Air conditioning system (negative pressure room)

Article details

1) Concept of negative pressure room (overview of air flow) where the image must convey
 • Air flow arrow from corridor → into room.
 • The room has a Pressure (-) symbol.
 • Air does not flow back out into the hall.
 • Door closed = System works perfectly.

2) Supply – Exhaust relationship (heart of the system) concept from picture
 • Supply is less than Exhaust.
 • Exhaust fan is the one that “pulls” the pressure.
 • Negative ΔP (-5 to -15 Pa).
 • There is no Return Air back to the AHU.

3) Alignment of the distribution head - suction head (Air Distribution). The picture should be seen.
 • Supply is on the clean side / top side.
 • Exhaust is near the source of contamination (bed / work site / low level).
 • Air flows through people → then is sucked away.
 • No short circuit.

4) Exhaust system + releasing air Key message in the picture
 • Exhaust separately
 • Passes HEPA / BIBO (in the case of high-risk rooms)
 • Release above the roof. Far from the air inlet
 • Does not recirculate.

5) Pressure control system (Control & Sensor) what the image must convey
 • DP Sensor measures between room ↔ hall.
 • Exhaust Fan + VSD controls pressure.
 • There is a light/display showing the status of NORMAL / ALARM.
 • Warns when the door is stuck open or ΔP is lost.

6) Checklist summary picture (for site engineers) Summary from one picture.
 • ACH by room type.
 • Exhaust > Supply
 • No Return Air
 • DP Control + Alarm
 • The room must be airtight.
 • TAB & Commissioning