– Is the HVAC system over 10 years old?

– Are energy bills escalating without a logical explanation?

– Do building occupants lodge comfort complaints?

– Are repair costs continually rising?

– Has the building developed an indoor air quality problem? 


An aging HVAC system will lose efficiency, compromise comfort and require more frequent repairs. At some point, the equipment will need to be retrofitted or repaired to restore lost performance.

There are ways to retrofit existing HVAC systems to improve indoor air quality and save energy. High-impact retrofits include installing air economizers, heat and energy recovery ventilation, demand control ventilation, and building automation systems. There are other energy-efficiency upgrades that can help to reduce the cost of providing outdoor air for ventilation.

Installing air economizers can help ventilate and cool a building in an energy-efficient way. Air economizers draw in outdoor air in order to meet the thermostat setpoint without using the air conditioner. This process is known as “free cooling.” The economizer controllers determine when the outdoor environment is favorable and commence the free cooling process. Economizers typically operate at night when outdoor air is cooler than indoor air and use significantly less energy compared to air conditioning. Air economizers also require sophisticated control systems to operate efficiently. Routine maintenance is also recommended given that dampers can get stuck open and waste a lot of energy.