ASHRAE Standard90.2 2018
$67.71
ASHRAE Standard 90.2-2018 – Energy-Efficient Design of Low-Rise Residential Buildings (ANSI Approved)
| Published By | Publication Date | Number of Pages |
| ASHRAE | 2018 | 106 |
ASHRAE/IES Standard 90.2 establishes minimum whole-building energy performance requirements (design, construction, and and verification) for energy-efficient residential buildings.This 2018 revision of Standard 90.2 seeks to deliver residential building energy performance that is at least 50% more efficient than the energy efficiency defined by the 2006 IECC. Changes from the 2007 edition include:* New definitions, and clarifications to existing definitions* Clarification of which elements of the standard apply to new construction as well as to additions and alterations* Guidance on the use of international climate data from Standard 169 for users outside of the U.S.* Clarification to prescriptive envelope performance data tables* New performance specifications for ground-source heat pumps* Clarification on minimum lighting efficiency provisions for single-family, large single-family, and multifamily homes* Clarification on pool heater pilot lights, pump motor efficiency, and roof and gutter de-icing systems* Clarification on compliance verification authority in locations outside of the U.S.* Revisions to emphasize key building data and reports necessary for compliance determination * Clarification for modeling software requirements* Clarification for lighting modeling requirements* Clarifications to address multizonal building air-leakage testing procedures* A new normative appendix that addresses proper installation techniques for critical components of buildings that provide thermal resistance
PDF Catalog
| PDF Pages | PDF Title |
|---|---|
| 1 | ANSI/ASHRAE/IES Standard 90.2-2018 |
| 3 | CONTENTS |
| 5 | 1. PURPOSE 2. SCOPE 2.1 Buildings and Portions of Buildings Covered 2.2 Systems Covered 2.3 Exemptions. This standard does not apply to the following: 2.4 Health, Safety, and Welfare. This standard shall not be used to abridge any safety, health, or environmental requirements. 3. DEFINITIONS, ABBREVIATIONS, AND ACRONYMS |
| 6 | 3.1 Definitions |
| 8 | 3.2 Abbreviations and Acronyms 4. ADMINISTRATION AND ENFORCEMENT |
| 9 | 4.1 Application 4.2 Authorization. Administrative requirements relating to construction permit requirements, enforcement, locally adopted energy standards, regulatory interpretations, claims of exemption, and rights of appeal are specified by the authority having ju… 4.3 Alternative Materials, Methods of Construction, or Design. The provisions of this standard are not intended to prevent the use of any material, method of construction, design, equipment, or building system not specifically prescribed herein. 4.4 Severability. If any term, part, provision, section, paragraph, subdivision, table, chart, or referenced standard of this standard shall be held unconstitutional, invalid, or ineffective, in whole or in part, such determination shall not be deeme… 4.5 Other Laws. The provisions of this standard shall not be deemed to nullify any provisions of local, state, or federal law. Where there is a conflict between a requirement of this standard and such other law affecting construction of the building,… 4.6 Referenced Standards. The standards referenced in this standard are part of the requirements of this standard to the prescribed extent of such reference. Where differences occur between the provision of this standard and referenced standards, the… 4.7 Normative Appendices. The normative appendices to this standard are part of the requirements of this standard. 4.8 Informative Appendices. The informative appendices to this standard, and informative notes located within this standard, contain additional information and are not requirements for compliance with this standard. 4.9 Reference Standard Reproduction Annexes. The reference standard reproduction annexes contain material that is cited in this standard but contained in another standard. The reference standard reproduction annexes are not part of this standard but … 4.10 Construction Documents 4.11 Climate. Determine the climate zone for the location. For U.S. locations, follow the procedure in Section 4.11.1. For international locations, follow the procedure in Section 4.11.2. 5. ADDITIONS AND ALTERATIONS 5.1 Additions. Additions to existing dwelling units shall comply with either Sections 5.1.1 or Section 5.1.2 |
