Air Curtain Vestibule RequirementASHRAE Approves Air Curtains as an Exception to the Vestibule Requirement

The leading policy-maker for the heating, refrigeration and air-conditioning industry has formally approved the use of adequately certified and installed air curtains as an exception to the vestibule requirement.

This new standard is effective with the 2019 edition of ASHRAE/IES Standard 90.1-2019, Energy Standard for Buildings Except for Low-Rise Residential Buildings. It is similar to the guidelines first established by the International Code Council (ICC), effective with its 2015 International Energy Conservation Code (IECC). However many states continued to defer to ASHRAE 90.1.

The ASHRAE version mirrors but is not identical to the IECC. It spells out previously approved exceptions to the vestibule requirement but adds two provisions regarding the use of air curtains.

These exceptions allow for:

Self-closing doors in buildings in Climate Zones 0, 3, and 4 that have an air curtain complying with Section 10.4.5.

Self-closing doors in buildings 15 stories or less in Climate Zones 5 thru 8 that have an air curtain complying with Section 10.4.5.

The new standard is a much-anticipated move for the robust air curtain industry. The decision comes after an intense examination of air curtains and their effectiveness in comparison to vestibules for energy savings.

How Air Curtains Work and Their Benefits

An air curtain separates one environment from another by creating a “curtain” of projected, moving air over the opening of a doorway. The wall of air acts as an invisible barrier, preventing outside air penetration.

Air curtains, like those manufactured by Powered Aire Inc., tout energy savings, climate control, comfort, and the capability to repel flying insects in a variety of commercial applications.

Until recently, their use and effectiveness as a vestibule replacement were left up for debate. Recent studies, however, showed air curtains save more energy when compared to vestibules according to comprehensive studies commissioned by the Air Movement and Control Association and Concordia University.

ASHRAE 90.1 Vestibule Exception Standard

Section 10.4.5 of the ASHRAE 90.1 vestibule exception standard sets the criteria for approved vestibule exception air curtains.

“Air curtain units shall be tested in accordance with ANSI/AMCA 220 or ISO 27327-1 and installed and commissioned in accordance with the manufacturer’s instructions to ensure proper operation and shall have a jet velocity of not less than 6.6 feet per second (2.0 m/s) at 6.0 in (15 cm) above the floor and direction not less than 20 degrees toward the opening. Automatic controls shall be provided that will operate the air curtain with the opening and closing of the door.

Powered Aire Inc. currently offers four AMCA-rated models that meet the criteria for replacing a vestibule.  Models are installed out of sight, above doorways or ceilings allowing for a building’s aesthetics to be uninterrupted.

Contact Air Control Products for more information about Powered Aire Air Curtains for your establishment.