Blog – Construction Drying, Temporary Climate Solutions

Dehumidifiers vs. Air Scrubbers: What’s the Difference?

While it may seem as if they perform similar tasks, an air scrubber and commercial dehumidifier are two different types of equipment. By knowing the differences in their operations and effectiveness in various situations, you can make an educated decision about which is best for your application. When your focus is on business continuity, choosing the best equipment will reduce the time that it takes to restore an affected area and save on rental costs.

Air Scrubber

Air scrubbers have fans that draw air through a pre-filter and a HEPA filter at rates that vary between 150 cubic feet per minute (CFM) and 900 CFM. The HEPA filter in the scrubber removes particles, not vapor, in the air.

If you use an air scrubber in a room that has mold damage, for example, the scrubber will remove mold spores and other allergens from the air. It will not, however, remove the humidity in the air. To capture settled spores, professionals often use oscillating fans in the same room as the scrubber, placing them in a strategic manner, so the moving air stirs up spores that settle on surfaces


A dehumidifier speeds up the natural evaporation process. Dehumidifiers draw in air at rates of up to 400 CFM, but the air doesn’t pass through filters. When air passes over metal fins that are cooled below the room’s dew point temperature, the fins condense moisture out of the air and pump it to a drain that’s inside the dehumidifier or to an external drain or bucket. A commercial dehumidifier may remove up to 300 pints of water per day, depending on the size of the equipment and the amount of moisture in the air.

The water that a dehumidifier removes from the air is in the form of vapor, or gas. The gas forms because water has vapor pressure that evaporates. To promote the formation of a gaseous vapor, professionals often use fans and a dehumidifier, as the moving air diffuses the gas and moves it to the chilled plates. In a room that has mold damage, for instance, a rented dehumidifier will remove excess moisture from the air, but not any particles. When dew point condensation occurs and the chilled plates remove excess water vapor from the air, the dehumidifier reduces the vapor concentration, which allows more water molecules to evaporate.

After remedying damage caused by water damage or high humidity levels, remediators dry the air using dehumidifiers, which clients may rent. The workers then place at least one air scrubber in each area or room, depending on the size of the affected area, along with fans that prevent stagnant air zones where spores can re-settle.

Rather than purchase the dehumidification equipment, companies often rent them. Polygon, a leader in water damage restoration, offers equipment rentals. We work with clients to provide them with custom total climate control solutions that maintain the quality of indoor air, reduce the load on the HVAC system and keep the building healthy. Contact Polygon today to learn more about rental services and to set up a consultation.

[Photo from Metropolitan Transportation Authority of the State of New York via CC License 2.0]

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