ASHRAE+62.1-2022+(1) - Page 054
Extracted Content
(This appendix is not part of this standard. It is merely informative and does not contain requirements necessary for conformance to the standard. It has not been processed according to the ANSI require- ments for a standard and may contain material that has not been subject to public review or a consen- sus process. Unresolved objectors on informative material are not offered the right to appeal at ASHRAE or ANSI.)
INFORMATIVE APPENDIX H APPLICATION
This appendix contains application and compliance suggestions that are intended to assist users and enforcement agencies in applying this standard.
Although the standard may be applied to both new and existing buildings, its provisions are not intended to be applied retroactively when it is used as a mandatory regulation or code.
For the most part, Standard 62.1 is specifically written for new buildings because some of its requirements assume that other requirements within the standard have been met. In the case of existing buildings, retroactive application and compliance with all the requirements of this standard may not be practical. However, the principles established in this standard may be applied to most existing commercial and institutional buildings. Some existing buildings may achieve acceptable IAQ despite not meeting the requirements of Standard 62.1 due to, for example, good maintenance and capital improvement procedures; building materials that, by virtue of their age, have very low contaminant emission rates; and many other factors.
H1. APPLICATION
H1.1 New Buildings. All sections and normative appendices should apply to new buildings falling within the scope of this standard.
H1.2 Existing Buildings. The standard should be applied to existing buildings at least in the circumstances described in the following subsections.
H1.2.1 Additions to Existing Buildings. All additions to existing buildings should meet the requirements of this standard as if the addition were a new building. An exception may be made when an existing ventilation system is extended to serve the addition. In this case, the existing system components, such as fans and cooling and heating equipment, need not meet the requirements of this standard. However, the extended existing system should remain in compliance with ventilation codes and standards that were in effect at the time it was permitted for construction.
H1.2.2 Repairs. Repairing (making operational) existing equipment or other building components does not require the building or any of its components to retroactively comply with this standard.
H1.2.3 Replacement. Any component of a building that is removed and replaced should meet the applicable requirements of Section 5, “Systems and Equipment,” for that component. An exception may be made in cases when replacing a component of like size and kind, provided all requirements of codes and standards used at the time of original system design and installation are met. For example, replacement of an air-conditioning unit with one of similar capacity would not require retroactive compliance with ventilation rates and other requirements of this standard. Unaltered components do not need to be retroactively brought into compliance except when there are substantial alterations (as defined below).
H1.2.4 Substantial Alterations. If a building is substantially altered, the requirements of this standard should be met as if the building were new. A building would be considered substantially altered if the cost of the revisions exceeds 50% of the building’s fair market value, excluding the cost of compliance with this standard.
H1.2.5 Change in Use. If the space application category, as listed in Table 6-1, changes—such as from office to retail—the minimum ventilation rates required by Section 6, “Procedures,” should be met for that space.
H1.2.6 Contaminants. Ventilation requirements of this standard are based on chemical, physical, and biological contaminants that can affect air quality.
H1.2.7 Thermal Comfort. Control of thermal comfort is not required by this standard. Requirements for thermal comfort are contained in ASHRAE Standard 55. Note that there are strong correlations between peoples’ perception of IAQ and their perception of thermal comfort.
H1.2.8 Limitations. Acceptable IAQ might not be achieved in all buildings meeting the requirements of this standard for one or more of the following reasons:
a. Because of the diversity of sources and contaminants in indoor air
52 ANSI/ASHRAE Standard 62.1-2022