There are two types of bathroom fan sensors:

• one that tracks the humidity levels in the room; and
• one that senses movement in the room.

Some fans have both types of sensors and some only have the humidity sensor.

A fan with both types of sensors are your best bet, because they can also tackle the other job fans are responsible for — removing nasty smells. By having the motion sensor, the fan can start when it detects movement in the bathroom. Now you don’t have to worry about your child turning on the fan after using the bathroom.

A humidity sensing fan is also an asset in other areas of your home. Take a look at your laundry room and basement to see if they would benefit from this type of fan.

There are several benefits to having a fan with humidity and motion sensors.

• By keeping the moisture under control, it prevents the growth of mildew, mold, and bacteria.
• It eliminates smells.
• It can help maintain bathroom furniture. Wood products soak up that excess moisture which causes warping. High humidity can also make paint peel. A humidity sensing fan keeps humidity at bay, eliminating these issues.
• It’s energy-efficient and saves on utility bills. With the built-in humidity and motion sensors the fan only works when needed and will turn itself off. So it only runs when needed unlike older fans which run non-stop until you remember to turn them off. Look for ENERGY STAR certified devices.
• The automatic control means ease of use. Never worry about forgetting to turn on or off the fan again.

When you are buying a fan with a humidity sensor, there are a few things to consider.

Room size – This will help determine the size of fan you need. On the fans packaging look for the CFM (cubic feet meter) number. This indicates how much volume of air the fan can move. It is directly related to the size of your bathroom and important in deciding which fan to get.

It is recommended that your fan is able to completely refresh the air in your bathroom eight times an hour (every 7.5 minutes). The rule of thumb is one CFM per square foot room for bathrooms up to 100 square feet. For bathrooms larger than 100 square feet, you will need to calculate the needed CFM by dividing your bathroom’s volume — to determine your bathroom’s volume, multiply its length by width by ceiling height — by 7.5 — which is how long in minutes you want the refresh cycle to be.

Air flow needs – Refers to how much air the fan can exhaust. You don’t want a weak and undersized fan.

Fan speed – Fans come with either fixed or adjustable speeds.

Sensor type – Humidity sensor or humidity and motion sensor.

Fan housing – You want to make sure it fits in the space you have to install it.

Noise levels – Fan noise levels are measured in sones, so if you want a quiet fan look for the one with the lowest sones. Anything over 2.5 sones is considered loud.

Features – Fans come with different features. There are fans with built-in Bluetooth speakers, emit warm air, have timers, and include a light feature.

Number of fans – If you have an enclosed shower area or toilet stall, you should get two fans.

Bathroom fans are wired directly into your home electrical system. If you are replacing your fan with a fan that fits in the same space, it is a job a confident DIY-er can do. However, if you aren’t comfortable working with electricity, your bathroom doesn’t currently have a fan, or the new fan doesn’t fit into the old fan’s space, you need to hire a certified electrician to install it.

As you can see, bathroom fans have come a long way. Nowadays, you can find a fan to satisfy even your inner “techie-geek”.