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Gone are the days that dryers could be vented directly through an exterior wall with just a few feet of straight duct. Buyers now expect conveniently located laundry spaces — but these location preferences come at a cost.

Typically, second-story laundry spaces or those in close proximity to bedrooms require longer dryer exhaust runs. Length isn’t the only issue though; these exhaust runs also require more bends and turns than most clothes dryers are designed for.

This is problematic for everyone involved — builders, contractors, even homeowners. Longer exhaust runs reduce dryer efficiency, extend drying time and make it challenging to comply with the building code. 

Added Challenges with Strict Building Codes 

The 2012 International Residential Code (IRC) specifically states that a dryer exhaust duct system cannot exceed 35 feet from the dryer location to the wall or roof termination. Plus, each elbow in the duct reduces the maximum allowable length by 5 feet. 

Adding to this, each dryer has its own specification for exhaust duct length. Although restrictions vary based on the particular model’s capability, most are limited to a duct run of 35 feet.

While these restrictions may seem strict, the consequence of stretching an exhausts’ capability can be deadly. Long exhaust ducts are more susceptible to lint buildup within the ductwork, which causes 2,900 clothes dryer fires annually. 

A properly applied dryer exhaust fan, preferably one that is UL Listed, may be the only solution that makes everyone happy – including the home inspector and the local fire chief. 

How Dryer Exhaust Fans Solve the Problem of Long Duct Runs

If you have more than 30-40 feet of dryer exhaust duct, the best way to meet the code and reduce the risk of fire is to use a dryer exhaust fan. Here’s how it works:

1. Increase Exhaust Lengths

While most dryer specifications are fairly restrictive, some dryer exhaust fans can safely increase the duct run up to 130 effective feet. The fan keeps the air moving in the duct at the proper velocity, allowing the dryer to work efficiently. 

2. Ensure Consistent Airflow

The leading cause of home fires is from lint ignition in the dryer or dryer duct. Dryer exhaust fans reduce the risk of link buildup and fire by maintaining airflow that keeps lint suspended while exhausting it to the outside.

3. Monitor Lint Buildup

Select dryer exhaust fans actually monitor pressure increases from duct blockage, notifying users when it’s time to clean the dryer exhaust duct. Periodic inspection and cleaning help ensure long-lasting use and safety.

Dryer Exhaust Duct Power Ventilators That Go a Step Further

Any dryer exhaust fan is better than none, but Fantech’s UL listed Dryer Exhaust Duct Power Ventilator (“DEDPV”) goes added lengths to ensure safety.

Its visual indicator panel notifies homeowners and professionals alike if lint buildup occurs. This way, preventive measures like cleaning and maintenance can reduce the risk of dryer fires. If a dryer fire does occur, the DEDPV automatically shuts down the fan to prevent spreading the fire further.

In addition, the DEDPV features a patented pressure sensing switch that automatically turns the DEDPV on when the dryer is operating so homeowners never neglect using the fan. Plus, its airtight, galvanized steel housing ensure no leakage into the building while the fan is operating.

Watch as our ventilation experts break down how the DEDPV works.