| 10 | 5.2 Alterations. Alterations to existing dwelling units shall be such that the altered dwelling unit uses no more energy than the existing dwelling unit prior to its alteration. Alterations to existing dwelling units shall comply with Sections 5.2.1 … 6. PERFORMANCE RQUIREMENTS 6.1 The dwelling unit shall be planned, designed, and constructed to achieve the Energy Rating Index (ERI) by climate zone shown in Table 6-1. 6.2 The ERI of the proposed design shall be determined using the energy simulation program conducted in accordance with ANSI/RESNET/ICC Standard 301-2014, including Addenda A-2015 and E-2018, as modified by the modeling requirements included in Norma… 6.3 On-Site Power Utilization. When on-site power production is used to meet the ERI requirements of Section 6.1, the following requirements for building thermal envelope and envelope air leakage shall be met. 6.4 Performance Verification and Compliance Reporting 7. REQUIREMENTS 7.1 Building Thermal Envelope Components 7.2 HVAC Systems |
| 11 | Table 5-1 Central Air Conditioner and Heat Pump Specifications (I-P) Table 5-1 Central Air Conditioner and Heat Pump Specifications (SI) Table 5-2 Gas Furnace and Gas Boiler Specifications Table 5-3 Water Heater Minimum Efficiency Table 6-1 Maximum Energy Rating Index for Compliance with This Standard |
| 12 | Table 6-2 Maximum SHGC and U-factors When On-Site Power Is Used (I-P Units) Table 6-2 Maximum SHGC and U-factors When On-Site Power is Used (SI Units) 7.3 Indoor Environmental Quality |
| 13 | 7.4 Potable Water Heating Table 7-1 Envelope Component Maximum SHGC and U-factors (I-P) Table 7-1 Envelope Component Maximum SHGC and U-factors (SI) |
| 14 | Table 7-2 Minimum R-Value and Insulation Depth for Slab Constructions when On-Site Power Is Used (I-P) a Table 7-2 Minimum R-Value and Insulation Depth for Slab Constructions when On-Site Power Is Used (SI) a |
| 15 | 7.5 Lighting Table 7-3 Maximum Branch Length (I-P) Table 7-3 Maximum Branch Length (SI) |
| 16 | 7.6 Other Systems |
| 17 | 8. VERIFICATION 8.1 Minimum Provisions 8.2 Building Envelope Verification |
| 18 | 8.3 Mechanical Systems Verification 8.4 Lighting Systems 8.5 Potable Hot-Water Systems 8.6 Other Mechanical Systems. Other regulated mechanical systems included in the proposed design shall be verified to match the proposed design and to be installed according to manufacturer instructions. 8.7 On-Site Power Systems Verification. When on-site power production is present and used for compliance, the following shall be verified: 8.8 Re-Inspection and Testing. Where any work or installation does not pass the initial test or inspection, the nonconforming work or installation shall be reported in writing to the AHJ, owner, and contractor, and the necessary corrections shall be … 9. REPORTING REQUIREMENTS 9.1 Compliance Reporting. The simulation program shall generate reports documenting compliance of the proposed design and the owner, or owner’s authorized agent, shall deliver compliance reports to the authority having jurisdiction (AHJ) timely wit… |
| 19 | 9.2 Other Documentation |
| 20 | 10. NORMATIVE REFERENCES |
| 22 | NORMATIVE APPENDIX A: SOFTWARE REQUIREMENTS A1. Simulation Program A1.1 The simulation program shall be approved by the rating authority and shall, at a minimum, have the ability to explicitly model all of the following: A1.2 The simulation program shall have the ability to produce hourly reports of energy use by energy source. A1.3 The simulation program shall be capable of performing design load calculations or using the output from ANSI/ ACCA 2 Manual J software to determine required HVAC equipment capacities and air and water flow rates in accordance with Section 7.2 fo… A1.4 The simulation program shall be tested according to ASHRAE Standard 140, Sections 7 and 8, except for Sections 7.2.3 and 8.2.2, and the results shall be furnished by the software provider. A1.5 The simulation program shall generate reports documenting compliance of the proposed design with Sections 7 and 6. Compliance documentation shall include the following information regarding the building, its site, and the simulation: A1.6 The simulation program shall incorporate the rule set from ANSI/RESNET/ICC Standard 301 along with all the