Will an Attic Ventilation Fan Cool Your House?

As summer approaches, you may want to think of ways to lessen the heat and humidity in your home. Fortunately, you have plenty of options to do so. However, one frequently overlooked method of making your living space more comfortable is providing adequate attic ventilation.  

Your attic space gets particularly hot because as the sun’s rays fall on your roof, it absorbs the heat and then radiates it into your attic. That’s why the temperature in the attic can get up to 150 degrees Fahrenheit. An attic fan is an excellent means of getting rid of the hot air in the area. By reducing the temperature in the attic, your air conditioning unit won’t have to work as hard in cooling down your living space. 

What is an Attic Vent Fan?

Just as its name implies, an attic fan is an exhaust fan installed in the attic. It primarily serves as an air exchange mechanism in your home. Often attached to the roof or gable vent of a house, the fan displaces the air in the attic space and replaces it with air from the outside. 

An attic fan supplements the passive venting structures installed in a house, improving attic ventilation that can help boost the energy efficiency of the air conditioning system. During the height of summer, temperatures inside the attic can reach over 160 degrees F. That can easily impact the performance of your HVAC system. 

How does Attic Vent Fan Work?

Attic fans work by getting rid of the stiflingly hot air in the area and bringing in cooling air from outside the house. Good attic ventilation prevents the heat from seeping down into the rest of your living space, making your AC unit work harder to cool the house.  

Your home may already have a built-in attic venting in the form of soffit vents installed in the house’s eaves. Cool air enters through those vents. The air heats up, rises, and exits through the venting in the roof. However, attic fans can help blow out hot air faster from the attic space. This cools your home quicker than if you allow passive venting to let the hot air out. 

That being said, an attic fan is not always effective in cooling your living space. Even the best attic ventilator can create some problems depending on particular situations. For example, a high-powered attic fan can draw the cool air from your house and push it out through an inadequately sealed ceiling. 

Back drafting water heaters or furnaces is another problem a high-powered attic fan can create. This occurs when the fan sucks the combustion gas out of the burners and into the house. Moreover, proper attic ventilation may not be enough to cool a home during the worst of the summer months. 

3 Types of Attic Fans

If you’re looking to increase your home’s attic ventilation, you can choose between different attic fans. All types can be roof-mounted or installed on gable ends. Finding the one that works best for your situation can help lower your AC unit’s energy consumption by effectively cooling down your attic space. 

Smart Attic Fans

These attic fans offer the latest innovations in attic ventilation solutions. They’re equipped with a built-in thermostat and/or humidistat that changes the motor’s speed depending on the condition in the attic space. 

A smart attic ventilator adjusts automatically to the climate in the attic, thus maintaining ideal temperatures in the area all year round. This helps make your home more energy-efficient, especially during the summer months.  

Smart attic fans prevent extreme heat build-up in the attic during hot weather. Without such action, the scorching temperature can move down your living space, forcing your cooling system to work harder. Smart attic ventilators usually feature a smartphone app. The app lets you control the fan’s settings and determine the current condition in your attic. 

Solar Attic Fans

Do you want to provide sufficient attic ventilation without driving up your electricity bills? A solar attic fan may be the answer. This type of fan cools down your attic without using electricity from the grid. As a result, its power consumption doesn’t add to your energy expenses.  

As its name implies, a solar attic fan runs on solar power. This means it pushes out the air from the attic and draws in cool air from the outside using solar energy. Some models are equipped with an AC/DC inverter, which lets you operate the fan with electricity from the grid at night and with solar energy during the day. 

A solar-powered attic fan helps keep your home cool. On top of that, it lets you reduce your carbon footprint in two ways. Using this type of fan helps lessen the energy usage of your power-hungry AC unit, thus reducing your electricity consumption. In addition, it relies on solar power, which does not release greenhouse gasses. 

