3.2.3 Geographic and Climate Data

The following data needs to be specified or derived in some manner. Software developers may use any acceptable method to determine the data. For instance, zip code could be entered and every thing else could be derived from this. Alternatively, state, county and city could be entered and the other variables could be derived from those. If the software allows for the parameters to be individually specified, then data validation should be employed to verify that the inputs are consistent with each other. Standard 90.1 Appendix B maps U.S. states and counties to the climate zones. Standard 90.1 Appendix D maps U.S. states and cities to additional climate information, including design temperatures.

Zip Code
Applicability	All projects
Definition	One of approximately 44,000 postal designations in the United States
Units	List or text
Input Restrictions	None
Baseline Rules	Not applicable

Latitude
Applicability	All projects
Definition	The latitude of the project site
Units	Degrees (º)
Input Restrictions	None
Baseline Rules	Same as proposed design

Longitude
Applicability	All projects
Definition	The longitude of the project site
Units	Degrees (º)
Input Restrictions	None
Baseline Rules	Same as proposed design

Elevation
Applicability	All projects
Definition	The height of the building site above sea level
Units	Feet (ft)
Input Restrictions	None
Baseline Rules	Same as the proposed design

DOE Thermal Zone
Applicability	All projects
Definition	One of 9 thermal zones defined in ASHRAE 90.1-2004 and later. These are numbered zero (0) through 8. Used to determine building envelope and other criteria.
Units	List
Input Restrictions	None
Baseline Rules	Same as proposed design

DOE Moisture Zone
Applicability	All projects
Definition	One of three moisture zones defined in ASHRAE 90.1-2004 and later
Units	List: Moist (A), Dry (B), or Marine (C)
Input Restrictions	None
Baseline Rules	Same as the proposed design

Time Zone
Applicability	All projects
Definition	The time zone measured from GMT
Units	List
Input Restrictions	Typically derived from other inputs such as zip code or state
Baseline Rules	Same time zone as the proposed design

Daylight Savings Time Observed
Applicability	All projects
Definition	An indication that daylight savings time is observed. The schedules of operation are shifted by an hour twice a year and this affects of solar gains, temperature and other factors
Units	Boolean (True/False)
Input Restrictions	Typically derived from other inputs such as zip code or state
Baseline Rules	Same as the proposed design

State
Applicability	All projects
Definition	State where the project is located
Units	List
Input Restrictions	None
Baseline Rules	Not applicable

County
Applicability	All projects
Definition	The county where the project is located
Units	List
Input Restrictions	None
Baseline Rules	Not applicable

City
Applicability	All projects
Definition	The city where the project is located
Units	List
Input Restrictions	None
Baseline Rules	Not applicable

Design Day Data
Applicability	All projects
Definition	A data structure indicating design day information used for the sizing of the proposed system. Note that this information may not necessarily match the information used in the annual compliance simulation.
Units	Data Structure: contains the following: Cooling Design DB (1%), Cooling Design Wet-Bulb (1%), Heating Design Temperature (99.6%)
Input Restrictions	Must match climate data in Standard 90.1, Normative Appendix D.
Baseline Rules	Not applicable

Weather File
Applicability	All projects
Definition	The hourly (i.e., 8,760 hour per year) weather data to be used in performing the building energy simulations. Weather data must include outside dry-bulb temperature, outside wet-bulb temperature, atmospheric pressure, wind speed, wind direction, cloud amount, cloud type (or total horizontal solar and total direct normal solar), clearness number, ground temperature, humidity ratio, density of air, and specific enthalpy.
Units	Data structure
Input Restrictions	The weather file selected shall be in the same climate zone as the proposed design. If multiple weather files exist for one climate zone then the weather file closest in distance to the proposed design and in the same climate zone shall be used. Weather data should be representative of the long term conditions at the site
Baseline Rules	Weather data shall be the same for both the proposed design and baseline building

Ground Reflectance
Applicability	All projects
Definition	Ground reflectance affects daylighting calculations and solar gain. The reflectance can be specified as a constant for the entire period of the energy simulation or it may be scheduled, which might be appropriate to account for snow cover in the winter.
Units	Data structure: schedule, fraction
Input Restrictions	Default of 0.30
Baseline Rules	Ground reflectance shall be the same for both the proposed design and the baseline building when it is specified to capture snow cover. When specific design features are incorporated to increase or reduce reflectance for the purpose of enhancing daylighting, there can be variation between the proposed design and the standard design, when appropriately documented.