A Super Vac representative discusses how to calculate air changes per hour in this Central Alabama Training Solutions firefighter ventilation training video. In the fire industry, it’s generally accepted that 10 air changes are required to properly ventilate most rooms, fully removing the stagnant air from all of the room’s corners. This video demonstrates a Super Vac battery fan in use, while Regional Sales Manager Gary Wilkins provides this insight. Below is the video transcription:
A lot of you have already seen the Super Vac battery fan today and heard us talk about it. We wanted to set up a final demonstration before you all go home. What we have set up here is a display of setbacks on the fan. This here is a prime example of where you really need that extra distance.
Our fans are designed with a StreamShaper guard as standard. We’re going to give this fan a 15-foot setback because as you can see, we’ve got that L-ramp coming up to the door, so you can’t set a fan up right there.
So that extra distance allows you to set up straight on to the doorway. It gives you a chance to clear the doorway for the handline crews and everyone going in and out. We’ve got it set back and when you turn it on, it does not have to be right on the doorway in that instance. It’s battery-operated, variable speed.
You’re just simply going to turn it on with the on-and-off switch. You’re going to still be able to adjust your tilt angle, making sure you’re sealing the doorway. Behind it, you can see how we’re effectively ventilating out of that hole. We’re clearing that smoke, so you can get in for salvage, overhaul search and all your other functions on the fire ground.
The fans blow 10,840 cfm. That number actually means something. That’s just not a number we’re sitting here talking about. You can take the cubic volume of space inside this burn building, cubic volume, being your length, width and height of your walls to determine how much stagnant air is inside of this building at the time.
It’s generally accepted that it’s going to take about 10 exchanges of air to completely clear a structure. If it’s 10,840 cubic volumes of air in a structure, and a 10,840 cubic volume fan, it’s going to take 10 minutes to ventilate.
That’s where that number really plays in. We’ve talked about the different sizes of fans and different numbers. We’ve got a calculator available on the Super Vac website. It will actually break it down a little bit more for you. In general terms, a 1,200-square-foot home with standard 8-foot walls will take about one minute longer for every 1,000 CFMs.
That can let you know how long it’s going to take to clear all of that smoke out and to get it clean enough to go in there. The nice thing about battery-powered fans is we’re not putting any CO into this building right now. You’re clearing that out without compromising firefighter safety. With gas-powered fans, you’re clearing out that smoke, but you’re adding other cancer-causing agents back to the area. These are things to keep in mind. Again, we sell everything from negative pressure fans, gas fans, battery fans to electric fans, so we have a solution to meet every need.