Ventilation 2 min read
Ventilation needs by laboratory type, the main components of a ventilation system, and what to consider when choosing a canopy hood for work at the bench.
Laboratory ventilation is the core infrastructure that protects staff from chemical and biological contaminants and maintains comfortable conditions in the laboratory. A ventilation system consists of air supply, exhaust, ductwork, fans, cooling and heating, filters, controls and other auxiliary equipment. Alongside general ventilation, local exhaust equipment such as fume hoods, canopy hoods and extraction arms is used.
Laboratory Types and Their Ventilation Needs
- Biological laboratories: biochemistry, cell biology, immunology, pharmacology and microbiology laboratories working with biologically active materials; clinical laboratories also belong to this group. They usually have chemical fume hoods and Class I and Class II biological safety cabinets.
- Chemistry laboratories: laboratories for organic and inorganic synthesis and analytical work, usually with more than one fume hood.
- Animal laboratories: areas for observing and treating laboratory animals and for pharmacological observation, together with animal housing rooms.
- Physics laboratories: areas working with lasers, optics, high- and low-temperature materials and analytical instruments.
What Is a Canopy Hood?
A canopy hood is an open system that locally removes the heat, odours, steam and acid vapours that may be released during tests and experiments, usually carried out at the bench. These ventilation units are extraction systems built to suit each project; separately from the general laboratory ventilation, they carry volatile, toxic and hazardous gases produced during local tests and analyses to the outside before they spread into the room.
What to Consider When Choosing a Canopy Hood
Material
Canopy hoods are made of grade 304 or 316 stainless steel, or of galvanised steel with an electrostatic epoxy coating; the material is chosen according to what the hood will be exposed to.
Dimensions
- Standard depths are 600, 750 and 900 mm, with a height of 500 mm.
- Lengths are 750, 900, 1000, 1200, 1500 and 1800 mm.
- There are also small 400 × 400 × 500 mm (height) hoods that hang directly above an instrument, particularly atomic absorption (AAS) spectrometers.
Fan and Exhaust Connection
- The fan connected to the ventilation outlet is sized according to the dimensions of the hood.
- The exhaust ductwork connects to the outlet on top of the hood and to the fan, and is taken to the outside through a connection matching the fan diameter.
- Depending on how the hood is used, exhaust pipes may be stainless steel, polypropylene or PVC; pipe diameters vary with the air volume.
- The single-speed fan control switch is mounted on the energy panel of the bench it serves or on the wall.
KRCLAB designs, manufactures and installs laboratory ventilation systems; canopy hoods and extraction arms are part of its range.
