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How To Put In A Bathroom Fan Where There Isn’t One

How To Put In A Bathroom Fan Where There Isn't One

By letting in fresh air, a well-ventilated bathroom contributes to its comfort and cleanliness. Good ventilation minimizes damage or the formation of mold while reducing airborne infections. To improve the ventilation in your bathroom, you might need to install a bathroom fan.

In order to install a bathroom fan, do the following:

  • Fan size selection
  • Determine the vent route
  • Find a location to mount the fan
  • Find the source of power for the fan
  • Assemble your tools
  • Clean up the area
  • Place the fan

If you are unsure of your ability to complete this type of DIY project because it involves properly sizing, installing, and wiring a ventilation fan, it is always preferable to consult a professional. If you’re up for the challenge, stick with us to learn the specifics on how to carry out each stage. Additionally, we’ll go over the advantages of bathroom fans and what to do if your bathroom isn’t properly ventilated.

Thinking About Bathroom Fans

Determine the fan’s size that you require. You must compute the CFM (cubic feet per minute) rating of your bathroom in order to decide which fan is suitable for it. Multiply the cubic footage of the room (length, width, and height) then divide the result by 7.5 to get the CFM.

Choose the ideal location for the fan. The location is frequently close to the shower or bathtub area, which tends to produce more moisture.

Where should the fan be vented? The position of the vent should comply with any local building or area code regulations. It is necessary to send air terminal points outside.

Advantages Of Bathroom Fans

A bathroom fan takes away moisture to stop mildew from forming in addition to enhancing air circulation and getting rid of offensive odours. At the very least, using a fan will help you avoid expensive repairs like rusting fittings, warped wood, and peeling paint.

Additionally, maintaining a well-ventilated space is now a top responsibility to protect our health in light of COVID-19 and other airborne diseases. It keeps your bathroom clean by reducing airborne toxins and preventing pollution. The steps to installing a bathroom fan are provided below if you’re ready to take advantage of them.

Bathroom Fan Installation Guide

Fan Size Selection

How To Put In A Bathroom Fan Where There Isn't One

Check the recommended size when selecting your fan. You should calculate the bathroom’s square size or cubic footage before making a decision.

  • Cubic feet = Length x Width x Height

Applying the CFM formula:

  • Number of CFM = (Length x Width x Height) / 7.5 (round up to nearest 10)
  • As an illustration, (6 feet x 8 feet x 8 feet)/7.5 equals 51.2 (round up to 50)

Select the CFM that, after getting this measurement, comes the closest to matching the size of your bathroom, in this example 50 CFM.

CFMs and some are used to rate fans. The fan’s box contains this information.

  • The unit of measurement for airflow and fan draw is cubic feet per minute (CFM).
  • The fan’s noise is measured using sone. The fan is louder the higher the number.

Determine The Vent Route

How To Put In A Bathroom Fan Where There Isn't One

The location of the vent is crucial for effective ventilation. The exhaust from a bathroom fan must be directed outside of the house and set vertically close to the ceiling.

Decide where the duct should be run as well. The quickest and most direct path from the fan housing to the exterior should be considered the ideal placement.

Check to see that it won’t be stretched too far.

Directly through the roof, through a wall, a gable vent, and an eaves-of-soffit vent are the four best positions.

Find A Location To Mount The Fan

Never forget that a fan’s primary functions are to dispel aromas, aerate the area, and lessen damage to existing bathroom fixtures. Choose a location that produces humid, damp air, such as between the shower/tub, toilet, and door. Pick a location that is both aesthetically beautiful and where the fan can operate effectively, of course.

You must also make sure the fan can connect to the ventilation system and the power source.

Find The Source Of Power For The Fan

Decide whether to instal the bathroom fan utilising a shared electric circuit load with the other appliances in the bathroom or to run it on its own separate circuit. Whenever possible, use the current switch.

