How to choose a diffuser
1. Determine the airflow
It is usually given in the ventilation design. If not: area × height × air change rate. Air changes: homes 1–2, offices 2–4, kitchens and bathrooms 5–10. Divide the total airflow by the number of diffusers in the room.
2. Choose the type for your ceiling and interior
- Square ceiling diffusers (PDK, NCD) — Apartments, offices and shops with ceilings up to 3.5 m. Distribute air in 1–4 directions along the ceiling.
- Swirl and panel diffusers (DPF, RD, DCc) — Armstrong grid ceilings, offices, open spaces. The swirling jet mixes air quickly — fewer draughts at high airflow.
- Linear slot diffusers (SD, SDH, SDT) — Modern interiors, stretch and plasterboard ceilings. A linear jet along the ceiling or a window. SDH — concealed, plastered-in installation.
- Gypsum diffusers (CRL, PCR, SQR) — Almost invisible: built into the ceiling and painted together with it. For small airflows in living rooms.
- Swirl diffusers and nozzles (VDL, DVA, JN) — High rooms of 4–15 m: warehouses, halls, shopping centres. Swirl diffusers with a thermostatic element switch between heating and cooling automatically; JN nozzles throw air 10–30 m.
3. Check three numbers in the configurator
- Outlet velocity — up to 3 m/s for quiet rooms, up to 5 m/s for commercial spaces.
- Velocity in the occupied zone — up to 0.25 m/s to avoid draughts.
- Pressure drop — preferably up to 30 Pa.
The configurator highlights them in green, yellow or red and recommends a size itself.
4. Colour and request
The standard colour is white RAL 9016. Any other RAL colour is painted to order. Add items to your request — our manager will confirm the price and lead time.