ASHRAE-90.1-2022- - Page 046

Extracted Content

5.3 Simplified Building Compliance Path (Not Used)

PRESCRIPTIVE TRADE-OFF

INSTALL AND LABEL PRODUCTS CORRECTLY

SEMIEXTERIOR AIR BARRIER EXCEPTION.

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5.4 Mandatory Provisions requirements found in Section 5.8.1. 5.4.1 Insulation. Where insulation is required in Section 5.5 or Section 5.6, it shall comply with the INSTALL AND LABEL PRODUCTS CORRECTLY PRESCRIPTIVE TRADE-OFF

5.4.2 Fenestration and Doors. Procedures for determining fenestration and door performance are described in Section 5.8.2. Product samples used for determining fenestration performance shall be production line units or representative of units purchased by the consumer or contractor.

5.4.3 Air Leakage

a. Air leakage control for the building envelope shall comply with this section. Materials and assemblies

that are part of the continuous air barrier and fenestration and doors shall comply with Section 5.8.3.

air barrier of an adjacent conditioned space . 2. Single wythe concrete masonry buildings in Climate Zone 2B.

leakage of the building envelope shall not excee d 0.35 cfm/ft [2] under a pressure differential of 75 Pa (0.30 in. of water), with this air leakage rate normalized by the sum of the above- grade and below- grade building envelope areas of the conditioned space and semiheated space and in accordance with this section.

a. Whole- building pressurization testing shall be conducted in accordance with ASTM E3158. For buildings

less than 10,000 ft [2] of gross conditioned floor area, and that contain no more than one single-zone system, air leakage testing may be conducted in accordance with ASTM E779, ASTM E1827, or ASTM E3158. Testing shall be conducted excluding HVAC related elements and be performed by an independent thirdparty verification and testing provider in accordance with Section 4.2.5.1. b. Where a building contains both conditioned space and semiheated space, compliance shall be shown

using one of the following as applicable:

1. Separately for the conditioned space and for the semiheated space, with the air leakage rate for the conditioned space normalized by the exterior building envelope area of the conditioned space and the air leakage rate for the semiheated space normalized by the semiexterior building envelope area of the semiheated space
2. For the conditioned space and for the semiheated space together, with the air leakage rate for the overall space normalized by the sum of the exterior building envelope area and the semiexterior building envelope area minus the semiexterior building envelope area that separates the conditioned space from the semiheated space c. Where the measured air leakage rate exceeds 0.35 cfm/ft [2] but does not exceed 0.45 cfm/ft [2], a diagnostic

evaluation, such as a smoke tracer or infrared imaging, shall be conducted while the building is pressurized, and any leaks noted shall be sealed if such sealing can be made without destruction of existing building components. In addition, a visual inspection of the air barrier shall be conducted, and any leaks noted shall be sealed if such sealing can be made without destruction of existing building components.

44 ANSI/ASHRAE/IES Standard 90.1-2022 (I-P)