Primary States (Heat Recovery Enthalpy Suitability Determination) - Johnson Controls - Metasys - LIT-12011147 - Software Application - Controller Configuration Tool - 13.1

The Heat Recovery Suitability output is set to Cool if heat recovery is allowed, the temperature inputs are reliable, and Clg HR is True. The Clg HR tells the command hierarchy whether the exhaust air is cold enough with respect to the outside air temperature to make cooling energy recovery suitable. The exhaust air temperature must be below the outdoor air temperature by the Deadband/2 before the CLG HR is set to True.

The Heat Recovery Suitability output is set to Heat if heat recovery is allowed, the temperature inputs are reliable, and Htg HR is True. The Htg HR tells the command hierarchy whether the exhaust air is warm enough with respect to the outside air temperature to make heating energy recovery suitable. The exhaust air temperature must be above the outdoor air temperature by the Deadband/2 before the Htg HR is set to True.

The Heat Recovery Suitability output is set to None if Heat Recovery isAllowed is False, any temperature input is not reliable, or both Clg HR and Htg HR are False.