Attic fans keep your attic moisture-free, extending the life of your room and reducing, significantly, condensation on your walls and indoor humidity. They can also help lower room temperatures, especially in the warmer months, and reduce air conditioning costs.
Above all, attic fans are known to be extremely energy-efficient. Most reports indicate that the standard attic fan consumes only about 10% to 15% of the energy required to power a basic air conditioner.
You can enjoy all these benefits while saving even more on energy with solar-powered attic fans. Indeed, some solar attic fans don’t use electricity at all. Instead, they rely 100% on solar power.
We’ll discuss more on how attic fans work and how to pick the right one shortly. But, first, the following are a few excellent options to consider if you’re in a rush.
What are Solar Attic Fans?
Solar attic fans are a simple, convenient, and highly energy-efficient way to add ventilation, prevent the buildup of moisture and protect the structural integrity of your home. Unfortunately, these fans come in all shapes and styles. The following considerations should help you identify the right one for your needs.
Solar attic fans are solar-powered ventilation fans that regulate the heat level of the building’s attic by removing hot, humid air and replacing it with cool air from outside the house.
Attic temperatures can reach a scorching 160˚F during the peak of the summer season. Some of this hot, humid air eventually finds its way down to the rest of the house, raising temperatures in the living areas and subsequently increasing cooling and air conditioning needs/costs. Solar attic fans remedy this situation by keeping the attic at reasonable temperatures.
How Do Solar Attic Fans Work?
The basic principle of attic fans is that they push hot air out of your attic space. This same action results in cool air being pulled into the attic from outside the house via the gable vents, turtle vents, and soffit vents in your eaves. This way, the attic fan can replace the stifling attic air with cool, fresh air to improve overall air conditioning in the home.
Most attic fans comprise three main parts, a thermostat, a wall switch, and a timer. The attic fan thermostat is a small device that looks like a small metal box. It’s usually attached to a rafter or truss within a foot or two of the attic fan. You can set the desired attic temperature from the wall switch.
The thermostat keeps the fan running as long as the current attic temperatures exceed the set temperature and shuts down the fanning when the temperature drops below the setting. Some attic fans are also wired to a timer for programmed air conditioning.
The only difference between conventional attic fans and solar attic fans is the power source. Whereas traditional attic fans rely on electricity for power, solar attic fans harness the sun’s power to run the motor.
Some “hybrid” solar attic fans use both solar and electricity. They will run on solar on sunny days and switch to electricity once the sun goes down or in the winter season.
The switching can be manual or automatic. In manual switching, you’re required to switch on electric power when the sun goes down. Auto-switching models do so without further human help.
Solar Attic Fan Pros
Solar attic fans, in general, are incredibly beneficial. They improve home comfort by lowering attic temperatures, remove stale air for greater indoor air quality, and extend the lifespan of your roofing materials by reducing condensation and the growth of mold and mildew.
Solar attic fans are even more valuable. The following are some of the notable advantages over 100% electric-powered models;
- Eco-friendly: Solar attic fans are friendly to the environment since they rely on renewable solar power. By investing in a solar attic fan, you’re effectively reducing your carbon footprint and making the earth a better place.
- Increased energy savings: As electricity prices go up, the price of solar installations have gone down consistently for the past decade. Moreover, whereas electric power now costs around $0.12/kWh, solar power costs $0.00.
- Easy installation: Solar attic fans are far easier to install compared to their electric counterparts. There’s barely any installation work, and the electrical wiring process, which often makes electric fan installation a bit complicated, is eliminated.
- Incredibly quiet: Compared to conventional fans, solar attic fans are very quiet. Better still, the fan sits in the attic, so any little sound it generates hardly ever reaches the people down on the floor.
Solar Attic Cons
Despite the many advantages, though, solar attic fans come with a few drawbacks that you need to keep in mind;
- Reliance on the sun: Overreliance on the sun means 100% solar-powered attic fans automatically go off whenever there isn’t enough sunlight. You can’t use the fans at night or in the winter months.
- High upfront costs: The addition of the solar panel often drives solar attic fan costs up. You’ll pay up to 3x for a solar fan in most cases compared to a similar-sized electric fan. It takes at least five years to recover the additional cost.
