Table of Contents
Laminar flow is the linear movement of a fluid or gas in a smooth or disturbance-free path.
Polymerase chain reaction (PCR) is an amplification technique for DNA/RNA which is frequently used in diagnostic testing, forensics, and genomics.
A vertical laminar flow workstation provides clean, turbulent free, filtered air that moves in a vertical motion. The mechanical filter is located at the top and filtered air pushes down onto the work surface before exiting out the front opening of the sash. If the workstation is a Class II Biological Safety Cabinet, the filtered air recirculates.
Horizontal laminar flow is the direction that air moves in relation to the work surface. The HEPA filter is located in the rear of the clean bench and air is pushed from back to front in a horizontal pattern. This horizontal air is used with a clean bench.
Vertical laminar flow hoods and workstations provide process protection, protecting samples from contamination. Typically, vertical laminar flow workstations offer a lower profile making them ideal for smaller labs with limited space.
Horizontal laminar flow hoods provide process protection, protecting samples from contamination. Horizontal laminar flow hoods push clean air from the back of the unit towards the operator. This flow direction helps prevent turbulence over the samples when working.
The International Organization for Standards (ISO) has cleanliness standards for cleanrooms. ISO 5 means an environment with a maximum of 100 particles greater than or equal to 0.5 microns per cubic foot of air. Class 100 was the Federal Standard that was used prior to the global adoption of the ISO 5 designations.
High-efficiency particulate air (HEPA) filters are mechanical filters designed to filter particulates. HEPA filters physically block particles from passing through. They provide an efficiency value based on most penetrating particulate size (MPPS) such as 99.997% effective at 0.3 microns.
High-efficiency particulate air (HEPA) filters typically improve in efficiency as the filter is used. HEPA filter lifetime varies based on environment and use but most manufacturers suggest replacement between 1-3 years. The general test for a HEPA filter to be changed out is when the pressure drop across the filter is twice the amount relative to installation.
High-efficiency particulate air (HEPA) filters typically improve in efficiency as the filter is used. HEPA filter lifetime varies based on environment and use but most manufacturers suggest replacement between 1-3 years. The general test for a HEPA filter to be changed out is when the pressure drop across the filter is twice the amount relative to installation.
Biological safety cabinets offer a minimum of personnel and environmental protection. The PCR Workstation protects the samples but does not protect personnel or the environment from samples handled. The PCR Workstation does not meet the requirements or definition of a biological safety cabinet.
The UV bulbs in an AirClean Systems workstation are designed to operate for 1000 disinfection cycles and deliver an adequate level of energy to decontaminate the workstation. The UV bulbs are manufactured to provide a specific dose of UV irradiation for surface disinfection.
UV light can damage cells and various forms of UV irradiation may cause cancer. Our polycarbonate shields naturally reflect UV-C light to protect the operator during surface disinfection.
Laminar flow hoods are units designed to provide some level of process protection. They are necessary for applications such as: handling nucleic acid, electronics assembly, cell culture, and tissue culture.
Ductless fume hoods are primary engineering controls designed to protect the operator from hazardous fumes or vapors. Ductless fume hoods use a blower to pull contaminated air through carbon and/or HEPA filters and return clean filtered air back into the environment.
Total exhaust fume hoods are engineering controls designed to protect the operator from hazardous fumes or vapors. Total exhaust fume hoods use an external blower to pull fumes through ductwork and exhaust them into the external environment.
Carbon filters are used to filter out contaminants from gas or liquid solutions. In gaseous filtration, as fumes pass through the carbon filter, Van Der Waals forces trap the chemicals on the carbon's surface.
Activated carbon is a form of carbon that has been treated to increase surface area for filtration efficiency. Activated carbon is commonly used in carbon filters because the treating process increases filter capacity.
Bonded carbon filters are gas-phase filters that filter potentially hazardous chemical fumes or vapors. Bonded carbon filters have panels of solid carbon compared to granular. They produce less dust and eliminate dead zones from carbon shifting, a common problem in granular carbon filters.
Granular carbon filters are gas-phase filters that filter potentially hazardous chemical fumes or vapors. Granular carbon filters use closely packed, loose granular carbon. They can potentially produce contaminated dust and experience carbon shifts in shipping. This leads to dead spots on the filters.
Activated carbon is typically treated with steam, pressure, or chemicals to increase adsorption capacity. This treatment creates an extremely porous structure with enhanced surface area to capture chemicals.
Activated carbon filters filter organic chemicals. Volatile organics such as; alkanes, alcohols, and aromatics are captured by bonded carbon filters. Impregnates (carbon additives) can be used to increase the capacity of inorganics and amines that have not been captured by general activated carbon.
Adsorption is the process where molecules become stuck to a surface via electrostatic interactions.
Ductless fumes are safe, but applications should be verified by a professional prior to use. Ductless fume hoods often employ additional safety measures to ensure safe operating conditions such as; airflow sensors, filter breakthrough sensors, and ports for supplemental filter testing.
Ductless fume hoods do not need to run continuously. Ductless fume hoods typically offer blower controls to allow for easy on/off control.
Carbon filters have finite capacity based on the amount of carbon contained in the filter. Most carbon filters have recommended replacement on an annual interval. This ensures no risk of filter breakthrough or exposure. Many ductless manufacturers utilize electronic sensors to monitor the exhaust air and indicate when a filter is nearing saturation and should be changed out. Filter life is directly related to a variety of factors including; the type of chemical, the volume of chemical evaporated, frequency of use, and at what temperature is the chemical being handled during use.
Safety filters are filters that protect the environment from potentially contaminated carbon dust produced from granular carbon filters. A safety filter (failsafe carbon or HEPA/carbon blended filter) acts as a backup if the primary filter fails.
Many ductless fume hood manufacturers offer monitoring devices built into the system. We have safety sensors to check the filter exhaust for breakthrough, and colorimeter tube testing can be employed to provide a ppm readout for target chemicals in the exhaust stream.
Many ductless fume manufacturers offer face velocity monitoring to measure the velocity at the sash. Some ductless fume manufacturers offer automatic blower control that adjusts the blower to maintain a face velocity. Others simply incorporate a simplistic visual indicator that verifies airflow.
Ductless fume hoods offer many benefits compared to total exhaust. Ductless fume hoods are portable which eliminates the need for installation, they are lower in energy costs due to exhausted conditioned air, and they trap chemicals rather than exhausting them into the environment.
Ductless fume hoods can have lifetimes exceeding total exhaust fume hoods. Although the life span of a ductless fume hood is based primarily on environment and use, construction materials like lab-grade polypropylene can extend fume hood life by preventing rust or corrosion.