ASHRAE-90.1-2022- - Page 211

Extracted Content

Design energy cost = as calculated in Section 12.5 Energy cost budget = as calculated in Section 12.5 c. The energy efficiency level of installed components and systems that meets or exceeds the efficiency lev els used to calculate the design energy cost . d. For new buildings, one of the following is met:

1. The building envelope complies with Section 5.5, “Prescriptive Building Envelope Compliance Path.”
2. Using Section 5.6, “Building Envelope Trade-Off Compliance Option,” the proposed envelope per- formance factor shall not exceed the base envelope performance factor by more than 15% in multifamily residential, hotel/motel, and dormitory building area types. For all other building area types, the limit shall be 7%. For buildings with both residential and nonresidential occupancies, the limit shall be based on the area-weighted average of the gross conditioned floor area . e. Verification, testing, and commissioning requirements of Section 4.2.5 shall be met. f. Proposed building systems, controls , or building envelope documented in Table 12.7.2(d) that do not have criteria in Sections 5 through 10 shall have verification or testing to document proper installation and operation in accordance with Section 4.2.5. Informative Note: The energy cost budget and the design energy cost calculations are applicable only for determining compliance with this standard. They are not predictions of actual energy consumption or costs of the proposed design after construction . Actual experience will differ from these calculations due to variations such as occupancy, building operation and maintenance, weather, energy use not covered by this standard, changes in energy rates between design of the building and occupancy, and precision of the calculation tool.

12.3 Simplified Option (Not Used)

12.4 Simulation General Requirements 12.4.1 Simulation Program. The simulation program shall be a computer-based program for the analysis of energy consumption in buildings . For components that cannot be modeled by the simulation program, the exceptional calculation methods requirements in Section 12.4.5 shall be used.

Exception to 12.4.1: When approved by the adopting authority, a separate computer-based program shall

be permitted to be used to calculate on-site renewable energy .

Informative Note: ASHRAE Standing Standard Project Committee 90.1 recommends that the simula- tion program implement the rules of Section 12 that control simulation inputs and outputs be adopted for the purposes of easier use and simpler compliance.

12.4.1.1 The simulation program shall be approved by the adopting authority and shall, at a minimum, have the ability to explicitly model all of the following:

a. 8760 hours per year b. Hourly variations in occupancy, lighting power, miscellaneous equipment power, thermostat set points,

humidity set points, and HVAC system operation, defined separately for each day of the week and holidays c. Thermal mass effects d. Ten or more thermal zones e. Part-load performance curves for mechanical equipment f. Capacity and efficiency correction curves for mechanical heating and mechanical cooling equipment g. Air-side economizer and fluid economizer with integrated control h. The budget building design characteristics unless otherwise specified in Section 12.5

12.4.1.2 The simulation program shall have the ability to either

a. directly determine the design energy cost and energy cost budget or b. produce hourly reports of energy use by energy source suitable for determining the design energy cost

and energy cost budget using a separate calculation.

12.4.1.3 The simulation program shall be capable of performing design load calculations to determine required HVAC equipment capacities and air and water flow rates in accordance with Section 6.4.2 for both the proposed design and the budget building design .

12.4.1.4 Simulation Program Testing Requirements 12.4.1.4.1 The simulation program shall be tested according to ASHRAE Standard 140, except for Sections 7 and 8 of Standard 140. The required tests shall include building thermal envelope and fabric load tests (Sections 5.2.1, 5.2.2, and 5.2.3), ground coupled slab-on- grade analytical verification tests (Section 5.2.4),

ANSI/ASHRAE/IES Standard 90.1-2022 (I-P) 209