Passivent Airstract Roof Ventilation Terminal

A range of roof mounted natural ventilation terminals which combine low airflow resistance with excellent weatherability. They can be used as part of a sustainable, low energy natural ventilation strategy to provide an exhaust only outlet for used air. Also available with iAT - intelligent airflow technology for still, windless days, and unusual events such as high occupancy levels or unusual heat gains.

Features and benefits:

• Robust terminal with cladding and louvres manufactured from high-impact ABS on an aluminium frame.
• Unique patented double-bank louvre arrangement including 4mm insect mesh combines maximum rain rejection with good airflow performance.
• Base unit constructed from marine grade plywood from renewable forests with an aluminium frame to mount the Airstract terminal on; can be insulated if required.
• Fixed to roof structure (steelwork or timber) for maximum rigidity, and made weathertight with flashings (by others) before the terminal is fitted.
• Flexible installation: Airstract terminals are suitable for use on flat and pitched roofs covered with profiled or standing seam sheeting, tiles or slates, and ‘green roofs’.
• Motorised base dampers control the airflow, and are available with excellent thermal performance and airtightness levels.

Coefficients of discharge:

Based on double-bank louvres with base

dampers - Airstract square/rectangular 0.57, Airstract circular 0.54.   

Wind resistance:

Resistant to continuous wind loads at 51 m/s, demonstrated by independent BRE tests.

Airtightness:

Approx 9.7 m3/hr/ m2 at 50 Pa.                

Weather resistance:

External louvres have been independently tested at BSRIA to BS EN 13030: 2001 ‘Performance testing of louvres subjected to simulated rain’.

• Class A 100% at 0.00 m/s.
• Class A 100% at 0.50 m/s.
• Class A 99.71% at 1.00 m/s.
• Class A 99.06% at 1.50 m/s.

Acoustic performance:

Air intakes sited at roof level generally allow in less noise. Acoustic treatment can be applied to Airstract and systems to deliver planned acoustic attenuation performance, based on independent testing by The University of Salford.

Available in square or circular designs.

Free Area (without base louvre):

• 575 x 575 = 0.157 m².
• 575 x 800 = 0.246 m².
• 575 x 1025 = 0.319 m².
• 575 x 1250 = 0.368 m².
• 800 x 800 = 0.386 m².
• 800 x 1025 = 0.525 m².
• 800 x 1250 = 0.625 m².
• 1025 x 1025 = 0.716 m².
• 1025 x 1250 = 0.906 m².
• 1250 x 1250 = 1.030 m².

Free Area (with base louvre):

• 575 x 575 = 0.064 m².
• 575 x 800 = 0.101 m².
• 575 x 1025 = 0.139 m².
• 575 x 1250 = 0.176 m².
• 800 x 800 = 0.182 m².
• 800 x 1025 = 0.249 m².
• 800 x 1250 = 0.316 m².
• 1025 x 1025 = 0.331 m².
• 1025 x 1250 = 0.421 m².
• 1250 x 1250 = 0.561 m².

Bespoke Airstract terminals can also be manufactured in aluminium. These provide even greater airflow performance whilst still featuring the patented double-bank louvres for maximum weather protection. A wide range of larger sizes available too. Enquire for more details.