Smart Labs Toolkit

Optimizing Laboratory Ventilation with Computational Fluid Dynamics

Computational fluid dynamics (CFD) analysis is essential for optimizing laboratory ventilation systems, enhancing energy efficiency, safety, and overall lab performance through detailed simulations and strategic design adjustments.

Ventilation is a large topic in laboratory efficiency as it is one of the largest energy consumers in the lab space. CFD analysis deals with the simulation and analysis of fluid flow, heat transfer, mass transfer and other similar transport processes. This process is based on laws of physics and has been routinely applied in a wide variety in industrial areas ranging from aerospace and automotive to competitive sports. The goal of CFD simulations is to convey a wealth of information including time-varying three-dimensional (3D) distributions of air velocity, pressure, temperature, chemical concentrations, and plume dispersion. In terms of laboratory spaces, the information provided by CFD simulations can guide heating, ventilation, and air conditioning (HVAC) design to help develop effective design of laboratory ventilation systems. In early stages of lab design, such analyses can help identify potential issues with HVAC design and develop mitigation strategies to create safe and sustainable spaces.

CFD In Action

In 2023, The United States Department of Agriculture (USDA) collaborated with CPP Wind Engineering Consultants to conduct an internal flow modeling assessment for USDA Forage Animal Production Research Laboratory. The overall goals of this study were to assist the mechanical engineering teams in optimizing the mechanical ventilation system of laboratories inside of main campus buildings. Key design objectives during the analysis were vent placement and velocity optimization for temperature and air exchange effectiveness at 8 air changes per hour occupied. Three spaces in levels 1 and 2 (shown in Figure 1 and Figure 2) in the building were tested and assessed in various configurations.

Map of floor 1 in laboratory.

Figure 1. The spaces assessed in Level 1

Map of floor 2 in laboratory.

Figure 2. The spaces assessed in Level 2

All simulations represent the time-averaged conditions where flow and temperature fields have reached their equilibrium. The configuration of each space focuses on heating and cooling loads along with base air change effectiveness and the optimization of each space. For spaces with façades to the outside two base case simulations representing a cooling and heating mode were analyzed followed by two optimization simulations. For spaces not sharing a façade with the outside, a base simulation followed by an optimization simulation was conducted. The diagrams below share an example of each configuration and the simulations conducted at the Forage Animal Production Research Laboratory.

Data models showing a heating simulation in a lab space

Figure 3. Level 1 space with façade

Another set of data models showing a heating simulation in a lab space

Figure 4. Level 2 space with façade

The heating simulations conducted for each space illustrate how variations in supply air temperature and buoyancy can significantly impact ventilation dynamics. Specifically, the space featuring a façade with significant glazing area demonstrates lower air change effectiveness and inadequate mixing compared to the space without a façade. This variation can be attributed to a multitude of factors, including architectural design, airflow patterns, and thermal characteristics.

The simulations conducted within various spaces at USDA’s research laboratory underscore the effects of over-glazing on lab environments. Excessive glazing can introduce additional heat loads and disrupt efficient air mixing, thereby compromising the overall thermal comfort and performance of the laboratory space. These findings emphasize the critical importance of thoughtful design considerations and optimized ventilation strategies in ensuring the effectiveness and sustainability of laboratory environments.

High level findings from the evaluations included key outcomes involving optimization improvements in the design along with greater context in challenged areas. After CPP completed their analysis of the various spaces in the laboratory, USDA was able to share possible quantitative and qualitative returns of investment from implementing a CFD simulation in their laboratory spaces which include:

  • Improve lab design explicitly
  • Incorporate information from risk analysis to inform potential impacts from higher risk activities
  • Design team incorporates lessons learned from models
  • Provide pilot case to better understand CFD analysis as a tool for lab design
  • Understand the difference between interior and exterior facing labs with significant glazing

CFD at NREL

The National Renewable Energy Laboratory (NREL) recently constructed the new Research and Innovation Lab (RAIL) facility on the main campus in Golden, Colorado, which contains two laboratory spaces. The same group that conducted the CFD analysis at the USDA facility (CPP Wind Engineering Consultants) also performed an internal flow CFD analysis at RAIL to optimize airflow. This analysis took place before the design process, which proved to play a crucial role to optimizing ventilation in the lab space. The proposed laboratory room contained various supply and exhaust, as air is supplied via ceiling-mounted diffusers and exhausted via ceiling exhaust grills, fume hoods, and other equipment.

Several design iterations were simulated to optimize the ventilation performance within the laboratory. The analysis found that the use of laminar diffusers was able to improve ventilation effectiveness performance significantly compared to using two-way radial diffusers. These findings highlight the importance of considering various design options and their impact on airflow dynamics to create an efficient environment built for research and innovation.

CFD and Smart Labs

The Laboratory Ventilation Risk Assessment is a method to provide a systematic evaluation for risks associated with lab operations, involving collaboration between facility and research staff, environmental, health, and safety professionals, and industrial hygienists. The demand for ventilation establishes the current airflow requirements that is used to design systems or compare how systems are currently operating. Quantifying the demand for ventilation enables evaluation of the potential for flow reduction and energy conservation.

Visualizing the three-dimensional airflow patterns and flow path of contaminates helps identify areas where hazardous substances may accumulate and energy inefficiencies due to poor ventilation effectiveness. A CFD analysis can also validate design to ensure safety standards and regulatory requirements are met. By identifying potential areas of concern through CFD analysis and correlating them with the risk assessment, measures can be taken to mitigate exposure risks.

A key factor in the Smart Labs process is to integrate various technologies and best practices to enhance the efficiency and safety of laboratory operations. CFD analysis can be used to optimize the type and placement of advanced systems within laboratory spaces to monitor and control airflow, temperature, and contaminant levels. This enables adaptive ventilation strategies that respond dynamically to changing laboratory conditions, ensuring optimal safety and energy efficiency.

Use CFD in Your Next Laboratory Project

The cutting-edge technology of Computational Fluid Dynamics (CFD) analysis represents a transformative tool for both developing a design plan and enhancing existing laboratory spaces. By grasping the complexities of ventilation and airflow patterns, CFD analysis offers valuable insights that can revolutionize the efficiency and safety of laboratory environments.

Key Takeaways

  • Ventilation efficiency is crucial for laboratory sustainability and energy conservation.
  • CFD simulations offer detailed understanding of airflow dynamics, temperature distributions, and contaminant dispersion.
  • Practical application of CFD analysis demonstrated in the case studies demonstrate the effects over-glazed labs have on ventilation effectiveness
  • Integration of CFD with Smart Labs initiatives enhances efficiency and safety through real-time monitoring and adaptive ventilation strategies.