Building Your Bench Top Fume Hood

When building your lab, you want to make sure you choose the right equipment that is best suited for your needs. At Genie Scientific, we offer multiple fume hood designs tailored to use. In this article we examine one of our most sought after fume hoods, the bench top fume hood. Genie Scientific’s Vice President of Operations, Garrett LeVan, addresses how to choose the correct fume hood, while walking us through the building and pricing process.

How can clients get started in deciding which fume hood is right for their lab?

One of the main starting points when determining what fume hood is right for the customer is their required interior working dimensions. What is the internal height, width, and depth you need to safely perform the experiment inside the fume hood?  Measure out the footprint of your equipment and apparatus that will be going in the hood.  You also want to keep in mind any plans for the future, you want to have the flexibility to expand without overloading the hood.  

Does Genie offer different size options for a bench top fume hood?

We offer our bench top fume hoods in six standard widths and three standard depths, so it gives the client a lot of flexibility even within our standard product line. You can find a link to our specific sizing here.

What is the most common sash type for a bench top fume hood?

A vertical rising sash is the most commonly ordered for bench top fume hoods. It is less expensive than other styles due its simplicity.  Our Vertical Sash is driven by our PowerLink™ chain and sprocket counter balance system back by a never-fail LifeTime Warranty. 

What is the next step after deciding on sash style?

After you pick your sash style, we want to talk about the interior liner. This is the inside lining of the fume hood that comes in direct contact with the chemicals, vapors, fumes etc. that you’re working with during your experiment. Our standard liner material is our ChemTough fume hood liner. It is a superior general-purpose liner made from phenolic resin and has excellent resistance to a broad range of chemicals; it is also fire rated. This liner is structurally sound, so you can screw things directly into it and you don’t need to worry about damaging the hood.

Do you offer any other types of liners?

We offer stainless steel, polypropylene, and more

What other variants do you need to take into account when creating the fume hood?

Airflow requirements are the most critical. You must identify what type of airflow requirements, as well as the exhaust and bypass type you want in your fume hood. There’s two distinct positions on a fume hood. The first is when the vertical sash is fully open-- that’s called set up position. This becomes the maximum opening to allow the loading of the fume hood. (It’s important to double check this measurement and make sure your equipment is not greater than the opening measurement, so you can load your items properly.) The second is the operating position, that is the position of the sash when the experiment is being performed.

Depending on your airflow needs and operating position, you then choose from two bypass types on your fume hood. There is the option of open bypass constant volume exhaust system, which is the most common for labs. The other option is a restricted bypass that goes with a variable air volume exhaustive system. A VAV (variable air volume) is an exhaustive system that typically maintains fume hood face velocity by adjusting lower motor speeds, in response to changes in sash position. This type is normally used when there is a multitude of hoods at a facility, as it becomes expensive to run on a singular fume hood.

 

What aspects affect the cost of the fume hood the most?

The items that can have the greatest cost impact are the fume hood accessories.  There are many options for electrical, plumbing,

A bench top fume hood sits directly on top of base cabinet.  You can select from a simple welded table frame to specialty storage cabinets for acids or flammable solvent storage with self-closing doors.

  • Table Frame – A welded 4 leg tube table
  • Standard Base Cabinets – Steel cabinets with 2 doors and a shelf
  • Corrosive Storage – Steel cabinet with a molded one-piece polyethylene liner so safety store Acid or Bases.  Cabinet can be vented into the fume hood if desired
  • Vacuum Pump Cabinet – Steel cabinet designed to house a vacuum pump. The unit is sound deadened and has outlets to power the pump
  • Flammable Cabinet – Double wall steel cabinet with self-closing doors to protect flammable chemicals from a fire in the lab

You can read more about our bench top options here.

 

Next, we look at plumbing options. Fixtures are factory mounted on the hood and plumbed with hard copper pipe so the plumber in the field can make a quick and easy final connection.  Standard fixtures are for compress air, gas, nitrogen and cold water.  Specialty fixtures for pure water and steam are available with a variety of outlets.

