Attic Fans Pros and Cons – 12 Facts You Need to Know
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Regarding energy cost and consumption, solar attic fans trump other attic ventilation fans. But this does not rule out that it is more expensive than other attic fans. Still, it may be a beneficial investment – weigh the top 12 solar attic fans pros and cons yourself.
Pros of Solar Attic Fans
Solar Attic Fans Keep Your Attic Cool
Poor ventilation and heat accumulation in your attic will ripple effect on various parts of your home. For one, the heat may damage the roof, the attic, the contents of the attic, and the insulation. However, with a solar attic fan installed, the hot air will be blown out, keeping the attic cool and well-ventilated.
Apart from that, without an attic fan, your attic can get hotter and steal cool air from the rest of your house. This heat may then leak into the other parts of the building, where it would increase the workload of your cooler. This, in turn, will raise your utility bills. But with a solar-powered attic fan, this will not happen; your attic will be kept cool, and you will have more utility bill savings.
Solar Energy Is Available When It Matters
When the skies are cloudy, and it appears like it is about to rain, attic temperatures fall, and the demand for cooling falls. On such days, you may have little or no need for a solar attic fan. So, the absence of the sun would be of less concern.
But on sunny days, when hot air rises, the need for cooling presents itself. Since the sun will be available to power solar attic fans, you get to keep your home cool when it matters the most.
This is unlike turbine attic fans. These types only work when there is wind. So, they would be non-functional if there is no wind on a hot day.
They Help Reduce Attic Humidity in the Summer
In the summer, humidity is higher because hot and humid air holds more water. This elevation in ambient moisture promotes the growth of mold and fungi in the attic. If left unchecked, the growth will damage your attic and its content. But with the coolness and air circulation solar attic fans provide, you can avoid this.
Solar Attic Fans Come With No Energy Consumption Cost
If you are using an electricity-powered attic fan, the energy consumption will add to your total electricity bill. Since these types of attic fans work harder when it is hot, you may pay even more as the weather gets hotter.
But with solar attic fans, this does not apply. The energy that powers the attic ventilation fan comes from the sun, and the sun is free to use. So, you get more energy savings.
Apart from that, solar attic fans can help reduce your cooling and heating bills. During the warmer seasons, these attic fans push out warm air, thus reducing the workload of your air conditioner. In cooler seasons, the same ventilation fans can help pull air into your attic, making the functions of your heating more efficient.
Solar Attic Fans Run on Renewable Energy
Since solar-powered attic fans run on the renewable energy of the sun, they are environmentally friendly. They do not produce greenhouse gases, so you get to worry less about the carbon footprint of your home. You also get to worry less about the adverse effects of greenhouse gas emissions on your own health.
Solar-Powered Fans Are Safer
There is the possibility of traditional line-powered attic fans creating negative pressure zones. When this happens, they will pull air from the air conditioning system of the home. But beyond that, they may also pull toxic gases like carbon monoxide from combustion devices in the house. The retention of such toxic gases in the house is potentially lethal. This is unlikely to happen with a solar fan.
You May Get Government Incentives for Using Solar Power
While a solar attic fan can be expensive, you may qualify for a government incentive if you get one. The federal government and some state governments offer rebates to lower the cost of going solar. You may confirm the incentives available to you before buying your solar attic fan.
Solar Attic Fans May Prevent Ice Damming
During winter, attics with poor ventilation and insulation may suffer ice damming as warm air leaks from the interior.
The leaking attic air will melt the snow on the roof. Then when the melted snow refreezes, it will form ice at the edge of the roof. As more snow melts, the ice at the roof’s edge holds the water back like a dam. This water retention may then damage the sheathing and walls of the home.
In the presence of an attic fan, it would prevent this. The fan will facilitate ventilation, preventing warm air from accumulating in the attic in the first place.
Cons of Solar Attic Fans
They Are Expensive
Compared to alternative types of attic fans, the cost of getting a solar attic fan is high. On average, you can sell a solar attic fan for $300 to $600. Then if you cannot install it yourself, you may have to shelve out $150 to $300 for installation. In total, you may spend $450 to $900 to get a solar fan and install it.
