We get this question a lot from friends and family. As much as we'd like to instinctively answer "YES!", the fact is most people will likely never have their vent cleaned. This is because we are usually only called to a customer's home because their dryer taking too long to dry or getting to hot, and in some cases has actually broken. It's frightening to think about how close to starting a fire their dryer may be at this point (the common household dryer can reach temperatures of nearly 475 degrees fahrenheit), but what if you are not actually experiencing issue with your dryer? Let's start by examining the consequences of an even somewhat dirty dryer vent...
A dryer is a fairly simple appliance, it consists of a tumbling drum which can heat to very high temperatures and a fan which vacuums the moisture from inside the drum out through the dryer vent. Though all dryers have built in lint traps, these only capture a fraction of the lint produced by the dryer. Typical dryer ducts are built using 3 or 4 inch wide pipe inside of the wall and are generally not supposed to be any longer than 30 feet. The longer the duct the more likely the exhaust flow is to be constricted. Traditionally, vertical vents which exit through the roof tend to clog more easily with lint because the lint is not likely to exit through the roof and builders likely use constricting vent caps to keep birds and rainwater out. IF YOU KNOW YOUR VENT EXITS THROUGH THE ROOF AND YOUR HOUSE IS ANY MORE THAN 8-10 YEARS OLD YOU ABSOLUTELY SHOULD HAVE YOUR VENT CLEANED FOR SAFETY ALONE! This is not to say even new homes may not also need their vents cleaned, many times households with several children or pets run the dryer several times a day which will inevitably lead to a clogged vent.
Now let's look at the secondary cause of a clogged dryer vent and a dryer that's working too hard. Most modern dryers operate using sensors that detect whether or not the clothes is dry or not called "Auto-dry" or "Sensor dry". This means if your dryer vent is not allowing the moisture and humidity to escape properly the dryer will literally tell itself to get hotter and dry longer, or turn off their burner which will effectively mean the laundry is tumbling cold. This translates over directly to more electricity and more money! Just how much money?
This means your clogged vent may easily be costing you an extra $15-30 a month, shorting the life of your expensive dryer and most importantly, posing a MAJOR fire hazard!
In a nutshell, do you HAVE get your dryer vent cleaned? The only thing you have to do for your home is pay your mortgage and utilities but if you want to make sure your machine is running efficiently and not putting you our your household in danger then yes you should at the minimum have your dryer duct thoroughly cleaned every 2-3 years and inspected annually.