When modeling point sources near structures, the Building Profile Input Program (BPIP) and BPIP-PRIME executables are used to calculate downwash values for input to air dispersion models like AERMOD and CALPUFF. One limitation of BPIP is that it can only model buildings with flat roofs. Buildings featuring a sloped or pitched roof must be approximated.
To aid users in making these approximations, Lakes Environmental created a Sloped Roof utility in the latest release of CALPUFF View. This utility allows users to automatically create multiple building tiers based on the defined top and bottom tier to create the appearance of a sloped roof.
To define a sloped roof: Step 1: Completely define the bottom tier of your building. Step 2: Completely define the top tier of your building. If your building comes to a point, define the smallest possible tier [0.1 x 0.1 m.]
Step 3: Click Slope Roof button. The following tool will load:
Step 4: Type in the number of tiers and click the Generate button.
The tiers will be created equally distributed along the range of dimensions specified. Sloped roof tiers will only be created if the bottom and top tiers are completely defined. The Sloped Roof utility works for many different types of buildings including basic tapered buildings, sloped and double-sloped roofs, mixed tier shapes, and roofs with varied slopes.