Ducting & Ventilation

Selecting the Right Ventilation Grille and Terminal Geometry

Terminal geometry determines airflow volume, throw direction, and weather protection at building boundaries. Round diffusers slip directly into circular duct ends or cored holes. Square and rectangular profiles mount over framed openings on flat exterior elevations.

Interior diffusers balance local airflow rates within occupied zones. Exterior caps must deflect backdrafts, rain, and debris while maintaining full exhaust velocity.

• Round diffusers: Fit standard round wall cutouts; ABS models offer adjustable faceplates or multi-position push controls to balance supply and extract air.
• Square and rectangular grilles: Cover exterior exhaust penetrations; aluminium alloy models include rainproof downward louvres to shed driving water.
• Hemispherical hoods: Wall air outlet caps with curved shields prevent wind-driven backdrafts on exposed exhaust hoods and chimneys.

Specifying Materials for Environmental Exposure

Operating conditions dictate your choice between polymer and metal air hardware. Outdoor terminals face ultraviolet radiation, temperature shifts, and rain. Internal fittings handle conditioned air, cooking vapors, or humid extract streams.

• Stainless steel: Grade 304 stainless steel resists corrosion in outdoor exhaust hoods, roof caps, and damp utility penetrations. It prevents rust streaking down exterior masonry.
• Aluminium alloy: Lightweight and naturally weather-resistant, aluminium suits rectangular outdoor exhaust grilles and rainproof louvres.
• ABS and molded plastic: High impact strength and rust immunity make ABS ideal for indoor bathrooms, kitchens, and ceiling soffits.
• Cabinet vent mesh: Small plastic or stainless mesh covers allow moisture-proof air transfer in enclosed equipment closets and electrical joinery.

Hydronic Venting and Passive Ventilation Ducting

Ventilation includes air purging in closed hydronic loops alongside ducted airflow systems. Trapped air pockets inside heating circuits cause cold spots, reduce flow, and accelerate pipe erosion. Installing a dedicated radiator auto air vent allows heating circuits to purge gas continuously.

For zero-energy roof exhaust, a passive turbine roof vent extracts warm air and process fumes using external wind power. These units mount directly over 110-200mm pipe stacks, eliminating power drops and electrical wiring on metal roofs.