Try the “organic” approach. You can do things like add curtains and blinds on all windows facing east and west. If possible, delay heat-generating activities, such as cooking & baking, until the evening on hot days.
You air con will also work most efficiently when you set it to a reasonable temperature. The general consensus is the following:
24 – 25°C in summer
17 – 19°C in winter
Also, you can save considerably on your power bill for every 1°C of cooling or heating that you do without (around 10% per degree).
For example, when it’s 36° outside, setting your air conditioner to around 25°C, rather than say, 21°C, can save a significant amount of energy without your system needing to run constantly. Because it’s so hot outside, 25°C will seem comparatively cool and you won’t be wasting power trying to make your home super-cool.