ASHRAE+62.1-2022+(1) - Page 010

Extracted Content

2. Time of observations
3. Site description
4. Description of facilities on site and on adjoining properties
5. Observation of odors or irritants
6. Observation of visible plumes or visible air contaminants
7. Description of sources of vehicle exhaust on site and on adjoining properties
8. Identification of potential contaminant sources on the site and from adjoining properties, including any that operate only seasonally c. Conclusion regarding the acceptability of outdoor air quality and the information supporting the con clusion

5. SYSTEMS AND EQUIPMENT

5.1 Building Envelope and Interior Surfaces. The building envelope and interior surfaces within the building envelope shall be designed in accordance with the following subsections.

5.1.1 Building Envelope. The building envelope, including roofs, walls, fenestration systems, and foundations, shall comply with the following:

a. A weather barrier or other means shall be provided to prevent liquid-water penetration into the envelope.

Exception to 5.1.1(a): When the envelope is engineered to allow incidental water penetration to occur

without resulting in damage to the envelope construction. b. An appropriately placed vapor retarder or other means shall be provided to limit water vapor diffusion to

prevent condensation on cold surfaces within the envelope. Exception to 5.1.1(b): When the envelope is engineered to manage incidental condensation without

resulting in damage to the envelope construction. c. Exterior joints, seams, or penetrations in the building envelope that are pathways for air leakage shall be

caulked, gasketed, weather stripped, provided with a continuous air barrier, or otherwise sealed to limit infiltration through the envelope to reduce uncontrolled entry of outdoor air moisture and pollutants.

Informative Note: In localities where soils contain high concentrations of radon or other soil-gas contaminants, the AHJ might impose additional measures such as subslab depressurization.

5.1.2 Condensation on Interior Surfaces. Pipes, ducts, and other surfaces within the building whose surface temperatures are expected to fall below the surrounding dew-point temperature shall be insulated. The insulation system thermal resistance and material characteristics shall prevent condensate from forming on the exposed surface and within the insulating material.

Exception to 5.1.2: Where condensate will wet only surfaces that will be managed to prevent or control

mold growth. A management plan must be submitted along with the design specifying design assumptions and limits of the plan. The plan must be provided to the owner.

5.2 Buildings with Attached Parking Garages. In order to limit the entry of vehicular exhaust into occupiable spaces, buildings with attached parking garages shall be designed to

a. maintain the garage pressure at or below the pressure of the adjacent occupiable spaces, b. use a vestibule to provide an airlock between the garage and the adjacent occupiable spaces, or c. otherwise limit migration of air from the attached parking garage into the adjacent occupiable spaces of

the building in a manner acceptable to the authority having jurisdiction (AHJ).

5.3 Requirements for Buildings Containing ETS Areas and ETS-Free Areas. The requirements of this section must be met when a building contains both ETS areas and ETS-free areas. Such buildings shall be constructed and operated in accordance with Sections 5.3.1 through 5.3.8. This section does not purport to achieve acceptable IAQ in ETS areas.

5.3.1 Classification. All spaces shall be classified as either ETS-free areas or ETS areas. 5.3.2 Pressurization. ETS-free areas shall be at a positive pressure with respect to any adjacent or connected ETS areas.

Exceptions to 5.3.2:

1. Dwelling units, including hotel and motel guestrooms, and adjacent properties under different ownership with separation walls that are structurally independent and that contain no openings. This exception shall apply only when a. the separation walls are constructed as smoke barriers in accordance with the requirements of

applicable standards;

8 ANSI/ASHRAE Standard 62.1-2022