LOCATION AND MOUNTING IS KEY
The proper placement is vital to the function of NJK Precision equipment. For NJK-02 mounting, this guide was created to help explain best practices for a variety of different mounting situations, including:
The guide contains detailed diagrams of the various mounting scenarios and mathematical equations to help make installation decisions. The flexibility of the programming and operation of NJK Precision equipment is one of its best features.
Notably, mounting the NJK Precision Sensor Flow Frame even with the face of the duct takeoff allows for air to enter and exit with all areas of the Sensor Flow Frame exposed to the flow of air.
It’s also important to remember that outside air minimum and maximum dampers located in a shared plenum can allow minimum airflow to pass through the maximum airflow sensor when maximum dampers are closed, causing a false reading through the maximum air sensor. To alleviate this, install sheet metal extension sleeves on both the minimum and maximum outside damper inlets to direct the air into the proper sensor and to eliminate false readings through sensors on unopened dampers.
This guide explains that when mounting installation to the right of the NJK Precision Sensor Flow Frame, it must be mounted in an exterior wall inlet directly after the inlet rain louvers. This installation allows for air to enter and exit the NJK Precision Sensor Flow Frame with smooth flow and dependable flow readings.
The NJK Precision Sensor Flow Frame can also be installed in the air handler floor grating or ceiling takeoff directly with little or no ductwork leading into or out of the NJK Precision Sensor Flow Frame. The ductwork entering or leaving the air handler must be the full size of the opening and the NJK Precision Flow Frame to eliminate air being passed through a single portion of the NJK Precision Flow Frame and offering an altered sampling of airflow.
The guide also explains that the NJK Precision Airflow Measuring Station’s preferred mounting is upstream of dampers and louvers. The Airflow Measuring Station can be mounted downstream as well with proper placement. As dampers close (dampers are less than 100% open), less airflow passes over the Flow Frame at the top edge of the duct as air is directed downward. This provides an artificially low airflow signal. Placement of the Flow Measuring Module placed on the Flow Frame side, perpendicular to the dampers or louvers, adds in the normalization of the airflow signal. After air balancing has been completed, the Signal Processing Unit’s gain adjustment can compensate for any additional system effects. Similar airflow concentration effects will occur with a set of dampers or louvers downstream and near the Airflow Measuring Station.