1/3rd of the energy consumed in the United States is used to heat and cool buildings. The old but true cliché “out of sight, out of mind” is often the reason for neglected maintenance guidelines for your HVAC system. HVAC systems are usually installed where they are not seen, such as in a section of the basement, a closet, on rooftops, or in mechanical rooms. This makes them easy to ignore. The systems are simply taken for granted, until they fail. Decreased efficiency, utility overpayment, discomfort, loss of productivity, eventual premature replacement, and higher repair costs are the result.