Using Condition for Different Mode of AHU/ERV
Mode#1 is used when the outdoor temperature is extreme, and are not within the comfort zone. Mode#2 is used when the outside temperature is moderate and between 68F and 78F. It is also used when the ambient temperatures are cooler and drier than indoor temperatures. The graph on the right shows the outside temperature in Pittsburgh throughout the year. |
Primary Cooling/ Heating
Mode#1: Energy Recovery Ventilator.
Mode#1: Energy Recovery Ventilator.
Secondary Cooling/ Heating
Here, the AHU should be around 100% outside air, close to a dedicated outdoor air system in Mode #2. This is dependent on entering outside air & loop water temperatures. Using the following economizer options results in the LEAST amount of energy consumption. The water‐side economizer geothermal heat pump option is energized when the air‐side economizer enthalpy wheel option cannot maintain comfort conditions due to extremes in outside weather conditions. In the summer, these options can only be used if the air is sensible.
Here, the AHU should be around 100% outside air, close to a dedicated outdoor air system in Mode #2. This is dependent on entering outside air & loop water temperatures. Using the following economizer options results in the LEAST amount of energy consumption. The water‐side economizer geothermal heat pump option is energized when the air‐side economizer enthalpy wheel option cannot maintain comfort conditions due to extremes in outside weather conditions. In the summer, these options can only be used if the air is sensible.