Petrillo, The Fire Station, The Station Articles

Fire Station Exhaust Systems

Issue 1 and Volume 21.

Manufacturers offer several systems to fire departments, districts, and emergency medical services squads in the way of station exhaust systems to remove toxic vehicle exhaust before it can become a problem in apparatus bays, station living quarters, and office spaces.

Exhaust systems for emergency services buildings fall into two categories of equipment: source capture systems that attach a hose directly to a vehicle’s exhaust pipe and hoseless exhaust removal and air filtration systems.

Hoseless Systems

Air Vacuum Corp. makes the AIRVAC 911 engine exhaust removal system, says John Koris, Air Vacuum’s regional sales manager. “It’s a fully automatic system that requires no personnel intervention,” he says, “and the system removes both gases and particulates from diesel exhaust.”

Koris says AIRVAC 911 is a ceiling-mounted filtration system that suspends two- by two- by two-foot units over exhaust points to create a direct path into and through the unit. “When a fire department gets a call, the doors open and trigger door switches that have a photo-beam backup, kicking on the system so it can pick up any backwash as the apparatus leaves,” Koris says. “When the apparatus returns, the system kicks on automatically and extracts any exhaust put into the building.”

1 The Tully (NY) Hose Company chose Air Vacuum Corp.’s AIRVAC 911 engine exhaust removal system for its fire station. (Photo courtesy of Air Vacuum Corp.)
1 The Tully (NY) Hose Company chose Air Vacuum Corp.’s AIRVAC 911 engine exhaust removal system for its fire station. (Photo courtesy of Air Vacuum Corp.)

Koris notes that Air Vacuum uses a smart timer to make the system fully automatic. “The smart timer, located on the apparatus room floor or in a utility or communications room, runs all of the units on a cycle, usually of 15 minutes, to remove all the exhaust in the apparatus bays,” he says. “It also has a manual override to turn the system on, like during cold months when you might keep doors closed but want to check chainsaws and other gas-powered equipment.”

The number of units installed in a system depends on the engineering standards for the space involved, Koris points out. “Typically, the standards for exhaust removal in a fire station call for four to six air changes in the cubic footage of the apparatus bay, so you might have one unit per bay or piece of apparatus or one unit every two or three bays.” Filter change in the units is typically based on the level of activity, Koris adds. “Carbon filters have a life cycle, and we recommend a maximum of 24 months of use for them,” he says. “The prefilter should be changed quarterly.”

12 Air Vacuum Corp. installed its AIRVAC 911 engine exhaust removal system in this station for the Westerly (RI) Fire Department. (Photo courtesy of Air Vacuum Corp
2 Air Vacuum Corp. installed its AIRVAC 911 engine exhaust removal system in this station for the Westerly (RI) Fire Department. (Photo courtesy of Air Vacuum Corp.)

Daniel Orto, president of Air Technology Solutions, says his company makes the AirMATION vehicle diesel exhaust removal system. “It is a standalone, ceiling-suspended air filtration process,” Orto says, “powered by a 3,000-cubic-feet-per-minute (cfm) direct-drive blower that pulls, directs, and removes diesel exhaust fumes.” Orto points out that Air Technology Solutions uses electrically communicated motor (ECM) technology that uses low amounts of energy. “The motor is variable-speed-low, medium, and high-that uses up to 75 percent fewer watts,” he says. “The amps max out at 4.7 amps, which is half of what most blowers use with a permanent split capacitor (PSC) motor. The ECM motor is environmentally friendly, and it’s very low energy use saves fire departments money in its operation.” AirMATION has a low-voltage timer control module that can be customized for various types of activation systems, such as photoelectric beams, and carbon monoxide (CO) and nitrogen dioxide (NO2) sensors. “The system can work with existing alarm systems,” Orto observes, “and can be set for a delayed start for hands-free operation”

The units are 24 by 24 by 66 inches in size and weigh 240 pounds. Air Technology recommends a prefilter change once a year and a change in the MERV 16A high-efficiency particle filter and the carbon-blend filter every three to four years.

Source Capture Systems

Mike Johnson, sales manager for MagneGrip Group, says the MagneGrip source capture system his company makes captures exhaust before it can enter the apparatus bay area and prevents exhaust from seeping into living areas and offices. “Our magnetic system gives a 100 percent seal around the vehicle’s tailpipe,” Johnson says. “The tailpipe adapter has holes in the back to allow ambient air to be inducted to cool the exhaust itself and a check valve around that which prevents any backwash into the apparatus bay area.”

Johnson says that MagneGrip is adaptable to any type of vehicle, manufacturer, or chassis. “We have a one-size-fits-all nozzle that is five inches in diameter, which allows more velocity and cooler exhaust flowing through the hose,” he says. “Most fire apparatus today have a five-inch exhaust, but for those six- and seven-inch exhausts, we have an expander to accommodate them and also a reducer for smaller exhaust pipes.”