Features to Consider When Buying a Solar Attic Fan
Most of the factors you need to consider when buying a solar fan are the same ones you’d prioritize when buying any attic fan. They include;
Fan size (CFM): This is the first and most important factor as it determines how well the fan can cool your attic. To determine the right fan size for your attic, determine the area of the attic (length x width) and multiply the answer by 0.7. Therefore, for a 50 x 20 = 1,000 Sq. Ft. attic, you need 1,000 x 0.7 = 700 CFM.
- Solar panel capacity: The capacity/size of the panel directly impacts the power of the fan (CFM) and the amount of space the fan can serve effectively. Most solar attic fan panels range from 10-20 watts. But, if you can find 40 watts or more, that would be very good.
- Is the panel adjustable? An adjustable panel allows you to change the angle to trap maximum sunlight. Otherwise, you may miss out on sunlight when the position of the sun changes. Most adjustable solar attic fan panels can be adjusted to 45 degrees.
- More blades = a better fan: First, a high number of fan blades increases the amount of air the fan moves in one rotation. Secondly, studies show that fans with more blades tend to be quieter. Anything above five blades is good.
- Construction material: The construction material determines the longevity of the fan. Ideally, you want an aircraft-grade aluminum fan housing, non-corrosive aluminum fan blades, and an aluminum animal screen. The solar vent should be made from pure aluminum powder-coated flashing.
- Make sure it’s a quiet fan: Noise is one of the most significant drawbacks of fan systems. Alongside the considerations above, make sure you’re getting a quiet fan that won’t interfere with your activities inside the house.
Best Solar Attic Fan with 25 Year Warranty
1. Natural Light Energy SAF 16-Watt Solar Attic Fan with 25-Year Warranty
We’ve picked at least three products from Natural Light because they make some of the best solar attic fans. They also offer very generous warranties. This first product, a 16-watt solar-powered fan, is a simple, environmentally sensible solution that’s 100% powered by solar energy. It’s also sleek, efficient, and impressively quiet.
The fan is fully functional out of the box and installs effortlessly on fiberglass-asphalt shingle roofs. No electrical wiring is needed. You also don’t require a permit to install the fan. At 16 watts, it’s powerful enough to serve an area up to 1,300 square feet, operating at 1134 CFM.
It uses a high-impact photovoltaic solar panel and comes with a unique, adjustable mounting bracket that allows the solar panel to be positioned at an angle of maximum exposure to sunlight for optimal fan performance. Better still, the mounting bracket allows air to continually circulate around the solar panel, keeping it cool for a more consistent output.
It’s an incredibly durable fan, constructed from 1100 series, commercial pure grade aluminum with no seams that may allow air leaks. The fan is also powder-coated inside and out for weather resistance and maximum durability. It comes with a 25-year warranty.
Pros
- Powerful performance, up to 1134 CFM
- Ideal for spaces up to 1,300 square feet
- Durable commercial-grade aluminum build
- 25-year manufacturer warranty
Cons
- 16 watts is on the low end
2. Natural Light SAF35BLLP 35-Watt Solar Attic Fan with 25-Year warranty
This second product, the model SAF35BLLP solar fan, is slightly different. First off, as you can tell from the model number, it’s a 35-watt fan, thus generates about twice as much power as the 16-watt fan. The extra power allows it to operate at up to 1597 CFM during sun hours, making it ideal for spaces up to 2,550 square feet.
However, what sets it apart is the round, ultra-low-profile design. Measuring 27.2 x 27.2 x 8 inches (the box), it’s designed specifically for users who want a lower visual impact on the roof. Essentially, it rises less than eight inches above the roof. The black housing and black background further contribute to the low visual impact.
The rest of the features are similar to other Natural Light Energy solar attic fans. It’s a high-impact, weather-resistant, 100% solar-powered attic fan that comes in an adjustable mounting bracket for optimal performance. The heavy-duty housing, constructed from pure aluminum (seamless to prevent leaks) and powder-coated, ensures durability while seamlessly blending to the roof.
It uses a direct current motor with isolated brackets for quiet operation and boasts a precision-balanced, 5-wing fan blade system (made on non-corrosive aluminum) for high CFM output.
Pros
- Attractive, low-profile design
- Features a protective animal screen
- Maximum 1570 CFM, ideal for up to 2550 Square Feet
- Backed by a 25-year manufacturer warranty
Cons
- It’s not effective in all climates
3. Natural Light SAF65 65-watt Solar Attic Fan with a 25-year warranty
If both the 16-watt and 35-watt options wouldn’t suffice, Natural Light Energy offers a mega 64-watt solar attic fan that will most definitely solve your problems.