modifications to that rule set required in Normative Appendix B, “Modeling Rule Set,” such that the following apply: A2. Simulation Requirements A2.1 Performance Calculations. The proposed building performance and baseline building performance shall be calculated using the following: A2.2 Climatic Data. The simulation program shall perform the simulation using hourly values of climatic data, such as temperature and humidity from representative climatic data, for the city in which the proposed design is to be located. For cities o… A2.3 The calculation procedure shall not allow the user to directly modify the building component characteristics of the Energy Rating Index reference design or the index adjustment design. |
| 23 | NORMATIVE APPENDIX B: MODELING RULE SET B1. Requirements for performance modeling B1.1 General. This section provides normative requirements for the simulation program and process used to generate the Energy Rating Index (ERI) score. Once software providers have complied with these requirements, and the simulation program is accep… B1.2 Energy Modeling Rule Set for Determining the Energy Rating Index of the Proposed Design. The rule set used to determine the ERI shall be in accordance with ANSI/ RESNET/ICC Standard 301-2014, except where noted in Table B-1. Table B-1 Energy Rating Index (ERI) Input Variables for Use with ASHRAE Standard 90.2 for Purposes of New Construction Compliance Calculationsa (Continued) |
| 24 | Table B-2 Lighting Control Credits |
| 25 | NORMATIVE APPENDIX C: AIR LEAKAGE TESTING C1. Air Leakage Testing C1.1 Testing shall be performed by a fan pressurization technique in accordance with ASTM E779, ASTM E1827, or ANSI/RESNET/ICC 380, Section 3. C1.2 Testing shall be permitted to be conducted at any point after the building has been enclosed. C1.3 Single-Zone Buildings. Single-zone buildings shall be tested with a single fan pressurization test and represent the leakage rate for the entire structure. C1.4 Multizone Buildings. Multizone buildings shall be permitted to be tested either as an individual zone or by inducing equal pressures in adjacent zones. Multizone buildings shall have a random sample of a minimum 20% of all zones tested, includin… C1.5 Test Protocol |
| 26 | NORMATIVE APPENDIX D: INSTALLATION REQUIREMENTS D1. Installation of Insulation Materials— General Requirements D1.1 Insulation materials shall be installed in accordance with the requirements of this appendix, the insulation manufacturer’s installation instructions, or applicable industry standards for insulation installation. D1.2 Installed insulation materials, amounts, and locations shall comply with the proposed design. In no case shall installed insulation amounts be less than those required to deliver the maximum U-factors defined in Tables 6-2 or 7-1, as applicable. D1.3 Installed insulation materials shall fully cover all areas requiring insulation in accordance with the proposed design. D1.4 Insulation installations shall be essentially absent of gaps, voids, compression, buckling, and damage that are readily observed by normal inspection practices. Inspections for and corrections of noncompliant installations shall occur prior to e… D1.5 Insulation materials that are intended to also serve as an air barrier shall comply with the air barrier requirements of ASHRAE/IES Standard 90.1, Section 5.4.3.1.3, at the installed thickness and shall be installed in accordance with the manufa… D2. Installation of Materials Other than Insulation that Provide Thermal Resistance D2.1 Air Spaces D2.2 Wood Framing |
| 27 | INFORMATIVE APPENDIX E: PROCEDURES FOR GENERATING PRESCRIPTIVE PATHS E1. Prescriptive Compliance Guides E1.1 Worst-Case Home Plan Guides. For a specific home plan to be constructed in a specific weather location, a set of prescriptive specifications may be developed such that under the worst-case home orientation the specified home plan will comply wit… E1.2 Local Area Prescriptive Guides. For a specific weather location, a prototype home configured in accordance with Section E1.2.1 shall be used to generate local area prescriptive guides for the specified weather location. Figure E-1 Isometric schematic of prototype to be used for Sections E1.2 and E1.3 of this procedure. E1.3 Climate Zone Prescriptive Guides. For a specific climate zone, a prototype home configured in accordance with Section E1.3.1 shall be used to generate climate zone prescriptive guides for the specified climate zone. |
