Having an attic fan and adequate ventilation is essential for our home, to keep it healthy and comfortable. After all, much like our lungs, our houses have to breathe and ensure the fresh air comes in, dirty air goes out. Having efficient home ventilation is now ever so important.

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attic ventilation fans pros and cons

It guarantees that our homes’ indoor air is spotless and completely free from contaminants. That’s why I felt the need to dive into some of the most frequently asked questions revolving home ventilation.

Today I’ll shed light on the following topics:

  • How ventilation works?
  • Benefits of attic ventilation
  • Best attic ventilation options including performance factors, pros and cons
  • Recommended amount of ventilation and how to calculate the ideal amount for home
  • How attic ventilation fan works and different types of them
  • Attic ventilation fans pros and cons
  • Attic ventilation fans pros and cons
  • My professional verdict on Attic ventilation fans
  • Some bonus tips on attic ventilation fans

So, let’s dive right in, shall we?

In simple terms, ventilation provides the ability to expel odors and moisture from our homes and filter out all the dirt, mold, and debris present in the air that can be dangerous.

Ventilation is crucial for those family members suffering from allergies or respiratory illnesses. It works through the process of moving air around. It is changed or replaced in different spaces, improving the quality of the household’s indoor air.

Well, that’s a tricky question! It requires some math as we now have to get to the more technical side of topic. It’s crucial to carefully calculate the required amount of ventilation for your home because excess ventilation wastes heat, and too little is unhealthy.

It’s hard to balance it out, and that applies both for new and older households. The standard method to calculate how many roof vents you need is calculated by their net free area (NFA). This is the amount of space a vent has available for air to flow in or out.

The total NFA of the roof vents must be split half/half, between intake and exhaust. For example, let’s say your attic space is 1,200 sq ft. You will then need to half that, giving 600 sq ft. for both intake and exhaust.

They must both be balanced to be effective in the hot summer and prevent ice damming in the cold seasons.

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Some notable benefits of attic ventilation includes:

attic ventilation saves electricity bills

When attic temperature rises in summer, this unfiltered air eventually finds it’s way into our home’s lower living spaces. It then results in our AC’s to work harder, leading to higher electric bills.

Having adequate ventilation in the attic lets fresh and cooler air in, while exhausting hot air, ensuring moist air doesn’t stay in; maintains a constant comfortable temperature.

attic ventilation increase roof lifespan

Heat and moisture are common causes of roof damage. When your attic gets overheated causing roof shingles to dry out and crack much faster. Compromises your roof’s lifespan and leads to expensive repair work. Having good attic ventilation installed, it doesn’t get too hot.

attic ventilation prevents molds

When temperature goes down, the warm, moist air present in the home rises into an improperly ventilated attic and condenses onto cold surfaces. This increases the risk of mold and mildew growth.

Ice damming risk is higher when your attic retains hot air rising from below, making the roof’s snow-melt. Resulting water flows down to the roof’s edges and refreezes.

The best attic ventilation prevents this by allowing warmer air to escape before the snow and ice start melting.

Following are the best attic ventilation option including their pros and cons:

ridge vent for attic

Ridge vents are placed along the roof’s top edge, where the faces meet and usually provide a way for stale air to leave the attic. They are difficult to spot unless you know what you’re looking for, which gives them an aesthetic advantage over other options, hence their popularity.

Pros

  • Better visual appeal that blends in
  • Prevents premature ageing in roof areas caused by uneven temperatures
  • Extremely reliable and requires minimal effort to maintain
  • Cost efficient as no power is needed to run it

Cons

  • The initial cost of these vents is usually high
  • The installation can be tricky and, if done incorrectly, can seriously damage your roof
  • They run the risk of leaking water during heavy rains
  • Mostly work better in colder climates than warmer temperatures
soffit vent for attic

Soffit vents are installed under your roof’s eaves to keep your attic cool by drawing in fresh outside air. This allows hot and humid air to escape out of your other vents.

Pros

  • Relatively easy to install
  • Help reduce your cooling costs
  • Incredibly effective and reliable in cold climate
  • Relatively low maintenance cost

Cons

  • Mostly meant for air intake, so if not paired off correctly with another exhaust vent, they won’t cool your roof efficiently
  • Can end up collecting moist air, which causes damage to your roof over time
power vent for attic

One option you can consider is power attic vents, also known as PAV’s. These vents are powered either electrically or solar. Can be intake or exhaust vents. Most powered vents are controlled by thermostats.