Traditional Attic Fans

A traditional attic fan is the most common type of exhaust fan found in many American homes. It provides high-powered attic ventilation, pushing out a lot of air through the vents.  

Traditional attic fans usually come with a thermostat and operate on a single speed that can push up to 2,000 cubic feet of air per minute. They’re usually the least expensive choice. As such, they’ll help you save money on your AC unit’s power consumption without a significant impact on your budget. 

Benefits of Attic Vent Fans

Is an attic fan a good investment for you? There’s no doubt that installing an exhaust fan in your attic offers some advantages. Let’s take a look at some of the benefits attic fans provide. 

Increase Energy Efficiency of your AC

An unventilated attic is akin to having a sauna sitting right on top of your living space. Your air conditioning system needs to work hard to fight the heat seeping down from the attic. Cooling down the upper area of the house as close to outdoor temperatures as possible before turning on your AC unit will help reduce its power usage.

Attic fans do the job of lowering the temperature in the attic by pushing out the hot air. As a result, your AC system won’t have to work so hard, increasing its energy efficiency.

Cool Down Your Second Floor

Do you find the second floor of your house warmer than the first floor, even with air conditioning? The heat coming down the attic and radiating into your living space may be the reason. Sealing the attic space and providing proper insulation are possible solutions. In a properly sealed and insulated attic, an exhaust fan or attic fan helps stop the heat from entering the lower portions of your home. As a result, the second floor may stay as cool as the first floor. 

Reduces the Cause of Roof Damage

Attic fans don’t just provide ventilation, but they also reduce moisture and humidity in the attic. During cold months, the cold air under the roof interacts with the warm air in the attic, which leads to condensation and moisture under the roof. The presence of moist spots can lead to damage that will affect the roof’s integrity. Such damages will entail high costs to repair. 

Supports Attic Insulation

The insulation materials in your attic can deteriorate over time. Extreme heat and humidity can accelerate the process. Because an attic fan removes hot and humid air, it may aid in prolonging the lifespan of your attic’s insulation. 

Drawbacks of Attic Vent Fans

Although an attic fan can greatly enhance attic ventilation, installing one also has some drawbacks. Knowing what those are can help you decide whether an attic fan will fit your situation, needs, and budget. 

Costly to Operate

An attic fan that runs continuously will consume an average of about 180 kWh per month. Currently, the per kWh price of electricity in the country stands at around 11.18 cents. That means operating an attic fan can add roughly about $20 to your electricity bill. On top of that, if you were to add a humidistat to measure the amount of moisture in your attic, it can mean an additional $90 to $150 on your power expenses. 

Can Lead to Roof Leaks

Where you place an attic ventilator is crucial as that will determine whether it can extend or shorten the life of your roof. An improperly located attic fan can lead to roof leaks. For example, installing the fan at a certain angle sucks in the water that pools on a particular section of the roof. Moreover, as the blade of the fan rotates, the vacuum it creates can draw in water through the roof’s seams, causing leaking issues. 

Leaking can damage your ceiling. Even worse, it can cause mold problems in the whole house. The presence of molds puts your furnishings and your health at risk. 

Requires Good Insulation

Without proper insulation, you won’t reap the full benefits of installing an attic fan. To enable the ventilator to do its job properly, you’ll need to give it a hand by insulating the attic. Providing good insulation blocks the entry of heat through the roof, allowing your attic space to maintain a cool climate. That means you can’t simply install an attic fan and expect a reduction in your power expenses. You’ll still need to implement additional measures to achieve your goal. 

Won’t be Enough for the Whole House

An attic fan helps provide adequate attic ventilation. It does so by pushing out hot air from the attic, an action that also draws in the cool air from the outside. This plays a part in reducing the temperature in the lower portions of your living space. However, the fan won’t cool the whole house, especially during the year’s hottest months. For that, you’ll still need to run your AC unit. 

