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2019 Energy Code- Chapter 4

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2019 Energy Code- Chapter 4 Table of Contents Page 4-i Table of Contents 4 Mechanical Systems .............................................................................................................. 1 4.1 Overview......................................................................................................................... 1 4.1.1 HVAC Energy Use ................................................................................................... 2 4.1.2 Mandatory Measures ............................................................................................... 2 4.1.3 Prescriptive and Performance Compliance Approaches .......................................... 3 4.2 Equipment Requirements ............................................................................................... 4 4.2.1 Mandatory Requirements ......................................................................................... 4 4.2.2 Equipment Efficiency ............................................................................................... 5 4.2.3 Equipment Not Covered by the Appliance Efficiency Regulations .......................... 19 4.2.4 Controls for Heat Pumps with Supplementary Electric Resistance Heaters ........... 19 4.2.5 Thermostats ........................................................................................................... 20 4.2.6 Furnace Standby Loss Controls ............................................................................. 21 4.2.7 Open and Closed Circuit Cooling Towers .............................................................. 21 4.2.8 Pilot Lights ............................................................................................................. 21 4.2.9 Commercial Boilers ................................................................................................ 24 4.3 Ventilation Requirements .............................................................................................. 25 4.3.1 Natural Ventilation ................................................................................................. 26 4.3.2 Mechanical Ventilation ........................................................................................... 27 4.3.3 Direct Air Transfer .................................................................................................. 33 4.3.4 Distribution of Outdoor Air to Zonal Units ............................................................... 34 4.3.5 Ventilation System Operation and Controls ............................................................ 34 4.3.6 Pre-Occupancy Purge ........................................................................................... 41 4.3.7 Demand Controlled Ventilation ............................................................................. 43 4.3.8 Occupant Sensor Ventilation Control Devices ........................................................ 46 4.3.9 Fan Cycling ........................................................................................................... 47 4.3.10 Adjustment of Ventilation Rate ............................................................................... 49 4.3.11 Acceptance Requirements ..................................................................................... 50 4.4 Pipe and Duct Distribution Systems .............................................................................. 51 4.4.1 Mandatory Measures ............................................................................................. 51 4.4.2 Prescriptive Requirements for Space Conditioning Ducts ...................................... 58 4.5 HVAC System Control Requirements ........................................................................... 60 4.5.1 Mandatory Measures ............................................................................................. 60 4.5.2 Prescriptive Requirements ..................................................................................... 80 4.5.3 Acceptance Requirements ..................................................................................... 96 2016 Nonresidential Compliance Manual January 2017 Page 4-ii Table of Contents 4.6 HVAC System Requirements ........................................................................................ 96 4.6.1 Mandatory Requirements ....................................................................................... 96 4.6.2 Prescriptive Requirements ..................................................................................... 98 4.7 Water Heating Requirements ...................................................................................... 109 4.7.1 Service Water Systems Mandatory Requirements ............................................... 111 4.7.2 Mandatory Requirements for High-Rise Residential and Hotel/Motel ................... 114 4.7.3 Prescriptive Requirements for High-Rise Residential and Hotel/Motel ................. 116 4.7.4 Pool and Spa Heating Systems ........................................................................... 119 4.8 Performance Approach ............................................................................................... 120 4.9 Additions and Alterations ............................................................................................ 121 4.9.1 Overview ............................................................................................................. 121 4.9.2 Mandatory Measures – Additions and Alterations ................................................ 122 4.9.3 Requirements for Additions .................................................................................. 124 4.9.4 Requirements for Alterations ............................................................................... 124 4.10 Glossary/Reference .................................................................................................... 129 4.10.1 Definitions of Efficiency ........................................................................................ 129 4.10.2 Definitions of Spaces and Systems ...................................................................... 130 4.10.3 Types of Air ......................................................................................................... 131 4.10.4 Air Delivery Systems ............................................................................................ 132 4.10.5 Return Plenums ................................................................................................... 132 4.10.6 Zone Reheat, Recool and Air Mixing ................................................................... 132 4.10.7 Economizers ........................................................................................................ 133 4.10.8 Unusual Sources of Contaminants ....................................................................... 137 4.10.9 Demand Controlled Ventilation ............................................................................ 137 4.10.10 Intermittently Occupied Spaces ........................................................................... 138 4.11 Mechanical Plan Check Documents............................................................................ 138 4.11.1 Field Inspection Checklist .................................................................................... 138 4.11.2 Mechanical Inspection ......................................................................................... 140 4.11.3 Acceptance Requirements ................................................................................... 140 2016 Nonresidential Compliance Manual January 2017 Mechanical Systems –Overview Page 4-1 4 Mechanical Systems 4.1 Overview The objective of the Building Energy Efficiency Standards (Energy Standards) requirements for mechanical systems is to reduce energy consumption while maintaining occupant comfort. These goals are achieved by: 1. Maximizing equipment efficiency, both at design conditions and during part load operation 2. Minimizing distribution losses of heating and cooling energy 3. Optimizing system control to minimize unnecessary operation and simultaneous use of heating and cooling energy The Energy Standards also recognize the importance of indoor air quality for occupant comfort and health. To this end, the Energy Standards incorporate requirements for outdoor air ventilation that must be met during all operating conditions. This chapter summarizes the requirements for space conditioning, ventilating, and service water heating systems for non-process loads in nonresidential buildings. Chapter 10 covers process loads in nonresidential buildings and spaces. This chapter is organized as follows: Section 4.1 provides an overview of the chapter and the scope of the mechanical systems requirement in the Energy Standards. Section 4.2 addresses the requirements for Heating, Ventilation, and Air Conditioning (HVAC) and service water heating equipment efficiency and equipment mounted controls. Section 4.3 includes mechanical ventilation, natural ventilation, and demand controlled ventilation. Section 4.4 covers construction and insulation of ducts and pipes and duct sealing to reduce leakage. Section 4.5 covers control requirements for HVAC systems including zone controls and controls to limit reheating and recooling. Section 4.6 covers the remaining requirements for HVAC systems, including sizing and equipment selection, load calculations, economizers, electric resistance heating limitation, limitation on air-cooled chillers,
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