economy cycles, opening windows and user-controlled local environments (e.g. use of small fans or local controls) which enable a larger comfort range and a reduction in air-conditioning loads.
Footnotes ~ Show 1 footnote
- An economy cycle has a large fresh air intake, and also a large spill or relief air outlet. Rather than recirculating most of the air in the building as is normally done, with an economy cycle the air is not recirculated. It simply comes in, provides cooling, then is vented out again. ↩