Scientific Instruments: Filtered Vs. Vented Fumed Hoods

Thursday February 28 2019

Chemical fume hoods are used to contain or ventilate potentially harmful airborne elements from processing environments. They are primarily installed to shield personnel from inhalation exposure, but can also provide protection from chemical spills, fires, and runaway reactions in clean rooms or handling chambers. Methods for controlling fumes, vapors, and airborne particulates vary depending on distinct laboratory conditions, budgets, best practices, and the type of scientific instruments in use.

There are numerous fume hood design types, but these can typically be broken down into two overarching categories: filtered and vented fume hoods. These scientific instruments perform similar processes, with advantages and drawbacks depending on your unique requirements. In this blog post, Glas-Col compares filtered and vented fume hoods to help you select the right scientific instruments for your application.

Fume Hood Location Options

Perhaps the foremost advantage of filtered fume hoods over vented types is their exceptional portability. They are free-standing scientific instruments that can be repositioned at will. Make simple adjustments to counteract poor air flowability throughout the laboratory, or redistribute the instrument between personnel to maximize returns on investment (ROI).

Fume hoods with a built-in duct are limited by building codes and structures, and once they are installed they cannot be adjusted. They will also be restricted by any existing HVAC infrastructures in place in your facility.

Up-Front and Ongoing Costs

Running cost comparisons of these scientific instruments does not provide a clear-cut answer as to which one is cheaper. Generally, vented fume hoods are more expensive to purchase than filtered alternatives. The filters themselves can represent a significant ongoing cost that can range up to hundreds of dollars per filter in extreme cases. It is important to evaluate your process conditions and requirements ahead of time to determine the cost of your required filters and how often they will need to be replaced.

However, installing a vented fume hood will incur significant labor costs and will require some downtime to prepare the site and subsequently carry out the installation. A filtered fume hood is much less invasive. You may also expect increased energy bills with a vented fume hood due to the fact that the ventilation system will be continuously expelling conditioned air from the building.

Air-Quality and Performance

Air-quality is one of the most critical factors with chemical fume hoods, and this is a factor that can be easily compared. A ductless fume hood cannot guarantee 100% filtered air, as they are often equipped with activated carbon (C) and formaldehyde filters. These catalyze fumes and vapors before the air is recirculated into the working environment. They are extremely efficient, but recirculation is never 100% effective.

While the main benefit of filtered fume hoods is their high mobility, the standout feature of a vented fume hood is its air quality. Process vapors and particulates are exhausted outside into the atmosphere, ensuring optimal air quality in the laboratory environment.

Scientific Instruments from Glas-Col

Glas-Col is one of the leading suppliers of scientific instruments in the US. We supply an extensive range of scientific instruments to academic and industrial-scale facilities across the world, from heating mantles and specialist glassware to high-performance chemical fume hoods.

If you would like to learn more about these discerning scientific instruments, read our previous post Laboratory Equipment: Tips for Optimising Fume Hood Performance. Otherwise, contact us directly with any questions.