Every commercial laundry has a duct or series of ducts – the exhaust system – that remove the hot, moisture-laden air from dryers and exhaust it outdoors on the roof or via an outside wall. This hot air is filled with lint particles that, over time, deposit inside the duct. Lint can stack up until it is inches thick. Regular maintenance is needed to remove the accumulation. Maintenance is commonly done every three to six months but may be needed as often as monthly. When maintenance is ignored, the lint buildup – which can eventually occupy 50-75% of the duct – can cause a lot of problems

The common signs that a laundry exhaust needs cleaning include:

Of all these things, fire is by far the number one concern. The lint buildup not only creates a fire hazard, but it inhibits fusible (low melting point) links on the fire dampers inside the duct that are supposed to close during a fire to prevent the flames from spreading. If the links are coated with lint, they may not be able to melt at the proper temperature so the fire damper may not close. Air quality is another issue, you get excess lint into the air because the exhaust can’t take it out and the lint gets into the heating and air conditioning system. Lastly, if you’re not getting the right flow through your vents, the back pressure can trip a relay switch and shut your dryer off. For hotels and similar establishments, customer service can be directly affected by the lack of laundry exhaust cleaning. Slowed drying times means towels and sheets not getting to the rooms on time, particularly when the house is full.

Cleaning laundry ducts requires openings in the ducts so that lint can be removed (sometimes by crawling through the ducts). Even though building codes require that most laundry ducts be initially installed with such “access doors,” occasionally one or a few may need to be added so a thorough cleaning can be done. (We have found that those who install the ducts do not necessarily know how much access is required for proper cleaning.)

In essence, there are plenty of good reasons for maintaining the exhaust systems in a commercial laundry setting. A regular cleaning schedule is part of any recipe for a smooth-running operation.