Dryer Vent Inspection
Dryer vent code compliance issues are responsible for a wide variety of complications and fire hazards. After the National Fire Protection Association released a report stating that metropolitan fire departments responded to an average of 15,970 home fires, caused by dryer related issues, each year between the years 2010-2014, mainstream media and other news networks have been proactively spreading awareness of the household fire hazard. Prevention of a fire, or other dryer vent related complications, starts with an inspection. Taking a closer look, with a knowledge of the code requirements and safety hazards is half the battle. In this article, we’ll get into the details of conducting a dryer vent inspection and explain exactly what we look for when we inspect our customer’s dryer vents. If you’re located in or around Nashville TN and would like a quote on a dryer vent inspection, you can send us an email or call us here.
Full List of Dryer Vent Code Compliance Issues & Safety Hazards
- Plastic Flexible Transition Hose – This code violation is a big fire hazard and should be resolved immediately. No section of the vent should be plastic with the exception of the exterior dryer vent cover. Only metal UL Listed (2158A) flex hosing should be used as a flexible transition duct and should be less than 8 ft in length and not concealed.
- Concealed Flex Hose – If you have flexible transition hose being used in a crawlspace, attic, or running between a wall or ceiling, this is a code violation. Many times, flexible hosing can trap lint in the inner ridges, get easily punctured by small creatures and/or disconnect. Any section or your dryer vent which is concealed should be galvanized steel hard pipe.
- Restricted Duct – Your dryer vent should not be restricted in any way (crushed, compressed, bent or clogged with lint and debris). This can cause airflow restrictions and is a safety hazard.
- Duct Tape – If any section of your dryer vent has duct tape this is a violation of code and should be replaced with UL Listed-FX flex tape (for flex hoses only) or UL Listed-181 connector tape. Duct tape is great for most things but when it comes to dryer vents it begins to dry out and fall apart with time.
- Connector Screws – Dryer vent connections shouldn’t have any type of screws that protrude into the duct. This can cause lint to get snagged on inside of the vent and cause a hazardous blockage and is a code violation because of this. As mentioned above, only UL Listed connector tape should be used to secure the connections.
- Disconnected Vent – Your dryer vent should be securely connected at all points and venting the moist, hot air through an exterior wall of your home. Disconnected dryer vents that are exhausting air within your home are a hazard to your health and a code violation.
- Too Close to Opening – Dryer vents should terminate no less than 3 ft from an opening of your home (door or window) according to codes.
- Screens – If your dryer vent has a screen installed, in line with the duct, at any point in the system, this poses a serious fire hazard because screens accumulate lint and debris and can block airflow from the dryer exhaust. This code violation is particularly problematic and something we see all too often.
- No Vent Cover/Damper – You dryer vent should have a back draft damper or exterior vent cover installed.
- Combined With Another Vent – Your dryer vent should be stand-alone and should not be connected to another vent of any type.
- Wrong Size – According to code your dryer vent should be 4 inches in diameter and no less than 0.0157 inches thick.
- Incorrectly Secured – Code requires your dryer vent to be installed with metal hanger straps supporting it at intervals of no more than 12ft long.
- Too Long – The maximum length of a dryer vent, according to codes, should not exceed 35 ft including elbows (Each standard 90 elbow is equivalent to 5 ft and each 45 degree elbow is equivalent to 2.5 ft in length). Transition ducts are not included in this measurement.
Our Dryer Vent Inspection Process
So now that you know what we look for when conducting a dryer vent inspection, let’s briefly talk about the process. The first thing we check when inspecting the dryer duct is the flexible transition duct behind the dryer. To do this, we typically pull the dryer out and ensure that the duct is the correct material,/length and isn’t crushed, damaged or disconnected.
Next, if the vent runs between a wall or ceiling we use a camera to inspect the inside of the vent and check the type of material and make sure there are no screws or other possible obstructions. If it’s a ground level dryer vent we simply enter the crawlspace to get a closer look. It typically takes only a few minutes for us to quickly inspect the vent and ensure that there are no code violations (screws, duct tape, disconnects etc).
Lastly, we turn the dryer on and check the exterior vent cover whether it’s on the ground level, over 20 ft high, or on the roof. We ensure there are no screens and the correct 4″ dryer vent cover is installed with out any possible restrictions to the airflow. Then we check the airflow using an anemometer to make sure the airflow is at least 1100 FPM (feet per minute).