Heating and cooling your home costs an average of more than $1,000 a year [source: ENERGY STAR]. So, it's clear that choosing an upgraded HVAC system will help you save energy and money. Choosing an ENERGY STAR-rated HVAC over a generic system could increase your home's energy efficiency by 9 percent [source: ENERGY STAR]. But even if you buy the most efficient HVAC system, it won't perform to its full potential unless it is properly installed. ENERGY STAR to the rescue again. They have developed Quality Installation (QI) guidelines to help ensure your HVAC system reduces your energy costs by up to 30 percent over non-QI installations by considering things like whether the size of the unit is correct for your home [source: ENERGY STAR]. You can also save money by dividing your heating and cooling system into multiple zones throughout your home. You'll have to purchase more than one HVAC system, but in a larger home it makes sense, because you can control the temperatures of each zone individually, rather than from a single-point censor.