Air distribution in a supermarket is often on display. Most sales floors have no suspended ceiling, so ducts, hangers and services all sit inside the customer's line of sight. In the same volume, refrigerated display cases run continuously, and in humid weather their cold surfaces are where condensation shows first. An air system has to answer both questions at once.

Illustrative image: JVTIADUCT fabric duct system in a hypermarket sales floor.

Three practical constraints on the sales floor

The first is appearance. Bare galvanised sheet metal with an insulated jacket rarely sits comfortably beside shelving and lighting. The second is condensation. When supply air above a refrigerated case is cold enough, humid room air will condense on the duct and diffuser surfaces and start to drip, right where fresh produce is displayed. The third is the refit window. A trading store cannot close for long, so the lighter the duct and the simpler its removal, the more usable the night shift becomes.

How a fabric duct answers them

A fibre fabric duct is a lightweight textile air dispersion system suspended from the roof structure, and it is itself a visible finished surface: colour and routing can be set to suit the store palette so the duct reads as part of the lighting and shelving composition. Air is introduced at low velocity over a large area — the duct wall is permeable, or fitted with engineered outlets along its length — so air leaves the full run of the duct, reducing strong local draughts and the temperature differences between aisles. Because air passes continuously through the permeable wall, the duct surface stays close to the supply air temperature, which lowers the risk of surface condensation. The duct is light enough to be taken down section by section for cleaning, so a refit disturbs trading less.

Selecting by zone

JT-H suits general sales areas. Above fresh and refrigerated zones, or wherever supply air is cold or the room is humid, JT-T, the insulated composite type, is the better choice for reducing condensation on the duct and on nearby cold surfaces. JT-N, the non-combustible type, covers large volumes where the building specification requires it. Fire performance of the duct material can be checked item by item against EN 13501-1, EN 13823, UL 723 and CE documentation.

Coordinating services early

Most rework in supermarkets comes from service clashes: the duct, the sprinkler run, the lighting track and the cable tray all competing for the same layer of space. Fixing the route and outlet type at concept stage, and designing the removal method at the same time, is what keeps filter changes and cleaning from turning into another ceiling job.

For a store, good air distribution has to do two things: look right from the aisle, and stay dry above the chiller.