Bathroom Exhaust Fan Venting Options

Are you looking for good bathroom exhaust fan venting options? This is an important decision and one that you will live with for several years to come.

Hence, you must explore all possible alternatives so that you can choose the one that suits your bathroom’s requirements and gives you adequate ventilation. 

Why do you need Bathroom Exhaust Fan? 

There are several reasons why a good ventilation system for your bathroom is such a crucial decision. Some of these are related to your and your family’s health, while others are important for keeping your bathroom in a well-maintained state.  

  1. The basic purpose of installing an exhaust fan in your bathroom is to remove unpleasant odors from your bathroom. When you have a ventilation system in place, it will keep the atmosphere of your bathroom clean and fresh. 
  2. Another important task performed by a bathroom exhaust fan vent is to reduce humidity. Excessive moisture is terrible for your bathroom and can cause wallpaper or paint to peel off or even make your doors warp. Humidity may also cause mold to grow and accumulate, which can be very difficult to eliminate.  
  3. Additionally, exhaust fans also improve the safety factor of your home by decreasing fumes caused by cleaning products. We often use aggressive chemicals to clean bathrooms, and this can cause serious health issues, particularly for small children and the elderly. 
  4. Does your mirror steam up when you’re in the shower? A bathroom exhaust fan vent also helps to eliminate foggy mirrors. The water vapors and moisture on walls and mirrors can be controlled with a good ventilation system.  

Bathroom exhaust fans have to vent outside so that all the bathroom moisture is expelled, and there are several different ways in which this can happen.  

Bathroom Exhaust Fan Venting Options

There are several different kinds of bathroom ventilation options. Unfortunately, some of these are terrible, such as installing a vent buried below the attic insulation or simply installing a vent in wall space. I would strongly advise you to avoid both of these options. 

Some of the different solid venting options are:

  • Ceiling to wall
  • Venting through the roof
  • Through-the-wall installation
  • Low profile wall installation
  • Soffit vent installation
  • Attic vent installation

All of these options are pretty popular, and each has its pros and cons. Before you decide which bathroom exhaust fan venting option is the best one for you, you need to explore them in detail. 

Ceiling to Wall 

This is the most popular kind of bathroom fan venting option. If you want to use this method, you will need to install the fan in your ceiling and add a vent to the exterior wall.

You can place the vent in a straight line across the bathroom ceiling or add one or two additional turns or bends. In either case, the vent will ultimately go to the exterior wall.  

A vent hood is placed on the bathroom vent so that its flapper keeps out pests and rain from entering the vent hose.  

The biggest disadvantage of the ceiling to wall exhaust fan venting option is the possibility of animal intrusion. This happens most commonly because of birds as they often nest inside the vent. Such a bird nest can obstruct the airflow completely, making the bathroom exhaust fan vent less effective. 

Another major disadvantage of the ceiling to wall exhaust fan vent is its vulnerability to rain. Rainwater can enter through the vent and affect its efficiency. You can minimize the possibility of this happening by sealing the vent thoroughly using exterior caulking and making sure that the vent cover is complete.

Roof Vent Installation

Another very popular method of installing a bathroom exhaust fan vent is to connect it to the roof directly. 

In this case, you will install a special roof vent to keep out animals and rain. The vent will be made of metal, preferably stainless steel, because it has to be strong enough to withstand external elements. While plastic vent covers are cheaper, they will not be suitable. 

It is very important to insulate the duct hose that goes through your attic. Because the bathroom temperature air will be expelled through the attic, you may have mixture-related issues and possible damage in the attic.

There are two possible scenarios. If the attic air is quite warm and bathroom air passing through the exhaust vent is cold, the temperature difference may result in water beading inside or outside the vent. This moisture will ultimately damage your attic.

The opposite can also happen. If the air in your attic is cool while the air in the exhaust vent is warm, the same effect will be created. With the continuous presence of moisture in your attic, you could have issues such as wood damage or mold growth. 

Additionally, when you cut a hole in your roof, there is a possibility that the hole may leak at some time in the future. 

