Three duct types
An on-site hotel laundry runs back-to-back all day. When lint chokes the dryer exhaust the machines slow down, linen falls behind, and the same blockage is a fire risk - two problems, one duct.
The short answer
A hotel depends on a steady flow of clean towels and sheets, and an on-site laundry running back-to-back all day pushes an enormous volume of lint through the dryer exhaust. As that lint builds it does two things at once: it restricts airflow so loads take longer to dry and the laundry falls behind, and it is combustible fuel that raises the fire risk. Cleaning the duct protects both continuity and safety.
The continuity problem
Commercial dryers push large volumes of hot, moist air through long duct runs, and lint collects far beyond the filter - behind the dryer, inside the wall, at every joint and at the exterior vent. As that layer thickens it chokes the airflow the dryer relies on to carry moisture away, so cycles run longer and linen comes out damp. In a hotel that means the towel and sheet supply falls behind exactly when housekeeping needs it, and staff push machines harder to catch up - which packs the duct faster still.
A restricted run also wastes energy: the dryer works harder for the same result, cycle times stretch, and components wear. The early warning signs are practical ones - loads taking longer to dry, a hot laundry room, weak airflow at the external vent, damp linen after a full cycle - and they are the same signs that airflow is restricted enough to be raising the temperature toward ignition.
The safety problem
Lint is fine, dry and highly combustible. Choking the exhaust drives operating temperatures up until the packed fluff can ignite at the heating element, and once alight a fire runs along the exhaust duct into the surrounding structure. In a hotel a laundry fire is not a contained appliance fault - it can trigger evacuation of guests, property loss and a closure that stops trade for weeks. The cost of the downtime often dwarfs the cost of the machine.
There is a second route too. Spa towels and robes carrying massage or emollient oils can self-heat after a hot cycle and combust when folded or trolleyed, even out of the machine - a real hazard for any hotel with a spa or pool. Segregate and process oil-contaminated laundry the same day, cool it fully and unload promptly.
How often and what we clean
Hotel dryers run more often and collect lint faster than domestic ones, so intervals are short and driven by throughput rather than a fixed rule. Housekeeping empties the lint filters every cycle; the full exhaust duct is cleaned on a risk-based schedule that heavy, near-continuous use pulls forward - many operators land on a quarterly or twice-yearly clean and adjust from inspection. We clear the whole run to atmosphere - filter, duct, any booster fan and the external termination - so airflow returns to full and the fuel a fire needs is not sitting in your ductwork. Keeping the run clear keeps the towels coming and the risk down at the same time.
Questions
Lint restricts airflow, so loads take longer to dry and come out damp. In a hotel that means the towel and sheet supply falls behind housekeeping - and staff pushing machines harder only packs the duct faster.
It is risk-based on volume, not a fixed rule. Filters are emptied every cycle; the full exhaust is cleaned on a schedule that heavy use pulls forward - many hotels settle on quarterly or twice-yearly and adjust from inspection.
Loads taking longer to dry, a hot laundry room, a burning smell, weak airflow at the external vent, and damp linen after a full cycle. These also mean airflow is restricted enough to be raising the fire risk.
Yes. Towels and robes carrying massage or emollient oils can self-heat after a hot cycle and combust when folded or trolleyed. Segregate them, process the same day, cool fully and unload promptly.
The whole exhaust run to atmosphere - filter, duct, any booster fan and the external termination - not just the filter, so airflow returns to full and combustible lint is removed from the ductwork.
Phoenix Duct Clean · by the numbers
We clean the full dryer exhaust so linen dries at full speed and the fire risk stays down. Call to plan cleaning around your busiest turnaround.