By Alan M. Petrillo
Almost every first-due apparatus carries a ventilation fan of some sort on the rig, and often fire departments have special compartments designed on their pumpers, aerials, and rescues to accommodate an assortment of ventilation equipment.
The types of ventilation fans available today range from gasoline- and electric-powered units to hydraulically powered blowers that use the water flow from a hoseline to move volumes of air.
From Ejector to Positive Pressure
Roger Weinmeister, president of Super Vac, says since the mid 1990s there has been a strong push among fire departments toward using positive-pressure ventilation (PPV) equipment and away from traditional smoke ejectors. “That trend reached a high point about 10 years ago and now is moving more toward electric-powered fans with big motors,” he says. “Gasoline-powered fans require a lot of maintenance,” he notes, which is one of the chief reasons for the swing toward electric motors on positive-pressure fans, along with a movement toward variable speed motors. “The nice thing about a variable speed fan is that it can fake out normal 60-cycle electricity and make the fan run faster on its variable speed, which gives the fan a little bit more push and makes for a higher-capacity fan,” Weinmeister points out. He maintains that variable speed fans make up the bulk of the electrical positive-pressure fan market today.
|A firefighter sets up a Super Vac electric PPV fan at the entrance
to a building. (Photo courtesy of Super Vac.)
Weinmeister estimates that a variable speed fan can increase the fan’s capacity by 30 to 40 percent. “A typical motor runs at 1,700 revolutions per minute (rpm), but with a variable-speed motor, you can get up to 2,400 rpm for the same size motor,” he notes. “The higher speed gets you better performance.”
Super Vac’s most popular electric positive-pressure ventilation fan is its VR3. Its biggest seller has a 6½-horsepower (hp) Honda motor with an 18-inch fan that displaces 15,500 cubic feet per meter (cfm) of air. Its next most popular fan is a 20-inch-blade model with the same horsepower motor but a larger shroud that can push up to 18,500 cfm.
Smoke ejectors are still used by a lot of fire departments, Weinmeister says, and are the right way to go in a lot of situations, especially where there is limited egress. “A smoke ejector used the right way to vent can pull fresh air from all over a building and exhaust it where the seat of the fire was located,” he observes.
Weinmeister recommends that fire departments choose the largest fan that will fit easily into a compartment. “You want to move the most air possible,” he notes.
He says that his company has battery-powered ventilation fans that it is excited about. “They give firefighters the ability set up a vent without a generator or power cords and will push almost as much air as a gasoline-driven fan,” he says. “They’ll run about 20 minutes, then can be supplied off a cord from the fire vehicle.”
Allowing for Entry
James Neils, chief executive officer of Ventry Solutions Inc., notes his company makes both gasoline and electric PPV fans that can be used for aggressive attack to remove smoke from a structure to allow fire crews to make entry. “Our fans allow firefighters to set up about 10 feet outside of a building and shoot air into the structure to clear the air,” Neils says. “We make eight gas-powered models and one electric version.”
|Super Vac’s most popular gasoline-driven PPV fan is its GXi series that uses a Honda GX engine. (Photo courtesy of Super Vac.)|
The 1½-hp electric model puts out 12,060 cfm, Neils points out, while Ventry’s smallest gasoline model is a 3½-hp version that moves 16,500 cfm. The company’s largest gas-powered positive-pressure ventilation fan moves 29,500 cfm, he says. The models weigh from 50 to 82 pounds.
Joan Rodman, Ventry’s marketing manager, says the company’s fans have three major attributes: a set of three legs to allow the fan to be aimed where the flow needs to be directed, an open flow guard made of metal wire heavily reinforced to allow air to reach the propeller, and an aircraft-style safety propeller specially designed for each motor to move the maximum air volume.
Neils adds that the propellers are manufactured in small batches with a fiberglass and Kevlar shell bonded over a wooden core. “We end up with a very strong, lighter, and safer propeller that’s more efficient and smaller in terms of the overall size of the fan,” he says.
Johan Gidspedt, president of Tempest Technology, says his company’s main focus has been on PPV technology and makes three types: belt-drive, direct-drive, and electric blowers. “Our gasoline-powered blowers seem the most popular, although electric blowers are gaining in popularity,” Gidspedt points out. “Electric power blower technology has caught up with gasoline power, so they’re almost comparable today.”
