UFAC – FAQ’s – AET Flexible Space

UFAC – FAQ’s

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Under Floor Air Conditioning – Frequently Asked Questions

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faq-question

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 300 mm is required for a standard AET TU-4 Fantile, or as low as 180 mm is possible with the slimline TU-S Fantile

Do high heeled shoes get trapped between the bars of the grilles?

The grilles have been designed to stop pens and pencils falling through. The nominal gap between the bars is 6.3mm / 6.4mm and can be walked upon with most high heel shoes.

Is there reduced lettable space due to the zonal units?

Compared to the area taken up by the large air ducts of an air only system, the loss of lettable space is less with AET Flexible Space.

How much cooling is available from CAM's?

Cooling depends on space temperatures, water temperatures, water flows etc but generally the AET Flexible Space system can accommodate loads of up to 200 W/sq m.  AET will select CAM’s and specify the number of Fantiles required.

Do the Fantiles cause draughts?

If the fan terminals are correctly located, draughts will not be an issue for users.  Watch the smoke test video to understand more about the air dispersion.

Do the floor terminals get dusty and dirty?

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 out by the CAM.

How is the floor void channelled into supply and return air paths?

A fire resistant air segregation baffle made from silicone cloth is installed in the void to create supply and return air paths

Are UFAC systems expensive?

UFAC systems are generally more expensive then Fan Coil units and cheaper than conventional ceiling based VAV systems.  When considering total cost of construction UFAC systems are typically more economical.

Is there a risk of condensation in humid climates?

The system have operated in a wide range of climatic conditions from -20 deg C and +50 deg C and condensation has not been found to be a problem

Are UFAC systems noisy?

As there is little or no ductwork in underfloor plenums the noise generated can be substantially less than that from a conventional ducted system. Sound transmission or cross talk between offices can be a concern but this can be minimised with the correct choice of partition and quality of seals. Additional sound baffles can be installed in ceiling voids

How does the slab thermal mass effect UFAC systems

After the initial thermal mass has charged and the building has settled, it may be possible to run the system for less hours due to the thermal flywheel effect.  Free cooling may also be implemented where suitable outside temperatures exist.

Are there any specific fire safety measures required?

Each country has their own fire safety measures for underfloor plenum. Most floor tiles meet fire rating requirements and generally applicable codes state that placing wires and cabling in an air supply plenum is not a problem where they are placed inside a conduit or rated to be non-combustable.