Crawl Space Exhaust Fan System


  • Portable Crawl Space Fan-1,115 CFM on high
  • Air is exhausted through a 10” duct and out a 8”x16” foundation vent
  • Moves air from the crawlspace to outside the crawlspace
  • Frame made of durable ABS plastic
  • The frame and base easily slips apart for entrance into crawl space
  • Equipped with a 9’ cord
  • Has a three speed controller and uses 115 Volts, 0.88 Amps
  • No costly electrician needed!
  • Meets OSHA standards
  • Has an OHSA approved grill around the fan blades
  • Motors are energy efficient and totally enclosed for moisture areas
  • Has a corrosion resistant frame
  • Humidistat, rain detector, thermostat and weather station sold separately. See
  • Fan Controllers
  • Stands 22″ tall when assembled
  • Houses a 12″ fan


Crawl Space Exhaust Fan System

by Crawl Space Door Systems, Inc.

Why do I need crawlspace ventilation?

Crawlspace Portable Exhaust Fan System for foundation ventilation

Portable Exhaust Fan System

The presence of moisture is what leads to
mold, which can be bad for your health and
costly to remove. According to the Environ
mental Protection Agency, the way to control
mold is to control moisture. The main source
of crawl space moisture is ground evaporation, and ventilation allows this evaporation to
dissipate. Proper ventilation exhausts moisture from the crawlspace and replaces it with fresh, drier air—providing effective moisture control. Ventilation also helps to remove strong odors and dangerous radon gas from the crawlspace. For further reading take a look at our Why Ventilate the Crawlspace page.

What is a portable exhaust fan system?

The Portable Exhaust Fan System converts our Portable Fan to an Exhaust Fan to help pull unwanted moisture out of the crawlspace. The Portable fan is connected to a 10” - 2ply - double walled -flex duct and to a 8"x16" foundation air vent to newly designed duct connectors. Evacuating air from the crawlspace removing radon, odors and moisture from under the house.

What is CFM?

CFM means Cubic Feet per Minute. CFM helps determine what size fan will suit your crawlspace ventilation
needs. When purchasing a fan you want to know how much air the fan will move. Air movement is measured in CFM. To calculate the volume of air in the crawlspace you multiple the height x width x length of the crawlspace. For example, if your crawlspace is 40’ long, 20’ wide and 3’ high the vol ume on air in the crawlspace is 2,400 (40x20x3) cubic feet. If you want to replace all of the air in this crawlspace every 4 minutes you need a 600 (2,400/600) CFM fan.

What is the benefit of using a Fan Control System?

Portable Exhaust Fan System with Controller

Portable Exhaust Fan System with Controller

A fan control system has various components, including humidistats (instruments for measuring and controlling humidity) and a thermostat. The fan control system turns the fan on and off. The fans can be controlled to come on when the crawlspace humidity reaches a certain preset amount. Similarly, they can be set to not come on if humidity is higher outside the crawlspace than inside the crawlspace, or when the temperature in the crawlspace is cold enough to freeze pipes. See our fan control products.

When I am finished using the portable fan exhaust system, what other uses can the various parts provide me?

The portable fan can continued to be used to move "dead air" in the crawlspace.

The 8”x16” manual air vent can still be used to ventilate the crawlspace, providing 95 NFA-double most air vents on the market.

Additional information

Weight 24.00 lbs
Dimensions 25 × 25 × 25 in

Portable Exhaust Fan Systems Videos