The Fume Hood, also known as fume closet, is one of those useful equipment that are often used in the lab. It is a type of local ventilation device that is designed to limit exposure to hazardous or toxic fumes, vapors or dusts. Descriptively, the fume hood is typically a large piece of equipment enclosing five sides of a work area, the bottom of which is most commonly located at a standing work height. Subsequently, we shall be discussing the fume hood uses in laboratory: what is fume hood?
In addition to the fact that it helps in the management of the disposal of some unhealthy air substance, the laboratory fume hood is the local exhaust ventilation system used in laboratories and is the primary method used to control inhalation exposures to hazardous substances.
When used properly, fume hoods offer a significant degree of protection for the user. Understanding the limitations, the appropriate maintenance techniques, and overall design of the fume hood will ensure your safety while using hazardous materials.
The purpose of fume hood is to prevent the release of hazardous substances into the general laboratory space by controlling and then exhausting hazardous and/or odorous chemicals. In the event of an accidental spill, the fume hood will contain the spilled chemicals and exhaust the fumes away from the user and laboratory zone.
There are two major types of fume hood. They are: Ducted and Ductless Fume Hood.
1. Ducted Fume Hoods: Industrial processes use mostly these Fume Hoods. A large variety exists. In most designs, conditioned (i.e. heated or cooled) air is drawn from the lab space into the fume hood and then dispersed via ducts into the outside atmosphere.
The fume hood is only one part of the lab ventilation system. Because the recirculation of lab air to the rest of the facility is not permitted, air handling units serving the non-laboratory areas are kept segregated from the laboratory units.
2. Ductless Fume Hoods: These generally have a fan mounted on the top (soffit) of the hood, or beneath the worktop. Air is sucked through the front opening of the hood and through a filter, before passing through the fan and being fed back into the workplace. With a ductless fume hood, it is essential that the filter medium be able to remove the particular hazardous or noxious material being used.
Their uses are that:
- protect the user from inhaling toxic gases (fume hoods, biosafety cabinets, glove boxes)
- protect the product or experiment (biosafety cabinets, glove boxes)
- protect the environment (recirculating fume hoods, certain biosafety cabinets, and any other type when fitted with appropriate filters in the exhaust airstream)
Fume Hood Uses in Laboratory: What is Fume Hood
This great instrument that has so gained the attention of this content has been defined and simply explained for you know not to just what it is but also to know what it looks like, what it is made of, and what its purpose is. Looking into fume hood uses in laboratory: what is fume hood therefore, this article will be dissecting some of its uses in the laboratory:
What Fume Hood Does
- It should be equipped with the functions that the harmful gas emerging in fume hoods can be thinned and discharged into outside of room by means of absorbing gas outside of cabinet.
- It should be with functions to prevent harmful air from flowing in reverse into room from inside of fume hoods. To ensure this function, it’s the best way to connect one fume hood with a ventilation fan with a single pipe. In case it’s not workable to use a single pipe, parallel connection is only suitable for pipes in same room and in same floor. It’s better to install the ventilation fan at the end of pipe(or floor ceiling).
- Insulating the inside and outside of fume hood with unmovable glass window in front of fume hood.
- There should be corridor for fume hood to absorb air from outside or replacement device when the waste air is discharged.
- To prevent harmful gas from escaping inside of fume hood, it needs somewhat suction speed. The elements which decide the suction speed for fume hood when inletting air is the relation between heat produced for test items and times of changing air. Among them it’s the most important for test items and property of harmful substance. It’s stipulated in general that the innoxious pollutant is 0.25~0.38 m/s. The harmful pollutant with poison and danger is 0.4~0.5m/s. It’s 0.5~0.6m/s for pollutant with strong poison or with small amount of radioactivity. It’s 0.5m/s for gaseous material which it’s 1m/s for shot-like particle.
- To ensure such wind speed, the fan needs to have necessary static pressure. Also we need to pay attention to noise problem when we confirm wind speed. The limited value is 70dBA for background noise grade in laboratory. Increasing cross section area of pipe will reduce wind speed and lower noise. The power of pipe and exhaust fan needs to selected carefully considering of pipe cost and construction problem.
- The functions of heat and acid resistance: Sometimes it needs to place electricity stove in fume hood, there’s extreme strong corrosive harmful gas emerging during some tests. The worktop of fume hood, guide panel, water and gas fitting are all with chemical resistance property.
