The V-Series Lab Exhaust Fan - A New Way to Exhaust Fumes from Labs

In laboratory design across North America, it's common to see large, metal-clad exhaust systems with dilution nozzles towering over rooftops. These systems aim to minimize re-entrainment by diluting hazardous fumes with ambient air. While the intention is sound, the assumption that dilution is the only compliant strategy is increasingly outdated. Enter the V-Series — a high-performance, corrosion-resistant lab exhaust solution developed by PLASTEC Ventilation.

100% Corrosion Resistance with Polypropylene

The V-Series is made entirely from polypropylene (PP), offering unmatched resistance to corrosive gases like hydrochloric acid, sulfuric acid mist, and other aggressive compounds commonly found in lab exhaust. Unlike metal systems that require heavy coatings or exotic alloys to survive in harsh environments, the V-Series is inherently resistant to chemical attack, offering durability without added complexity or cost.

High Velocity Discharge: 3,000 FPM by Design

Where traditional systems use dilution to achieve low concentrations near air intakes, the V-Series takes a different approach: momentum-driven plume rise.

• Discharge velocity: 3,000 feet per minute (fpm) through a speed nozzle
• Optional vertical stack extension: 5 to 10 feet to further enhance plume rise
• No dilution air required: the system exhausts the full airflow volume at high speed, preserving total mass flow while maximizing vertical momentum

This results in a tall, narrow, and efficient plume that rapidly carries contaminants above rooftop level — even in the presence of crosswinds.

Why Dilution Isn’t Always Necessary

ANSI/ASHRAE and ANSI Z9.5 standards don’t mandate dilution. They require that exhaust systems prevent hazardous exposure at air intakes or occupied areas. The key metric is effective dispersion, not the use of ambient air.

According to plume rise calculations (Briggs model):

Where:

• : plume rise (meters)
  
  
• : exhaust velocity (m/s)
  
  
• D : stack diameter (m)
  
  
• U: wind speed at stack height (m/s)

Increasing exhaust velocity  is often more effective at increasing plume height than diluting with ambient air.

A well-directed high-momentum exhaust can outperform bulkier, diluted flows.

This is further supported by Gaussian plume dispersion models, which show that increasing the effective stack height exponentially reduces contaminant concentration at ground level and nearby intakes.

Where:

 

• : contaminant concentration at ground level (µg/m³)
  
  
• Q : pollutant mass flow rate (µg/s)
  
  
• u : wind speed at stack height (m/s)
  
  
• 
  : horizontal and vertical dispersion coefficients (m)
  
  
• H: effective stack height (m), including plume rise

This equation illustrates that as H increases, the exponential term sharply reduces ground-level concentration — making vertical momentum a powerful tool for compliance.

Translation: With a focused, fast-moving plume, the V-Series can achieve the same (or better) dispersion without extra fans, inlets, or larger infrastructure.

The Hidden Cost of Dilution

Adding dilution to an exhaust system often means increasing the total airflow volume significantly — sometimes by 50% or more. While this lowers the concentration of contaminants, it also comes with real energy costs:

• More air requires a larger fan required
• Larger fans require higher motor horsepower
• High horsepower motors require more electricity consumption

For example, doubling the airflow to achieve dilution could easily require a motor with 2 to 3 times the power, depending on system resistance. This leads to:

• Higher upfront equipment costs
• Increased energy bills over the system's life
• Oversized ductwork and support structures

In contrast, the V-Series achieves effective dispersion without artificially inflating system volume, keeping energy consumption and costs in check.

Compact, Compliant, Cost-Effective

The V-Series allows lab designers to:

• Reduce structural loads and footprint (lightweight PP vs. heavy coated metal)
• Eliminate dilution fans and reduce power consumption
• Simplify installation with standard stack sections and pre-configured controls
• Lower total installed cost and lifecycle maintenance

Designed for Modern Labs

From academic campuses to biotech facilities, laboratories are increasingly seeking safer, simpler, and more sustainable solutions. The V-Series delivers on all three fronts:

• Corrosion-proof construction
• Energy-efficient operation
• ANSI/ASHRAE compliance by design

For engineers and designers ready to rethink lab exhaust, the V-Series offers a powerful alternative. Same protection, smaller footprint, better value.