Pros

  • You can completely control the amount of fresh air channeled
  • Runs automatically
  • Can be electronically or solar-powered

Cons

  • Power vents can be pricey to buy and also expensive to install
  • Since they have mechanical moving parts, can be prone to failure

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An attic ventilation fan’s main use is to pull out hot air from your attic to help reduce high levels of present heat and humidity. This then keeps the hot air from making its way through the rest of the house and raising the living space temperature.

By doing this, it also reduces the amount of work your AC has to do. You can either mount them on your gables or on your roofs. They can also be either turned on and off manually or automatically by a thermostat.

You should also keep in mind that your attic must be well sealed and insulated from the rest of the house for it to work efficiently.

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They serve a long-term purpose by removing the attic’s hot and moist air and leaving your living space below the attic floor alone. The fan then circulates the air within the room, pulling in fresh air from the vents and pushing the present hot air outside.

They are especially useful during hot seasons. This is because you can reduce the attic’s temperature, extending your roofs shingles and sheathing life.

Meanwhile, during cold months, they can prevent ice damming by cooling the attic and balancing the temp between the attic and the outside. This prevents the snow from melting on your roof and then refreezing on the edges.

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It’s time to understand the different types of attic vent fans available in the market.

solar attic fan

If you have an upstairs room that gets uncomfortably hot in summer, consider buying a solar attic fan. These fans are fueled by sunlight and replace the hot air from your attic with the much cooler air.

This means that your HVAC system doesn’t have to work hard to cool your living area. In turn, conveniently reduces your energy usage and electricity bills. However, while they perform well during sunny days, their performance may decline if there isn’t any sunlight.

They won’t work at all when it’s clouded over. Despite this, though, they are still useful to have, especially if you live in hot and humid areas. A solar fan costs from $200 to $500 or more, on average.

Pros

  • Improve the comfort of your home cost efficiently
  • Convenient and energy efficient
  • Prevent moisture-related damage from damaging the roof
  • Reduce your carbon footprint
  • Unlike conventional electric fans, solar fans don’t pull in carbon monoxide and dangerous fumes as they move air gently, keeping your attic pressure at a safe level

Cons

  • Can be expensive to buy and install.
  • Require direct sunlight to operate
electronic attic fan

Electric fans are extremely powerful. Many of these fans use a thermostat that automatically switches them on or off, depending on the attic temperature.

This allows for better energy management, but their running costs are still more than the other options. It’s even worse during hot seasons when you have it on for most of the day.

Also, installing these fans involves wiring, so you have to hire an electrician, which raises your home-improvement budget even higher. They would typically cost you from $100 to $400 on average.

Pros

  • Cheaper to buy compared to a solar fan
  • More powerful compared to a solar fan
  • Very consistent
  • Great option for humid climate
  • Mostly controlled with a thermostat, so they only power up if the temperature peaks above a certain level
  • All-year-round ventilation

Cons

  • Isn’t an eco-friendly option
  • Can be costly
wind powered turbine attic fan

Much like the solar alternative, this one also relies on green energy and is the right choice for reducing their electricity costs. They are typically installed along or close to your roof’s peak.

The wind rotates the fan, sucking out the air through the turbine and replacing it with the cooler outside air. Turbine fans are powered solely by the wind, so if it isn’t blowing, the turbine doesn’t function. Priced from $20 to $100.

Pros

  • Eco-friendly green option
  • Rarely break down
  • Low cost to purchase and maintain
  • Saves money on electricity

Cons

  • Lack consistency and reliability
  • Lifespan can be reduced when exposed to frequent storms or attic moisture

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Like any other appliances attic fan performance gets affected by factors like weather, use, built quality, mode of operation etc. Below are the major performance factors of attic vent fans:

An attic fan can cools down your living space whenever the outside air outside is cooler than your home’s temperature. Some attic fans have thermostats, which only turn on when the air inside reaches a set temperature.

