For a long time, homeowners have depended on attic fans to vent excess heat during the summer. The fans work by extracting hot air from the house and dumping it outside, allowing cool, fresh air to enter the house.
What makes them exceptionally effective is that warm air has a natural tendency to rise, partly explaining why the house’s upper floors are warmer than lower ones. By removing the hottest air in the room, roof-mounted attic fans create room for cool, fresh air to enter the house.
We’ll discuss more about these fans shortly, including their advantages over other fan types and how to pick the right one.
What are Roof Mounted Attic Fans
Attic fans are ventilation fans installed in the attic. They regulate heat levels in the building’s attic by exhausting hot air.
Having one makes sense because the attic is often the home’s hottest area during the summer season. An unvented attic can reach 150˚F in the peak of the summer, at least 50˚F higher than the rest of the home.
Venting this extra hot air at the attic rather than waiting for the air conditioner down below to handle everything significantly lowers indoor temperatures while simultaneously easing the burden on the air conditioner and the ground fans.
There are two main categories of attic fans – roof-mounted and gable mounted. Gable-mounted attic fans are installed behind a static gable vent that already exists in the building. If it uses solar energy, the panel can mount to one of the exterior walls. Gable-mounted attic fans are generally larger in physical size compared to roof-mounted models.
The installation process can be a little challenging if the house doesn’t have an existing gable vent. In that case, it may be necessary to hire a professional.
Roof-mounted attic fans are installed on the roof, pitched or flat. They can also function in lofts, barns, workshops, and garages. A key advantage of roof-mounted attic fans over gable-mounted models is sturdiness. Roof-mounted models are a lot sturdier. They can withstand intense hurricanes and tornadoes without any risk of damage.
Roof-mounted attic fans are also easier to install. However, it’s always advisable to hire a professional for proper positioning and a more reliable installation. Also, some manufacturer warranties only hold if the installation is done by a licensed professional.
How do Roof Mounted Attic Fans Work?
It’s a straightforward process. Roof-mounted attic fans create a breeze through open windows and doors. They blow out the hot, damp air in your home, creating a “vacuum” in the rooms. Cool, fresh air from outside, then gushes into the house to fill the vacuum.
This fresh air itself feels a lot cooler and instantly lowers indoor temperatures. However, it’s not the only way attic fans create cooling. The breeze created as fresh air from outside enters the house also causes a cool feeling as it passes over the skin.
Advantages of Roof Mounted Attic Fans
Though not as popular as air conditioners and standard floor-standing fans, attic fans can be extremely beneficial to your air conditioning campaign.
- More even cooling: Air conditioners rarely cool the attic. The cooling effects are restricted mainly to the individual rooms. As such, the attic may remain hot even while the rooms below are air-conditioned. This negates most of your efforts because the heat from the attic above will always seep below the ceiling. Roof-mounted attic fans help remove attic heat via the roof.
- Reduced heating costs: In the absence of the attic fan, the air conditioner and fans at the ground need to run faster and longer to reach and maintain the thermostat setting. This can result in massive air conditioning bills. Some studies report that lowering attic temperatures by as little as 10% can reduce overall cooling bills by up to 30%.
- HVAC longevity: High cooling bills isn’t the only thing you should worry about when your air conditioner and standalone fans are running harder and longer. The extra load also causes faster wear and tear. You’ll notice more frequent AC breakdowns and need multiple fan repairs every cooling season. Eventually, the appliances may also have a shorter life.
- Prolonged roof life: The heat inside the attic usually condenses when temperatures drop sharply at night. The resulting condensation is very bad for your roof. It causes the iron in metal roofs to rust. Also, it forms a breeding ground for mold and mildew that can damage the roof and wood structures in the attic.
What Size Attic Fan Do I Need?
A roof-mounted fan’s performance is measured in cubic-feet-per-minute (CFM), which refers to the amount of hot air in cubic feet that it can remove per minute. Therefore, a 1,000 CFM attic fan can remove 1,000 cubic feet per minute.
According to the Home Ventilating Institute (HVI), your attic fan should exhaust your entire attic at least ten times per hour. An easy way to do the calculation is to multiply your attic “floor” size in square feet by 0.7 to determine the required CFM size.
So, if your attic measures 2,000 square feet, you need 0.7 x 2,000 = 1,400 CFM. Adjust this value 15% upwards for steep or dark-colored attics.
