AIR TURNOVER RATES AND THEIR REQUIRED VENTILATION
It seems like the only constant these days is change. Don’t believe me? Take a look at your cellphone. There was probably a time not long ago when it was the latest and greatest tech gadget ever released. Now, it’s likely been replaced by one or two updated versions, with features you wish yours had! But change isn’t necessarily a bad thing, especially when it comes to proper ventilation. Getting the right amount of fresh air moving through your facility is vital to your employees’ safety and productivity.
So, how do you accurately calculate your ventilation needs? It starts by determining the rate at which you need to completely replenish the volume of air in a given room. This is known as an air turnover (or air change) rate, and is usually expressed as minutes per air change (although it can sometimes be seen as “number of air changes per hour”). The number of air changes needed ultimately depends on the type of facility or the work being done in a particular area. For example, a typical warehouse should have an air change approximately every 7 minutes, though this can vary between 4 and 10 minutes. By contrast, a welding room needs to replenish its air at a rate of every 3 minutes to protect employees against heat buildup and noxious fumes.
Once the air change rate is determined, we can proceed with our calculation. For purposes of this article, we’ll make the math easy (because….hey….who doesn’t love easy math?!). Let’s say you have a 100’ x 100’ building with a 10’ ceiling height. Based on the work being done, we’ve decided on an air change every 5 minutes. Your calculation would look like this:
100’ x 100’ x 10’ 100,000 ft3
5 minutes = 5 minutes = 20,000 CFM
Based on our calculation above, you would need to move 20,000 cubic feet of air per minute (CFM) through your facility in order to achieve a complete air change every 5 minutes.
Now that you know your ventilation needs, what’s next? Why not call Patterson? They have the people and the products to help you build the ventilation system of your dreams! You’ll be the envy of the industrial park, and your employees will thank you!