ACPH Calculation:
Equipment’s Used: Direct reading
Thermo Anemometer or Propeller Type Anemometer, Measuring Tape.
Procedure for
air changes monitoring:
- Measure the actual area volume of which air changes to be monitored using measuring tape and record the same.
- Draw a grid in the room or on a paper as per the room diagram and mark all terminal filters positions.
- Mark the sampling points for terminal filters on paper.
- Start the AHU of respective area.
- Ensure that all the doors are properly closed.
- Check the velocities at 4” to 6” below or away from the filters and record the same.
- Ensure that no object is present below the Anemometer while taking the reading, except the built-in equipment.
- Take each reading at least for 15 second.
- Check each filter at least for 5 test spots pre-established and marked.
- Calculate the average velocity for each filter.
- Calculate the terminal filter/grill area. (L x B)
- Calculate the CFM for each filter / grill by multiplying the average velocity with effective filter / grill area.
- Do the total of CFM of all filters of respective area to get the Total CFM for that area.
- Calculate the Air Changes by using following formula,
Air Changes per Hour =
Total CFM x 60
______________
Room Volume
Record all the readings.
FREQUENCY: Yearly or during AHU Validation and Area
Qualification
