← All Blogs

How To Clean Out Dryer Vents


An integral part of the laundry process is the clothes dryer and as such, plays an essential role in finishing the laundry for the day. However, whenever the drying process starts to get longer by the day, it is time to look for the cause. The likely culprit in most cases is a restricted or blocked dryer vent causing a lack of proper air flow. Let’s look first at the typical causes for long dry times, and how to clean out a dryer vent.

Airflow Restriction

All clothes dryers operate on the concept that to dry clothes, fresh air, heat, and movement all need to happen at the proper time. One analogy is to remember back when people used clotheslines to dry their laundry. The sun represents the heat source, the breeze is the fresh air, and the movement is that caused by the breeze. These three things essentially describe the operation of a dryer.

When dry times increase over time, and the clothes never seem to dry, the most common cause is a lack of airflow between the back of the dryer where the vent connects, and the end of the vent, probably an outside wall or the roof.

Referring to the analogy earlier, the breeze, or airflow, forces the moisture in the clothing to dry up when combined with heat and movement of the garments. When the airflow component is missing, the clothing still feels warm to the touch but damp due to this lack of airflow.

Cause of Long Dry Times

As the airflow restriction worsens, dry times become excessive, sometimes taking two or more timed dry cycles to dry the clothes which is unacceptable and expensive. The reason for long dry times is a direct result of poor airflow through the dryer in almost every case. Of course, if the dryer does not produce any heat, in which case the clothing is always cold to the touch, a different cause for the long dry times exists.

Modern dryers use thermostats and moisture sensing technology to help determine the level of moisture content in clothing and proper heat levels. During the drying cycle, the garments contact the moisture sensing strips inside the dryer and send a signal to the control of the dryer. The control uses the information and determines when or if to turn the heater on, or to turn it off.

As the moisture level decreases, the estimated time remaining changes and eventually, the dryer stops, indicating the end of the cycle. Presumably, the clothes are dry. In the case of restricted or blocked airflow, many dryers continue to produce heat, causing a damp feel to the clothing. The result of extended dryer use in this condition eventually causes one or more of the over-temperature protection devices to trip that will either shut down the dryer or allow the dryer to run, but with no heat.

How to Clean Out a Dryer Vent

Sometimes, a damaged or crushed dryer vent, “transition hose”, at the back of the dryer creates an airflow restriction which produces the dreaded long dry times scenario. Depending on the type of vent used, reforming a metal vent into a perfect circle is a simple fix, and if the entire vent system is clear and lint-free, dry times should immediately return to normal.

The use of 4” metal vent meets most dryer specifications. Metal withstands the high heat produced by dryers, and it will not dry out and crack like the plastic or vinyl hose does. Before starting to clean the vent, some necessary tools should be close at hand until they are needed. Here is a list of the tools required:

Important Note: Due to the high possibility of personal injury while climbing ladders, extreme caution must be exercised. It is strongly recommended to hire a skilled professional technician accustomed to this type of work.

  • A low to medium velocity blower/vac typically included with a residential wet-vac. High-velocity air blown into the vent could blow the vent apart inside the walls and too high-velocity of suction could pancake or compress the dryer vent inside the wall. Damage to the vent inside the walls could occur because it may have been installed incorrectly or the wrong type of material was used, like; the wrong type of tape to connect and seal the joints, aluminum duct or vinyl hose instead of a galvanized steel duct and/or the wrong size duct (usually 3” instead of 4”).
  • Extension ladder to reach the dryer vent’s termination point (in North Texas, usually on the side of the home, between the two levels with a two-story home and typically on the roof of a single-story home). The end cap or “termination hood” of the dryer vent is often packed with lint and might be the cause of the blocked airflow. Also, if the wrong type of vent cap was installed it is possible that birds or other animals could build a nest just inside the vent cap or vent termination hood.
  • 4” inch diameter rigid or semi-rigid transition hose in the proper length. Never use plastic or vinyl vent. Both are flammable and susceptible to becoming brittle over time and cracking. If a dryer fire occurs, the metal vent will not burn, but plastic and vinyl do.
  • A 4” diameter brush and rods to move through the entire length of the dryer exhaust duct, which will help loosen the lint that has been cooked and crusted onto the walls of the vent pipe over the years. Without this “agitation” you may suck up or blow out some loose lint from the dryer vent, but the majority of the lint will remain.
  • Breathing masks and other types of breathing protection as necessary.
The tools listed above provide a basic set of tools for a simple vent cleaning procedure. However, not all jobs are quick and straightforward. Some jobs require extensive work and should not be attempted by those who are not versed in the correct procedure in how to clean out dryer vent.

On to the necessary steps of the cleaning procedure:
  • Remove the vent from the back of the dryer and the wall.
  • Remove the end cap of the vent located either on the roof or side of the home, typically, and set aside for now.
  • Use the blower to blow air into the vent system from the inside of the house. Be prepared for a significant amount of lint to fly out of the vent!
  • Inside the house, vacuum up any loose lint and install new vent if desired or necessary.
  • Allow the dryer to run for at least five minutes to blow any loose lint from inside the vent to the outside.
  • If the airflow and vent operate normally now, reinstall the end cap.
Learning how to clean dryer vent duct represents considerable savings in electricity and gas usage over time due to the increased efficiency of the dryer and cuts down on costly repairs as well. Additionally, a fresh load of clean clothes from a properly running dryer does not have a musty smell due to excessive moisture from a restricted vent.

Awareness of the importance of keeping the dryer vent clean and free from debris is helping people realize that an efficient dryer is one of many smart techniques homeowners use to keep their expenses in check. The cost of preventative maintenance versus the excessive cost of wasted energy shows that keeping the laundry system operating at peak efficiency is critical.

It is recommended to keep your appliances such as your dryer in good working order, including the vent system. HomeSafe Dryer Vent Cleaning in the Dallas/Fort Worth area specializes in all areas of dryer venting. From vent cleaning to total vent restoration and customization, we do it all! All it takes to make your laundry day a pleasure again is a phone call! Call us Today on (214) 681-9848!