Air conditioners are bad for the environment so it’s obviously good if you can avoid using one. It’s easier than you think! At Freshome they have complied a handy list that has many tricks to keep your house cool without using AC. Over at PlanetFriendly there is a list of alternatives to air conditioners.
The most common sources of internal heat gain are; appliances, electronic devices, and lighting. Be aware from where the heat is comming. Now if you have air conditioning, use it wisely. Don’t put lamps, televisions or other heat-generating appliances next to your air-conditioning thermostat, because the heat from these appliances will cause the air conditioner to run longer. The heat they produce will make it think your house is warmer than it really is, and your system will run harder than it needs to.