Installing a bathroom exhaust fan is a great way to reduce the levels of moisture in your home. Excessive moisture levels can lead to a wide variety of problems, including poor quality air and bad odors. The results of moisture can range from mildly annoying to health problems that can have a real impact on the quality of life for people living in the home. In this article, we will take an in-depth look at bathroom exhaust fans, how they work, how to install them, and some considerations about how they are used.

4 Main Benefits of Bathroom Fans

Generally speaking, there are four main benefits of a bathroom exhaust fan, and we will detail them below in no particular order of importance.

  1. Reducting Humidity Levels

The presence of excessive moisture can have a significant impact on your bathroom. Wall coverings can peel, crack, and break and in extreme circumstances, bathroom doors can even warp and become impossible to close. Any steps that can be taken to reduce the humidity levels in the bathroom will make upkeep in the space easier. The presence of humidity will also promote the rapid growth of unhealthy mold, and this can be hard to remove once it takes hold in your bathroom.

  1. The Elimination of Odors

The elimination of unpleasant odors may not be a priority for everyone, but a bathroom exhaust fan can get rid of any lingering bathroom smells. This makes the bathroom a more pleasant place to be, and the atmosphere will feel cleaner for the next user. Air fresheners simply mask a scent, and in many cases, this can be just as bad as an unpleasant odor.

  1. Foggy Bathroom Mirrors

Many people suffer from foggy bathroom mirrors that cannot seem to be clear enough to use. This is caused by excessive moisture, and bathroom exhaust fans can remove the water vapor that causes this phenomenon. This will also make other glass or tiled surfaces drier to the touch when using the bathroom.

  1. A Reduction of Airborne Contaminants

A bathroom is typically cleaned with caustic chemical cleaning products that can create health issues when inhaled. Also, if mold is present, the spores will be in the air, and this can exacerbate breathing conditions and trigger allergic reactions. A bathroom exhaust fan will vent airborne contaminants out of the home and help to control mold growth.

How Do Modern Bathroom Exhaust Fans Work?

There are many types of bathroom exhaust fans available, but they are often included with extra features, such as heat lamps, humidity or moisture sensors, and lighting systems. The most common basic product is a fan with a light, and the bathroom exhaust fan can be installed much like a recessed light.

Some models have timers to ensure that the fan isn’t left on all day, wasting valuable energy. The aforementioned moisture or humidity sensors will automatically turn the bathroom fan on based on the current humidity levels. These types of fans often have a manual override switch if you need to vent an unpleasant odor. A heat lamp is also a useful option that can provide heat when needed or operate separately as needed if you simply need ventilation.

How Much Ventilation Do You Need?

It’s suggested that ventilation rates should be based on at least eight air changes per hour. Airflow is measured in cubic feet per minute or CFM, and a single CFM of airflow is required for each square foot of bathroom space. Following this rough formula, a 6’x9’ bathroom would need at least a 54 CFM bathroom exhaust fan.

Generally speaking, the larger your bathroom, the larger the bathroom fan, and the height of the ceiling can also be a factor. A larger bathroom between 50-100 sq ft should have the aforementioned 1 CFM per sq foot. If the bathroom is larger than 100 sq ft, tally up each bathroom fixture to estimate your needs. A toilet, shower, or tub is worth 50 CFM each, and you can add 100 CFM for a tub with jets. Most bathroom exhaust fans are rated from 50-110 CFM, so you should be able to find a unit to suit your needs. There is another formula developed by Home Depot that has proven to be popular with HVAC industry experts, and we detail this below for completeness.

Before you make a final decision, make sure you look at the sones rating. This is the noise level of the bathroom fan, and the lower the rating, the quieter it will be. If you regularly clean the bathroom fan, this will also make it quieter to use. It’s also a great idea to choose an EnergyStar rated bathroom fan as it will be more efficient and use less energy.

4 Steps to Install a Bathroom Exhaust Fan

  1. Determine the Size: The most accurate formula comes from Home Depot, they recommend: Length x Width x Height x 0.13 = CFMs needed (round up to the nearest 10).
  2. Electrical Options: It’s important to understand how you will power the fan and where it will be located.
  3. Remove the Old Fan: If there is an old bathroom fan in place, it needs to be disconnected and removed to accommodate the new unit.
  4. Install the New Bathroom Fan: The new bathroom fan can be installed in two different ways. The first option mounts the fan without any attic access. The second option mounts the exhaust fan with attic access. Either option can be used, but the bathroom fan must ultimately vent the outside of the home.

Installing a bathroom exhaust fan may be a project for an experienced DIY enthusiast with the relevant skills and tools. If you’re not sure how to proceed, it’s a better idea to contact your local HVAC technician for expert help and advice. A bathroom exhaust fan is a crucial part of your HVAC system, and if it works well, it can make your home more comfortable and less prone to a number of problems.