A highly efficient exhaust fan will remove humid, contaminated and stale air from enclosed space. However, to achieve this you must choose the right type of exhaust fan.
But more importantly, even as you choose the exhaust fan, it is important to consider CFM, space, installation and duct requirements.
Let’s explore the various exhaust fans you can choose for clean air.
1. Wall-Mounted Exhaust Fans
Wall mounted exhaust fans are installed directly through an exterior wall to pull humid or contaminated air from a room to the outside.
They are commonly used in kitchens, bathrooms workshops or storage rooms. Usually a hole is drilled in the wall and fixed with an electrical hookup then the fan is installed.
These types of fans are cost effective with high efficiency and require low maintenance.
However, you should remember that, mounting wall exhaust fans too high, too low or near a heat can result to air circulating pointlessly without actually exiting the room.
Wall mounted exhaust fans can only offer single room coverage, since the fan is right in the wall, noise is directly transmitted into the room.
2. Ceiling-Mounted Exhaust Fans
Ceiling-mounted exhaust fans are installed in the ceiling, pulling air upwards into the roof ventilation or duct system.
They are commonly installed in spaces where wall access is limited, such as bathrooms, offices, or small commercial spaces.
These types of fans can vent straight into the roof, or through ducts leading elsewhere. In most cases, they’re quieter and sleeker than wall-mounted units.
Ceiling mounted exhaust fans have a complex installation since cutting into the ceiling, running ducts through roof vents, and sealing roof penetrations is tedious.
Most ceiling-mounted units are designed for small to medium spaces therefore they are not suitable for heavy-duty industrial use.
3. Inline (Duct) Exhaust Fans
Inline exhaust fans are usually installed inside a ventilation channel system to pull or push air along the system connecting to more than one room. They are best used in commercial spaces, kitchens and server rooms.
These fans have high power since they can move a lot of air and are less noisy. Additionally, they have a better performance since the fans are mostly axial fans and centrifugal fan design. As a result, this helps overcome static pressure as compared to other fans.
While quieter in rooms, the fan still makes noise in the attic or ducts. Poor duct design amplifies this into whooshing, or rattling sounds.
You need attic or ceiling cavity space to fit the fan and ducts. Not possible in some apartments or low-clearance structures.
4. Window Exhaust Fans
Window exhaust fans are the type that are installed directly into a window opening. These fans require are known for their affordable installation since it’s mounted on a window, pulling indoor air out and fresh air from outside in.
Additionally, window exhaust fans are good for small spaces like apartments and bathrooms and can be removed and relocated easily. They are a quick fix for odors smoke, cooking smells etc.
However, window exhaust fans look tacky compared to other exhaust fans. They are of low capacity with limited power and coverage, hence only useful small spaces.
Since they are installed on windows, they are directly exposed to rain, dust, snow, and wind, making it a hassle in cleaning and maintenance.
5. Rooftop Exhaust Fans
Rooftop exhaust fans are mounted on the roofs to pull out larger amounts of air. These exhaust fans are often used in factories, warehouses, and big commercial spaces where continuous air flow is needed.
In critical areas where air quality affects workers health, rooftops exhaust fans are ideal. They are durable since they are built for heavy-duty and continuous operations, keeping indoor air safer.
These types of fun require rooftop penetration and ducting with weather-proof materials, making it costly to install. They tend to be loud and high-power consumers therefore Poor-quality rooftop fans can vibrate through the roof, or transmit noise indoors.
Maintenance and access is harder and dangerous since you will need safety gears, lifts or ladders.
6. Kitchen Range Hood Exhaust Fans
Kitchen range hood exhaust fans are often mounted above cooking surfaces to suck out smoke, heat, or grease. They are suitable in kitchens since they keep walls, cabinets, and ceilings from getting sticky and yellowed.
These fans help control heat buildup while cooking and improve air quality in the kitchen reducing risks like fire outbreaks. Usually, they require frequent maintenance because grease filters may clog and neglect can lead to reduced performance.
Their bulkiness can dominate small kitchens, reducing space for your cabinets and other kitchen designs. Installation costs are high since its ventilation system is penetrated through the walls or ceilings.
7. Bathroom Exhaust Fans
Bathroom exhaust fans are installed in bathroom ceilings to remove moisture and odor to the outside, preventing mold, mildew, and ceiling damage.
They improve indoor air quality, especially in small, poorly ventilated bathrooms, extending the life of paints, drywalls, and other bathroom fixtures.
Their sizes are compact and affordable, hence easy installation as compared to other exhaust fans. Unlike other exhaust fans, they are compact, relatively inexpensive, and easy to install compared to other exhaust systems.