Nevertheless, a roof vent is a good option for your bathroom exhaust fan venting and is quite popular. Millions of homes use this method. If you decide to go with a roof vent installation, make sure that you use a licensed professional for the job. 

Through-the-Wall Installation

This bathroom exhaust fan method is used when the exhaust fan is placed vertically instead of being placed horizontally within the bathroom wall. These exhaust fans are generally available as part of a kit that includes a short duct, an exterior cover, and some other parts that you need to install the fan. 

In addition to your bathroom, you can install the through-the-wall exhaust fan in the garage, kitchen, mudroom, or any other room where you need better ventilation. It is important to note that you can install this kind of exhaust fan only on exterior walls so that the venting goes outside immediately. The vent section is relatively small, about one or two feet only, and there are no turns or bends. 

The exhaust duct is placed right behind the exhaust fan in through-the-wall fans. Whereas in bathroom fans, it is placed differently, often coming out of the side. This makes the through-the-wall exhaust fans easier to install in walls if the vent can go through the wall and reach the outside immediately. 

Low Profile Wall Installation Fans

You can also choose to install a low-profile fan, another kind of through-the-wall exhaust fan for vertical installation. This type of bathroom exhaust fan is not very thick and can fit comfortably between wall studs in a vertical position. 

If you choose this kind of bathroom exhaust fan, the vent can be installed right outside it if you place it in an exterior wall. Because the venting comes out on the fan’s side, it will be offset slightly. 

Additionally, you can choose to route the vent of your low profile fan upwards inside the wall, over your ceiling, and then outside. If this is not suitable for your bathroom, you can also opt to route the vent downwards or upwards through your wall, all the way up to your roof.

Soffit Vent Installation

The soffit vent installation is probably the bathroom exhaust fan that is used least often. Before you decide to use this type, check the building code in your locality, as this venting option is not allowed by all municipalities.

The underside of a roof overhang is called the soffit. This usually has a passive type of venting installation known as soffit venting. If you install your exhaust fan in the soffit, this may result in some interference with the venting of the current soffit vent. While this is not a preferred option, it is likely to work out if you have to choose it for any reason.

To prevent animal and air intrusion, you can use a spring-loaded soffit vent cover. These custom vent covers are designed for installation on the soffit. The spring loading on these vents pulls the cover back when the flow of air stops and thus prevents any possible intrusions.   

Attic Vent Termination

While the attic vent termination is an option for bathroom exhaust fan venting, it is my least preferred one. However, I would like to share some important details about how it works. 

To start, nearly all building codes specify that a contractor is not allied to use the attic as an exhaust space. This applies to both bathroom vents and dryer vents. Despite this, people do continue to use attic vent termination quite often. 

Often, the reason is that the homeowners or contractors become lazy and use the attic to vent the bathroom. This means that instead of going outdoors directly, it goes into the attic. Very often, they lay the vent loosely on the attic’s insulation or the attic floor. A worse option is to bury the vent below the insulation.

More commonly, the vent is placed near the outside, just a few inches behind the gable vent, beneath the ridge vent. Among the various options, this is a slightly better one. 

However, there are some very serious downsides to this option of bathroom exhaust fan venting. Firstly, since building codes do not permit this kind of vent installation, if you ever decide to sell your house, the home inspector will likely mention it in his report.

Additionally, when such a lot of moisture gets blown regularly into your attic, it is likely to cause moisture damage or mold growth. Either of these will require an astronomical expense to fix. 

The easiest and most convenient strategy for preventing mold growth in your attic is controlling moisture by ensuring that all your bathroom exhaust fans vent to the outside.  

Final Words

You have read through various bathroom exhaust fan venting options that you can choose from. Remember that the most important factor for venting decisions is to ensure that the bathroom exhaust fan vents towards the outdoors. 

My top recommendation is the ceiling to wall venting exhaust fan, while the second-best is the roof vent installation. If these are not suitable for you, then the third recommendation is the vertical wall installation.