Other Considerations When Buying the Best Roof Mounted Attic Fan
Every homeowner has their preferences. Some may even prefer gable-mounted attic fans over roof-mounted models. However, if you decide to invest in roof-mounted ventilation fans, we strongly recommend that you prioritize the following considerations.
- Solar or electric? 100% solar-powered models are an incredibly energy-efficient choice but useless when there’s no sunlight. Meanwhile, 100% electricity-powered models will increase your power bill but are reliable throughout. Hybrid options are the best.
- Mesh bird screen: The best roof-mounted attic fans include a mesh bird screen to keep away litter, birds, and insects from entering the attic. If it’s missing, you need to buy one separately.
- Hard-wired or plug-in? Electric or hybrid attic fans can be hard-wired to the home’s power system or plugged into an existing socket. Hard-wired models give you greater peace of mind and are safer. However, it would help if you had an electrician for the job.
- 115V or 230V: Still on powering, although most attic fans are rated 110-120V, for easy installation, a few models are rated require 230V wiring. Remember that it’s hazardous and straight out prohibited to wire/connect a 230V appliance to a 115V wiring/outlet.
Roof Mounted Attic Fan Maintenance
Attic fans are low-maintenance appliances that won’t trouble you much. However, it’s still important to inspect them once in a while to ensure that everything is working correctly.
Among others, make sure the thermostat is working correctly. If need be, warm it up using a heat gun. Also, check the fan blades to make sure they are in the best shape. Broken blades or a blade system that feels sticky must be services immediately.
Leaking water and fan noises are two other concerns. If you notice water leaking from around the fan, call a professional to fix the issue. As for fan noise, proper maintenance should help eliminate the strange sounds. Otherwise, you may need to replace the fan.
Reviews of the Best Roof Mounted Attic Fans
The following are eight of the best roof-mounted attic fans. We’ve picked products from different performance (capacity) and price ranges, so everyone can find one that suits their needs. However, all the options on this list are highly efficient and extremely reliable.
1. Broan Nu-Tone 356BR Attic Ventilator, Roof Mount Ventilator Fan
The Model 356BR Broan Nu-Tone ventilator is a 1500 RPM ventilator fan with a thermally protected and permanently lubricated split capacitor motor for reliable performance.
It features four precision-balanced 14-inch metal blades for powerful airflow with minimum noise and a 22 ¼ x 22 ¼ -inch PVC housing with a 23 ¼ inch (diameter) plastic dome ultraviolet protection and durability.
It’s a 1600 CFM ventilator with a 120V rating (8.0 amps at 60-Hz), making it sufficient for large spaces up to 2,280 square feet. A 23-inch diameter gauge metal flashing allows for nailing and hot tar application, while an included installation template is designed to make the installation process easier. A built-in adjustable thermostat makes it easy to select the best cooling level for the ultimate comfort.
The ventilator works just as well as a replacement solution for various Broan Nu-Tone attic fans, including the model 69V, 68V, and 68W, as it does in new constructions.
A mesh bird screen helps keep debris, twigs, and other foreign particles at bay, while the one-year warranty ensures worry-free use. The dome rises about 8.0 inches from the roof.
- It’s a powerful 1600 CFM fan
- Ideal for up to 2,285 square feet
- 14-inch steel blades for maximum airflow
- Thermally protected, permanently lubricated motor
- 1-year warranty
- Not HVI certified or UL listed
- No continuous motor operation
2. AIR Vent 53827 Roof Mounted Power Attic Ventilator Fan
Air Vent is another company that makes excellent attic fans, as evidenced by the unique model 53827 attic ventilator. The electric-powered attic vent uses a thermostat to fight heat and humidistat control to prevent moisture buildup in the attic for a relaxing and healthy home.
Moreover, the low-profile dome is unobtrusive when installed on the roof face slanting away from the front of your home. It’s the perfect replacement for wind turbines and roof posts.
Each ventilator is constructed from a pre-painted 220-gauge galvanized steel dome which is far more durable than aluminum. The screws are painted to match the dome color.
Also, each dome is raised for greater airflow and easier flashing. Six brace struts firmly hold the dome in place while a plastic screen keeps away animals, birds, and debris from entering the ventilator.
You’ll also appreciate the oversized 24-inch x 24-inch G-90 galvanized base flange that offers easy nailing and flashing. A stiffening rib is included to improve edge sealing and add rigidity. A 5-year limited warranty backs it.