It’s the most powerful solar attic fan currently available, capable of delivering up to 2105 CFM on sunny days, enough to serve spaces up to 3,350 square feet. For context, keep in mind that the average American home is about 2,600 square feet.
Interestingly, it’s not much larger than the other models in physical size, measuring about 27 x 27 x 10 inches. It also weighs a mere 35 pounds. The fan installs with relative ease. You should be done with the installation in one hour at most.
It works on most roof types, including flat roofs, sloped roofs, asphalt, tile, clay, and wood shake. You get to choose from powder-coated black satin, powder-coated gray, and bronze finishes.
Like other Natural Light solar attic fans, the model SF65 comes in a heavy-duty commercial, pure aluminum housing that blends beautifully into the roofline. Inside the housing are a precision-balanced direct current motor and non-corrosive aluminum 5-wing fan-blade system.
A protective animal screen made from stainless steel keeps out debris, bugs, birds, and all kinds of litter. Meanwhile, the heavy-duty flashing, made from aluminum, attaches seamlessly to prevent leaks while ensuring maximum airflow.
Pros
- Powerful 2105 CFM performance, ideal for up to 3,300+ sq. Ft.
- Adjustable mounting bracket maximizes sunlight capture
- Durable commercial, pure-grade aluminum housing
- 25-year warranty for worry-free use
Cons
- Professional installation required
4. Remington Model SF-30 30-Watt Solar Attic Fan with Thermostat/Humidistat
The Remington SF30-BLK is a 30-watt solar fan designed to cool your attic and home to take the stress off your HVAC and furnace systems. It’s 100% powered by solar energy and features a thermostat and humidistat to adjust airflow based on temperatures and humidity levels in the attic.
The stylish fan is constructed from powder-coated steel and can operate at up to 1,550 CFM, making it a good solution for spaces up to 2,500 square feet (virtually the entire house for average-sized homes). A low-profile steel mesh keeps out litter, debris, and small animals. It’s the least expensive solar fan in its category.
Other key features of the model SF30 from Remington include the high-quality polycrystalline solar panel (fitted with a powerful brushless DC motor) and the sleek hail and weather-resistant design. The panel can be tilted/adjusted for maximum sunshine exposure. The 18 x 18 x 12-inch fan weighs about 27 lbs.
You’ll appreciate that the solar fan allows you to automatically switch the power source (to electricity) to continue using the fan at night. Many other fans claim so, but you eventually find that you need to turn the switch manually.
This fan has a 110-Volt inverter (sold separately). The best thing about the SF30, though, is the 30-day risk-free trial period and lifetime warranty.
Pros
- Up to 1,550 CFM, ideal for 2,500 square feet
- Built-in thermostat and humidistat
- Adapter (solar to electricity) sold separately
- Life-extending, DC brushless motor
- 30-day money-back guarantee, lifetime warranty
Cons
- Requires electrical wiring
5. Remington Solar 20-Watt Solar Attic Fan with Thermostat/Humidistat
If the model SF30 is beyond your budget, or if you just need a smaller solar attic fan, the 20-watt model SF20 would be an excellent alternative.
It’s a simple, cost-effective fan, ideal for domestic use in the storage shed or attic or commercial applications such as workshops. It’s also 100% solar-powered, meaning you don’t have to worry about the power bills.
The fan is straightforward to install. It comes operational out of the box and doesn’t require electrical wiring. It’s also extremely durable, thanks to the high-quality galvanized steel construction. The steel housing is powder-coated for an attractive finish that’s both corrosion and weather-resistant.
Once installed, the SF20 runs silently, moving up 1,280 cubic feet of air per minute at maximum speed. The brushless DC motor ensures decades of efficient performance without wear, while the seamless flashing and shroud guarantee a weather-tight installation. A stainless steel animal protection screen helps keep out debris, birds, and litter. It’s best suited to spaces up to 1,800 square feet.
It’s a low-profile fan that measures 18 x 18 x 18 inches and comes in a grey or black finish. It’s also very light at about 29 lbs. and operates silently. Every purchase is backed by a 30-day money-back guarantee and lifetime warranty.
