Specify the Geographic Location

When you create a project, define its geographic location using the street address, nearest major city, or the latitude and longitude.

This project-wide setting is useful for generating location-specific shadows for views that use them, such as solar studies and walkthroughs.

The location provides a basis for weather information, which is used during energy analysis.

For building systems engineers, the weather information also directly affects heating and cooling requirements for a project.

1. Click Manage tabProject Location panel Location.
2. In the Location Weather and Site dialog, click the Location tab.
3. For Define Location by, select one of the following:
   • Default City List: Displays a list of major cities from which to select a location. Until you specify a different project location, the location is defined as <Default> and is set to the longitude and latitude of the major city specified for your locale. No Internet connection is required. When you select a city from the Default City List, the Weather tab is populated with data from the closest weather station listed in the 2007 ASHRAE Handbook.
     Note: The Default City List option is recommended for HVAC sizing.
   • Internet Mapping Service: When your computer is connected to the Internet, this option displays an interactive map through the Bing™ mapping service. Until you specify a different project location, the location is defined as <Default> and is set to the longitude and latitude of the major city specified for your locale.

     Autodesk Subscription members also have access to a list of weather stations for selecting weather data to use in analyses. Weather data are available worldwide at 12-kilometer intervals, with the exception of the United States 2004 data, which are available at 20-kilometer intervals. New data are added annually.

     Building systems engineers: If the Use HVAC design data from weather station option is selected on the Weather tab, the fields are populated with data from the selected weather station.

     Note: The Internet Mapping Service requires a working Internet connection in order to be fully functional. If Internet service is unavailable, you can still use this method to specify a project location; however, the corresponding longitude and latitude for the location cannot be set until your Internet connection is restored, as described in this topic.
4. Specify the project location using one of these methods:
   1. Default City List:
      • Nearest major city. For City, select a city from the list.

        The corresponding Latitude, Longitude, and Time Zone values are displayed.

      • Exact location. Enter values for Latitude and Longitude.
   2. Internet Mapping Service: For Project Address, enter the street address, city and state, or latitude and longitude of the project, and click Search. Enter latitude and longitude coordinates as <latitude>, <longitude>. The value you enter for Project Address in this dialog does not affect the project address that displays in the title blocks of sheets for the project.

      Your search results display.

      1. If necessary, respond to any of the following alerts as described. For additional information, see Troubleshooting Location Dialog Issues.
         • Address not found. Either refine the project address and click Search or, for a newly established address, enter a nearby address, click Search, and then drag the project location map pin to the appropriate location.
         • Multiple results found. Click one of the hyperlinked locations displayed in the project location tooltip.
         • No Internet connection. Check your Internet connection. If no connection is available, click OK to close the Location dialog and save your project address. When a dialog notifies you of a mismatch between the project address you entered and the selected map location, click Continue. If you do not have access to the Internet at all, no further steps are needed; the project address is stored as text. If the Internet is only temporarily unavailable, when Internet service is restored, re-open the Location dialog, click Search, and continue with the steps in this procedure.
      2. Use the following tools to adjust the map as needed.
         • Pan. When you place the cursor over the map, the cursor changes to a hand, and you can click and drag the map to pan the view.
         • Zoom. Use the scroll wheel on your pointing device to zoom in and out.
      3. Adjust the map pins as needed.
         • Project location map pin. When you move the project location pin , the Project Address field displays a searchable latitude/longitude value. Click Search to resolve the address and display it in the Project Address field. If multiple results are found, click one of the hyperlinked locations displayed in the project location tooltip.
         • Weather station map pins. For Autodesk Subscription members, the map includes a project weather station pin and alternate weather station pins , which represent the 8 weather stations that are closest to the specified project location. The same 8 weather stations display on the Weather Stations list. By default, the closest weather station is defined as the project weather station. Place the cursor over a weather station map pin to display a tooltip with the following weather station information: station ID, year for which the most recent weather data is available, latitude, longitude, distance from project location, and elevation. To change the project weather station, click an alternate weather station map pin, or select a different weather station on the Weather Stations list.
5. If the project is located in an area that observes daylight saving time and you want shadows to be adjusted accordingly, then select Use Daylight Saving time.
6. Building systems engineers: Click the Weather tab, and verify the Cooling and Heating Design Temperatures, and the Clearness Number for the project location.

   Optional: Adjust the Cooling and Heating Design Temperatures, and the Clearness Number for the project location.

   • If you specified the project location by using the Default City List, by default, the weather is determined by the closest weather station listed in the 2007 ASHRAE Handbook. However, in some remote locations the nearest ASHRAE weather station could be hundreds of miles away. The default weather settings may not be appropriate for these remote locations or in areas with unique local conditions. For these situations, clear Use closest weather station, and then override the default values as needed.
   • For Autodesk Subscription members with Internet access, the Weather tab is populated with data from the selected weather station rather than with ASHRAE data. In most cases, the climate conditions for the selected weather station are comparable to the conditions at the project location. However, if the project location is in an area that has unique local conditions, the default weather settings may not be appropriate. For these situations, clear Use HVAC design data from weather station, and then override the default values as needed.

   Value	Definition
   Dry Bulb	The dry bulb temperature, commonly referred to as air temperature, is the temperature measured by a thermometer exposed to air, but protected from direct solar radiation and moisture.
   Wet Bulb	The wet bulb temperature is the temperature to which air may be cooled by evaporating water into it at constant pressure until it is saturated. The smaller the difference between the wet bulb and dry bulb temperatures, the greater the relative humidity.
   Mean Daily Range	The mean daily range is the mean of the difference between daily maximum and minimum temperatures.
   Heating Design Temperature	The heating design temperature is the outdoor dry bulb temperature that is exceeded during at least 99% of the hours in a typical weather year. Depending on the required comfort level in the space under consideration, the percentage (99%) can be varied.
   Clearness Number	According to the 2007 ASHRAE Handbook - HVAC Applications, Section 33.4, clearness is specified as: Clear and Dry - greater than 1.2 Average - 1.0 Hazy, humid - less than 0.8

7. Click OK.