- It’s a powerful 1170 CFM ventilator
- Ideal for up to 1,650 square feet
- 6-bladed fan system
- Features 60-120˚F thermostat
- 5-year limited parts warranty
- Few performance certifications
- Not Energy Star compliant
3. MaxxAir Roof Mount/Mounted Power Attic Ventilator
Another low-profile dome attic ventilator on the list, this product from MaxxAir, is a galvanized steel heavy-duty unit with no brittle plastic parts that may bake or chip in the sun. Six-point suspensions (anchor points) ensure stability while the galvanized steel mesh grilles protect against insects, birds, and rodents without blocking airflow.
It’s an incredibly efficient 1080 CFM ventilator, designed for spaces up to 1,600 square feet. The heavy-duty PSC thermally protected motor draws a paltry 2.6 amps and is engineered for a long life of the reliable operation. Large, 14-inch fan blades are precision-balanced to ensure maximum airflow with minimum vibration and no heat distortion.
Maxx Airpower roof vents are factory assembled for easy installation – no special tools are required. They are also built for stability and high wind resistance. This particular model is UL and CUL listed for safe handling and backed by a 2-year limited warranty.
- Powerful 1080 CFM fan for up to 1,600 Square Feet
- Galvanized steel mesh keeps out animals and debris
- UL and CUL listed for safe handling
- Backed by a 2-year manufacturer warranty
- Not Energy Star certified
4. LIVING Model ILG8SF301 Hybrid Ready Smart Exhaust Solar Roof Attic Exhaust Fan
So far, we’ve only looked at electric-powered ventilators, which isn’t out of order since they tend to very powerful and extremely reliable.
However, for the environment-conscious, there are many solar-powered attic ventilators to consider. I-Living’s first one is equipped with a powerful 20-watt adjustable polycrystalline solar panel for energy-saving attic ventilation.
It runs 100% on solar when there’s strong sunshine but can switch to electric power on cloudy days and at night. More importantly, it’s a powerful 1750 CFM fan designed for spaces up to 2,000 square feet.
A built-in smart thermostat helps keep indoor temperatures between 65-130˚F, while a screen guard keeps unwanted debris and animals out. An IP68 waterproof brushless motor powers the entire system.
The solar panel is adjustable up to 45 degrees for maximum sunshine capture, while the fan houses a 14-inch aluminum blade system for maximum airflow. A critical quality that sets this fan apart is the adapter kit (sold separately).
The kit offers extra features and functions such as a non-stop running AC power supply and an on/off switch. An optional power cord with an on/off switch is also available separately.
- Features powerful 1750 CFM fan system
- Ideal for spaces up to 2,000 square feet
- Several add on features available separately
- Backed by a 15-year warranty
- Screen mesh sold separately
- AC/DC adapter kit sold separately
5. GBGS Solar Powered Exhaust Fan AC Power Backup
Another great option if you prefer a hybrid electric/solar attic ventilator is this GBGS 2-way power fan system. It’s primarily a solar fan. When the sun is shining brightly out there at greater than 14 volts, it will run exclusively on solar power.
However, as soon as the solar energy drops to 0-14V, the two power options begin to work together to keep the fan running. If solar power drops below 0V, the fan runs exclusively on electric power. This arrangement keeps the fan operational even at night and on rainy days.
The brushless DC motor fan is IP68 waterproof for durability and moves air at 1750 CFM. This makes it an excellent choice for spaces up to 4,200 square feet. Seven 14-inch aluminum fan blades deliver an axial flow type for consistent, reliable cooling. The fan runs on 100V-240V (AC) or 18V, 1A (DC).
A smart power controller is included for automatic switching of power supply between solar and AC/DC. You’ll also find a 3-meter (9.84-foot) cable in the package to connect the fan to the AC/DC adapter and a 10-meter (32.8-foot) cable to connect the fan host to the 20-watt/18V polycrystalline solar panel.
- Hybrid solar/electric attic fan
- Galvanized steel housing and mounting frame
- Solar panel adjusts horizontally and vertically
- Front side metal mesh prevents birds, debris
- Reliable warranty, up to 10 years on the motor
- A tad expensive at close to $300
6. Canada Go Green 4 Seasons Solar Powered Polycarbonate Vent
Purposely designed for harsh weather conditions, the 4Seasons10W solar fan from Canada Go Green is a high-efficiency brushless motor fan with Japanese ball bearings for optimal performance at low vibrations.
