When buying or replacing office equipment, compare the energy consumption of various models. Even for machines with similar speeds and features, energy consumption can vary by tenfold. In summer, set the thermostat between 80 and 85 degrees. During non-business hours, raise the thermostat to a higher setting, but not more than five degrees. Where practical, use ceiling fans or portable fans to circulate and cool the air, rather than lowering your thermostat.
Fans are cheaper to operate than an air conditioner.
Install programmable thermostats. These units adjust the temperature automatically. Close window blinds during the day to keep out heat. Use awnings to keep sun off windows. Install shading screens on unshaded south, east and west-facing windows.