- AHU (Air Handling Unit)
- The plant that conditions a building's air: fan, filter bank, coils and damper sections in one casing. Most of this catalogue lives inside one.
- FCU (Fan Coil Unit)
- A small fan-and-coil unit serving a single room or zone, common in hotels and apartments. Its washable panel filter is the room-side first line of defence.
- Pre-filter
- The first, coarse stage of a filter train, catching dust and lint before they reach coils and fine media. Protecting every stage downstream is its whole job. Air Filtration Products →
- Fine filter
- The second-stage filter, M5 to F9, removing pollen, smoke and bacteria-carrying dust. The stage that decides indoor air quality in a commercial building.
- HEPA filter
- The absolute stage: H13 and H14 filters removing 99.95 to 99.995 percent of particles at 0.3 micron. Specified for operation theatres, pharma cleanrooms and electronics. HEPA filters →
- EPA filter
- Efficient Particulate Air filters, H10 to H12: the class between fine filters and HEPA. For cleanrooms that do not need H13, specifying it anyway wastes pressure drop. EPA filters →
- Filter grade
- The letters that describe what a filter catches: G for coarse, M and F for fine, E and H for EPA and HEPA. Coarse before fine is the rule; each stage exists to protect the next.
- Pressure drop (ΔP)
- The resistance a filter or terminal adds to the airstream, in pascals. Every extra pascal is fan power, paid for the life of the installation.
- Face velocity
- Airflow divided by face area, in metres per second. Above design velocity, dust holding falls, pressure drop climbs and noise rises.
- Dust-holding capacity
- How much dust a filter loads before reaching its final pressure drop. Bag and deep-pleat formats carry more media, hold more dust and run longer between changes.
- Arrestance
- The share of coarse dust a filter captures by weight, the right measure for pre-filters. Efficiency, its counterpart, measures the finest particles and belongs to fine and absolute stages.
- Grille
- A frame of blades at the end of a duct, aimed at a room. Its strength is direction: air steered away from desks, beds and doorways. Air Distribution Products →
- Diffuser
- A terminal that sends air into a spreading, mixing pattern through swirl vanes or radial cones. It pulls room air into the stream and delivers comfort at low velocity.
- Linear slot diffuser
- A continuous line of slots on one plenum, the architectural standard for modern office ceilings. One-way to four-way patterns from a single linear face. linear slot diffusers →
- Swirl diffuser
- Fixed radial vanes that spin supply air as it leaves the face. High induction mixes it with room air within a short distance, the choice for high-airflow ceilings. swirl diffusers →
- Jet nozzle
- A focused, aimable column of air for tall and long spaces, with throws ordinary terminals cannot reach. The terminal for airports, auditoriums and halls. jet nozzles →
- Throw distance
- How far air travels before its velocity falls to a reference speed, usually half a metre per second. It depends on the airflow you actually run, not the catalogue maximum.
- Terminal velocity
- The reference speed at the end of the throw, roughly where a seated person stops noticing the air. A lower reference velocity means a longer stated throw for the same terminal.
- Induction
- Room air pulled into the supply stream by a diffuser's or nozzle's discharge. High induction means rapid mixing and even temperatures close to the terminal.
- Disk valve
- A disc in a ring or spigot for exhaust and spot supply: closed tight or open to a conical spread. The toilet-extract workhorse. disk valves →
- Plenum box
- The sheet-metal box behind a diffuser or grille that connects duct to face and evens the airflow. Sized to keep pressure drop and noise low. plenum boxes →
- Volume control damper
- The tap of the duct system: blades that throttle airflow at branches and terminals. Balancing engineers use them to bring every outlet to design flow. volume control dampers →
- Fire damper
- A life-safety device that seals a duct where it penetrates a fire-rated wall, slab or shaft. When heat arrives, a fusible link or actuator closes the blades and the duct stops carrying fire. fire dampers →
- Non-return damper
- Gravity blades that open to airflow and fall shut against reverse flow. For exhaust stacks and plant rooms where wind or standby fans push air the wrong way. non-return dampers →
- Pressure relief damper
- A weighted or spring-loaded door that opens when duct pressure passes its set point and closes again below it. Keeps rooms and plant within design pressure. pressure relief dampers →
- Air balancing
- Commissioning the system so every terminal delivers its design airflow, damper by damper. Done once at handover, then again every time the system changes. Air Control Products →
- Louver
- The building's nostril: blades that admit air while shedding rain, with mesh behind against birds and insects. Drainable blades go further, walking wind-driven water out of the frame. fresh air louvers →
- Free area
- The open fraction of a louver or grille face that passes air. Every screen and drainable profile costs free area, and free area lost is fan power spent.
- Return air
- Room air drawn back to the AHU for reconditioning instead of discharge. Return grilles, risers and transfer paths are half of every system. return air risers →
- Fresh air
- Outdoor air the system introduces for ventilation, taken in through the louver and its screens. How well the building breathes is decided at that opening.
