Cleaning rigid and flexible ducts without damaging them

Most systems combine two very different types of duct. Rigid sheet-metal trunks, common in older installations and commercial buildings, have smooth hard walls that tolerate firm brushing and higher air pressure. Flexible duct, used for most residential branches, has a thin plastic inner liner wrapped around a wire helix, with insulation and an outer sleeve over the top. Clean it the way you would clean sheet metal and you risk tearing the liner or pulling the duct off its fitting.

Before cleaning, we identify the type and condition of each run, often with the camera. Sheet-metal sections are cleaned with rotary brushes sized to the duct. Flexible branches get softer brush heads or air whips, which use bursts of compressed air to knock debris loose without scrubbing the liner. Pressure is adjusted to suit the run. Where a flexible duct is sagging or kinked, we take extra care, because those low points tend to hold the most dust. Joins and fittings are checked as we go.

Some apartment conversions in West End and Milton use rectangular sheet-metal ducts above bulkheads, while nearby houses run entirely on flexible ducting. We plan access points and equipment for each layout separately. Where a single job includes both, we switch tools at the junction between materials. Any existing tears, kinks or loose connections found along the way are recorded in your photo notes, so you know the condition of the ductwork as well as how clean it is.