 The standard electrical package for our hood comes with:

  • (2) 120V-20AMP GFI Duplex Outlets
  • (1) Light Switch wired to vapor proof T8 florescent light fixtures
  • (1) Blower Switch with illumination pilot light
  • (1) Analog Airflow Monitor

All items are prewired to a junction box on top of the hood making life easy for the electrician to make the final connection to the building power. We can install any type of electrical on the fume hood and wire it to a junction box. We also offer explosion proof fixtures for class 1 division 1 environments.

After all these decisions have been made based on the clients needs, the information is handed to our estimator team where a quote will be built and given to the client.

 

Pricing Your Lab Furniture & Fume Hood

Genie Scientific offers a wide range of standard items, but also excels in customizing materials for your lab. With the backbone of skilled craftsmanship and the daily exciting to push beyond our comfort zone, Genie can build your lab to suit the exact specifications you desire. Made-to-order designs, like anything else have a pricing process enabling you full transparency with your purchase. Below a Genie Scientific estimator, James DiLorenzo has answered several questions about our pricing process at Genie.

How does the process begin?

It starts with a sales lead from our team. They determine what the customer is looking for,  i.e. something custom or not. We chart all of our sales activity, then I generate a price to give the customer so they can decide whether or not they want to do business with us.

Next, we start something called “the take off”. The customer will write out all the equipment or we’ll look at drawings the customer provided and get dimensions.  Based on what they want, we start filling in the blank with items they desire. Here we’re using our expertise to ascertain what items fit within the confines of the room and we write out what they want. From there I enter this information into our accounting software and pull prices, or make custom prices based on if something is normal or niche. I dial in the pricing worksheet and include margins based on engineering, if it’s outsources or in-house, the quantity, as well as lingering details like freight/crating . These details get added up to a final price that the customer can act on.

Are there any other variants that you take into account when pricing steel designs?

Before tax, everything is material and labor. Say it’s a standard cabinet, we have a built in price for that since we make it often. But if its something with specific dimensions, I go in and find price materials and add our standardized labor rate and overhead. Once we add material and labor, we add our markup and tax. Then we need to account for consultations, architectural drawings and submittals, engineering, crating and securing of the product for delivery, freight, and depending on the project size we charge for site visits.

Tell me more about estimating cost for fume hoods--

A lot of the time, customers will ask for one of two types of fume hoods: bench top and walk-in fume hoods. We have standardized lines for both and often customers request fume hoods that meet these parameters. We have 3-8ft bench top and walk-in fume hoods.

At what point does a fume hood become a custom project?

If the project is not within our standardized height and depth or requires different materials, it becomes a  custom item. If it’s explosion proof, if they want certain types of doors, if they want certain types of electrical plumbing fixtures, we design it.  I should also mention that if someone is buying a bench top fume hood, we provide base cabinets at a cheaper cost.

Other custom designs include a variety of saches. The sache is the door or opening for the fume hood. We offer vertical sliding or horizontal rising saches and we offer combination saches that have sliding glass windows on a vertical rising window. We do different types of liners, steel and resin, chemical and heat resistant, based on what the customer is working with. We also offer electrical fixtures that we can prewire into the hood. Plugs, light switches, plumbing lines for water, air, and different gases.

Any other information you’d like to share about Genie?

Just to advise prospective clients that we may not be as big as companies in the Midwest, but because of that we have a more hands on approach to our projects and are fortunate enough to work with an incredibly skilled team. We are used to creating things that are outside of our comfort zone, so no project is too small or too big for us to tackle.

Comparing Steel vs Plastic Casework For Your Lab

As with any design or structural element of your laboratory, intended use is the focal point of the equipment you source. Consider what are you are going to be using your equipment for and how the surrounding environment might affect this chosen or required placement. The two most common types of lab casework are metal and plastic laminate. In the following article we will discuss the pros and cons of each type for your lab.

Steel Casework - When choosing steel casework for your lab, there are two common materials to choose from: carbon cold-rolled steel with a powder coated finish and stainless steel.

