Exhaust Fan Size Chart and Guide

When it comes to maintaining proper ventilation in your home or office, an exhaust fan is a vital component. 

Whether you're battling the humidity in your bathroom or the cooking fumes in your kitchen, exhaust fan ensures optimal air circulation

Why is exhaust fan size so important?

The size of an exhaust fan directly impacts its effectiveness. An undersized fan may not provide adequate ventilation, leading to moisture buildup, odors, 

and poor air quality. On the other hand, an oversized fan may consume unnecessary power and cause noise.

How do I choose the right size?

Exhaust fans are sized based on their sweep angle (the diameter of the fan blades) and air displacement capacity, typically measured in cubic feet 

per minute (CFM). The larger the room or area to be ventilated, the higher the CFM rating required.

Step 1: Measure the Room Size

To determine the appropriate exhaust fan size, the first step is to measure the size of the room where it will be installed. In Indian homes, exhaust fans 

are most commonly used in bathrooms, kitchens, and sometimes storage rooms.

Small rooms (such as bathrooms): Typically measure approximately 6 to 8 feet in length and width.

Medium rooms (such as kitchens): Measure approximately 10 to 12 feet in length and width.

Large rooms: Any room greater than 12 feet in length and width is considered a large room.

Step 2: Calculate the Required CFM

A general rule for calculating the required CFM for a room is based on its area. You need at least 1 CFM for every square foot of space.

 In fact, for a typical Indian bathroom (6 x 8 feet (48 square feet)), you'll need an exhaust fan that provides at least 48 CFM.

Indian kitchens often involve cooking with large amounts of oil, spices, and steam, so the required CFM is often higher. For medium-sized kitchens, 

an exhaust fan with 100 to 200 CFM is ideal to ensure effective removal of cooking fumes and odors.

Step 3: Refer to the sizing chart

Here are quick sizing guidelines based on room size:

Bathrooms (up to 50 square feet): 4-6 inch exhaust fan, 50-100 CFM

Kitchens (up to 100 square feet): 6-9 inch exhaust fan, 100-200 CFM

Large rooms (over 100 square feet): 9-12 inch exhaust fan, 200 CFM and above