Ventilation fans have been a mainstay in the fire industry for many decades, and during that time, these fans have evolved considerably. This article looks at the evolution of ventilation and its impact on UK firefighting.
Initially, ventilation fans were utilised in negative-pressure applications, but in the 1980s, field testing showed positive-pressure ventilation (PPV) to be more effective. In search of greater output and easier set-up, many fire departments switched from electric- to petrol-powered fans during this time, especially on first-responding engines. The electric fans of this era flowed 5,000 to 6,000m3 per hour, while a petrol blower could easily exceed 14,000m3 per hour. Petrol blowers also eased set-up, eliminating the use of extension cords and the need to identify an appropriate power source.
However, with these higher-output fans came other pitfalls – size being the biggest one. Many of the petrol-powered fans were extremely heavy and required considerable apparatus compartment space. In the UK, where space comes at a premium, these fans only compounded the storage problem. Moreover, these fans were known to be noisy and often contaminated storage compartments with their petrol 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 improved drastically, making these fans more clean, quiet, portable and reliable than ever. In fact, earlier this year, Super Vac introduced a new battery fan, powered by DeWalt or Milwaukee lithium-ion batteries. This fan is one of the most versatile platforms because these batteries are interchangeable with many other power and rescue tools found on today’s trucks. Super Vac also managed to find a way to deliver an AMCA-certified 18,400m3 per hour with this compact fan, making this a viable replacement to gas fans. AMCA, the Air Movement and Control Association, is a true third-party airflow certifier with a PPV test known as AMCA 240. For more information, see amca.org.
Here’s a look at how battery fans are revolutionising the fire-ventilation scene:
Reduction of noise pollution
Noise is one of the major drawbacks associated with ventilation, which is especially true of petrol-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 battery fans. The decibel reading for the Super Vac V18-BD and V18-BL produces an 85dB reading at 1m in front of the fan, and 75dB from 3m, which is only slightly louder than the sound a shower makes. With these quieter fans comes improved communication.
Portability and easier set-up
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. Take for instance Super Vac’s new battery fan. This lithium-ion technology can operate for up to 45 minutes at maximum airflow on battery power before electrical hook-up is required, while the fan’s built-in wheels and handle add manoeuvrability.
And with this added manoeuvrability comes more PPV fan use. We are now realising that PPV fans can be utilised for more than just salvage and overhaul operations. Many fire departments are using fans to pressurise 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 2–3m) of the structure entrance to achieve the required airflow, which often is an encumbrance to firefighters as they access the building. That, however, isn’t the case with Super Vac’s new fan. After undergoing AMCA testing, Super Vac determined its battery fan delivers maximum output (18,400m3 per hour) when positioned 5m away from the door, lending more room for charged hoses and working crews.
A breath of fresh air
Many fire departments employ petrol-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.
Minimising storage constraints
Storage space comes at a premium on UK 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. At just 21kg and 66 x 66 x 30cm, the Super Vac battery fan is super compact and can actually be stored on its side in shelf-style compartments.
Overall, with all that said, ventilation is a critical factor in effective fire-ground 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 UK firefighting tactics.
For more information, go to www.supervac.com
About the Author
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, Dave has authored numerous firefighting articles. Currently, he is a Structural Protection Team Member at the BC Fire Commissioner’s Office.
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