Only a few more months and the heat will be here again bringing extreme hot temperatures. No doubt you will be using your air conditioning system more and want it to perform as you expect.
What can you do to help your air conditioning unit perform at it's best and reduce running costs?
Use your home to help
Before looking at the air conditioner itself consider first how you can use your home to help reduce the heat load.
Keep your windows and external doors properly sealed
Homes that are "leaky" make the air conditioner work harder to keep it cool. In Australia it's said we live in glorified tents due to the amount of air leakage of our homes.
Gaps around windows and doors allow heat from outside to come inside which the air conditioning has to fight against and can greatly affect the performance of a system. So take steps to ensure all external doors and windows are properly sealed.
For more information about sealing your home check out http://www.yourhome.gov.au/passive-design/sealing-your-home and https://www.csr.com.au/building-knowledge/practical-tips/leaky-windows-minimising-air-leaks
Check and fix ceiling insulation
If you can check the insulation in your ceiling space. If the insulation in the ceiling has been disturbed by other trades, spread it out evenly across your ceiling space to help reduce heat gain and improve the performance of your system. Replace any insulation that is required and install in areas that are uninsulated. Also check sarking for any holes or tears and repair.
For more detail see about insulation and its benefits to air conditioning check out http://www.yourhome.gov.au/passive-design/insulation-installation
Shade your windows
Direct sunlight through glass can have a big impact on your air conditioning system. You know what it's like to get in a car after it has been in the sun in 40 degrees all day. So shade your windows using curtains and blinds and use exterior shutters if you have them.
Have a look at http://www.yourhome.gov.au/passive-design/shading for more information.
Use efficient lights and appliances
Old incandescent lights, convert about 90% of the electricity they use into heat. If you still have those old lights consider changing them to LED's that can reduce heat gain and also save you money in energy costs. Old appliances, like refrigerators can also generate a lot of heat. Think about replacing them with newer more energy efficient appliances will save you money in running costs not only with the appliances themselves but reducing the load on the air conditioner.
Turn off computers when not using them
The electronics in computers and IT equipment generate heat and they use fans to expel that heat into the room. Many commercial companies have dedicated air conditioning just to keep their IT equipment cool. So don't let computers and electronics run unattended for hours as this generates heat which the air conditioning unit has to fight against and results in high energy costs.
Improve your air conditioner's performance
Once your home is sealed tight, properly insulated and shaded what further areas can be looked at to improve your air conditioning system.
Check and clean/replace filters
This is one of the first things that we check and the cause of 90% of under-performing air conditioning systems. Filters that are blocked with dust restrict air flow, reducing the amount of cooling. Sometimes they can reduce airflow enough to freeze your air conditioning coil. So check your filter regularly and change or clean when it's dirty.
Use system in relation to weather
Operate system in relation to weather. Setting the temperature to 21°C while its 40°C outside is inefficient and will cost you money in high energy bill costs and put strain on the system. Likewise in winter set temperature low rather than 25°C+. Ideal temperature settings are 22-24°C in summer and 19-21°C in winter, but this is just a guide. Also operate system before extreme temperatures. If the forecast is 40°C+ start the unit earlier or setup an automatic schedule.
Clear and clean the outdoor unit
Don't attempt to hide the outdoor unit by putting a cover around it or with greenery. They need airflow and space around them to operate properly and efficiently. When that air flow is obstructed, you are "choking" the air conditioner and reducing it's ability to expel the heat into the outdoor air, making it work harder and costing you money. So keep the outdoor unit clear and clean any debris and leaves around it.
As you can tell from the list of things above, a lot of factors can influence how well your air conditioner performs.
If after taking all these steps the system still doesn't perform as you expect, it may be time to consider repairing or upgrading to a newer more energy efficient unit.