Factors to Consider for Attic Vent Fans

Like most things in life, attic fans are not a fits-all proposition. Homes have varying needs, and homeowners who opt to install attic fans have different considerations. In choosing the best attic fan, you may want to look at the following factors. 

Material

The heat inside an attic typically rises way over 100 degrees F during the hottest months of summer. Meanwhile, the temperature can drop below zero degrees during winter. Thus, the best attic fan for the home should be able to withstand the extremes of hot and cold. Inexpensive fans may have components that will fail in no time. For example, blades may turn brittle during winter and snap under regular use. 

Fans made of metal may cost more, but they can better cope with fluctuating temperatures. Look for attic fans with bodies and blades constructed from sheet metal and steel. These materials are more durable than plastic and won’t get easily affected by moisture. 

Ease of Use

You’re less likely to use the fan if turning it on and off requires a great deal of effort. Imagine having to trudge up the attic to switch on the fan. Fortunately, many models come with remote controls. The remote function lets you operate the fan from the floor below. You can also customize the fan’s settings with the touch of a button. 

Some fans can be wired to programmable thermostats or may come equipped with one. This will turn the fan on when the heat in the attic reaches a specified level. These models suit homeowners who don’t want to monitor the attic’s temperature and manually switch on an attic fan. 

Safety

Safety is a primary concern when it comes to installing a fan for attic ventilation. This is particularly true for furnaces located in the attic. A high-powered attic ventilator can produce enough draft to blow out the furnace’s pilot light. In such cases, the gas from the furnace will go into the attic. 

Attic fans can push out the gas outside, but when they shut off, the gas will build up in the attic and eventually seep down the rest of the house. This poses risks to you and your family. Attic and whole-house fans can also draw carbon monoxide into the living space through damaged flues. As such, ensure that your ducts are in good working condition and that you have proper ventilation for all equipment that uses gas and other fuel. 

Venting Requirements

Attic fans can only do their job correctly if the attic has sufficient ventilation. If you place a fan in an area that doesn’t have enough air circulation, it will pull in air from inside your home. That defeats the purpose of installing a fan.  

On the other hand, if there’s too much ventilation, the fan may not work efficiently at pushing the hot air out of the entire attic space. Getting expert advice on the type of attic fan that suits your home can help with this tricky requirement. 

Thermostat Adjustability

Here’s how most attic fans work. When the temperature inside the area reaches a certain level, the fan switches on and pushes the hot air out. This cools the attic resulting in a steady drop in temperature. When the temperature has gone back down to a set level, the fan turns off. 

With an adjustable thermostat, the fan turns on and off automatically. There’s no need for you to switch it on manually. All you need to do is set the dials, and that’s it. Aside from the convenience thermostat adjustability offers, it also helps save money. That’s because the fan runs only when there’s a need for it to do so. 

Air Volume and Square Footage

The CFM (cubic feet per minute) refers to the airflow that attic fans produce. Like with the venting requirements, you’ll need to match the fan’s CFM with the size of your attic. Installing a fan with a higher CFM than what your attic space needs will unnecessarily add to your power consumption. Meanwhile, purchasing a fan with a too low CFM is an exercise in futility as it won’t be enough to provide proper attic ventilation.  

Some fans come with the CFM listed on the packaging. If not, look for the square footage the attic fan was designed for.  

Noise Level

The noise that attic ventilators create is a potential problem you’ll need to consider. Depending on the type of fan you install, it can produce a slight hum or a screeching whine. Fans can become particularly noisy as they age. Tightening the screws, replacing the ball bearings, and balancing the blades can help lessen the racket.  

Newer models now come with smaller blades and quieter motors which significantly tone down the noise they create 

FAQs

Final Word

Attic fans do an excellent job of ventilating the upper portion of your home. With a cool attic, the AC unit doesn’t need to work doubly hard to lower the temperature of your living space. This can help you save money on your power bills. How well fans work depends on several factors. Take note of those considerations to ensure that you get your money’s worth. 

Updated on 02-02-23