At 400 CFM, it’s a little smaller (capacity-wise) compared to the fans we’ve looked at so far. This makes it best suited to medium-sized rooms up to 500 square feet.
It’s also a little different from the two solar fans above in that it’s not a hybrid solar/electric fan. The 4-seasons runs explicitly on solar power and automatically goes off when the sun is unavailable. For instance, it operates as a standard passive vent at night.
It’s exceptionally quiet, though, thanks to the few moving parts. The 10-watt mono-crystalline panel features one of the highest quality solar cell types in the industry that work very well, even in low sunlight.
Watertight flashing and an animal-proof construction allow the fan to stand up to harsh weather and pesky wildlife, while the ABS-PC anti-UV/freeze construction guarantees greater longevity. The entire system is CSA approved and backed by a 10-year limited manufacturer warranty.
- It runs exclusively on solar power
- Anti-UV/ freeze construction
- Watertight, animal-proof construction
- Low-profile 4.7-inch height
- 10-year manufacturer warranty
- Low performance (400 CFM)
- No backup electric powering
7. Cool Attic CX1000AMWGUPS Power Roof Galvanized Steel Vent Dome
If you’re on a budget, then this dome vent fan from Ventamatic would be the ideal solution. It’s the only product on this list priced under $100 and offers all the benefits of an attic fan.
You’ll cost-effectively reduce air conditioning costs and prevent weather-induced home deterioration. It’s also a low-profile dome fan that rises only about 10 inches above the roof.
The 18-pound dome fan is constructed from galvanized steel for a long life of reliable use. Galvanized steel mesh grills help keep away insects, birds, and rodents. The fan blades are precision balanced for powerful airflow with minimal vibration.
The system is fully pre-assembled for easy installation (no special tools required) and built for stability and high wind resistance. A built-in adjustable thermostat automatically detects ambient temperatures and controls the speed of the fan for optimal comfort.
This fan is rated 1080 CFM and is ideal for large rooms, up to 1,600 square feet, and comes with a 2.6 amp motor. The fan itself features 14-inch aluminum fan blades for maximum performance and increased longevity. It plugs into the standard 120-volt power outlet. A 24-month limited manufacturer warranty backs each purchase.
- A powerful fan at 1080 CFM
- Constructed from galvanized steel
- Features galvanized steel mesh
- It’s the most affordable on this list
- Short 24-month parts warranty
- No labor warranty
8. Natural Light Solar Attic Fan 48-Watt Black with a 25-Year warranty
Let’s round off with arguably the most powerful fan on the list – the model SAF48 from Natural Light. It’s a sleek 48-watt solar fan (doesn’t use electricity) with a massive 1881 CFM capacity.
More importantly, it’s fully operational right out of the box and installs with ease. No electrical wiring is needed. You also don’t need expensive city permits. Besides attics, you can use the fan in several areas where air circulation is needed, including barns, workshops, and storage sheds.
The solar panel is adjustable, up to 45-degrees horizontally, for optimal performance and mounts on 3/12 to 12/12 pitch roofs (flat roof installation and wise wall mounting not recommended). It’s 20.1 inches x 21.3 inches and arrives with a 9-inch adjustable bracket.
Meanwhile, the dome under the solar panel measures 23 inches x 4.0 inches. The system also includes a heavy-duty leak-proof aluminum flashing/base that’s 27.25 x 6.25 inches.
This fan comes in a heavy-duty powder-coated aluminum housing and features a protective animal screen. The precision-balanced direct current motor is secured to an isolation bracket for quiet operation, while the aluminum 5-wing fan blade system ensures powerful airflow. A 25-year warranty backs the entire system.
- It’s an 1881 CFM fan, great for up to 2825 Sq. Ft.
- Durable powder-coated aluminum construction
- It comes with a powerful 40-watt solar panel.
- Reliable 25-year manufacturer warranty
- A tad expensive at over $400
- No backup electric powering
Roof-mounted attic fans can be precious in achieving your air conditioning goals. They effortlessly ventilate the extra hot air in the attic, instantly lowering temperatures in the living areas. By eliminating the hot attic air, they also reduce the burden on your air conditioners and floor-standing fans. If you haven’t got one yet, you should strongly consider doing so.