Looking for the best solar attic fan for your home?
In this proHVACinfo guide, you’ll learn:
- What are solar attic fans? (and how are they different?)
- What are the different types of solar attic fans?
- How many solar fans do I need? (check out our simple guide)
- How do solar attic fans work? (and how can they save you money?)
- What do you look for in the best solar fans? (learn what to look out for!)
And much more!
Our Overall #1 Rated Pick
April 11, 2021
QuietCool 40 watt Solar Powered Gable Mount FanCheck on Amazon
As more homeowners are trying to make more environmentally friendly choices, manufacturers are increasing the number of green, renewable energy products to meet the demand.--break--The result is a minefield of choices.--break--We did the hard work for you, and after reviewing many solar powered attic fans, we gave our best overall title to the QuietCool 40 watt Solar Powered Gable Mount Fan.--break--Why?--break--This is a superb attic fan across a range of criteria. It’s constructed with the best materials, and fit and finish are excellent.--break--Unlike many budget options, there are no sharp edges, so you are unlikely to cut yourself during installation – always a plus!--break--Most importantly, considering that this fan operates on solar power, it still outperforms many plug in models when it comes to air flow.
Short on time? Below is a quick recap of our favorite solar attic fans! Keep scrolling to learn more!
QuietCool 40 watt Solar Powered Gable Mount Fan
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Natural Light Solar Attic Fan
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Eco Worthy Solar Gable Fan
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Remington Solar Attic Fan
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Remington Solar 20 Watt Solar Attic Fan
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What Are Solar Attic Fans (and what makes them different)?
Solar attic fans are solar powered fans that are either mounted in your roof or in a gable end, with the express purpose of drawing hot, moist air out of your attic and expelling it to the outside.
By doing so, they can drop summer attic temperatures by as much as 50 degrees Fahrenheit, which will have an instantly noticeable effect, not just when it comes to comfort, but also on your energy bills!
Solar Attic Fans vs. Conventional Attic Fans
A common question we see about solar attic fans is how they differ from conventional fans.
Of course, the biggest difference is obvious! Conventional attic fans require power from your home, while solar attic fans are powered by the sun.
The difference in power source means that solar attic fans are less expensive to the operate, since they run from clean, renewable source.
For that reason, solar attic fans are very popular for those looking to minimize their carbon footprint.
Solar attic fans are also generally easier to install than their electrical counterparts for the same reason.
Attics generally aren’t set up with the necessary wiring to power an attic fan, and running a line to the attic significantly complicates installation and setup.
Of course, along with all those benefits are some tradeoffs.
By definition, solar attic fans are powered by daylight, so they don’t necessarily run at night (there are exceptions to this, which we discuss below).
They’re also generally more expensive, because the technology is newer (of course, this is offset by lower ongoing costs).
What Are The Different Types Of Solar Attic Fans?
Solar attic fans can either be roof mounted or gable end mounted. Keep reading to find out more about each style.
A roof mounted solar attic fan is mounted over a ventilation hole close to the top of your home’s roof. Around the hole is a plate to which the fan mounts.
They are simple to install, but be conscious when purchasing that you choose a model suitable for the pitch of your roof.
Some roof mounted models can only be used with flat roofs, while other require a particular angle.
With roof mounted models, the solar panel typically sits right over the fan, meaning that there is no separate mounting for the panel.
Gable end solar attic fans are installed in the gables of your home, which are the flat sides that rest on the inside of your roof’s peak.
These fans are installed vertically, but because the horizontal surface of your home isn’t optimum when it comes to collecting sunlight, the solar panel usually has to be mounted on the side of your roof that receives the most light and a wire needs to be run to the fan.
The tradeoffs when it comes to gable vs. roof are fairly straight forward – roof mount solar attic fans are usually all in one, and don’t need wiring run to distant panels.
Gable end solar attic fans do require some extra wiring, however usually outperform roof mount when it comes to volume of air moved.
How do Solar Attic Fans Work?
Using the power of the sun to drive a motor, solar attic fans pull the hot, humid air out of your attic and send it outside.
As the hot air is expelled, a negative pressure is created in the attic, and by the laws of fluid dynamics, fresh air will be drawn in through your existing soffit vents in order to neutralize the pressure.
This perpetual flow of fresh air keeps the temperature stable at a comfortable level, and prevents the oven like conditions found in stagnant, fanless attics.
Solar attic fans usually only run in direct sunlight.
Some do have the ability to keep working in low light conditions, but unless they are equipped with some kind of hybrid system, they will not operate at night.
This is because solar panels require contact with sunlight to create their electric field.
Once they generate electricity, it flows to the edge of the panel where it’s transported to an inverter by means of a conductive wire.
