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ASHRAE 62.2-2013 Whole Building Calculation Spreadsheet

This is an Excel based spreadsheet that includes a Macro for clearing all the entered data. By entering the State or Province, the city, the square footage, the number of bedrooms and the number of floors, the sheet will calculate the appropriate 'N' factor and CFM for whole building ventilation to meet the latest version of the ASHRAE 62.2 Standard. By adding a blower door number, the sheet will calculate the rate and subtract the infiltration credit. And by entering any existing fans airflows in bathrooms or the kitchen, the sheet will calculate a modified rate that will allow those fans to remain in place. The sheet also includes a whole building intermittent control option and report page that can be used as a sign off for the system.

There are two primary ventilation system components to the ASHRAE 62.2-2013 Standard: whole building ventilation and local exhaust ventilation. The basic whole building flow rate can be fairly easily calculated from the formula included in the Standard or by referring to the table. But the rate can be reduced by using the "infiltration credit" if a blower door has been used to verify the performance of the building. For the 2013 version of the standard, the whole infiltration credit can be used for existing homes as well as for new homes (for new homes excessive infiltration is limited).

This spreadsheet does that calculation automatically. It includesTMY3 weather data for 1100 cities in the US and Canada. The sheet will also make the calculations required for existing buildings, allowing existing fans to remain installed in bathrooms and kitchens. The sheet also calculates the 'N' value, ACH₅₀, ACH_natural, and a target CFM₅₀ for achieving 0.35 air changes per hour.