PRESSURE PROFILE PLATES
EASY ACCESS TO AIRFLOW AND PRESSURE DATA
The age of the plug fan is here. EC motors, 0-10V variable speed capability, direct drive and fan hub intlet cone have all become industry standards. We have introduced our range of pressure profile plates, which leverage plug fan technology, to provide an easy and consistent means of measuring system total airflow and system total static pressure.
A plug fan is a high efficiency, backward curved impeller that is direct-coupled to its drive motor. The construction of the fan features a fan inlet cone through which air is drawn from the suction side of the system.
This inlet cone comes from the manufacturer with a pressure tapping installed. The purpose of this tapping is to allow for reference of the fan inlet suction pressure, which can be used in conjunction with the system total suction pressure to calculate system total airflow.
The tapping is typically sized to accommodate 3 – 6mm pressure hose.
By installing the Pressure Profile Plate on the exterior panelling of the air handling unit and plumbing the 3 x pressure ports to reference the designated compartments (system discharge chamber, inlet cone and system suction chamber) a permanent solution becomes available for static pressure reference as well as a system total airflow calculation.
FLOW CALCULATION
Utilising the static pressure measured at both the fan hub inlet cone and the suction chamber, the total volumetric flow rate of the fan can be calculated using the following formula:
*Where k is the model specific fan hub coefficient published by the fan manufacturer. Fan manufacturers include EBM Papst, Ziehl Abegg and Sanmu. Typically, the published coefficient is for a flow rate in cubic meters per hour. This value can be divided by 3.6 to convert to litres per second. The input units required may vary between manufacturers.
Excerpt from the EBM Papst Centrifugal Plug Fan product catalogue detailing fan models and corresponding k-values.
EXAMPLE CALCULATION
