Bathroom remodel; Exhaust fans

Traditional bathroom fans move little air, are noisy and energy-inefficient, and can be a cause of moisture and expensive damages in the home structures - besides contributing to higher energy bills.

New fan exhaust solutions can overcome the limitations of old units, removing bathroom odors and moisture efficiently. A remodel is a good time to update the mechanical ventilation system of your bathroom (or of your house...).

Simple exhaust fans

Typical bathroom ventilation involves simple ceiling or wall exhaust fans. In this case you just have to choose a new high efficient exhaust fan.

Choosing a bath fan

New exhaust bath fans have more power (50, 70, 90 CFM/Cubic Foot per Minute; 25, 35, 45 L/s, that is, Liters per second) and are much quieter (0.5 sone is common) than older models. They also involve much lower energy usage (a third or less of that of old models).

See:Choosing a bath exhaust fan.

The fan-light solution

Be aware of the fan-light combination. Fan-light solutions may now include new efficient exhaust fans, with new motors and high output, and also compact and energy-efficient fluorescent bulbs. Just confirm it.

How much bath ventilation

Fan exhaust capacity is measured in Cubic Feet per Minute (CFM) or Liters per second (L/s). A normal sized bathroom demands a good-quality 50 CFM (25 L/s) exhaust fan. An undersized or poor-quality fan won't exhaust enough.

How to choose an exhaust fan

See: Choosing a bath exhaust fan

Location

Common bath exhaust fans should be located, whenever possible, over the shower or tub, in the ceiling. Placing a fan as close as possible to the source of the stale air is highly advantageous.

Timer

A timer (or another equivalent control) is highly recommendable, to ensure a continuous ventilation for a minimum of 20 minutes after each use of the bathroom. Consider it in your bath remodel.

Bathroom doors

Bathroom doors shouldn’t be too tight, to allow the entry of makeup air. Doors should have a 3/4" clearance or more to the finished floor …

Types of Mechanical Ventilation

Typically, the bathroom ventilation system involves one ceiling mount exhaust fan, but you may also have the less common 1) wall mount exhaust fan system or 2) a remote inline mount fan.

Another possibility is an integrated system for the whole house, that is, a 3) central mechanical ventilation system, involving both the exhausting of stale air and the supplying of fresh air to the bathroom and other rooms.

Note: Central exhaust systems systems are reliable, cheap and highly desirable or mandatory in airtigh homes. However they typically don't replace spot ventilation, that is, bathroom room exhaust fans (or kitchen fans).

See: Bathroom and Kitchen Exhaust fans