Do you want to find the best rated gable attic fan?
Gable exhaust fans are mounted vertically on the gable wall and help remove excess heat and moisture.
In this product review guide, I will go over...
- My #1 top pick for the best gable attic fan
- How to install a gable attic ventilator
- Tips on picking the best gable exhaust fan
- Ways to reduce noise and vibrations
Let’s get started with this guide!
My Overall #1 Rated Pick
My overall top pick for the best rated gable attic fan goes to the Quiet Cool AFG SMT-3.0. I chose this gable attic fan because it comes with a high quality ECM 10-speed motor which means it starts at ~3,000 CFM when the attic is very hot --- and then drops to 1,000 CFM as the heat dissipates.
This gable fan also comes with a humidistat to keep moisture below 60% along with an adjustable thermostat. You can also just plug this attic fan into a standard 120-volt outlet.
QuietCool AFG SMT-3.0
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Cool Attic CX2500
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My Top 5 Picks For Best Rated Gable Attic Fans
Are you short on time? To skip the details, and see my top picks, check out my list below. If you want more information and their pros and cons, keep scrolling.
What is a Gable Attic Ventilation Fan?
A gable attic fan is a ventilation fan that is installed vertically against your gable vent rather on top of your roof.
One of the biggest upsides to gable attic fans is that you don't have to cut a hole in the roof, you don't have to hire a roofer, and the "opening" already exists at the gable vent. Gable attic fans are either hardwired into the home’s electrical system, plugged into a standard 120-volt outlet, or are solar powered.
The average life expectancy of a gable attic fan is between 15 to 25 years.
How Do Gable Attic Fans Work?
When an attic hits a temperature, such as 95 degrees Fahrenheit, the gable attic fan will turn on. The gable fall will blow out the attic air and moisture --- while at the same time pulling in fresh outdoor air.
Pretty much all gable attic ventilators come with adjustable thermostats so you can choose a temperature level where you want the exhaust fan to turn on.
And when the attic temperature drops below this set level, the gable fan will automatically turn off.
Read Also: What Are The Best Roof Mounted Attic Fans?
In addition to thermostats, some gable attic fans come with humidstats --- these are sensors that detect humidity rather than temperature.
They act the same way as thermostats, but will turn the fan on automatically if humidity rises above 60% relative humidity as an example. And once the humidity drops below 60%, it will turn the gable fan off. The humidistat will work together with the humidistat to control the attic fan.
Besides the thermostat and humidstat for automatic control, most homeowners have a physical wall switch that allows you to shutoff the attic fan for whatever reason. This wall switch is usually located in the hallway below the attic entrance.
If this switch is in a hallway, it is highly recommended to tape the switch to the on position so nobody accidentally turns it off.
Solar Powered Gable Fan
For solar powered fans, there is usually isn't a thermostat.
This type of fan will turn on when the sun rises, and it will keep running all day at a lower fan speed. And then when the sun sets in the evening, the solar powered fan will turn off.
The solar powered gable attic fan usually doesn’t have a switch, and just turns on when the sun is out.
How Does A Gable Attic Fan Cool Down My Attic?
One of the biggest benefits of installing a gable attic fan is that it can cool down your attic during hot weather. Homes with attic fans may become substantially cooler than comparable homes with a cooling effect of up to 30 degrees.
Read Also: How To Install Roof Mounted Attic Fans?
The actual attic cooling will depend on different factors such as your existing insulation, house layout, climate, and the amount of intake vents. In an ideal world, the temperature of your attic should be about the same temperature as the outside air (though within 20 degrees is probably acceptable). In my experience as a home inspector, most homeowners just aren't aware of how hot attics can get.
Attics are a kind of "out of sight, out of mind" kind of thing. And I don't blame them. I mean, who wants to go into an attic?
Protecting Your Asphalt Shingles With A Cooler Attic
Most roof shingles today are made from a type of asphalt (and fiberglass) which is basically derived from crude oil. Unfortunately, if these shingles get too hot, they can literally cook on the roof surface — causing curling, cracking, and other deterioration.
