The task performed in medical and research laboratories require clean and sterile environments.Laminar flow hoodsprovide this environment because they have been designed to minimize dust and particulate matter contamination. These medical tools play important sanitary roles in any medical and research laboratory. Laminar hoods help to keep items in a laboratory clean and sterile by facilitating the constant flow of air in and out of the hood. There are different types of laminar hoods, each with its own specifications and features.
One of the main features of a flow bench is a filtration system that projects air and blows it across a work surface in a uni-directional pattern. A flow bench does not just provide a clean working environment but it also provides a sterile environment for various laboratory tasks.
A flow hood can be used for various purposes including keeping air and laboratory environments clean and sterile. A flow hood is a particle sensitive electronic device that is commonly used for specialized purposes in a laboratory. Laminar hoods can be custom made for a specific laboratory and are suitable for general laboratory tasks, especially in electronic, industrial, medical, and pharmaceutical settings.
How They Are Made
Most laminar air flow cabinets are made from stainless steel and do not have gas or joints to eliminate the build up or accumulation of bacteria and other types of micro-organisms. Laminar air flow cabinets are also known as clean benches because they keep the work environment thoroughly clean through a filtration process.
How They Work
Laminar air flow cabinets work by streaming air in a steady, uniform velocity. These laboratory devices work by drawing in air and passing it through HEPA filters to remove particles and contaminants. This helps to create a contaminant-free working environment. A laminar air flow cabinet consists of two types of filters including a pre-filter and an HEPA filter. The medical device is enclosed on one side to maintain constant air pressure and to prevent contamination of the air in the room.
Horizontal Laminar Flow Hoods
This type of laminar air flow cabinets are so named because of the way air flows through them. In a horizontal laminar cabinet, air flows from the top and passes through a sterile area in a horizontal direction. The cabinet features a large filter that covers the wall directly in front of the person working at the bench. A laminar hood is designed to provide a clean working environment and works well with a constant stream of positive pressure. The primary role of the horizontal laminar hood is to protect the substances on the work environment and not the person working in the lab.
Vertical Laminar Hoods
This type of laminar cabinet is just as effective as the horizontal hood cabinet but delivers air in a different fashion. With this type of hood, air flows from the top and goes straight down onto the work area. This hood features an air filter mounted directly above the work area. Air streams from the work area through holes at the base of the hood. Vertical hood cabinets provide protection for both the work area and the lab worker.
Class I Laminar Hoods
This is a very simple type of cabinet hood. It provides adequate protection to both the lab worker and the materials on the work area. However, Class I laminar hoods do not protect work substances from contamination. This type of hood works just like a chemical fume hood that contains hazardous fumes but does not disinfect.
Class II Laminar Hoods
This laminar cabinet provides protection against contaminants and disinfects the work area. The Class II laminar hood provides adequate protection from the dangers of hazardous materials and is suitable for that application.
Class III Laminar Hoods
This flow hood provides the highest levels of protection because it is airtight and protects the lab worker from the dangers of human pathogens. The Class III Laminar Hood is suitable for applications that involve potentially infectious substances.
Maintenance Requirements for Laminar Cabinets
Laminar cabinets are equipped with filters that trap particulate matter that may flow into the cabinet and contaminate the air in the hood. It is important to change hood filters regularly to ensure their efficiency. Filter lifespan vary and you should change the hood filter according to its specific life span.
Most flow cabinet feature a sliding glass that lifts to allow the lab worker to reach in his hand to pick an item. Once the lab worker lifts the window up, the hood blower begins to push air out of the hood preventing air from outside from mixing with the sterile air inside the cabinet. The blower plays an important role in the efficiency of the hood and it should be checked regularly to ensure it is blowing at a steady and strong rate.
Laminar cabinets are some of the most important machines in a laboratory. Their main function is to keep air in a lab sterile. Like any other type of machine, laminar hoods require maintenance and care to work properly.