3 Air Technology Solutions installed its AirMATION vehicle diesel exhaust removal system in this Richardson (TX) Fire Department station. (Photo courtesy of Air Technology Solutions
3 Air Technology Solutions installed its AirMATION vehicle diesel exhaust removal system in this Richardson (TX) Fire Department station. (Photo courtesy of Air Technology Solutions.)

The MagneGrip hose is a combination of materials made to withstand high temperatures and with a metal banded helix embedded in it for strength and durability, Johnson notes. “We have different types of hose sections: a stiffer, lower two-foot section at the tailpipe to prevent bending or kinking, then more flexible hose to the track system, which is designed to withstand temperatures to 700°F. Our new lower section hose is now rated to 1,000°F.” The system is activated when the apparatus engine starts, Johnson points out. “The exhaust blast hits a sensor to kick on the system immediately,” he says. “Or, you can have an onboard starter for when you turn the ignition key or attach a sensor to the brake lights because you put your foot on the brake when you start the engine.”

Typically, MagneGrip has one fan per bay area, sized by how many hose drops are needed. The hoses are hung on either a sliding track system that uses dollies running inside an H track or a six-inch aluminum tube rail system used for door-to-door coverage or when hooking up vehicles in tandem. Johnson says that as the apparatus pulls out of the bay, the hose follows along on the track or rail system, and at a certain point a steel cable inside the hose peels the nozzle off the exhaust pipe and remains in place until the vehicle returns. At that point, a firefighter has to push the unit down onto the exhaust pipe, allowing the vehicle to back into the bay, taking the hose with it.

4 The Monarch (MO) Fire Protection District chose a Fume-A-Vent source capture exhaust system for its fire station. (Photo courtesy of Fume-A-Vent
4 The Monarch (MO) Fire Protection District chose a Fume-A-Vent source capture exhaust system for its fire station. (Photo courtesy of Fume-A-Vent.)

MagneGrip also makes an air purification system, the Air Hawk, a ceiling-hung unit that circulates air in an apparatus bay area through a four-stage filter.

Dan Schroeder, sales manager for Fume-A-Vent, says his company’s system “is simple and maintenance-free that is 100 percent source capture without moving parts.” Fume-A-Vent runs ductwork through apparatus bays at the ceiling level, and at the end of each duct is a drop that lines up with an apparatus tailpipe in a parked position, Schroeder notes. “A sensor senses the change in pressure in the exhaust system and kicks on the system,” he says. “The apparatus pulls forward, and when it reaches the end of the hose length, the tailpipe adapter automatically pulls off and snaps back into position while the system runs. There is no filtration because the source capture exhaust is pulled by fans and pushed through the ductwork and into the outside atmosphere.”

Schroeder adds that when the apparatus returns from a call, “the officer gets out, the apparatus backs into the bay, and the officer connects the hose to the tailpipe. There are some fumes put into the bay until the apparatus is in its resting position, but the engine is burning hot and clean at that time.”

5 The tailpipe adapter on the Fume-A-Vent system snaps off the tailpipe when the apparatus pulls forward and reaches the end of the hose length. (Photo courtesy of Fume-A-Vent.)
5 The tailpipe adapter on the Fume-A-Vent system snaps off the tailpipe when the apparatus pulls forward and reaches the end of the hose length. (Photo courtesy of Fume-A-Vent.)

Bryan Reeves, technical program manager for Plymovent Corp., says his company offers pneumatic and magnetic source capture systems as well as a vertical stack rail system for vehicles with overhead exhaust stacks. “The pneumatic system incorporates an inflatable grabber nozzle that inflates around any exhaust pipe,” Reeves says, while the magnetic system uses “a magnetic grabber that securely attaches to the exhaust tailpipe-essentially an extension of the tailpipe to the outdoors.”

The vertical stack system is the simplest system of all in that there is no hose or nozzle to hook up, Reeves notes. “The vertical exhaust stack gets an adapter at the top, which allows the exhaust pipe to slide into the suction rail where the exhaust is moved outside as the engine starts and the exhaust fan is energized,” he says.

6 The Fume-A-Vent system runs ductwork through apparatus bays at ceiling level with drop-downs for each apparatus tailpipe. Fans push vehicle exhaust through the ductwork to the outside atmosphere. (Photo courtesy of Fume-A-Vent
6 The Fume-A-Vent system runs ductwork through apparatus bays at ceiling level with drop-downs for each apparatus tailpipe. Fans push vehicle exhaust through the ductwork to the outside atmosphere. (Photo courtesy of Fume-A-Vent.)

When a vehicle activates a system by starting, a fan is automatically energized, Reeves says. The vehicle then leaves the bay, with the grabber nozzle automatically releasing near the door threshold. “The fan stays on for a predetermined period of time and turns off automatically,” he points out. “It turns on again when the vehicle comes back to the station and the nozzle is again attached to the tailpipe.”

ALAN M. PETRILLO is a Tucson, Arizona-based journalist 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.

F.I.E.R.O. Fire Station Design Award Winner