When an attic gets extremely hot, it can prematurely age your roof. I have been to homes where I inspected a very faded asphalt shingle roof (looks almost white) and estimated an age of 25+ years. Later, I find out from the seller that it was replaced only 7 years ago.
The cause of the premature aging of the roof was very poor ventilation (and insulation) in the attic. During summer, it would probably reach over 150 degrees in the attic on certain days.
When your properly ventilate your attic of hot and humid air, you not only help keep your house cooler, but you are also helping to protect your roof.
Can A Gable Attic Fan Improve Your A/C?
Another large benefit of improving your attic ventilation is that it will help keep your whole house cooler because you don’t have a sweltering inferno in your attic.
I have been in attics during home inspections where I felt like I was going to pass out, as if I was going into a sauna. As you can imagine, this not only makes your interior hotter, but it also makes your air conditioning run harder and longer that normal.
This is especially true for the upper level of homes. I think we have all been to houses where the second level of the home is 10+ degrees hotter than the basement or ground level. Hot air rises, and when you combine that fact with a sweltering attic --- it can make the upper level of a home almost unlivable.
And just like a roof, a very hot attic can prematurely age your air conditioning system.
The standard life expectancy for an air conditioner is about 15 years. But if it abused, poorly maintained, and runs hard due to a hot attic, it may only last several years.
A cooler attic will also help reduce your electricity bill if your A/C doesn’t have to run as long.
Read Also: What Are The Best Solar Powered Attic Fans?
How To Prevent Ice Dams & Mold With Gable Attic Fans?
Another benefit of a properly ventilated attic is that it can help prevent ice damming.
Roof ice dams occur when snow melts on the upper roof, and the water drains to the lower roof, re-freezes, and then forms a type of “dam” blocking proper water drainage.
Basically, if you see icicles growing along the edge of your roof, you have a type of ice dam. The ice dam will prevent melting snow from properly draining down the roof and into the gutter.
This backed up water can leak into the house, causing ceiling damage, drywall warping, and may lead to mold problems. A bad ice dam can also tear off roof shingles, and destroy gutters.
The biggest cause of ice dams is lack of ventilation and insulation in the attic. If there is improper ventilation, then rising heat from the home’s interior will leak into the attic and stay there. This trapped attic heat will cause snow to melt on the upper roof, leading to ice dams (as the water freezes towards the lower roof or eaves).
Read Also: How Do Attic Fans Really Work?
A large health problem with a poorly ventilated attic is possible moisture buildup and mold growth. Moisture occurs when cool and warm air meet, which can happen during hot or cold weather.
If the attic is hot, and the home’s interior is cool, when these two air masses meet, water droplets can form inside the attic — water on the roof sheathing, rafters, drywall, insulation, and ceiling joists.
Mold only needs three things to grow..
- Food Source
Your attic is already dark, and the food source is the wood. Add in moisture from a poorly ventilated attic and voila — mold growth.
How To Install a Gable Attic Fan?
Homeowners frequently complain about noise and vibrations when installing gable attic fans, but this problem is easily avoided if you use sound dampening materials during the installation such as:
- Weather stripping around the metal frame where it meets the gable vent
- Rubber washers on the screws
- Rubber mounts
Likewise, some homeowners install the gable attic fan onto a separate piece of plywood, and then mount the plywood to the attic fan. This helps prevent vibrations and noise since it doesn’t touch the aluminum gable vent.
For the electrical work, some gable attic fans are “plug and play” compatible which means you can just plug the fan into an existing outlet in the attic. Other gable attic fans will require some simple electrical work such as connecting wiring together using wire nuts. If you aren’t comfortable with wiring, hiring a qualified contractor is recommended to install a gable attic fan.
The cost for the installation (excluding the fan) can be anywhere from $100 to $300.