Cold-rolled steel is less expensive than stainless and is most common in the industry. The cold-rolled steel sheet production process is referred to as the cold plate. Its sheet thickness is usually between 0.1 and 8.0mm, most commonly 4.5mm or less. It is painted and powder coated, giving the user more design options. Cold-rolled steel is not resistant to everything, but great value in terms of strength, durability, and aesthetic.

Stainless is mostly used when a high-level of sterility is necessary. It’s most commonly found in high corrosive and high-moisture environments. It is also commonly found in hospitals, morgues, labs working with blood or biological agents, or any lab that might experience a high level of abuse. Stainless steel is easily cleaned, will not rust and is recyclable.

Using steel casework for your lab has countless benefits over plastic laminate. It is the strong choice, with longer shelf life, that can withstand tough abuse experiments and has various chemical resistances when diving deeper into more specific types of metals. The lead-time for stainless or carbon-rolled lab equipment is longer than plastic cabinetry, as the welding and polishing aspect proves more difficult due to the durability of the product. For these very reasons they are also more sought after and trusted.

High-pressure, Plastic Laminate Casework

When choosing high-pressure, plastic laminate casework for your lab there is an option for standard grade or chemical resistant. This is ideal is you’re looking to build your lab on a budget, however depending on the indented use of the material it might not be wise. We explain more below.

Standard grade is the off-the-shelf, non-custom plastic material used in a wide range of circumstances.

Chemical resistant plastic is just as it sounds, it is customizable to withstand various chemicals during your experiment.

High-pressure laminate, otherwise known as plastic laminate, is easy to care for and made at a lower cost.  Plastic laminate has a hard, smooth, durable and easy-to-clean surface with a vast selection of colors and patterns. A few of your typical plastic laminate manufactures are Wilsonart, Formica, Nevamar and LisStat

The composition of high-pressure laminate is a melamine top sheet laid up on a MDF or particleboard core. Its application is made for light duty areas, like a break room or example laboratory. It also applies to special application processes like Electric Static Dissipative (ESD). Plastic laminate is ideal for shelving.

Deconstructing Epoxy vs Phenolic Resin for Your Laboratory

What is epoxy resin?

Epoxy is an adhesive, plastic, and paint or coating material used in a wide range of products. It is made from a mixture of materials, including (list here) , and then cured as a solid product.

When combined with plastic, epoxy is used as the resin mold to hold the plastic in place. It’s compatible with all common reinforcing fibers including fiberglass and carbon fiber, but epoxies cater to the desired application, experiment or manufacturing process. 

There are various advantages to using epoxy resin, but the main consideration is heat. Epoxy is an optimal material when dealing with higher temperatures in your laboratory, with a range capability of 300-350º C. Additional advantages include:

  1. Environmental and moisture degradation resistance
  2. Resistance to a wide range of chemicals
  3. High mechanical strength and impact resistance
  4. No volatile organic compounds

The main downside to using epoxy resin on your countertops is both the weight and the sourcing. Epoxy is very heavy, which adds to its durability but will also add in transportation and installment costs. In terms of sourcing, there is currently only one epoxy manufacturer in the world, which will give you less flexibility in cost and delivery terms.

What is phenolic resin?

Phenolic resin is a type of synthetic resin originally called Bakelite. It is heat-cured and formed from a reaction between carbon-based alcohol and aldehyde. In regards to laboratory equipment, phenolic resin carries almost all of the same properties as epoxy resin but at a lower cost to the client.

Phenolic resin is ideal for lab environments where contamination is a key concern. Phenolic resin is oil and moisture resistant, as well as resistant to most bacteria and fungus. As with epoxy, phenolic resin is optimal for environments working with high heats (up to 350ºF/ 176ºC).

At Genie we recommend using phenolic resin because it is locally sourced, which means lower cost and efficient delivery times for your projects. It’s also easier to work with, install, and it’s not as heavy giving it more customizable options.  Additional advantages include:

  1. Structurally sturdy
  2. Considered the new standard in a wide range of laboratories
  3. Can be mixed with a wide range of materials
  4. One of the very first plastics to be sold commercially
  5. Fire resistant