Finding the Best Industrial Ventilation System

Which Ventilation System is Right for Your Building?

An Industrial ventilation system is complicated. When designing a ventilation system numerous factors are involved. The height of the roof, the temperature of the process heat, average wind speed, and building materials can all have an effect on the building’s ventilation. Consequently, The Moffitt team knows the ins-and-outs of industrial ventilation systems. The ventilation engineering team can help find the right industrial ventilator for their facility.

Industrial Ventilation System Architect PlansFirst, you must determine the effectiveness of your buildings’ industrial ventilation system is to determine the required number of air changes per hour (ACH). This important metric describes how many times per hour the air in a space is completely replaced. For instance, a building with 30 ACH has all of its air replaced with fresh air every two minutes.

Furthermore, the higher the ACH, the quicker air moves through the building. As the air moves quicker it leads to the increased evaporation of moisture. Air with less moisture feels cooler and more comfortable. This measure determines the ventilation needs of a building. It is quite common amongst HVAC companies and ventilation designers.

A Look at the Numbers

Especially relevant is then finding the right air change rate. Determined by room size and air volumetric flow rate, matching the air change rate means making a cooler and more comfortable building.

  • In mathematical terms ACH = 60Q/Vol.


  • 60Q = the volumetric airflow rate in cubic feet per minute (cfm). This is how quickly the air moves through the building (Q). Multiply this number by 60 (for the number of minutes per hour).

Divided by

  • Vol = volume of the building.

This equation will help anyone find the proper number of air changes for the building. Most importantly it will allow you to determine the optimal number of air changes per hour. This is the first step to better ventilation.

The Moffitt team has a pretty good idea of how many air changes might be required for a building. As a result, of our 55+ years designing industrial ventilation systems we have lots of experience. As a result, we have compiled an extensive table that shows building types and the suggested number of ACH for those buildings. These are approximations that have been adopted for different types of buildings. These figures are not 100% certain. The data is time-tested and verified time and again.

After you find the ACH the next step is to find the right industrial ventilation system to facilitate those air changes. Consequently, the Vent Selector from Moffitt can make this easier.

Industrial Ventilation System Vent Selector

industrial ventilation system vent selectorThe Vent Selector (free registration required) allows anyone to find the type, size, and style of vent that would best suit a given building. First, the user selects the type of vent they think they will need. Next, they will input the ACH. Next, you enter the remaining information. This includes building dimensions, indoor and outdoor temperatures, and available supply air. Finally, the resultant output will display the optimal number of vents for that building. The number will be red if the original selection is incorrect.

After that, you enter the remaining information. This includes building dimensions, indoor and outdoor temperatures, and available supply air. The resultant output will display the optimal number of vents for that building. On the other hand, if the original selection is incorrect, the number will be displayed in red. For instance, a low volume ventilator will not work in a high heat facility like a steel mill. Therefore, in such an event the program will indicate that the user has made an inadequate selection.

Lastly, you submit the results to our design team for review. This will let the team find the right style, size, and quantity of industrial ventilators for your building. There are often unforeseen factors in the design process that require the eye of a member of the Moffitt design team. For instance, a gravity vent requires a buffer space for installation and access. The chart indicates the right ventilator, but only a ventilation engineer can indicate the right placement. A specific building’s layout may not allow for the system to work. You will need to choose another product in that event.

Moffitt Ventilation

In conclusion, there is no substitute for experience. Finding the perfect ventilation system takes practice. Fortunately, Moffitt Corporation has been designing industrial ventilation systems for over 55 years. The Moffitt team has put systems into hundreds of facilities in dozens of different types of industries. As a result, Moffitt wants to make sure that every building has the optimal industrial ventilation system and that everyone can work in a cool and comfortable space.

Note: the Vent Selector contains a copy of ACH table in a drop-down menu format. Simply choose the building type to view the proper ACH value.

Moffitt is now the exclusive U.S. partner for Colt Smoke Control & Daylighting Products.Learn More