Depending on the size of your attic, you may need more than one solar attic fan. So, if you are getting two, for instance, your total expenses may shoot up to $750 to $1500. Then in some jurisdictions, you might incur some extra costs due to the rules.
A Solar Attic Fan Needs Direct Sunlight to Function
Without the solar energy from the sun, solar attic fans will not work. So, on days without sunshine, you may not get anything out of your solar attic fan. Also, the presence of cloud cover, dust, or shade trees can affect the operation of the fan.
Apart from that, in regions that get only a few days of sunshine per year, solar attic fans may not be reliable.
A Solar Attic Fan Is Not as Powerful an Electric Fan
Solar attic fans usually have CFM ratings up to 1200 CFM. But a traditional attic fan such as an electric fan can have a rating as high as 1600 CFM. This means that solar attic fans cannot push attic air out, and electric attic fans can.
Installing a Solar Attic Fan Comes With the Risk of Roof Leak
During the installation of a solar attic fan, you will cut a hole in your roof. But if the hole is not cut or maintained correctly, it may become an opening for leaks. The risks are minimal if the installation is done by a professional.
Are Solar Attic Fans Effective?
The effectiveness of solar fans depends on some factors. They include:
Makeup Air
If passive venting (makeup air) in the attic is not enough, solar attic fans will resort to drawing conditioned air from the main parts of the house. If this happens, the cooling of the whole home will be affected.
Attic Insulation
When attic insulation is not efficient, warm air will move between the home’s interior and the attic. In warmer seasons, the hot air will rise into the attic. Then in winter, it will radiate towards the house. In both cases, it will undermine the effectiveness of the solar attic fan.
The Number of Solar Fans for Your Attic
The number of solar attic fans that will effectively cool your attic is dependent on the size of your attic. One solar attic fan is expected to push around 800 to 1200 CFM of air, and a 1000-square-feet attic needs at least 700 CFM. For attics with steep or darker roofs, the CFM requirement is 15% higher.
If the number of solar attic fans installed meets or exceeds the CFM requirement of your attic space, then they would be effective. But if they fall short, they may be ineffective.
The Size and Efficiency of the Solar Panel
To effectively remove lots of hot attic air, solar attic fans need to work non-stop. But this may not always be feasible. Sometimes, the sun gets blocked by clouds, and the attic fan may stop momentarily.
Fortunately, in the absence of direct sunlight, solar panels can work with diffuse sunlight. But diffuse sunlight might only be useful when the solar panel is large and efficient enough to absorb it.
How Long Do Solar Attic Fans Last?
With proper use and maintenance, solar attic fans can last up to 15 years.
Is a Solar or Electric Attic Fan Better?
The better choice between solar attic fans and electric attic fans depends on the user. Electrical attic fans are better because they offer stronger cooling (they are typically rated 800 to 1600 CFM). But this comes at a price – electric attic fans consume a lot of power, so your heating and cooling bills may rise. Conversely, solar attic fans are powered by the sun, which is free to use.
During periods of increased heating, electric attic fans work harder to keep the attic cool. Consequently, they consume more energy. But since solar-powered attic fans are powered by solar energy, sunny periods do not really affect their capacity.
Compared to a solar powered attic fan, electric attic fans are pretty cheap to buy. However, you have to get a professional installer to help you fix an electric attic fan.
Solar attic fans, on the other hand, are pretty expensive to buy. But unlike electric fans, you do not need an electrician for installation. So, you might get some savings on the total cost of installation.
Furthermore, the warranty on electric fans is relatively short (typically 1 year). The fans usually do not last as long as solar attic fans. On the other hand, solar attic fans sometimes have a warranty period of up to 25 years, and they last that long when maintained properly.
Final Thoughts
The pros and cons of getting a solar attic fan apply differently to individual properties. This is why it is necessary to review them personally before making a choice. Nonetheless, you can get some professional insight to assist in making an informed decision. While you weigh the pros and cons, ensure you consider all the factors that apply to you: your interior, your attic, your exterior, the position of the sun, and your region.