Depending on the level humidity, some fans may only run for a limited time, like 30 minutes, while others can stay on for more extended periods.

It would be best if you tried to open the windows before operating the fan to prevent putting stress on the fan motor. To avoid any long-term damage or wear, turn it off when you’re done, or let it turn itself off if it’s automatically set to shut off at a particular time.

If the fan comes with a thermostat, you can simply set it only to activate when the temperature hits a certain level.

All attic fans have their specified requirements for efficient attic ventilation to create the right balance of intake and exhaust air. So you should always make sure that your attic has adequate ventilation outlets for your fan.

If you aren’t sure if your attic is well ventilated for your fan to work effectively, then call in a roofing contractor in your area. They will check to determine that you have the proper amount of attic ventilation that is required.

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There’s always some advantages and disadvantages of everything. In order to enjoy the benefits of a product we must adjust ourselves with the drawbacks of it. It helps if we know the drawbacks before making our decision. Let’s start with the cons of attic ventilation fans:

May Expose you to Carbon Monoxide Intoxication

What do you use to burn your house’s furnace and heat your water? Is it propane (natural gas)? Well, getting an attic ventilation fan could put you at risk of being poisoned by carbon monoxide.

HICSI (Home Improvement Contractors of Staten Island) says that your powered attic fan could create a negative (or unfavorable) pressure inside the home. A negative air pressure means that the gases –those that get combusted to heat your water or burn your furnace – can get pulled into the house’s interior. One of the gases is carbon monoxide, and when inhaled, it could lead to a fatality.

So, how can you know whether your home is a negative-air-pressure zone? While the attic ventilation fan is running, open your window. If air is getting pulled towards the inside of the house, that is a sign of negative pressure.

There is no need to worry, though. You can mitigate this poisonous risk by following what the manufacturer directs. Importantly, make sure CO (carbon monoxide) detectors are installed. Each of the items needs to be fitted in each of the home’s levels. This should be your move to make if your garage is attached to the house or gas-burning appliances.

You don’t have to worry regarding the warning with the turbine-powered or solar-powered fans because they use less power.

May Create a Leak in your Roof

Well, this downside comes about when the installation is done improperly. Since the fan requires you to make an opening in the roof, spaces left uncovered will invite unwanted items. I’m talking about rodents, snakes, insects, and even water intrusion.

A FEMA report captures the effects of a hurricane on a roof whose off-ridge vents got installed unprofessionally. If your attic fan is not fitted correctly, it can get flipped up. This will allow lots of water to enter your house. Too much water may make you incur damage to your carpet, kitchen cabinet, and gypsum boards.

May Increase the Energy Usage of your House

This is an argument advanced against the idea of attic ventilation fans being energy efficient. Authors of a particular study say that although the unit may be energy-saving, thermostat attic fans’ operation may offset the gains. An attic fan with a thermostat may pull conditioned air away from the home’s interior.

In a report, an argument advanced by the National Bureau of Standards notes that attic fans do not save energy, mostly during hot temperatures. This is because, during the summer, the fan requires more energy to operate when the attic is quite heated.

It also takes too long to regain the money used in buying and installing the attic ventilation fan. I’m talking about 30 years of waiting.

May not Operate Optimally

This one applies to solar attic fans, which are dependent on the weather of the day. Most solar-powered attic fans do not support AC power sourcing, and so, they are solely reliant on the sun’s shine. An all-cloudy day means that the blades of the fan will stop spinning.

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Great at Energy-Efficiency

A heavily fat energy utility bill gets you scratching the back of your head way too hard. But, that won’t happen if you have installed a fan in your attic. As the unit vents humidly warm air in the house and replaces it with cooler air from outside, it saves you some money – mostly if you use air conditioners.

An attic fan will use around 75% of the power you need to run an air conditioner. This stat should tell you that a fan is a cooling option more affordable than an AC.

A special report by the Department of Commerce (US) and the National Bureau of Standards appraises the idea of saving with attic fans. Attic fans reduce the ceiling heat influx better than air conditioners, as they consume less power by the day compared to air conditioners.

If you have an AC, consider getting an attic fan. It will help you improve the longevity of the AC. How so? An AC works hard if you have a too-hot attic. The air conditioner will run more often, dramatically increasing your energy costs. The AC may not even last its average life expectancy of 15 years. But, you can ensure this happens by fixing an attic fan.

