How do the Air Box Junior HEPA and Carbon filters work? What is the benefit of using both in combination?

HEPA filter (intake) is for filtering particles and Carbon filter (exhaust) is activated carbon for odor removal. Take, for instance, cigarette smoke. The HEPA takes out all the particles first and if you follow it with a carbon filter, it will eliminate the smell. If you let the particles get to the carbon it will clog the carbon and not be efficient for odors removal

(note: CFM 250 is recommended for Air Box Junior)

I’m struggling to get rid of strong odors. How can Air Box carbon-activated filters help me?

How do carbon filters work? Carbon filters trap odors through a process called adsorption, which occurs when molecules attach to the outside of a surface rather than being soaked into it (that’s absorption). The more porous the activated carbon, the better, as this will increase the amount of surface space available for contaminants to latch onto when air passes through the filter.s

How can I improve the quality of my indoor air?

Research shows healthy buildings and homes have a big impact on occupants’ well-being and productivity. AIR BOX Filters can make your Indoor Air Quality healthier. Air Box obliterates excess heat, destroys odors and circulates healthy, fresh air 💨

What’s the difference between air filtration and ventilation?
  • Air Filtration: activated Carbon and HEPA filters are an important aspect of environmental control. When used in conjunction with equipment like inline fans, ventilation systems, and odor control solutions, they effectively trap organic and non-organic contaminants like mold, bacteria, pollen and prevent pathogens from entering commercial, industrial and residential environments.

Ventilation: the most practical method of controlling humidity is often through ventilation. It can easily lower humidity by increasing or decreasing the air exchanged throughout the room. This process is usually done by adding an inline exhaust fan to increase the amount of air moving through the room.

What is CFM?

CFM, which stands for Cubic Feet per Minute,is a unit of volumetric capacity. It is commonly used by manufacturers of fans, blowers and filters.

How do I calculate CFM to determine the proper matching of a fan to filter to space?

To determine the proper matching of fan to filter to space, you need to calculate your cubic room feet, L' x W' x H.' After you have your total cubic foot, divide by either 1, 2, 3, 4 or 5.

The more contaminants, heat and odor in the room, the lower the number you want to pick. This will be how many times you want to exchange the air in your room in minutes.

So if you have a 12' x 12' x 12' room that is 1,728 cu ft. For an air exchange every minute, you would need a 1,728 CFM fan and filter, every 2 minutes would be 864 CFM fan and filter, every 3 minutes would be 576 CFM, every 4 minutes would be 432 CFM fan and filter and every 5 minutes would be 345.6 CFM fan and filter.

You will notice the maximum cfm numbers on Air Box:

  • Air Box 1- 500 CFM
  • Air Box 2- 1000 CFM
  • Air Box 3- 1500 CFM
  • Air Box 4- 2000 CFM
  • Air Box 4+- 3500 CFM

These are maximum numbers. Air Box is made to work perfectly with our RUCK inline fans. So the CFM ranges are:

  • AirBox 1- 175-500 CFM
  • AirBox 2- 435-1000 CFM
  • AirBox 3- 745-1500 CFM
  • AirBox 4- 785-2000 CFM
  • AirBox 4+- 1075-3500 CFM

You can add a larger fan to the larger Air Boxes, like a Commercial Blower at either 2800 CFM or 3200 CFM.

How to calculate and determine CFM and the correct fan for a room?

We have always used a 3 minute air exchange for exhaust so volume of the room (LxWxH)/3 gives you the target CFM. Match that with a fan that can deliver that CFM factoring in the pressure drop of the system if possible. We typically allow for .75” for a carbon filter, AB filters are rated at .6”, and we make sure the fans is not exceeding the rated exhaust airflow of the filter.

For recirculating systems we say that you can run up to double the filters exhaust airflow and also double the target CFM.

We also use the following cookie cutter solutions:

  • 1 light = 6” fan with same size filter
  • 2-3 lights = 8” fan with same size filter
  • 4 lights = 10” fan with same size filter
  • 5-6 lights = 12”/14” fan with same size filter
Where do I position the inline fan in relation to the filter?

The inline fan can be used as a push or pull system.Usually the fan goes after the filter. We recommend you:

  1. Make the exhaust run as short as possible
  2. Make as few turns as possible
  3. Pull in fresh, cool air from the bottom
  4. Exhaust hot, used air from top
Can an Air Box filter be used without an active in-line fan attached?

Each Air box is design for their specified CFM. If you push, or do not have enough air flow, the carbon will not work to its best efficiency. It will work yes, but not optimally.

Can I wash my replaceable charcoal filters?

No you can't. You can use a vacuum cleaner to remove dust. For optimal performance, check and replace your filters regularly!

How often filters have to replace?

We recommend carbon filters be checked and replaced every 6-9 months and pre-filters every 6 months for optimal performance. Thanks for your interest in Air Box filters.

How long do replacement filters last on the shelf unused and sealed?

Approximately 1 year on a dry enviroment.

Does the Air Box Filter have chemicals in it?

We use 60 CTC carbon This means it will pick up 60% of it weight in CTC.
CTC is a chemical they use to rate the quality of the carbon. Typically the higher the CTC is the better the carbon is.

You take virgin carbon. You dry the carbon by running 150 degree dry air through it for 45 min.
You weigh a sample, say 100 mg t
You then run CTC through it until it doesn't pick up any more weight

Uses for Air Box
Air BOX activated carbon filters remove:
  • Organic contaminants
  • Non-organic contaminants
  • Viruses and pathogens
  • Cigarette/ woodfire smoke
  • Gaseous fumes
  • Cooking odors
  • Bathroom odors
  • Damp areas
  • Pet areas

Quick and inexpensive solution:
  • Industrial
  • Commercial
  • Residential
  • Health Clubs
  • Beauty Salons
  • Restaurants
  • Hospitals
  • Doctor/ dentist offices
  • Veterinarian Offices
  • Office Buildings
  • Shopping Malls
  • Schools


What is your Lead time

Processing can take up to (5) business days for in-stock Air Box units and replacement filters and up to (4) weeks for custom-built orders.

What is the shipping Cost?

We offer a flat rate for shipping which will be clearly indicated at check-out. Based on fluctuating gas prices and shipping costs, it’s important to note that freight quotes may vary on shipment date due to fuel costs and other additional fees. We want to be transparent and will notify you ahead of time if there is a change in shipping or freight cost.

Do you offer Whosale Accounts?

We offer the following commercial volume discounts:


  • All orders must be placed at:
  • Paid via credit card in advance
  • Buy (5+) or more units, get a 5% discount
  • Buy (10+) or more units, get a 10% discount


Offer does NOT include shipping or applicable taxes. We will ship to one commercial location in the USA or Canada


What Payment method do you accept?

We accept Credit and debit cards (Visa, Amex, Mastercard) and PayPal