Air conditioning

Air conditioning can make up half of your electricity bill. A few smart choices can keep your space comfortable and your costs under control.

Use natural ventilation to reduce air conditioning use

You don’t always need air conditioning running to stay comfortable.

• Use natural airflow where possible. Fresh air costs nothing and can be surprisingly effective.
• In tall spaces, slow‑moving ceiling fans or roof vents help hot air escape
• Sometimes one large ceiling fan can be more effective than several small ones
• Ceiling fans work year‑round. In winter, flip the small switch on the side to reverse the spin and push warm air back down into the room
• Stay warmer in winter by closing doors, adding door snakes, using heavier curtains and laying floor rugs
• Stay cooler in summer by opening windows, lowering external blinds and letting the evening breeze refresh the building overnight
• Install sensors so your air conditioner switches off when windows or doors are left open.

Set efficient air conditioning temperatures

Getting the temperature right saves money without sacrificing comfort.

• Aim for around 18°C in winter and 25°C in summer. Every degree outside this range adds roughly 10% to your running costs
• Keep your thermostat within a 2–3°C range to avoid constant cycling
• If needed, install locking covers so the settings stay where they should
• Winter warm‑up: start the first hour with outside air dampers closed
• Summer cool‑down: begin with dampers open to help the building shed stored heat
• Encourage staff to dress for the weather. A jumper is cheaper than cranking the heating!

Reduce heat entering and escaping the building

Keep the cool in and the heat out.

• Heat from people, lights, appliances and equipment pushes your AC harder. Reducing that load can cut cooling needs by up to 40%
• Choose energy‑efficient lighting, minimise unnecessary equipment use and separate heat‑generating gear from the main office where you can
• Insulation, double glazing, tinting, shades and blinds all make a big difference
• Ceiling insulation alone can reduce heating and cooling costs by up to 40%. Ask your contractor about wall insulation too
• Fit automatic door closers and shut doors to unused areas
• Close east‑facing blinds in the early morning and west‑facing blinds in the late afternoon
• Insulate exposed pipes and ducts so the heating and cooling go to people, not empty space
• Seal gaps around windows and doors with weather stripping or caulking
• In busy loading areas, install a relay switch so AC turns off when doors open. You can also use partitions or small local units for staff comfort.

Only heat and cool when you need to

• Switch off air conditioning as early as practical in the evenings and on weekends. Keep a small standalone unit running only where essential, like server rooms
• Reduce AC in areas people barely use, such as stairwells, lobbies or storage rooms
• Turn off unnecessary lights and equipment so your AC doesn’t work overtime
• Use timers on exhaust fans so they shut off when the building is empty
• Rewire bathroom fans so they only run when the lights are on.

Choose energy efficient air conditioning systems

• Consider installing energy efficient variable speed drives (VSDs) or inverter systems, which match the speed of the air conditioner’s fan motors with the amount of air that is needed, to save up to 30% on running costs
• You can also install VSDs on fans, chiller water pumps and heating pumps. Consider converting constant air volume systems to variable air volume systems, as well as converting dual duct systems to single duct systems
• In low-humidity areas, evaporative coolers make use of the cooling effect of evaporating water to save you up to 25 to 35% on running costs
• Automate your air conditioning system with an energy efficient programmable thermostat. An ‘old-fashioned’ thermostat turns the air conditioner on and off based on temperature, not whether the building is occupied, or whether you benefit from the cooling/heating
• Heat recovery can help capture and re-use waste heat from heat-generating processes. An energy recovery ventilation system can use waste energy from the exhaust air stream to condition the incoming fresh air
• Ensure you install the right sized air conditioning equipment to suit your premises, and avoid both unnecessary investment and higher operation costs.

Use an energy management system (EMS)

• An energy management system (EMS) can cut electricity use by up to 30% by taking charge of your equipment automatically
• It monitors loads, adjusts settings and chooses the most efficient heating and cooling strategy
• EMS is especially helpful in complex buildings, allowing different zones to run different temperatures and schedules.

Keep your system in good shape

• Regular inspections keep your AC working efficiently and extend its life
• Check for leaks, damage and correct refrigerant levels
• Keep filters clean and ensure airflow is strong.