An energy audit takes into account factors such as the age of the home, type of insulation, heating and cooling system, water heater, insulation, indoor air quality, lighting fixtures, and appliances. During a home energy audit, a certified inspector will use special equipment such as an infrared camera, blower door, draft gauge, and soap bubbles to look for air leaks, assess energy usage, and evaluate how you can save money. While not as thorough as a professional audit you can also do a DIY energy audit to pinpoint some places in your home you can improve.