If its ventilation system is too long or vents into the ceiling, moisture is trapped in leading to inefficiency in working.
Therefore, frequent cleaning and maintenance are needed to enhance proper working.
8. Industrial Exhaust Fans
Industrial exhaust fans are designed to suck out smoke or contaminated air from big commercial spaces or industries. They are heavy power consumers to keep running because of their high capacity ventilation systems.
These types, pull out heat, fumes, smoke and moisture making environment essential for workers health and fire prevention. Additionally, their durability and continuous operation are unimaginable since they are built to run continuously in harsh industrial conditions.
Installation can be quite costly because they need more electrical wiring as well as explosion proof and high capacity units with a good ventilation system.
Industrial fans are too noisy therefore workers at these places need hearing protection however, inline and centrifugal industrial exhaust fan types reduce noise but are costly.
Putting industrial exhaust fans in place is also complex. It requires skilled planning for ducting and makeup air.
Moreover, maintenance is expensive since you will need frequent servicing failure to which can cause breakdowns.
9. Centrifugal Exhaust Fans
Centrifugal exhaust fans are designed to move air effectively by building up higher static pressure. They pull air in at the center and throw it out at a 90 degrees angle using centrifugal force. These fans work well in commercial kitchens, laboratories, industrial plants and HVAC systems.
Unlike other exhaust fans, these centrifugal designs work with long ventilation systems, filters and bends. They are energy efficient offering better performance per watt.
Moreover, these fans are built for continuous use in demanding environments making them have a durable workhorse.
In most cases, the installation is more expensive than other exhaust fans because it need trained expertise. Their radial and backward curved fans can be loud under heavy loads.
In places like commercial kitchens, they tend to get more greasy or dusty therefore frequent routine care and service is needed.
10. Propeller Exhaust Fans
Propeller exhaust fans move huge volumes of air in open spaces by using large blades which push or pull air directly along the axis of rotation with no resistance.
They are affordable and simple to install compared to other exhaust fans. Commonly, they work well in warehouses, greenhouses, and factories where air movement matters and a ventilation system is not necessary.
Due to its simplicity, maintenance cost is lower. However, they use a lot of power per watt to pull or push air.
Durability is an issue especially where there is dust, grease or corrosive fumes which wears them down easily.
They are not ideal where precise airflow or filtration is required since they cannot push or pull air through vent systems that fight back.
11. Solar-Powered Exhaust Fans
Solar powered exhaust fans are ecofriendly fans that use photovoltaic panels to convert sunlight into electricity and work.
They are commonly used in greenhouses, remote cabins attics or sheds where electrical wiring might be a problem.
Once installed, there are no more costs in running them making them very affordable. Immediately the sun is out, their operation starts. This means they are weather dependent and can fail when there is no sunlight.
They use low power therefore can only work in smaller spaces. Many models only run at one speed, directly tied to how much sunlight they get.
Summary for Exhaust Fan Type & Specific Applications
| Type of Exhaust Fan | Specific Applications |
| Wall mounted | · Suitable for single rooms like kitchen and bathrooms |
| Ceiling mounted | · Bathrooms |
| Inline Duct | · Venting many rooms and perfect for low noise requirements |
| Window exhaust fan | · For quick installations and offers temporary installations |
| Rooftop exhaust fans | · Common in large industrial spaces and warehouses |
| Range hood exhaust fan | · Suitable for installation on kitchen and directly above the stoves |
| Bathroom exhaust fan | · Removes moisture and unpleasant smell in bathrooms |
| Industrial exhaust fan | · Designed for continuous and heavy duty use |
| Centrifugal exhaust fans | · Suitable where there are bends, filters or long ducts since they can handle resistance within the system |
| Propeller exhaust fan | · Designed for open spaces and can move large amount of air |
| Solar powered exhaust fans | · Uses solar to move air and common in greenhouses or sheds |
Conclusion
As you can see, these exhaust fans are classified depending on the specific places you can install them. Although the design and configuration may be different, the working principle still remains the same.
Therefore, you must understand your unique application requirements before choosing any type of exhaust fan.
FAQs
Which is the best exhaust fan for areas with small amount of smoke and dust?
Both axial and centrifugal exhaust fans will serve you well.
How do you choose a good exhaust fan?
You should consider this criteria: Where to install exhaust fan, design, size, air delivery efficiency (CFM), and type of contaminant.
Is there difference between exhaust and ventilation fan?
Yes, ventilation fans supplies fresh air into an enclosed space, while exhaust fan removes contaminated air from indoor to outside environment.
What is CFM in exhaust fan?
It is cubic feet per minute, which determines the amount of air the exhaust fan can move from a room (enclosed area).
