Laboratory ‎Fume Hoods & Enclosures

A ducted fume hood is connected to a building's exhaust system and vents contaminated air directly outside the facility, making it the preferred choice for applications involving strong acids, bases, solvents, or toxic compounds. A ductless fume hood uses internal filtration, typically activated carbon, to remove chemical vapors before recirculating air back into the lab, making it suitable for lower-hazard applications where ductwork installation is not practical. Ducted fume hoods are generally considered the safer and more versatile option, as they are not limited by filter capacity or the range of chemicals they can handle. LOC Scientific carries both ducted and ductless fume hood configurations.

LOC Scientific offers a comprehensive range of laboratory fume hood types, including standard ducted fume hoods, ductless fume hoods, VAV (variable air volume) fume hoods, add-air fume hoods, perchloric acid fume hoods, radioisotope fume hoods, low-bench fume hoods, demonstration fume hoods, and ADA-compliant fume hoods for wheelchair operators. Each type is designed for specific applications, hazard levels, and facility requirements. Our team works with lab designers and safety officers to identify the appropriate hood type for each application and ensure the selected product meets applicable OSHA, ANSI/AIHA Z9.5, and SEFA standards.

A VAV, or variable air volume, fume hood automatically adjusts its exhaust airflow based on the position of the sash, reducing energy consumption when the sash is partially or fully closed while maintaining a constant face velocity at all sash positions. VAV fume hoods are recommended for facilities focused on energy efficiency and labs with high fume hood density, where the cumulative energy savings from variable airflow can be substantial. They integrate with the building's HVAC exhaust control system and are best specified during new construction or major renovation. LOC Scientific supplies VAV fume hoods and can coordinate with facility engineers on system compatibility and control requirements.

A perchloric acid fume hood is a specially designed enclosure built to safely handle perchloric acid, a highly reactive oxidizer that can form explosive perchlorates when it reacts with organic materials in the exhaust ductwork. These hoods are constructed from non-reactive materials such as stainless steel or PVC, and the ductwork includes a built-in wash-down system that regularly rinses interior surfaces to prevent perchlorate buildup. Standard fume hoods must never be used with perchloric acid, as the risk of explosion from residue accumulation is significant. LOC Scientific supplies perchloric acid fume hoods and can guide installation requirements and safety protocols for this specialized application.

Selecting the right fume hood requires evaluating the types and quantities of chemicals being used, the hazard level of the work, the available ductwork and HVAC infrastructure, space constraints, and energy efficiency goals. High-hazard applications involving strong oxidizers, carcinogens, or radioactive materials require specialized hood types rather than standard ducted units. LOC Scientific's team works directly with lab managers and safety officers to assess these factors and recommend the fume hood configuration that provides the appropriate level of protection while meeting facility and budget requirements.

ANSI/AIHA Z9.5 recommends that laboratory fume hoods be tested at least annually for face velocity and containment performance, and more frequently in high-use or high-hazard environments. Fume hoods should also be tested after any maintenance, repair, or modification to the hood or the building's HVAC system that could affect performance. All LOC Scientific fume hoods are factory-tested to the ASHRAE 110 standard before shipment, and our team can establish an ongoing testing schedule aligned with your facility's safety program and applicable regulatory requirements.

Laboratory fume hoods must comply with ANSI/AIHA Z9.5, the primary consensus standard governing laboratory ventilation in the United States, which sets requirements for hood design, face velocity, performance testing, and maintenance. OSHA regulations under 29 CFR 1910.1450 also require that engineering controls such as fume hoods be used and maintained appropriately for chemical hazard control. LOC Scientific fume hoods meet ANSI/AIHA Z9.5 and SEFA standards and are factory-tested to ASHRAE 110, with performance documentation available for compliance purposes.

A fume hood is designed to protect lab personnel from chemical vapors and fumes by exhausting contaminated air out of the lab, but it does not provide protection from biological hazards or protect the sample inside the hood. A biosafety cabinet is designed to protect both the user and the sample from biological contaminants, using HEPA filtration and carefully controlled airflow patterns classified under biosafety level ratings from the CDC and NIH. Fume hoods are used for chemical work, while biosafety cabinets are required for work with biological agents. LOC Scientific can help you identify the correct containment equipment for your specific application.

Laboratory fume hood costs vary widely depending on the hood type, size, material construction, and whether specialized features such as VAV controls, wash-down systems, or perchloric acid compatibility are required. Standard ducted fume hoods are generally the most affordable, while specialized units such as perchloric acid hoods, VAV systems, and radioisotope hoods carry significantly higher price points due to their construction and control requirements. LOC Scientific provides project-specific pricing and can work with facility planners and procurement teams to identify solutions that meet both performance and budget requirements.