The demand for automotive heating, ventilating and air conditioning (HVAC) replacement parts is
affected significantly by seasonal variations. With mild winters during 2011-12, the demand for heating components,
particularly heater cores, dwindled as the number of vehicles brought in for regular HVAC maintenance declined.
Many installers and repair shops estimate that sales declined by as much as 15-25 percent simply because the parts
either lasted longer or provided just the adequate amount of heating that vehicle occupants desired.