Fluorescents get dimmer over time and should be replaced after about 10,000 hours of burn time. Trim trees that block natural daylight to windows, or block outdoor lighting fixtures and create shadows. Heating, Ventilation and Cooling Check operating hours . Install or reprogram setback thermostats to condition space only when needed. Maintain the system .
Regular maintenance improves efficiency, comfort and the life of the equipment.
Minimize use of lighting , particularly incandescent lamps, which increases room temperatures. Install an economizer on air-conditioning systems to take advantage of outside air on mild days. Isolate conditioned areas from non-conditioned space. Repair doors, windows, walls, vents and other openings. Use natural ventilation and cooling .