Typical Accessories for Ductless Fume Hoods

Once you’ve decided on a Ductless Fume Hood, you should consider what complementary accessories may further improve your respiratory safety engineering controls.

Here are some examples:

A Magnehelic Gage (or Filter Saturation Gage)

Magnehelic Gages (or Minihelic Gages) are used on Fume Hoods to measure filter saturation.

These compact devices are used to measure static pressure on particulate filters [i.e. pre-filters, HEPA filters, ASHRAE filters]. When the filter in your fume hood begins to clog, the needle on the gage will slowly increase over time. When it has reached a certain point, it is time to change the filter. If you do not monitor filter saturation, it can be difficult to tell when the efficiency of the filter starts to dwindle and neglect to capture hazardous particulate or dust.

If you have questions about filter saturation in your Sentry Air Systems Fume Hood, contact your Sales Rep.


Velometers are designed to measure hood face velocities in feet per minute. This measurement is taken at the inlet (or sash) of the hood.

Several health and safety organizations recommend good practices for fume hood face velocities. Here are some examples:

OSHA (National Research Council Recommendations Concerning Chemical Hygiene In Laboratories, Section4G): “[…] airflow into and within the hood should not be excessively turbulent; hood face velocity should be adequate (typically 60-100 fpm)”

ANSI/AIHA (American National Standards Institute/American Industrial Hygiene Association, Standard Z9.5-1992, Section 5.7): “Each hood shall maintain an average face velocity of 80-120 fpm with no face velocity measurement more than plus or minus 20% of the average.” (source)

S.E.F.A. (Scientific Equipment & Furniture Association, 1.2-1996, Section 5.2): “Government codes, rules, and regulations may require specific face velocities. A fume hood face velocity of 100 fpm is considered acceptable in standard practice. In certain situations face velocity of up to 125 fpm or as low as 75 fpm may be acceptable to meet require capture velocity of the fume hood.” (source)

Hour Counter

Hour Counters keep track of how many hours the Ductless Fume Hood is in operation. This can give the operator a better idea of when filter changes need to take place. The hour counter can easily be reset once the filters are changed.

Spill Trays

Spill Trays are helpful when chemicals, other liquids, and powders are being utilized in your Ductless Fume Hood. They allow for easy clean-up and are available in a variety of options including fiberglass, anti-skid material, NSF-Certified, and static-dissipative material.

Disinfectant Spray & Anti-Static Wipes

CaviCide® is a non-toxic surface disinfectant that is designed to kill certain bacteria and viruses [see product website for details]. It is recommended for use on a variety of laboratory and hospital equipment and will not harm the surface of your fume hood.

Pro-Wipes®880 are polypropylene nonwoven wipes. They are recommended for use in cleanroom environments because of their very low particle and fiber generation. These multi-layer wipes are compatible with a variety of acid solvents and common cleaning and disinfecting solutions (including Cavicide®). Ideal for use in a variety of laboratory, biomedical, and pharmaceutical compounding environments.


Clean & Polish Kit
This clean and polish kit is designed for use on acrylic and polycarbonate. Other cleaning solutions have the potential to scratch or mar these materials.
Sentry Air Systems manufactures an extensive line of Ductless Fume Hoods, ranging in size from 12″ Wide to 70″ Wide. Custom fume hoods are also available. For more information: