Air Valves: Supply & Extract

Ceiling-mounted air valves provide a clean, low-profile alternative to traditional ventilation grilles for supply and extract points in ducted ventilation systems. Available in plastic and metal (white RAL 9010 powder coat), in connection sizes from 100mm to 200mm, our range covers both supply and extract applications — as well as combination supply-and-extract valves for balanced systems. Supplied by our own eFans brand and Vent-Axia.

What is a ceiling air valve used for?

A ceiling air valve is the terminal fitting at the end of a duct run — it's the visible point where air enters or leaves a room. Supply valves introduce fresh air into the space; extract valves remove stale air. They're used in residential and commercial MVHR, MEV, and positive pressure ventilation systems wherever a neat, flush ceiling finish is required.

What's the difference between a supply air valve and an extract air valve?

A supply air valve is designed to distribute incoming fresh air evenly into the room with minimal draught. An extract air valve draws stale air out of the room and into the duct. Some valves are suitable for both purposes. For whole house MVHR systems, both types are needed — supply valves in living rooms and bedrooms, extract valves in kitchens and bathrooms.

What size air valve do I need?

Match the valve's connection size to your ductwork — 100mm is standard for most domestic installations, while 125mm, 150mm, and 200mm suit higher-flow commercial or whole-house systems. If you're unsure, check the duct diameter at the ceiling point and match accordingly.

Metal or plastic air valve — which is better?

Both perform the same function. Plastic valves are lighter and lower cost — ideal for most domestic applications. Metal valves offer a more premium finish and better durability in commercial or high-humidity environments. Both are available in white as standard.

Can I adjust the airflow through a ceiling air valve?

Yes — most of our air valves are adjustable. The central cone or disc can be rotated to increase or restrict airflow, allowing the system to be balanced after installation to ensure correct air distribution across all rooms

Can the same air valve be used for both supply and extract?

Yes — many models serve both supply and extract duties depending on airflow direction and system design. However, dedicated supply or extract valves provide finer control and reduced noise for specific applications.

Do air valves affect noise levels in a ventilation system?

Absolutely. Valves that are too small or poorly balanced can increase air velocity and cause turbulence or whistling. Proper sizing and adjustment minimise noise and maintain smooth, efficient airflow.

What airflow rate can an air valve handle?

Capacity depends on size, design, and duct pressure. Smaller valves (100–125mm) suit lower airflows, while larger options (150–200mm) handle high-volume commercial ventilation. Always align valve performance with system airflow requirements.