No Holes in Roof
A great benefit of gable attic fans is that you don’t have to cut a hole into your roof’s sheathing. With a gable attic fan, you simply mount or screw the fan into your gable vent.
On my home inspections, I frequently find signs of roof leaks. These roof leaks are usually from things installed on or through the roof such as skylights, plumbing vents, bathroom vents and chimneys.
Read Also: How Attic Fans Protect Your Roof?
How To Pick The Best Attic Fan for Your Gable Vent?
One of the most important things to consider when buying an attic fan is the CFM rating. CFM stands for “cubic feet per minute” or how much air is moved in sixty seconds.
Most gable attic fans will be rated from 1200 CFM all the way up to 3000 CFM. Most manufacturers will tell you the maximum size of an attic for their particular fan model.
It is important to follow manufacturer recommendations for adequate venting. Gable attic fans will be rated for a particular amount of “net free area” of ventilation. This refers to the amount of vent area independent of the gable vent where the fan be installed.
These vents may be another gable vent (other side of home), soffit venting along the eaves, the ridge vent, passive vents, or the gable vent on the other side of the roof. A general rule is to have one square foot of additional venting per each 300 CFM.
The opening of the gable vent must be large enough for the attic fan to exhaust the hot attic air. But there also must be enough additional venting elsewhere so the gable attic fan will be able to draw in fresh outside air.
If there isn’t enough additional venting, the attic fan may pull in air from the home’s interior and actually increase your air conditioning costs.
Read Also: How To Vent Attics Without Soffits?
Carbon Monoxide Hazard
If you have natural gas burning appliances, such as a gas-fired water furnace, and you don’t have enough venting in the attic for fresh “makeup air” — the attic fan can literally suck out the home’s interior air.
If this negative air pressure environment causes your gas-burning appliances to malfunction, this is known as “back drafting”. Back drafting is when an appliance exhausts it’s fumes into the home rather than to the outside.
When gas-burning appliances back draft, this can cause carbon monoxide poisoning to any of the occupants. It is very important that homeowners follow the manufacturer recommendations for required attic venting to prevent back drafting.
There are also simple tests to make sure your water heater or furnace is not “back drafting” when your attic fan is on. One simple test is called the smoke test. You simply light a match, and blow it out. Then put up the smoke next to the water heater or furnace flue pipe. If the smoke or flame is pushed out, then you know back drafting is going on.
Besides this simple test, always install a carbon monoxide detector on each level of your home if you have gas burning appliances!
Read Also: How To Install A Solar Attic Fan?
How Do You Inspect Attic Fans?
#1. Will It Turn On?
Locate the thermostat (small metal box) usually mounted on a rafter or truss next to the fan in the attic. Turn the temperature knob so it is below the current attic temperature. You can also use a heat gun, hair dryer, or lamp to heat up the thermostat if the attic is cold.
#2. Turn The Blades
If the attic fan doesn't turn on, try turning the fan blades. If the blades won't turn, you may have a seized motor.
#3. Operation Quality
If the the attic fan turns on, are their any weird noises? Does it run smoothly? Can you feel air flow or is it very weak? The fan screen or louvers should not be blocked with debris impeding air flow.
#4. Water Stains
A common problem with attic fans are leaks. Are there any signs of water leaks around the fan on the roof sheathing?
How Are Gable Attic Fans Different Than Other Types of Powered Ventilation?
Gable attic fans are different than roof mounted attic fans in that you don’t have to cut a hole in your roof (or walk on your roof) to install the fan. Besides the installation location, gable attic fans operate in the exact same way as roof fans.
Very similar to attic fans, most homes have bathroom exhaust fans which also help remove moisture and increase ventilation. Bathroom exhaust fans can also have thermostats, humidity sensors, and even come with lights and heaters.
Where To Buy The Best Gable Mounted Attic Fan?
You may be able to buy a gable attic fan from a big box store, if they even have a model in stock, but your best bet for more choices is Amazon.
