Why You Need Effective Ventilation In Parking Garage Design
Whether you’re adding underground parking to a building design or freestanding parking structure, you should pay special attention to ventilation.
Parking garage ventilation is an essential consideration for building designers due to the role it plays in ensuring the safety, comfort, and well-being of the building occupants. Proper ventilation in parking garages is how pollutants, such as carbon monoxide, that can accumulate from the exhaust fumes vehicles emit, are removed. Effective ventilation is also an opportunity to achieve energy and cost savings in the parking garage.
Here is why you should always thoughtfully consider proper ventilation when designing parking garages and the top strategies for implementing the most efficient and cost-effective ventilation system.
Why Is Improving Ventilation Effectiveness Vital in Parking Garage Design?
Air pollutants in an enclosed space, such as a parking garage, can negatively impact human health fast – faster than many believe. Parking garage ventilation systems play a vital role in controlling the environment inside the garages and ensuring the safety of those who use them. Insufficient parking garage ventilation can fall short of building codes, negatively impact human health, and increase project costs.
Here are the top reasons why you should boost the effectiveness of your parking garage’s ventilation:
Building Code Compliance
Regulating codes contain specific requirements that must be met. Natural ventilation for a parking garage must meet certain criteria for the areas and arrangements of openings and mechanical ventilation systems must provide minimum quantities of fresh air. While meeting the building code requirements can achieve adequate ventilation in most cases, specific designs of parking garages may still have some stagnant areas that are under-ventilated.
Impact on Human Health
Parking garages can experience a buildup of gases when there is insufficient ventilation. The most dangerous of these gases, when it comes to human health impacts, are carbon monoxide and nitrogen dioxide. Carbon monoxide is colorless and odorless, though it often appears alongside other gases. Thus, if you smell car exhaust in a parking garage, you are likely breathing in carbon monoxide.
Achieve Cost Savings
When planned properly, effective ventilation can also create cost savings, potentially reducing both equipment and energy costs. For instance, a ventilation modeling analysis may show that a smaller fan could match the performance of a larger fan in a given space, and as a result, reduces equipment size and cost. Modeling analyses can also reveal more effective locations for fan placement as well as account for variations of activity level.
This could help quantify the potential for reduced energy consumption and therefore reduced energy costs if the exhaust can be designed to be activated only at certain times, such as during high traffic periods like morning and evening rush hours in an office parking garage.
Comparing Natural Ventilation and Mechanical Ventilation
Above ground parking garages may have multiple types of ventilation designs available to dilute and remove air pollutants and ensure adequate air quality in the garage
- Natural ventilation (if sufficient openings to outdoors can be provided)
- Continuous mechanical ventilation (potentially with standby and high flow modes using CO and NO2 sensors)
- A combination of natural and mechanical ventilation: On-demand mechanical ventilation by means of CO and NO2 sensors
Natural ventilation harnesses the differences in air pressure inside and outside of a structure through wind forces and stack effect to provide structures with clean air and appropriate clearing of pollutants. It is highly dependent on the design of the building and its surroundings, such as how exterior openings are distributed relative to common wind directions, the use of decorative screens, and the proximity of nearby buildings.
For parking garages, mechanical ventilation typically involves the installation of exhaust fans. These fans extract stale air from the garage and induce fresh air to enter from outdoors through direct openings to exterior, plenums, ducts, or ventilation wells. The layouts of these ventilation openings are vital in determining whether all areas of a parking garage are adequately ventilated. A layout design that hasn’t been adequately analyzed may result in poor air quality once the building is constructed and in use, leading to costly corrective measures and retrofits.
Strategies for Effective Ventilation in Parking Garage Design
Effective parking garage ventilation is key to not only meet prescriptive code requirements, but also mitigate potential health impacts and elevate the design of the parking garage. Parking garage ventilation design can be improved in the early design stages of a project, both for brand new builds as well as garage renovations. This not only helps achieve the air quality performance targets, but also lowers potential costs over the long-term.
Here are the 2 major steps for choosing the best ventilation solution for your parking garage:
Pollutant Emission Modeling
Pollutant emission modeling is an incredibly useful tool to provide informed input parameters for parking garage ventilation design. It works by developing an estimate for peak traffic flow conditions, that is, the number of cars starting, idling, and queueing in the parking garage. The model considers how the emission rates are affected by the local climate and the local mix of vehicle types. These are combined to determine how much pollutants vehicles are emitting into the air in computational fluid dynamics (CFD) simulations.
Computational Fluid Dynamics (CFD) Simulations
The analysis can range from a CFD simulation of air movement inside the parking garage to more complex models including both the parking garage and impacts of site wind conditions. CFD simulations can provide details on air quality distribution within the garage, thus revealing opportunities to boost effectiveness, such as placing fans and air vents in strategic locations to better circulate and ventilate the garage.
These simulations can also track the path of air pollutants, show how they are likely going to flow through the garage, and calculate the concentration distribution of pollutants. In the case of carbon monoxide, the simulation can identify how quickly CO can build up to an unsafe concentration.
CFD is also capable of analyzing a parking garage’s ventilation system and evaluating its performance. It can help generate the necessary data to provide to regulatory bodies for atypical designs and improve the layout of vents, fans, and exhausts.
Moving Forward with Effective Parking Garage Ventilation
Parking garage ventilation provides fresh air from the outdoors and ensures stale, contaminated air is flushed out. A well-designed ventilation system offers enhanced air quality, safety, and comfort to occupants – all while introducing significant equipment and energy cost savings.
Achieving an effective ventilation system means testing the proposed design with a range of tools to reveal potential issues and mitigate them where they arise. This isn’t only to remain in compliance with local building codes – it is also to minimize the potential health impacts on those who use the parking garage and reduce long-term energy use by enhancing the effectiveness of the design.