Most fans use a 15 amp circuit breaker and a 14-caliber cable. As a result of the power increase, heating fans usually require a 20 amp circuit and a 12-caliber cable.

Standard ceiling fans include a downrod length ranging from 2 inches to 10 inches, which is suitable for standard size rooms with a ceiling height of 8 to 9 feet. However, downrods fan can go up to 177 inches, according to the manufacturer.

To get the right fan for the bathroom, use the guides defined by your Institute of Domestic Fans. The fan must have 1 cfm per square foot of space in the bathroom. For bathrooms of more than 100 square feet, calculate the requirements of cfm by adding 50 cfm per bathroom.

Most fans are classified from 50 to 110 CFM. For bathrooms of 50 square feet or less, it is recommended to buy a bathroom fan designed for small rooms, which usually has a range of 50 to 79 CFM. For larger bathrooms, select a fan that can move at least 1 CFM per square foot from the room.

Ventilation rates based on 8 air variations per hour are generally suggested. For most bathrooms this works at a CFM per square metre of the bathroom area. For example, a 7 x 10 casket would require a CFM 70 fan. A CFM 50 rating at a minimum of 50 mp is recommended.