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Custom Hoods, Fans, & Stacks


Off-the-shelf hoods, fans, & stacks often don't provide the level of efficiency required.  Even though they look simple, there is a large amount of engineering that goes into designing hoods.  Hoods are where ventilation systems start, and a poorly engineered hood will create a domino effect of bad performance in your system.  Off the shelf hoods are even less likely to perform because they must work in harmony with the rest of your system. There are very specific criteria to designing a hood that will work properly and if your vendor can't explain slot face velocity, hood design (shape etc), slot size, plenum velocity, etc all relative to your 

This "classic" type of hood is called a lateral and is the most common.  It is installed at the back of a tank and draws fumes from both the surface and off the parts as they are moved from one tank to the next.

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There are many types of hoods like this very large canopy hood.  Canopy hoods are used where overhead clarance is not a concern.  A drawback to canopy hoods is that they consume much, much more air than other types of hoods.  Chicago Plastic Systems builds many styles and sizes of hoods to meet our customers' needs.  We always meet or exceed the design standards of the ACGIH and SMACNA

Another type of hood is this polypropylene benchtop lab hood.  When the doors are closed, it draws very little air, requiring less energy to operate.  Hoods can be fabricated from any of the materials we work with.

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Low profile downdraft hoods like this one fill the space between 2 tanks and draw fumes from both sides.  This allows for maximum overhead clearance, but doesn't draw fumes off the parts being lifted from the tank.  There are advantages to each type of hood, so call us to help with selection for your project.


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FANS

Fans are the heart of a ventilation system. Chicago Plastic systems provides all types of fans to complete your project​​​​​​​, but the overwhelming majority are centrifugal fans.  These are the most cost efficient and economical to run.  We usually recommend corrosion resistant materials like fiberglass or plastic, but there are applications where a metal fan is best suited.  Fan sizing, like hood design can cause a system to not work properly.  Specifications like, wheel diameter, width percentage, speed and static pressure all contribute to the performance.  Rely on Chicago Plastic Systems to help you select the correct fan for the job whether it's a new install, replacement fan or blower for push air.

Centrifugal fans are best suited for corrosive ventilation.  Besides combining the best static performance and lowest operating costs, they are the most durable.  They are available in a wide variety of sizes and configurations to fit almost any application up to 60,000 cfm.

Axial fans are sometimes specificed by our customers because their initial cost is lower than other types.  One drawback is that they don't have very high static performance and therefore need to be carefully evaluated to determine feasibility.

Push blowers are another type of fan supplied by Chicago Plastic Systems used as part of a push-pull exhaust system.    While they are one of the most overlooked parts of a corrosive ventilation system, they can easily be specified incorrectly.  Let us help you with the proper selection of your blower today.

STACKS

Stacks are the point which the captured/cleaned air exits the building.  Like the other parts that make up a corrosive ventilation system, they are engineered​​​​​​​ for the customer's application. We fabricate different types of stacks for each job and take into consideration such things as stack velocity, maintenance and use, and environmental considerations.  Some types of stacks we build are no loss stacks, velocity stacks, backdraft stacks, and rain caps. Usually, stacks are made from PVC, but we can build them from CPVC, Polypro or other materials as 

These are called backdraft stacks.  Inside the larger top section is a kind of flapper that rests against a seat when the fan isn't running to prevent rain and snow from entering the stack.  When the fan is turned on, the air forces the flaps up for air to escape

The stacks pictured here are very tall to ensure that their discharge is above the roofline of the building.  Chicago plastic systems designs and installs the proper supports for all the stacks we build