Consulting in the science of buildings, structures and environment

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• Air Quality Overview

  Numerical and wind tunnel modeling are effective technologies available to assess exhaust dispersion and the re-entry of contaminants into a building.

  Our expert consultants help quantify the impact of pollutants on health and comfort for facility users and neighboring areas in this highly specialized field of study.

  Early in the design process, RWDI works with owners and design teams to develop air intake and exhaust system designs that minimize re-entrainment of hazardous and/or odorous exhausts.

  You might also find value in our Ventilation services.

• Benefits

  Reduce energy consumption: Allow energy reductions in buildings by confirming that sufficient dispersion and dilution of contaminants is achieved with lower exhaust flow rates and exit velocities. 
  
  Reduce occupant exposure: Optimize the location of intakes and the design of stacks and reduce building occupant exposure to unsafe levels of airborne contaminants and nuisance odors.
  
  Prevent costly retrofits and user complaints: Addressing problematic air contamination conditions at the design stage.
  
  Safety and health: Promotes a safe and healthy indoor/outdoor environment.

• Issues

  Exhaust re-entrainment occurs when exhausts become captured within the wind wake of a structure resulting in the exhaust impacting sensitive indoor and outdoor spaces.  Attention is required for the following:

  • Odor related complaints from users
  • Indoor environmental quality
  • Occupant health safety and wellness
  • Community safety
  • Reduced risk

  An exhaust re-entrainment study (often referred to as a wind wake analysis) can be conducted using numerical or physical modeling methods.

• Resources

  Information Sheets

  • Enhanced Safety & Energy Reduction in Laboratories
  • Healthcare Facilities - Where RWDI Can Help
  • Studying Exhaust Re-entrainment - How it Works
  • Exhaust Re-entrainment Studies - Benefits and Key Features
  • Sustainable Laboratory Design

  Technotes

  • Reducing The Risk Of Contamination From Laboratory Fume Hood Exhaust
  • Designing For Success: Save Time And Money With A Design Review (Page 2)
  • Boston Central Artery / Third Harbor Tunnel Project (Page 4)
  • Odour Control Basics (Page 1)
  • Stack Exit Velocity - What It Can And Cannot Do (Page 2)
  • Air Intake Placement For Laboratories - A General Overview
  • A Dilution Criterion For Laboratory Fume Hood Exhaust Stacks
  • Transit Station Fires Part 1 - Problem Of Separation Of Exhausts And Intakes
  • Transit Station Fires Part 2 - Separation Of Exhausts And Intakes: Modeling And Solution Concepts
  • Modeling of Helicopter Exhaust at Emergency Health Care Facilities
  • Medical Cyclotrons: Evaluating Impacts to meet Air Quality Standards
  • Optimizing Exhaust Stack Design and Placement
  • Reducing Environmental Impacts due to Construction Activities