Active Vs. Passive Odor Control

Placing odor control dispensers near entryways can aid in dispersing fragrance, but customers also need to consider whether their system is active or passive when determining the best place to install it.

Passive dispensers do not require batteries, fans or propellants, and rely on
natural air movement to deliver fragrance. Active dispensers, which include metered aerosol dispensers, rely on a mechanical or gaseous propellant to deliver scent.

“Metered air dispensers should be placed five to 10 feet from the entrance of the restroom, approximately 10 feet from the floor, and directly across from the sink and vanity area,” says Tony Chiefari, vice president business development, Claire Manufacturing Co., Addison, Illinois. “As a general rule, this location will be central to the most common area.”

For safety reasons, aerosols should never be placed in areas where they could potentially spray into someone’s face or create a slip-and-fall hazard, says Sauser.

“There are some propellants in aerosols that have an oily residue,” he adds. “It doesn’t happen a lot, but if you have fallout from an aerosol, it could get on the floor and become a hazard or discolor the floor.”

Another reason aerosol dispensers should be placed high on the wall is to prolong the time that the fragrance remains in the air.

“The size of atomization of an aerosol is between 80 and 100 microns, which will stay in the air for approximately 12 minutes,” says Paul Wonnacott, president of Vectair Systems, Memphis, Tennessee. “So for security and performance reasons, it’s critical that you mount the dispenser as high as possible. The higher the dispenser is mounted, the longer the fragrance will remain in the air because it takes longer to fall to the ground.”

Unlike molecules dispensed from an aerosol dispenser, molecules diffused from a passive cartridge are lighter than air and will stay in the air for longer, says Wonnacott; however, passive systems do not have the same coverage and certitude that you get with an aerosol.

Additionally, passive systems, unlike active systems, rely solely on natural airflow to disperse the product, making air movement a priority when considering placement.

“They need to be mounted reasonably high for security reasons,” says Wonnacott, “but they would be well-suited for areas where you have an opening or closing door, or where you have people passing regularly, creating a natural draft.”

Active odor-control systems are beneficial for large restrooms or restrooms with serious malodor issues, while passive systems work well in smaller restrooms or stalls, says Ward. Some restrooms benefit from a combination of both systems, depending on the type and size of facility, and its individual needs.

Strategically placing odor control dispensers in restrooms can maximize their effectiveness, but if the systems are not well maintained all bets are off. Units need to be easily accessible so that custodians can change batteries and/or cartridges when needed.

As with fragrances, figuring out the best place to install odor control dispensers is part science, part personal preference.

Kassandra Kania is a freelance writer based in Charlotte, North Carolina. She is a frequent contributor to Sanitary Maintenance.