In the process of calculating Fresh Air CFM, several key values and tables are essential. These values are typically provided in ISHRAE's book and are crucial for determining the appropriate ventilation requirements for different types of areas. Below, we have compiled a list of common values and tables that you will need.
The amount of fresh air required per person varies depending on the type of area. Here are some common values:
This value represents the amount of fresh air required per square foot of area. Common values include:
The occupancy value indicates the number of people typically present in a given area. This is often expressed per 1000 square feet or 100 square meters. Here are some common occupancy values:
To calculate the Fresh Air CFM for a specific area, you will need to use the formula:
Fresh Air CFM = (CFM per person * Number of People) + (CFM per square foot * Area in Square Feet)For example, for a restaurant with an area of 600 square feet and an estimated occupancy of 42 people:
CFM per person = 7.5
CFM per square foot = 0.18
Number of People = 42
Area = 600 square feet
Fresh Air CFM = (7.5 * 42) + (0.18 * 600)
= 315 + 108
= 423 CFMBy using these tables and the formula, you can ensure that any area receives the appropriate amount of fresh air for comfortable and safe ventilation.