Example Calculation for a Restaurant
Calculating the Fresh Air CFM (Cubic Feet per Minute) for a restaurant involves a step-by-step approach. Here's a detailed example to help you understand the process.
Step 1: Determine the Area of the Restaurant
First, we need to find the area of the restaurant. Let's assume the dimensions of the restaurant are as follows:
- Width: 30 feet
- Length: 20 feet
The area can be calculated using the formula:
Area = Width × Length
Area = 30 feet × 20 feet = 600 square feet
Step 2: Identify the Number of Persons
Next, we need to determine the number of persons that will occupy the restaurant. Based on standard occupancy rates, let's assume the following:
- Occupancy Rate: 70 persons per 1000 square feet
For our 600 square feet restaurant, the number of persons can be calculated as:
Number of Persons = (Occupancy Rate / 1000) × Area
Number of Persons = (70 / 1000) × 600 = 42 persons
Step 3: Find CFM per Person and CFM per Square Feet Values
According to the ASHRAE standards, the values for a restaurant are typically:
- CFM per Person: 7.5 CFM
- CFM per Square Feet: 0.18 CFM
Step 4: Apply the Formula
The formula to calculate the Fresh Air CFM is:
Fresh Air CFM = (CFM per Person × Number of Persons) + (CFM per Square Feet × Area)
Let's plug in the values:
Fresh Air CFM = (7.5 CFM × 42 persons) + (0.18 CFM × 600 square feet)
Fresh Air CFM = 315 + 108
Fresh Air CFM = 423 CFM
Step 5: Conclusion
For this restaurant, the required Fresh Air CFM is 423. To ensure a comfortable environment, you might consider installing a fan that provides approximately 500 CFM.
By following these steps, you can accurately calculate the Fresh Air CFM required for any restaurant or similar establishment. For more detailed guidance, check out our Step-by-Step Guide to Calculate Fresh Air CFM and Common Values and Tables for Fresh Air CFM.
