Are you tired of nasty cooking smells, steamy bathrooms, or a feeling of stuffiness in your home? Then it's time for you to get yourself an exhaust fan. The right exhaust fan can be a game-changer, blowing away odours, moisture, and stale air, leaving your home feeling fresh and comfortable.
But with so many options currently available in the market, how do you choose the right exhaust fan? Well, it all comes down to understanding your room size.
In this guide, we'll talk in detail about everything you need to know to choose the perfect exhaust fan, ensuring optimal air quality and comfort in every room of your home.
Why Is Exhaust Fan Size Important?
1 Effectiveness
Choosing the right size exhaust fan isn't just about adding a new appliance to the home; it's about effective ventilation. A fan that's too small for your room won't be able to move enough air, meaning odours and moisture will still be around. This can lead to issues like mildew growth in bathrooms or persistent cooking smells in kitchens, making the fan pretty useless.
2 Energy Efficiency
On the other hand, an exhaust fan that's too powerful can be overkill. It might be noisier than necessary and could even pull too much heated or cooled air out of your home, wasting energy and increasing your utility bills. Therefore, getting the size just right ensures your fan works efficiently, quietly, and effectively, creating a healthier and more suitable living environment.
Factors to Consider Before Choosing an Exhaust Fan
1. Air Movement Power (CFM)
The most important factor when choosing an exhaust fan is its "air movement power," measured in Cubic Feet per Minute (CFM). This number tells you how much air the fan can move out of your room in one minute. A higher CFM means the fan can clear more air faster. For example, a fan with a 100 CFM rating can remove 100 cubic feet of air every minute.
To get effective ventilation, you need a fan with enough CFM to completely replace the air in your room several times an hour. If the CFM is too low for your room's size, the fan won't be able to do its job properly, leaving you with stuffy air or lingering moisture. Always check the CFM rating, as it's the primary indicator of a fan's effectiveness for a given space. That's where fans like the Blauberg Turbo G Mixed Flow Inline AC Exhaust Fan - 250MM are designed for powerful air movement and can be suitable for larger spaces requiring significant CFM.
2. Noise Level (Sones)
Nobody wants an exhaust fan that sounds like a jet engine taking off. That's where "sones" come in. Sones are a measurement of how much noise a fan makes. The lower the sone number, the quieter the fan will be. For instance, a fan rated at 0.5 sones is extremely quiet, almost silent, while a fan at 3.0 sones will be noticeably louder.
For areas where quiet is important, like a bathroom or a bedroom, aim for a fan with a low Sone rating (1.0 or less). In a busy kitchen where other noises might mask the fan, a slightly higher sound rating might be acceptable. Always consider the noise level, especially if you plan to use the fan frequently or in a quiet part of your home.
3. Ducting
The ducting is essentially the "pipe" that carries the air from your exhaust fan to the outside of your house. It's a crucial part of your ventilation system. Proper ducting ensures that the moist or stale air is actually removed from your home and not just moved into another part of your attic or walls.
Ducting comes in different sizes and materials. The size and length of your ducting can affect how well your fan performs. If the ducting is too small or has too many bends, it can restrict airflow, making even a powerful fan less effective. It's always a good idea to ensure your ducting is properly sized and installed for optimal performance.
4. Special Features
Modern exhaust fans come with a variety of extra features that can make them even more convenient and effective. For example, some fans have a "humidity sensor" that automatically turns the fan on when it detects too much moisture in the air, like after a shower. This is great for preventing mould and mildew growth without you having to remember to switch it on.
Other useful features include built-in lights, which can be a practical addition, especially in bathrooms, combining lighting and ventilation in one unit. Timers allow you to set the fan to run for a specific period, ensuring proper ventilation even if you forget. Fans like the Fantech EDM Wall Mounted Fan with Backdraft Shutter offer practical features, including a backdraft shutter to prevent air from re-entering the room when the fan is off.
How to Choose the Right Size?
Step 1: Measure Your Room
First things first, you need to know the dimensions of your room. Grab a tape measure and note down the length, width, and height of the room where you plan to install the exhaust fan.
For example, if your bathroom is 8 feet long, 5 feet wide, and 8 feet high, you'll use these numbers in the next step. Accurate measurements are essential for getting the correct CFM calculation.
Step 2: Calculate the Room Volume
Once you have your measurements, multiply the length, width, and height to get the total volume of your room in cubic feet.
So, for our example bathroom (8 ft long x 5 ft wide x 8 ft high), the volume would be 320 cubic feet. This volume tells you exactly how much air is in your room.
Step 3: Determine Required CFM
Now, you'll use the room's volume to figure out the minimum CFM you need. A good general rule for most rooms, especially bathrooms, is to aim for one air change every minute. So, your required CFM will simply be the room's volume.
For our 320 cubic foot bathroom, you would need an exhaust fan with at least 320 CFM. However, for bathrooms smaller than 100 square feet, a simpler rule is often used: 1 CFM per square foot. So, an 8x5-foot bathroom (40 sq ft) would need a minimum of 40 CFM.
For kitchens, the requirements are typically much higher due to cooking fumes, often ranging from 100 CFM for a small kitchen to over 400 CFM for larger ones with powerful ranges. Always consider the specific use of the room.
For smaller rooms or specific areas like windows, a fan like the Fantech Stylvent Wall / Window Mounted Fan - 225 M3/H could be a suitable option for its airflow capacity.
Recommended Exhaust Fan Sizes for Different Rooms
| Room Type | Room Size (sq. ft.) | Recommended Fan Size (CFM) |
|---|---|---|
| Small Bathroom | Up to 50 sq. ft. | 50 CFM |
| Medium Bathroom | 51-100 sq. ft. | 80-100 CFM |
| Large Bathroom | Over 100 sq. ft. | 100-150 CFM+ |
| Kitchen | Any size | 150-400 CFM |
| Laundry Room | Up to 100 sq. ft. | 80-100 CFM |
| Garage | 200-400 sq. ft. | 200-300 CFM |
| Workshop | 150-300 sq. ft. | 150-250 CFM |
Conclusion
Picking the right exhaust fan doesn't have to be complicated. All you need to do is measure your room, understand what kind of airflow it needs, and choose a fan that matches. The right fan will keep your space clean, dry, and fresh without using too much energy or making too much noise.
Whether you're upgrading your bathroom or setting up a new kitchen, a well-chosen exhaust fan is a small change that makes a big difference. From better health to a better living environment, changing the exhaust fan is key to better health.
FAQs
No, it's not recommended. An exhaust fan that's too small won't effectively remove moisture and odours, leading to potential issues like mould or lingering smells. Always match the fan's power (CFM) to your bathroom's size.
CFM stands for Cubic Feet per Minute, and it measures how much air an exhaust fan can move in one minute. It's crucial because it tells you if the fan is powerful enough to clear the air in your specific room size.
The sound rating tells you how noisy the exhaust fan is. The lower the sound number, the quieter the fan. For example, a 0.5 sone fan is very quiet, while a 3.0 sone fan will be noticeably louder.
Yes, kitchen exhaust fans (often called range hoods) are designed to handle grease, smoke, and strong cooking odours. They typically need much higher CFM ratings than bathroom fans because of the heavier demands of cooking.
For bathrooms, it's a good idea to run the fan during your shower or bath and for at least 15-20 minutes afterward to completely clear out moisture. In kitchens, run it while cooking and for a few minutes after to remove smells and smoke.
