The right size
Make sure you have the right sized unit for your space. If it's too small, it won’t heat or cool the room sufficiently. If it’s too big, it will use more energy than is necessary.
Thermostat placement matters
If your thermostat is placed on an exterior wall or near a window, it can register an incorrect reading and cause your air conditioner to work harder than it needs to. You could also upgrade to a smart thermostat which can help you regulate your temperature more carefully.
Ceiling/roof insulation
The roof is the area with the largest potential to absorb or lose heat. This can be fixed by installing the right insulation.
Service your air conditioner regularly
Making sure your air conditioner is well maintained and that the filters are clean can go a long way in saving money on your energy bill. If your air conditioner has dust, dirt and debris in it or has a faulty part, it won't be running efficiently.
Servicing your air conditioner regularly will also prevent spot any problems early and avoid the need for costly repairs.
Upgrade to an energy efficient air conditioner
If you haven't upgraded your air conditioner in the past 10-15 years, it could be time for a replacement. Over time, your old air conditioner becomes more and more inefficient through normal wear and tear. When it comes to choosing a new air conditioner, look at the energy rating and ask your local air conditioning expert for advice.