So, as you run your fan after sunset and watch a drop in those degrees, be sure to get a lighter bill.

attic ventilation fans pros and cons

They help to protect Asphalt Roofing

This is one of the biggest, little-known tweaks of getting an attic fan. A house’s roof is an essential item, and knowing that your roof will last for a long time is a fulfilling thing.

If your house has asphalt roofing, you can prevent it from aging prematurely by getting attic fans. If the heat is unbearable in the attic, the color of the asphalt shingles will fade.
Asphalt is a material derived from crude oil. Without an attic fan, the overly-hot temperature will cook the roof’s shingles.

The US Department of Energy, through a scientific journal, acknowledges that ultraviolet radiation can alter the chemicals that make asphalt shingles. Some energy items from the sun break the chemical bonds. This breakage opens up a process called oxidation, which takes away the deep color of the shingles.

Imagine having a 20-year old roof that looks like it’s barely a toddler. You can only make this possible once you get an attic ventilation fan. Apart from fully-colored shingles, the wood sheathings will stay intact. In turn, this will prevent shingle ridging and bucking.

Help you to Live in a more Relaxed House

This should’ve been number one – don’t you think? Hot summers need a coolant – and what better way than to bring in an attic ventilation fan? By bringing down those degrees, you will get to live in a comfortable house.

The US Department of Energy accedes, in a post, that fans provide comfort during the summer for many families.

You know how it works – a hot attic means that the rooms get warm. Sometimes, it may get too warm that you feel like you teleported to Miami. First, the sun heats the top of the roof. Then, the heat gets conducted through the woodwork into the attic. Even after the sun sets, the temperature will still seep under the sheets and torment your sleep.

Help Prevent Mold and Mildew Growth

If your attic is poorly ventilated, the walls of your attic may get vegetated by mold. And this could happen whether its winter or summer.

During hot summer, your AC will blow out cold air into the interior. When that happens, hot air forms in the attic. A meeting of these different degreed temperatures invites the chemical change known as condensation. Thus, the moisture and mustiness invite fungus growth, which feeds on the wooden parts in the attic.

So, how long will the attic even stand without an attic ventilation fan?

In a brief guide, the EPA (US Environmental Protection Agency) notes that mold can cause many health problems, such as allergic reactions. Also, the mold can produce irritants and other substances that are potentially toxic (mycotoxins).

By reducing moisture in the room below the roof, mold growth will get inhibited, thanks to an attic fan. The unit will make your house stand for longer.

Help Prevent Ice Damming

Let me give you some pointers on ice damming, which happens during winter:

  • A poorly insulated attic invites warm air, and the air leaks into the interior.
  • Since the roof is snowed, the warm air causes the snow to melt. The melting effect makes the snow to form around the edges of the ceiling.
  • The melted snow then refreezes. Thus, the roof’s edge gets covered with ice, and a kind-of barrier is created.
  • When more snow melts, it gets blocked by the already-created snow ice barrier – the ice dam.

Ice damming is one strange phenomenon, but you can prevent it by getting an attic ventilation fan.

The Oak Ridge National Laboratory expands the discussion on ice damming in a study. The building science issue brings about rot and mold. Also, the danger of a falling block of ice can lead to a severe injury. Also, the service life of many roofing component and material get dented by ice damming.

So, what does this ‘dam’ do? It causes the roof sheathing to get damaged by water. Also, the home’s walls – drywall, wood joists, et cetera – may get destroyed. By now, you know that water is an enemy, and mold-mildew is its weapon.

Can Help you take Advantage of the Sun’s Energy

This pointer speaks specifically to attic fans that are powered by solar energy. You and I know that the sun is in abundance, and taking advantage will make you the greenest person.

Take yourself off the electrical grid and jump into renewable energy. Buying a solar attic fan will put you ahead all the time, especially when you do the cost-saving math.

The think tank REN21 reported in 2017 that around 19% of the global energy consumption depends on renewable energy such as solar power. More people are moving under the solar umbrella because it is not only cheaper but very efficient.

With the fan, you take a chance to contribute to a better planet by reducing your carbon footprint.

