Balancing Safety and Sustainability: Consulting at the Early Design Stage to Provide a High-Performance Building
Aimée Smith, Rowan Williams Davies & Irwin, Inc. (RWDI)
Consideration of exhaust dispersion and associated re-entrainment issues early in the design process is critical to provide a high-performance laboratory building that successfully implements energy-saving design techniques while protecting the building from infiltration of odors and other chemicals/emissions. Energy-reducing design techniques that could influence exhaust dispersion and safety include:
- Low energy use exhaust fans (variable volume flow and/or low discharge velocity)
- Co-generation support utilities and associated exhausts
- Openings in the building envelope (vents, windows, transitional spaces)
- Unique rooftop features (photovoltaic panels, wind/solar chimneys)
- Other natural ventilation features (wind scoops/towers)
When exhaust dispersion performance and location/design of these design features is considered late in the laboratory design process, it can be very challenging to optimize these sustainable strategies while ensuring environmental health and safety objectives are met.
It is a common misconception that exhaust dispersion modeling and the potential for re-entrainment should be considered later in the design process after the mechanical design has been significantly developed. In fact, consideration of these aspects at this stage of design, can limit the ability for changes to the exhaust and intake design, and feasible mitigation strategies are limited. In many cases, the mitigation options available at this stage of design will be in direct conflict with the architectural and sustainable goals for the project. Exhaust dispersion issues should be considered in an iterative and interactive manner throughout the design process, and not just as a modeling exercise near the end of the design process.
Considering these issues early in the design process can be critical to the success of strategies like natural ventilation. There may be existing conditions that could compromise the quality of air drawn into the laboratory, and potentially affect the sustainable features of the building (i.e., if natural ventilation openings will be impacted by an existing neighboring emission source). This is often overlooked at the early stages of design because the team members are typically focused on the design of the building itself.
Specific examples and case studies will be used to demonstrate the benefits of considering exhaust dispersion and potential emission infiltration during the early stages of laboratory design, and how this approach is critical to ensure a laboratory will meet sustainability and energy use goals, while satisfying appropriate safety objectives.
Biography:
Aimée Smith, associate, is a project director, with 10 years of consulting experience. Ms. Smith provides technical direction and leadership over a wide range of projects involving the science of high-performance buildings and specializes in exhaust re-entrainment studies for the design of building exhaust and air intake systems for laboratory, health care and other non-laboratory facilities (e.g., mixed use hospitality/residential and retail facilities). Ms. Smith has a masters degree in civil and environmental engineering and is a registered professional engineer in the province of Ontario. Ms. Smith provides design ideas to clients, gives technical direction, and ensures quality control measures are followed in RWDI work. She also leads research and development efforts for her team.