Fume hoods are a neccessity in most laboratory spaces, but they can be costly in energy usage. Over the years, technology and engineering has created more energy efficient fume hoods. These newer hoods operate at the same standards, but with a much smaller carbon footprint. To understand how, first we need to look at how a fume hood actually works.
A fume hood is a safety device thats primary use is to limit exposure to toxic or hazardous fumes and vapors. They do this by containing them within the hood operating area and exhausting them out into the atmosphere. This happens through the use of ductwork and a remote laboratory exhaust fan. These devices are essential for safety, but have a large pull on a lab/building’s energy consumption. Furthermore, fume hoods require a specific volume of air to be exhausted to operate safely and efficiently. This requires the need for supply air to replenish the air being exhausted by the hood. Which, in turn, makes them extremely costly to operate.
Manufacturers are engineering fumehoods to become more efficient in the way they capture and exhaust fumes and vapors. The original baseline has always been, in the United States, 100 feet per minute (FPM). This goes along with a typical set sash height of 18″ above the work surface. Through modeling and engineering, the manufacturers are able to reduce the velocity (speed) of air passing through the sash plane. By reducing the velocity of air from 100 FPM to 80 or even 60 FPM it reduces the cubic feet per minute (CFM, volume) requirements for supply air.
In other words, by reducing the air going out, you are reducing the amount of air needed in. This lowers the total operating cost drastically. People often refer to these newer style of hoods as low flow or high performance fume hoods. These devices are in use in many laboratories throughout the world and bring significant cost savings to the clients and owners. Most importantly, they don’t sacrifice or compromise safety.
Ductless fume hoods have been around for a long time. Their primary use is for low risk or light duty jobs within the laboratory. Ductless hoods operate by passing the contaminated air through a filter media and redistributing it back into the lab. In this case, there’s no need to exhaust the air into the atmosphere or require additional supply air. These devices typically have a charcoal-based filter which absorbs fumes and noxious odors. This prevents those toxins from dispersing back into the laboratory air.
Filtered fume hoods are the new generation of the old ductless style hoods. They operate on the same premise of filtering the contaminated air through a filter media and redistributing it back into the lab. However, the new filtered hoods have come a long way in the technology and chemistry they use to filter the air. These new filters can handle a lot more chemicals and hazardous fumes than its predecessor. Both the ductless and filtered hoods have one giant advantage over ducted: they don’t require mechanical ductwork. Futhermore, there’s no need for exhaust fans or supply air to feed the hood to operate properly. This advantage makes ductless and filtered fume hoods a very popular choice for energy efficiency.
Building owners, clients, architects, engineers, and contrators are all trying to create ways to increase the cost savings of buildings. Laboratory fume hoods, both ducted and ductless/filtered, are a great opportunity for reducing cost and energy consumption. Below is a chart which compares standard ducted 100 FPM hoods to the newer high performance/low flow fume hoods of today. As you can see, the cost savings speak for themselves.
Going one step further and comparing ducted hoods with ductless/filtered hoods, the cost savings are almost immediate. This is because you are completely removing the operating expense and upfront costs of supply air units, ductwork, and laboratory fans. However, you must look at all requirements of what the fume hood will do and what chemicals you will use over the life of the unit.
You can learn more about the difference between new and old fume hoods by checking out our article: New vs. Old Fume Hoods: What’s the Difference? For more tips on how to make your entire laboratory more energy efficient read: LEED Certified and Green Labs. The lab solutions specialists at Haldeman Homme will walk you through every step of the process, finding you the perfect layout for your space. Contact one of our Solutions Experts today to learn more.
This article is for informational purposes only. The results presented are not guaranteed and vary based on the amount of fume hoods, the size of your laboratory, and the mechanics of your building. Consult with an HHI professional for specifics in your laboratory or if you have any questions. Always use proper safety protocols when operating all equipment.