By Dave Rivett
Ventilation fans have been a mainstay in the fire industry for many decades, and during that time, these fans have involved considerably. This article looks at the evolution of battery fan technology and its impact on firefighting.
Initially, ventilation fans were utilized in negative pressure application, but in the 1980s, field testing showed positive pressure ventilation (PPV) to be more effective. In search of greater output and easier setup, many fire departments switched from electric- to gas-powered fans during this time, especially on first-responding engines. The electric fans of this era flowed 5,000 to 6,000 cubic meters per hour, while a gas blower could easily exceed 14,000 cmh. gas blowers also eased setup, eliminating the use of extension cords and the need to identify an appropriate power source.
But with these higher output fans came other pitfalls — size being the biggest one. Many of the gas-powered fans were extremely heavy and required considerable apparatus compartment space. When space comes at a premium, these fans only compound the storage problem. Moreover, these fans were known to be noisy and often contaminated storage compartments with their gas fumes. Additionally, these fumes could introduce carbon monoxide and other combustion products into the space being ventilated.
Fortunately, the 20th century ushered in battery-powered electric fans, and in the last few years, the technology has drastically improved, making these fans more clean, quiet, portable and reliable than ever.
Here’s a look at how battery fans are revolutionizing the fire ventilation scene:
REDUCTION OF NOISE POLUTION
Noise is one of the major drawbacks associated with ventilation, which is especially true of gas-powered fans. Noise pollution can adversely affect fire ground communication, both in close proximity to the fan and within the structure itself. But that’s no longer the case with the battery fans that are available today. Some PPV fans produce a reading as low as 85 db at 1 meter in front of the fan, and 75 db from 3 meters, which is only slightly louder than the sound a shower makes. With these quieter fans comes improved communication.
PORTABILITY AND EASIER SETUP
As previously mentioned, electric fans take more time to set up and often require the use of extension cords. With a battery fan, you only need to position the fan in front of the building entrance and then turn it on. And with the evolution of battery fan technology, the lifespan of these fans has greatly improved.
And with this added maneuverability comes more PPV fan use. We are now realizing PPV fans can be utilized for more than just salvage and overhaul operations. Many fire departments are using fans to pressurize fire attack stairwells and uninvolved areas of a structure to provide open egress for occupants and help limit the spread of fire.
IMPROVED BUILDING ACCESS
Speaking of PPV positioning, most fans must be positioned in close proximity (usually 2-3 meters) of the structure entrance to achieve required airflow, which often is an encumbrance to firefighters as they access the building. That, however, isn’t the case with some newer battery fans. After undergoing AMCA testing, these fans are capable of delivering maximum output (more than 18,000 cmh) when positioned 5 meters away from the door, lending more room for charged hoses and working crews.
A BREATH OF FRESH AIR
Many fire departments employ gas-powered fans because they are easy to set up and feature high flow rates, but the products of combustion associated with gas fans can adversely affect air quality and cause additional damage to building contents. Moreover, CO levels must be monitored when gas-powered ventilation fans are in operation, but this complication can be avoided by using a battery fan, which in turn can heighten fire crew safety.
With modern hydrocarbon-based fuel loads inside structures, smoke is much more than a nuisance factor. Smoke is fuel and can be highly flammable even in post-fire situations. The potential for smoke explosions is a reality. A battery-powered PPV with a high-flow rate is well-suited to evacuate smoke from a structure in an expeditious manner.
MINIMIZING STORAGE CONSTRAINTS
Storage space comes at a premium on the fire apparatus. Gas-powered blowers and high-capacity electric fans require considerable storage space and are often relegated to support apparatus. But modern battery PPV fans are much more compact.
Ventilation is a critical factor in effective fireground operations. There are a lot of factors that come into play when selecting a ventilation fan, and with the latest in battery fan technology, manufacturers are opening the door for an evolution of firefighting tactics.
Dave Rivett is an experienced overseas fire trainer. With more than 25 years of combined training experience, fire course design, incident command instruction and structural firefighting tactics, Rivett has authored numerous firefighting articles. Currently, he is a Structural Protection Team Member at the BC Fire Commissioner’s Office.