Heating, ventilating and air conditioning (HVAC) systems are used to regulate the environment within an enclosed space for the comfort of an occupant. Typically, the thermostat of the HVAC system regulates the environment by measuring the ambient condition and treating the air based on the measured ambient condition. For example, if the measured ambient temperature is out of the range set by the occupant of the HVAC system, the thermostat assumes that the occupant is uncomfortable and instructs the demand unit of the HVAC system to condition (e.g., cool or heat) the air to meet the set range.