FAQs

How UfAC works

What is UfAC?

Underfloor air-conditioning (UfAC) is a method of delivering conditioned air using the void under a raised access floor, commonly found in office buildings.
Since the raised access floor is airtight, there’s no need for the extensive ductwork and equipment typically required in conventional ceiling-based systems — the floor itself becomes a large supply air duct.

How does UfAC contribute to a healthier workspace?

Maximising floor-to-ceiling heights increases natural light, making workspaces brighter and more appealing.

How does UfAC speed up fit-outs?

— No need for traditional ductwork, fan coil units, or pipework.
— The system is quick to install and can be easily reconfigured when workspace layouts change.

How does UfAC reduce costs?

— In new builds, reducing slab-to-slab distances while maintaining generous ceiling heights lowers construction costs.
— Eliminating ceiling services means less material and labour costs.

How UfAC works?

— Conditioned air is produced by CAM units and blown into the floor void.
— Fantiles™, installed throughout the floor, introduce the conditioned air where it’s needed.
— Room air is drawn back to the CAM, where it mixes with fresh air, is reconditioned, and redistributed back into the floor void.

How is the system controlled?

Fantiles™ can provide independent user control, however, typically centeralised control is carried out at the CAM unit via the Flexmatic touch controller.

Do Fantiles™ cause draughts?

Not at all. Conditioned air is induced into the space drawing room air into the air plume making the system resulting is less obtrusive air flow.

Is a raised access floor necessary?

Yes, the raised access floor creates the plenum which is used as the ventilation zone for air circulation and distribution.

Can UfAC be used with any raised access floor?

Most raised access floor systems with a robust substructure are suitable, but pedestals and stringers must be checked to ensure compatibility.

What is the minimum floor void depth required?

A floor depth of 300mm is required for a standard AET TU-4 Fantile™, or as low as 180mm is possible with the slimline Fantile™.

Do the Fantiles™ get dusty and dirty, as they are located on the floor?

Dust and dirt build-up is possible depending on the use of the space and typical cleaning schedule, however, Fantile™ units are easily cleaned by simply lifting the grille and vacuuming. Any particles that enter the return path are filtered by the CAM.

Where are the CAM units located?

Off the floor plate within their own enclosure. CAMs (Conditioned Air Modules) are typically located within an enclosure (cupboard) around the perimeter of the building or central core. However, they can be placed anywhere above the raised access floor, depending on the desired layout and airflow requirements.

How many CAM units are needed?

CAM unit zoning — each CAM (Conditioned Air Module) can typically serve a zone of up to 250–300 m², depending on the building’s orientation, internal layout, and specific cooling requirements. Actual coverage may vary based on the geometry of the space and the intensity of internal heat gains.

Why has the system
grown in popularity?

What are the benefits to Architects?

— Going underfloor removes clutter from office ceilings, exposing architectural details and increasing floor-to-ceiling heights.
— Architects appreciate the design freedom and ability to highlight a building’s original features.
— The system’s flexibility accommodates unusual layouts and structural configurations.

What are the benefits to mechanical consultants?

The last decade has seen a shift towards greener, healthier workspaces. As a result, M&E consultants are increasingly specifying UfAC as part of their sustainability strategies.

What makes AET better than the competition?

As the manufacturer, AET has the expertise to ensure systems are always in the best hands.
Quarterly maintenance visits allow AET to proactively detect and resolve issues faster. Also, adjusting system settings seasonally avoids unnecessary callouts for simple adjustments.

All equipment comes with a 12-month manufacturer’s warranty. Extended coverage available with a service & maintenance contract.

How does UfAC improve space
efficiency & comfort cooling?

What about space saving?

— By eliminating ceiling-based services, AET’s system can reduce overall building height by 10-18%.
— In new builds, this can allow for additional floors within the same total building height.

What about comfort cooling?

— Fantiles™ allow individual temperature & fan speed control, creating a more comfortable and productive workspace.
— The system achieves noise ratings below NR38 and eliminates high-level draughts via vertical air induction.

How is AET’s UfAC system superior
to traditional displacement ventilation?

AET’s Flexible Space systems offer several distinct advantages over displacement ventilation systems:

Zonal control & personal comfort

AET systems employ individual floor-mounted fan terminals (“Fantiles”) in each zone — typically up to 300 m² — that allow occupants to independently adjust airflow and temperature. This zonal setup delivers more precise thermal comfort compared to displacement systems, which rely on passive airflow and often require large diffusers (sometimes causing drafts).

Improved air quality & efficient contaminant removal

With fresh air entering at floor level and rising warm air carrying contaminants up to ceiling returns, AET systems enhance dilution effectiveness more than displacement systems. Additionally, zonal configuration avoids cross-contamination between spaces — beneficial in multi-tenant and flexible environments.

Higher cooling capacity for dense heat loads

AET systems can handle heat gains up to ~300 W/m², using colder supply air (around 14 °C) and achieving higher induction via fan assistance. In contrast, displacement ventilation is effective only at lower loads (~40–50 W/m²) and with limited cooling capacity.

Lower construction height & cost savings

AET underfloor systems eliminate bulky ceiling ducts, reducing required ceiling voids by up to 300–500 mm. This results in savings on construction materials and energy — e.g., mixed-use towers in Hong Kong realized a 19 % reduction in energy demand and a £5 million saving in façade costs.

Adaptability & maintenance efficiency

The modular AET design supports easy reconfiguration (e.g., when floor layouts change), with minimal disruption. Maintenance is safer and more cost-effective since terminals are accessible at floor level, avoiding ceiling work and elaborate duct rerouting.

Service & Maintenance

How easy is the system to reconfigure?

While CAM units are stationary, as there are no duct connections, an individual Fantiles™ can be easily relocated in a matter of minutes with the use of basic hand tools.

Do you offer installation?

Our systems are installed by the appointed M&E contractor however, we do carry out installation during CAT-B reconfiguration works.

How is the system controlled?

Fantile™ can provide independent user control, however, typically centralised control is carried out at the CAM unit via the Flexmatic touch controller.

What is the typical life expectancy?

25-30 years, provided they are serviced and maintained correctly.