| 28 | E2. Compliance Guide Documents E2.1 Conditioned Space Enclosures E2.2 Equipment E2.3 Lighting and Appliances E2.4 Applicability E2.5 Compliance. The compliance guide shall provide summary documentation of the ERI results of the simulation analysis showing that the compliance guide conforms to the requirements of Section E1.1, E1.2, or E1.3 of this procedure. Table E-1 Weather Locations |
| 29 | INFORMATIVE APPENDIX F: EXAMPLE OF NAECA PRESCRIPTIVE PATH F1. Existing Building Envelope F1.1 Envelope components shall be in accordance with Table F-1. F1.2 Fenestration. Fenestration shall be limited as follows: F1.3 Envelope leakage not to exceed 5 ACH50 in Climate Zones 1 and 2, and 3 ACH50 in Climate Zones 3 through 8. F2. Mechanical Systems F2.1 Heating, cooling, and water heating equipment efficiencies shall be in accordance with 10 CFR Section 430. F2.2 Forced-air distribution systems located entirely within the conditioned space with a substantially leak-free air distribution system, where substantially leak-free is defined as leakage to outdoors not exceeding 3 cfm25 per 100 ft2 (10 m2) of co… F2.3 ANSI/ASHRAE Standard 62.2 compliant whole-house mechanical ventilation systems. F3. Lighting F3.1 Lighting equipment efficacies shall be in accordance with Section 7.5.2. Use the required lighting controls in Section 7.5.2. F4. On-Site Power F5. Appliances and Other Systems F6. Reference Standards |
| 30 | Table F-1 Maximum SHGC and U-Factors (I-P) Table F-1 Maximum SHGC and U-Factors (SI) Table F-2 On-Site Power Table |
| 31 | INFORMATIVE APPENDIX G: DUCTS IN CONDITIONED SPACE G1. DUCTS IN CONDITIONED SPACE G1.1 The duct system is located completely within the continuous air barrier and within the building thermal envelope. G1.2 The ducts are buried within ceiling insulation when all of the following conditions exist: G2. Detailed Duct Design |
| 33 | Figure G-1 Sample floor plans for locating ductwork in second floor of (a) two-story house and (b) townhouse. (Source: 2016 ASHRAE Handbook—HVAC Systems and Equipment; Chapter 10, “Small Forced-Air Heating and Cooling Systems,” pp. 10.5) Figure G-2 Sample floor plans for one-story house with (a) dropped ceilings, (b) ducts in conditioned spaces, and (c) right-sized air distribution in conditioned spaces. (Source: 2016 ASHRAE Handbook—HVAC Systems and Equipment, Chapter 10, “Small… Figure G-3 (a) Ducts in unconditioned spaces and (b) standard air distribution system in unconditioned spaces. (Source: 2016 ASHRAE Handbook—HVAC Systems and Equipment; Chapter 10, “Small Forced-Air Heating and Cooling Systems,” pp. 10.6) |
| 34 | Figure G-4 Buried and encapsulated ducts are separated into three categories based on the height of the loose-fill insulation. Source: https://basc.pnnl.gov/resource-guides/ducts-buried-attic-insulation-and-encapsulated Figure G-5 Three methods can be used to encapsulate ductwork to mitigate condensation issues. Source: https://basc.pnnl.gov/resource-guides/ducts-buried-attic-insulation-and-encapsulated Table G-1 Effective R-Values of Buried Ducts by Duct Insulation and Burial Depth |
| 35 | INFORMATIVE APPENDIX H: STEP-BY-STEP APPROACH FOR CALCULATING LIGHTING ENERGY USING THE PERFORMANCE PATH H1. Prefatory notes H2. Procedure |
| 36 | INFORMATIVE APPENDIX I: PLAN REVIEW INSPECTION CHECKLIST Table I-1 Sample Plan Review Inspection Checklist |
| 37 | INFORMATIVE APPENDIX J: SITE INSPECTION CHECKLIST Table J-1 Sample Site Inspection Checklist (Continued) |
| 39 | INFORMATIVE APPENDIX K: FRAMING FACTORS Table K-1 Envelope Assemblies Framing Factors |
| 40 | ANNEX 1: REFERENCE STANDARD REPRODUCTION ANNEX—ASHRAE STANDARD 169 |
| 42 | Table Annex1-1 U.S. Climate Zones by State and County |
| 56 | Table Annex1-2 Canada Stations and Climate Zones [Note: Design Conditions tables (SI and I-P) for each station, named by WMO#, can be accessed online at www.ashrae.org/169_2013data) |
| 61 | Table Annex1-3 International Stations and Climate Zones (Note: Design Conditions tables [SI and I-P] for each station, named by WMO#, can be accessed online at www.ashrae.org/ 169_2013data.) |
| 101 | A3. Climate Zone Definitions |
| 102 | Table Annex1-4 Thermal Climate Zone Definitions |
| 103 | Figure Annex1-2 World climate zones map. |
