Introduction to Our White Paper on NFPA 88A Parking Garage Requirements

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Drawing Awareness to Inconspicuous Parking Garage Requirements

As a consulting engineer, you're well-versed in the importance of designing effective and efficient ventilation systems to comply with the International Mechanical Code (IMC) and applicable state and local codes for enclosed and underground parking garages. However, some municipal and regional building codes adopt lesser-known standards that require additional design considerations. One such standard is NFPA 88A, developed by the National Fire Protection Association, which has recently been updated in its 2023 publication.

What’s New in NFPA 88A 2023?

Before 2023, NFPA 88A did not mandate mechanical ventilation for enclosed or underground parking garages. The updated 2023 version, however, includes new requirements that sometimes necessitate the use of mixing fans, also known as jet fans, even in spaces that meet the minimum criteria to be classified as open parking garages.

Key Requirements Retained from NFPA 88A 2019

Ventilation:

All enclosed parking structures must be ventilated by a mechanical system capable of providing a minimum of 1 ft/min per ft² of floor area (300 L/min per m²) during normal operation hours.

Mechanical ventilation is not required in open parking structures.

Mechanical ventilating systems must be installed per NFPA 90A.

Ductwork must be constructed of noncombustible material.

New Additions in NFPA 88A 2023:

Mixing Fans Specifications:

Must ensure no more than 10% of the space volume has air velocities below 1.3 ft/s (0.4 m/s).

Must be arranged to distribute supply air throughout the structure.

Design documentation must be provided by a registered design professional.

Must be controlled with an electronic interface to the automatic fire suppression system and fire detection and alarm system.

Control systems must turn off the fans when the fire suppression system is activated and provide post-fire override operations.

When Mixing Fans are Required:

If the shortest distance between any point of supply air to the closest point of exhaust air exceeds 300 ft (91 m).

In open parking structures where opposing openings are greater than 300 ft (91 m).

When supply or exhaust fans result in an average air velocity below 1.3 ft/s (0.4 m/s).

From these updated requirements, it's clear that mixing fans are not typically necessary for open parking garages. However, in cases where the opposing openings exceed 300 ft (91 m), or the distance between supply and exhaust air points is greater than 300 ft (91 m) in enclosed garages, jet fans become mandatory.

Fresh Air, Clear Minds

Designing parking garages remotely presents unique challenges. It's crucial to remember that your next project may differ significantly from previous ones, especially with the evolving code requirements. Here are some helpful tips to consider in your initial design:

Verify Code Language

Ensure you understand the CFM per SF of floor area requirements.

Consider DCV Options

Systemair offers gas detection controls to enhance your project's energy efficiency.

Understand Definitions

Check the applicable codes to determine what constitutes an 'open' parking garage.

To delve deeper into these updates and how Systemair’s jet fans can help you meet these requirements, download our detailed white paper.