Which CrewProtect Size Do You Need for Your Apparatus?

If you’re considering a CrewProtect for your firefighting apparatus, you are likely wondering which size unit you need.

In this article we’ll walk you through how to decide which size is right for your vehicle.

First, let’s talk about why size matters.

Why Does CrewProtect Size Matter? 

When choosing your air decontamination and filtration solution it’s important to get the right size unit. The size matters for a few reasons:

  • Each CrewProtect can move and process a specific amount of air, measured in Cubic Feet per Minute or CFM. The CFM decides the ACH, or Air Changes per Hour, the unit can do in a specific size cab. For the best results, we recommend having an ACH of at least 2 per seat that will regularly have someone wearing gear in it.
  • Getting this number of ACH may require a creative solution if your apparatus has space limitations or an awkward configuration. Using the ACH lets you choose a single CrewProtect or multiple to achieve the goal.
  • The amount of volatile organic compounds (VOCs), particulates, and aerosols in your apparatus varies widely based on the vehicle itself and how many sets of gear will be inside. Choosing a unit that can adequately process the air creates the best environment for your crew.

How to Choose a CrewProtect Size 

Image 1  Image 2

As you look at your CrewProtect options, there are a few things you will want to consider before making a choice:

  • What is the overall size of your cab in cubic feet?
  • How many seats/ potential gear sets are inside the cab?
  • Based on your cab size, how many Air Changes per Hour (ACH) can each CrewProtect unit do?
  • Which solution or combination of solutions gives you at least two ACH per seat/gear set?

When choosing a CrewProtect, your main goal is to have at least two ACH per potential gear set or seat in your apparatus. This may mean selecting one CrewProtect unit or using multiple to achieve this goal.

What is the ACH for Each CrewProtect Unit? 

The ACH for each CrewProtect will vary based on your cab’s cubic footage. You can easily determine the ACH with some basic math.

Each CrewProtect has a specified CFM rating:

ACH = 60/ (Cubic Footage of Cab/ CFM)


Your local fire department is looking for the correct CrewProtect units for a new apparatus. You figured out that the cab is roughly 335 cubic feet and that there are six seats or potential gear spaces.

First, let’s find the minimum ACH we need for this cab using the number of seats/gear sets and our goal to have 2 ACH per seat.

6 seats X 2 ACH Goal = 12 ACH minimum

After seeing the ACH minimum, your guess is that a CrewProtect 100 will be right for them.

Let’s figure out the ACH for this specific cab using a CrewProtect 100 to see if it will work.

ACH = 60/ (335/100)
ACH = 60/ 3.35
ACH = 17.9

Because we want to focus on complete air changes, we round this number down to 17.

A CrewProtect 100 would be adequate for this station’s needs.

Image 3

But what if they had a space limitation that made it impossible for the 100 to fit properly? Could they do the same with two smaller units? Let’s see if the CrewProtect 50 would work.

ACH = 60/ (335/50)
ACH = 60/ 6.7
ACH = 8.95 – Rounded down to 8

A single CrewProtect 50 does not have a high enough ACH to meet our recommendations. However, two CrewProtect 50 units could achieve an ACH of 16 in this cab, meaning two could be used to meet the goal.