Pros
- The hybrid adapter allows solar/electricity operation
- Life-extending DC brushless motor
- Includes built-in thermostat and humidistat
- 100% Satisfaction guarantee and lifetime warranty
Cons
- Hybrid power adapter sold separately
6. GBGS Solar-Powered Exhaust Fan AC Power Backup with Thermostat
Besides Natural Light and Remington, GBGS is another company that makes excellent solar-powered attic fans. We’ve listed two products from the manufacturer on this list, each rated at 20 watts. However, they aren’t the same. You’ll need to be extra careful to get the distinctions so that you can pick the one that best solves your needs.
This first option is a 1750 CFM standard solar-powered attic fan designed for spaces up to 2,000 square feet. It’s 100% solar-powered and works only when there’s sunlight. This means that it goes off at night. The manufacturer manual shows that it switches ON automatically when sunlight temperatures reach 77˚F and goes off automatically when temperatures dip below 65˚F.
The fan uses an IP68 waterproof brushless motor and boasts nylon-fiber-aluminum fan blades and a galvanized steel housing for durability. A smooth-air deflector in the shroud of the fan produces smooth airflow and increases exhaust performance. The fan is adjustable to work at 0˚, 15˚, 30˚, or 45˚ for maximum sunlight reception.
The fan works optimally on multiple roofing surfaces, including wood shake, asphalt, and standard sloped roofs. It measures 20 x 20 x 13 inches and is backed by a 10-year brushless DC motor, 20-year metal casing, and 25-year solar panel warranty.
Pros
- Adjustable solar panel
- IP68 waterproof brushless motor
- All-metallic construction for durability
- Long warranty
Cons
- No option for electrical power
- It’s a tad wide
7. GBGS Solar Attic Fan Surface Mount 1750 CFM, IP68 with Brushless DC Motor
If you’re interested in a two-way power supply alternative, this second model, though primarily a solar-powered fan, automatically switches to AC/DC (electric) power whenever there’s not sufficient sunlight.
The solar power setting works when the solar energy is equal to or greater than 14 volts. As soon as the voltage drops between 0-14V, it begins to use solar + electricity, automatically switching between the two energy sources as necessary to ensure continuous operation.
If the voltage drops below 0.0V, which usually happens at night, it switches to electricity only. The best part is that you don’t need to switch between the power sources – it all happens automatically.
Another key advantage of this fan is the high number of fan blades. Whereas most exhaust fans max out at five blades, this product has seven 14-inch blades. Yet, the noise level is as low as 40 decibels. The mounting frame is designed such that multiple similar exhaust fans can be assembled together. The front side metal mesh blocks out insects and debris.
The fan is made from galvanized steel with anti-UV coating treatment, and the solar panel adjustable for maximum sunlight reception. It’s a 1750 CFM fan and is recommended for spaces up to 4,200 square feet.
Pros
- Powerful 1750 CFM fan for up to 4,200 Square feet
- Two-way power supply (solar + electricity)
- Smart power controller included
- Built-in thermostat switch
- Durable, galvanized steel housing
- 25-year manufacturer warranty
Cons
- Requires electrical wiring
Solar Attic Fans FAQs
How much does it cost to install a solar attic fan? An Energy-Star rated solar attic fan costs $200 to $600, plus $150 to $200 for installation.
Where should I place my solar attic fan? It’s best to call a professional to determine the positioning that guarantees maximum solar energy capture for maximum fan performance.
How many solar attic fans do I need? It depends on the size of your attic and the CFM rating of your preferred solar attic fan. For a 2,000 square-foot attic, you can purchase one 1,400 CFM attic fan or two 70CFM fans.
Is a solar or electric attic fan better? Electric attic fans are more powerful and cheaper. However, solar attic fans are more energy-efficient and environment-friendly.
Attic vs. whole house fans: You need both. Attic fans are primarily needed to assist the whole-house fans. The attic fan minimizes the load on the whole-house fans and air conditioning system by reducing attic temperatures.
Is a solar attic fan worth it? Yes. For a $300-$600 investment, you can reduce your home heating costs substantially. Moreover, the solar attic fan is a one-time investment. You don’t have to worry about monthly power bills.
Summary
Investing in a solar attic fan is a no-brainer. A durable solar attic fan made from weather-resistant aluminum guarantees decades of reliable service and actively improves indoor air conditioning by lowering attic temperatures.
They also remove stale air, thus improving indoor air quality. If you can find one with a 25-year warranty, you’re good to go.