Amazon will have a variety of gable ventilation fans to choose from, as well as reviews from customers that can alert you to certain advantages and disadvantages of a product. At Home Inspector Secrets, I recommend buying from Amazon because…
- Ease of Shipping. Some products will ship in two days for free.
- Credibility. Amazon is the largest online retailer in the world.
- Reviews. Read reviews from customers on your prospective purchase.
- Great Deals. Shop from a variety of attic fans for the best deal.
What Are The Best Gable Attic Fans?
Here are my top picks for the best gable attic fans with their pros and cons...
The QuietCool AFG gable attic fan is my #1 top choice for gable exhaust fans.
This premium gable fan has a high quality ECM motor with 10 different fan speeds. It will start at 3000-cfm fan speed when the attic is very hot, and then drop to 1000-cfm as the temperature goes down.
And not only is there an adjustable thermostat, it also comes with a humidistat to keep the attic moisture below 60% --- helping to prevent mold growth.
This gable attic fan is plug and play which means you can just insert it into a standard 120-volt outlet.
- 10-speed variable ECM motor
- Includes thermostat and humidistat
- Plug and play compatible (120 volt outlet)
- Complaints of loud noise
The Amtrak Solar is one of the gable vent designed solar exhaust fans on the market.
It comes with a high quality 40-watt crystalline solar panel that can be installed on the roof without holes (roofer & permit not required).
The 10" high performance fan will start removing excess heat and moisture from the attic as soon as the sun rises in the morning (and stays on until sunset).
It is rated for attics up to 2,250 square feet.
- Solar powered and energy efficient
- No holes in roof required (easy install with quick connect wiring)
- 40-watt high quality solar panel
- Complaints of poor fan speed
- Complaints of low quality solar panel
- Does not come with thermostat (sold separately)
The Cool Attic CX2500 is an affordable and effective gable attic ventilator that will remove moisture and heat from your attic.
This gable fan is rated at 1650-cfm and requires at least 600 square inches of intake venting.
The thermostat is adjustable and the fan has a one speed setting. This gable fan is 2.1 amps and a thermally protected PSC-type motor
- 1650-cfm fan speed for effective heat removal
- A budget friendly price
- Adjustable thermostat
- Complaints of unbalanced fan blades
The Broan 35316 is a high quality gable attic fan so you can push heat out during summer, and stop ice dams during winter.
This single speed 4-blade gable exhaust fan has thermally protected and permanently lubricated motor --- it is also HVI certified.
The fan is rated for attics up to 2280-sf and has a maximum speed of 1600-cfm. The Broan fan also includes a built-in insect and pest screen.
- Mid level pricing
- HVI certified
- Well known brand
- Poor longevity with some customers
The iLiving is a very affordable and well-built gable attic fan and rated at 800-cfm.
The fan motor is variable speed with the purchase of a separate motor controller (KB 811012 Controller).
This 12" gable attic fan is UL-listed and has an OSHA compliant wire guards.
Perhaps the best part of this gable attic fan is that it comes with automatic shutters that opens and closes.
- Automatic shutters that open & close
- Variable motor speed (with separate controller)
- Galvanized steel frame
- Complaints of shutters not closing
- Shutters seal poorly
- Not a strong motor
My #1 Top Pick: QuietCool AFG SMT-3.0 Gable Attic Fan
My top pick goes to the Quiet Cool AFG SMT-3.0. Here's why...
#1. Variable Speed
When a fan motor is variable speed, it means it is a higher quality motor and it is more energy efficient AND more effective at exhausting the attic. The QuietCool fan starts at 3000-cfm fan speed, and then drops to 1000-cfm automatically as the temperature goes down.
#2. Plug & Play
No extensive wiring is required with this gable attic ventilator. You can simply plug it into a standard 120-volt outlet.
The QuietCool gable attic fan comes not only with an adjustable thermostat, but it also includes a humidistat which senses moisture. The humidstat will also turn the gable fan on when moisture goes above 60%.