The pressure difference across a natural ventilation opening is estimated using the target zone air temperature
at the previous time step.
Each data point consists of zone air temperature
, ambient temperature, thermal load heating rate from IT equipment, lights, and electrical equipment, and HVAC unit cooling rate.
Loggers measured zone air temperature
, relative humidity, and C02 levels, which far exceeded code limits.
VAV terminal faults cause zone air temperatures
out of the desired values, poor thermal comfort and more energy consumption.
The lower bound on the supply air temperature is set to ensure that the maximum difference in zone supply air and zone air temperature
is limited to a practicable value (in this case, the largest difference would be 7.9[degrees]C between a supply air temperature of 12.0[degrees]C and the core or east zone temperatures of 19.9[degrees]C).
In this mode, the reheat load is zero, and the branch airflow rate is modulated to maintain the desired zone air temperature
During occupied hours, part of the convective heat gain contributes to a higher zone air temperature
which is reached to balance the cooler ceiling surface temperature, thereby maintaining an equivalent operative temperature in the zone.
VAV boxes that were causing uneven supply air were identified via input from the closely spaced zone air temperature
In sensible heat balance equations for zones, the unknown variables are zone air temperatures
or sensible supply heat rates and not surface temperatures.
The desired thermal comfort is defined in Equation 8 as upper and lower bounds on the office zone air temperature
according to CEN (2007) for office room Category II.
In the energy model the heaters are controlled based on the perimeter zone air temperature
(set point 21[degrees]C), specifically the air temperature was sensed: for case 1 in the single zone; case 2 in the perimeter zone; case 3 in the lower zone; case 4 in the perimeter zone and for case 5 in the lower perimeter zone.
A four-variable cubic polynomial was elected for modeling EIR, power consumption, and cooling capacity of the heat pump outdoor unit as a function of outdoor air temperature, zone air temperature
, compressor speed, and condenser fan speed.