Curt Johnson, Tempest Technology’s sales director, says a lot of fire departments are putting the gas-fired positive-pressure fan on a rescue or an aerial and an electric model on a pumper, which often is the first piece of apparatus at a fire scene. “The electric PPV also has proven to be very popular in confined space work,” Johnson adds.
|Ventry Solutions Inc. makes the gasoline-powered 20GX160 (shown with legs extended) and the electric 20E1.5GFCI 1.5-horsepower models. Both have 20-inch propellers. (Photo courtesy of Ventry Solutions Inc.)|
He notes that Tempest has found departments are buying the smaller 16- or 18-inch variable speed electric units for pumpers, about the size of a standard smoke ejector, while with gas powered blowers, they are looking for capacity and tend to go with the larger 21- and 24-inch size PPV fans.
Gidspedt notes that Tempest Technology uses composite materials in some of the fabrication of its units, notably in the legs. “Our PPV legs are made of composite materials, which is done with weight in mind,” he notes. “We also have saved some weight using aluminum shrouds on our units.”
Johnson adds that the company released a new Special Operations power blower in seven models this year, designed with a shroud that creates a cone of air to seal in a fire building doorway. “It creates a laminar air flow instead of a broad cone shape,” Johnson says. “The focused shape crams more air into a smaller surface area, enabling us to build up a higher pressure and allow up to a 10-foot setback, instead of six to eight feet. It’s useful in high-rise structures where firefighters need to pressurize a stairwell and in larger structures of 5,000 square feet or more, like warehouses.”
|Euramco Safety makes its PowerStream PPV fans in both gasoline-driven and electric models. (Photo courtesy of Euramco Safety.)|
Effective Farther Away
Wayne Allen, president of Euramco Safety, says his company makes the GF165 model of PPV fan in 16-, 21-, and 24-inch models. “PowerStream is our new line of PPV fans in both electric and gasoline versions,” Allen notes. “GS is our gas version and the EX series is electric.” Allen adds that Euramco also sells “legacy blowers, which are put up close to the door.”
Although legacy products have to be placed about six feet from a door opening, Allen says Euramco’s PowerStream can be placed from 14 to 16 feet away from a door opening and still operate effectively. “The PowerStream drops the energy of the noise by half and dramatically increases the amount of open area for ingress and egress without disrupting the fan operation,” he says.
Allen notes that Euramco is launching a new category of large structure ventilation units this year. “It uses an off-the-shelf Honda engine of 20 to 25 hp,” he says, “with a 28-inch blower that’s able to be maneuvered close to the building on a small, lightweight trailer.”
|A Lehi (UT) Fire Department firefighter sets up a Tempest Technology gasoline-driven PPV fan during a training exercise. (Photo by Lehi Battalion Chief Rick Howard.)|
Steve Ibbotson, director of operations for Leader North America, says the most popular versions of his company’s ventilation fans are the 18- and 24-inch gasoline-driven positive-pressure fans. “Gas has always been the most popular, but the use of electric PPV fans has seen a resurgence,” Ibbotson says. “This has been due mainly to concerns about carbon monoxide emissions.”
Leader’s most successful model has been the 18-inch, 5½-hp MT236 version, Ibbotson says, although there has been recent movement toward Leader’s larger MT 240, a 6½-hp, 24-inch fan model.
Ibbotson notes that the big challenge with electric fans always has been their performance when measured against gasoline-driven PPV fans. “But with the introduction of our LeaderCAT (catalytic converter), the virtual elimination of carbon monoxide means the only consideration is the performance required of the fan,” he says.
Ibbotson says that Leader’s straight stream air flow engineering means that a much smaller ventilator with a smaller motor will deliver more PPV performance than larger conventional fans. “The combination of the pressure and volume of air off the ventilator and the entrained air allows us to use much larger fan blades,” he points out, outperforming conventional fans.
|Tempest Technology’s gasoline-powered PPV fans are often carried on aerials and rescues, like this 21-inch model. (Photo courtesy of Tempest Technology.)|
Fans also can be set back farther than traditional fans because of this technology, Ibbotson maintains, and have an automatic tilt at 10 degrees to ease in the setup, an ergonomic design for safe handling, and a double layered shroud for a high level of user protection and durability.
ALAN M. PETRILLO is a Tucson, Arizona-based freelance writer and is a member of the Fire Apparatus & Emergency Equipment editorial advisory board. He served 22 years with the Verdoy (NY) Fire Department, including in the position of chief.