ASHRAE-90.1-2022- - Page 287
Extracted Content
operation and maintenance, weather, energy use not covered by this procedure, changes in energy rates between design of the building and occupancy, and the precision of the calculation tool.
C3.1.3 The simulation program shall be capable of performing design load calculations to determine required HVAC equipment capacities and airflow rates in accordance with Section 6.4.2 for both the pro- posed design building envelope and the base design building envelope .
C3.1.4 Simulation Program Testing Requirements
C3.1.4.1 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), space -cooling equipment performance tests (Section 5.3), space -heating equipment performance tests (Section 5.4), and air-side HVAC equipment analytical verification tests (Section 5.5), along with the associated reporting (Section 6).
C3.1.4.2 The test results and modeler reports shall be posted on a publicly available website and shall include the test results of the simulation program and input files used for generating the results along with the results of the other simulation programs included in ASHRAE Standard 140, Annexes B8 and B16. The modeler report in Standard 140, Annex A2, Attachment A2.7 shall be completed for results exceeding the maximum or falling below the minimum of the reference values and for omitted results.
C3.1.4.3 The testing shall be performed for the version of the simulation program used to calculate the proposed envelope performance factor and base envelope performance factor .
Informative Notes:
- There are no pass/fail criteria established by this requirement.
- Based on the Section 3 definition, simulation program includes the simulation engine and the corresponding user interface. The testing of a simulation program only meets the requirements of Section C3.1.4 for that simulation program and cannot be used as proxy for documenting compliance of another simulation program that uses the same simulation engine .
C3.2 Climatic Data. The simulation program shall perform the simulation using hourly values of climatic data, including temperature, humidity, solar radiation, and wind speed and direction from representative climatic data, for the proposed design building envelope location. For cities or urban regions for which several climatic data sources are available and for locations for which weather data are not available, the designer shall select available weather data that represent the climate at the construction site . Selected weather data shall be approved by the authority having jurisdiction .
C3.2.1 Surface Exposure. Semiexterior surfaces separating conditioned spaces from unconditioned spaces shall be simulated as exterior surfaces with no exposure to wind or solar radiation.
C3.3 Purchased Energy Rates. The following rates for purchased energy shall be used to determine the proposed envelope performance factor and the base envelope performance factor :
a. Electricity: 0.98/therm
Exception to C3.3: Where approved by the authority having jurisdiction, actual annual rates for purchased
energy or state average energy prices published by the Department of Energy’s Energy Information Administration shall be permitted. The same rates shall be used for both the proposed envelope perfor- mance factor and the base envelope performance factor .
C3.4 Compliance Calculations. The proposed envelope performance factor and base envelope perfor- mance factor shall be calculated using the same
a. simulation program, b. climatic data, and c. purchased energy rates .
C3.5 Calculation of Proposed Envelope Performance Factor. The simulation model for calculating the proposed envelope performance factor shall be developed in accordance with Sections C3.5.1 through C3.5.11.
C3.5.1 Space Conditioning. All conditioned spaces in the proposed design shall be simulated as being both heated and cooled, even if no cooling or heating system is being installed. Temperature control set points and schedules shall be consistent with those in the building envelope trade-off schedules and loads for the applicable building area type. All semiheated spaces shall be simulated as being heated and not cooled. The heating temperature control set point shall be 50°F for all hours.
ANSI/ASHRAE/IES Standard 90.1-2022 (I-P) 285