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inspecting attic ventilation fans

If it won’t turn on, then that’s usually an electric issue. However, that can also be because of a faulty thermostat or even fan motor, in the worst-case scenario. If it’s a blown fuse, then this is an easy fix.

If that’s not the case, then assess if the thermostat is the cause. If that still doesn’t solve the issue, then sorry to say, it’s probably the fan motor. In which case, you better be ready to cough up some extra cash because that’s the most expensive part of the fan to repair.

If the fan’s motor is functioning, but the blades aren’t turning, this is probably a fan belt problem. You can simply remove the outer casing of the fan to inspect it. Generally, due to long term wear and tear, the belts can dry up and start to crack, but you can easily just replace it.

If it’s working but looks slow or sluggish, this is often an exhaust or even intake issue. You can just put a step ladder by the side of the house and go up to check for any debris that has gotten mixed in the intake. You can also check to see the fan is still correctly fixed onto the roof.

If the fan isn’t receiving enough airflow, it may start to rattle. You need to ensure that the attic windows are open and well-distanced by at least 30 feet from the fan to provide sufficient airflow for it to work effectively.

If the fan is starting to give out a burning or acrid smell from its exhaust, that’s generally due to the fan motor. The best and permanent solution for such cases is to replace the motor.

If it doesn’t go off, check the power source to ensure that it’s correctly wired. Every fan should have a switch, but if there isn’t one, then just shut it off at the circuit breaker.

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A whole house fan is installed between the living space and ceiling. It helps to cool your house by removing the hot air, escaping through the attic, allowing fresh air to circulate from the windows.

Whole house fans work better during mornings and late evenings when the outside air is cool and relaxed.

Whole-house-fan-pre-install

Image: Whole House Fan, Credit: Wikipedia

On the other hand, an attic fan works by carrying air through the attic, while removing the heat outside through the vents and pulling in fresh outside air.

Attic fans are more effective during the rest of the day when temperatures are hotter.

Attic-fan-weatherproof-cap

Image: Whole House Fan, Credit: Wikipedia

A whole house fan offers you more because while the attic fan only removes the hot air from the attic, whole-house fans generally keep both the building and the entire house cool.

Whole-house fans can be a bit difficult to install than the attic. You will need a professional to do this for proper wiring. However, they are simple to use, as long as they are properly installed. Additionally, they don’t need much maintenance.

Regarding price, attic fans can cost approximately $300 – $ 600, with most people spending $550, including labor. This makes them a cheaper option than whole-house fans as these can cost you from $1000 up to $1500.

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Yes, you very much would do well to have an attic fan as they can make a huge difference! The fact remains that they expel super-hot air from the attic and suck in cooler outdoor air instead.

It’s no different than having hot air trapped in your car on a hot summer day. When you enter it, to cool the car faster, you roll down your windows to get it all out. After this, the air conditioner can once more effectively cool the vehicle. It works the same way for attics.

Summers seem to keep getting hotter and hotter, with typical attics reaching up to 120-150 degrees during these heatwaves.

Attic fans can significantly reduce the temperature, which translates into a lower temperature for the entire home. Your AC may last longer, as it doesn’t need to be active as much.

In turn, this saves on energy consumption and cuts your electric bill by a fair amount. Also, as stated before, attic fans have shown to help extend the roof’s life as well. So, even if you feel that the energy-saving costs aren’t that high, it will definitely cut your home roof repair costs significantly.

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Last Words

Year after year, more than half of the country has been experiencing extreme heat conditions during the summers, resulting in more air-conditioner usage.

There is a resounding debate on whether this is making the problem worse, with governments having to regulate the usage of HFCs (hydrofluorocarbons). If you didn’t know, these are the chemical compounds present in AC’s, which also contribute to global warming.

It’s said that air-conditioning releases about 100 million tons of carbon dioxide each year! And this doesn’t even cover the amount of energy consumption AC’s use up.

This brings us to the question: In the pursuit of a cleaner and greener world, do you think we should limit our use of air conditioners by adopting attic fans instead?

What’s your thoughts on the attic ventilation fans pros and cons?

Save this post in your “Attic Remodeling Ideas” board of Pinterest and let your followers get benefitted from it.

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