Using a double switch, you may control fans that have lights attached. If you’re not sure how to do this, contact a licensed electrician.

Assemble Your Tools

Tools you’ll require include:

  • Stepping stool
  • Energy drill
  • Screwdriver
  • Multipurpose pliers
  • Duct tape in foil
  • Square for framing
  • Ducting that is flexible
  • Pencil
  • Screws
  • Cable nuts
  • Security glasses
  • Mask
  • Also included are roofing cement and roofing nails.

Clean Up The Area

Make sure the workspace is clear of any obstacles before beginning this project, such as furniture or other accessories. Don’t forget to use old drapes or newspaper to cover any glass fittings or mirrors. Make sure you have adequate illumination, and if necessary, perform this task with a friend.

Setting Up The Vent Fan

With your new bathroom fan, there are instructions for installation. Before beginning the process, always read the manufacturer’s instructions carefully.

  • Make a mark on the fan’s external opening. Trace the vent cap along the area where the fan will go. Mark the location for the new fan housing, then drill a hole to create the outside open point. Your point of reference will be this.
  • The fan housing’s dimensions. Before touching any wire or terminals during this step, switch off the power to the bathroom.
  • In order to suit your ventilation duct, locate the reference hole from the exit vent and measure the length and surrounding area.
  • Go back to the restroom. The intake port’s dimensions. Put the bathroom fan in the hole securely. Using the housing brackets and screws that come with the fan, secure the housing to the ceiling joists.
  • Install the flexible pipe from the inside by running the hose from the fan to the vent. Use the fan’s included screws or foil tape to secure the tubing. Always make sure it moves as quickly and smoothly as feasible.
  • To reach the escape vent, stay clear of any barriers and winding paths. This guarantees effective air ventilation and circulation.
  • Wire the fan to the electrical circuit load after preparing the wiring.
  • Insert the grille into the slots in the fan housing, then attach it.
  • The fan should now operate after turning on the circuit breaker.

Can A Bathroom Fan Be Vented Into A Plumbing Vent?

How To Put In A Bathroom Fan Where There Isn't One

Never ever vent a bathroom vent to a plumbing vent. The International Residential Code, or IRC, stipulates that bathroom exhaust air must be vented outside and that venting it into a plumbing vent violates Section M1051.1 of the IRC and presents hazards for sewage gas-related health and safety. Not to mention unsavory odors that might permeate the premises.

What Should I Do If The Bathroom Doesn’t Have A Fan?

There are techniques to minimise bathroom humidity even if the home’s design excludes a bathroom fan. The most popular method for keeping bathrooms dry and venting steam is to leave bathroom doors and windows open.

After use, always sweep floors and wipe off walls. Dehumidifiers can be used to remove extra moisture. Use a standing or tabletop fan to move air after using the restroom. Pick cleaning solutions that are sanitizing and combat bacteria and mold.

How Can You Keep A Bathroom Fresh Without Windows?

bathroom without windows No issue. Here are some ideas for sanitizing the space:

  • Utilize cleaning solutions and sprays that stop the growth of mold and mildew.
  • The greatest advice for keeping the bathroom clean and smelling fresh is to maintain a cleaning regimen.
  • Make sure to perform routine restroom inspections. Look for any leaks, mildew, early rust on bathroom fittings, warping of wooden furniture, or other issues and take immediate action.
  • To check for humid, damp air inside the bathroom, it’s a good idea to instal a hygrometer to measure the humidity of the space.
  • Place a fan besides the entryway to help with ventilation.
  • With some potpourri or bathroom aroma sprays, refresh the air.
  • Add indoor plants to your bathroom decor since they help reduce humidity and add brightness to a gloomy, dark area.


Although this is not a simple DIY endeavour, some fan kits include manufacturer’s instructions that will make installation simple. However, if the wiring and cutting procedure appears too difficult, you’ll feel more at rest if you hire a professional to handle it.

How To Put In A Bathroom Fan Where There Isn't One

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