Underfloor Diffusers

AirFixture Underfloor Air Diffusers

AirFixture offers the most complete line of UFAD diffusers to help you optimize your underfloor air distribution project.

Choose from directionally adjustable, manually adjustable volume or variable volume (VAV) operation in square, round, linear or rectangular configurations. Note that these features can be combined. Our most popular diffusers are VAV with directional and volume adjustment.

Our floor diffusers are available in a variety of colors, sizes, materials and airflow capacities to meet your project design needs. CV diffusers may include a basic galvanized steel catch pan or a larger acoustical boot, and our most popular selection is an aluminum VAV diffuser with manual airflow adjustability. Lower cost polycarbonate diffusers are available.

Patented HVAC Floor Air Diffuser VAV Technology

Our VAV diffusers use AirFixture’s globally patented Time Modulation VAV technology which intelligently controls air delivery based on the temperature demand of the occupied space.

These units incorporate a direct drive air valve that automatically adjusts individual terminals using Time Modulation logic to maintain the thermostat set point, making it the longest-lasting, zero maintenance VAV air valve in the world.

AirFixture has the floor diffusers HVAC experts around the world rely on to deliver outstanding ventilation and air quality for greater occupant comfort and health. Contact us to learn more about our products that will enhance your underfloor air distribution project.


A reference guide of our standard diffuser configurations, outlining sizes, shapes, designs and air flow capacities.

Literature outlining our standard and RAL diffuser color options.

A reference guide of our standard diffuser floor tile cutout sizes.

What our clients say about us

“Having worked with AirFixture at a past firm I know the care and thought they put behind their engineering support. They worked diligently with us to provide the most functional cost-effective design. When we were working towards our Construction Set Andy Bergman and his team had no problems reviewing several iterations of our design to ensure the end-user would be comfortable in both summer and winter conditions, and to ensure the Air Towers would meet the required sound performance so users would be comfortable from an overall environmental perspective. When we were in construction during COVID-19 in NYC, AirFixture did what it took to ensure we would have our units by or before the date they were promised to site, I could not have been happier in our choice of manufacturer.”

Christopher T. Varughese

Mechanical Designer