Once it reaches the inverter, the electricity is converted from AC to DC, allowing it to run the fan motor. Without sunlight, however, this process does not occur as these units don’t normally include any kind of battery storage.
How Many Solar Attic Fans Do I Need?
This is another common question about solar attic fans – it’s more common for this category of fans because they are less powerful than conventional models.
The number of fans you use is dictated by how much airflow you need to move, which is ultimately determined by the size of your attic.
See below for a helpful table of approximately how many 20-watt fans you’d need to approximate cooling capacity for attics of various sizes and slopes.
The slope is listed as the “rise” over the “run” of the roof (i.e. how many feet the roof rises for every 12 feet across).
You’ll notice that a steeper roof requires more power to cool.
This makes sense because a steeper roof has more air in the same space than a comparatively less steep roof.
Keep in mind that exact specifications differ for each attic, and depend on things like roof shape and pre-existing ventilation quality.
What Do You Look For In The Best Solar Attic Fans?
When it comes to choosing the best solar attic fans, there are a few features that, if they’re present in the model you’re looking at, are a sign of a good quality fan. The more of these features you can check off, the better!
Look for solid, well finished construction.
All metal is generally best as plastics do not deal well with exposure to sunlight, and as the job of a solar attic fan is literally to be exposed to sunlight, plastic construction would be a recipe for disaster.
Some solar fans have a panel that is adjustable, and can be tilted to optimize the direction of the face of the panel against the sun.
This not only improves operating efficiency and effectiveness, but it provides the homeowner with more flexibility in terms of where on the roof fan can be installed.
Thermostats and Humidistats
The best solar attic fans feature a humidistat for automatic operation based on high humidity, and a thermostat to turn on the unit when the temperature breaches the set limit.
Without these controls, the on and off procedure is entirely manual, meaning not only do you have to remember to turn the fan on and off, but you might have to venture into the attic to do so.
Because solar attic fans are seen as emerging technology, they are often equipped with smart functionality, too. This is definitely something to look out for.
Having app control will give you real time data about the conditions in your attic, and it will also give you control over the fans, the thermostat, the humidistat, and in many cases will even let you program a run schedule.
Because solar power relies on sunlight, most solar attic fans won’t run at night. If your fan happens to come with hybrid power that allows you to run it from the mains electricity in your home, this will allow you to keep the fan turning 24/7 and keep your attic conditions perfect at all times.
QuietCool 40 watt Solar Powered Gable Mount Fan (Our Top Pick)Check on Amazon
Quietcool makes some of the best attic fans on the market, and their solar versions are no exception!--break--This fan is easy to install, it’s very well made, and comes ready to go with everything you need to run it 24/7.--break--In the box you get the fan, the solar panel, an AC/DC inverter, and a built in precision thermostat.--break--It will keep your attic within 10 degrees of the outside temperature, helping to prevent oven-like conditions.--break--It’s built for the long haul, and there’s an incredibly generous 15 year warranty included. The energy savings based on the use of solar, and the overall home temperature reduction mean that the estimated return on investment while using this fan is just 3 years, after which, this fan is technically making money for you!
- Plug and Play--break--State tax incentives available--break--Quiet operation
- Round frame leaves gaps--break--Mounting tabs could be sturdier
Natural Light Solar Attic Fan (High End Pick)Check on Amazon
If you’re looking for an ultra-premium solar attic fan, this roof mounted model from Natural Light is a great option for you.--break--It’s the most powerful on test at 48 watts, and will move up to 1881 CFM in spaces up to 2825 square feet. It boasts the highest quality materials on the market, and the manufacturer backs this up with an industry leading 25 year limited warranty.--break--This model is simple to install, and can be up and running in under an hour.--break--It offers a sleek look, and because of the aluminum construction, it will stay looking good for years to come.
- 1,800+ CFM air movement--break--Corrosion resistant
- Thermostat sold separately--break--Not suitable for flat roofs
Eco Worthy Solar Gable Fan (Best Budget Pick)Check on Amazon
Eco Worthy have genuinely impressed us with their solar gable fan.--break--It comes supplied with a 30w solar panel for effective cooling, and because it only requires 4 volts to run the fan, it will still run even on cloudy days.--break--This solar attic fan is easy to install, and the manufacturer offers tremendous customer service.--break--The solar panel has an adjustable hinge so you can optimize exposure to the sun, and comes complete with mounting brackets and all required hardware.--break--The fan is pre wired, making it plug and play, and the motor is rated to over 10000 hours running time.
- Roller bearings for smooth fan operation--break--1960 CFM--break--Price
- No Thermostat--break--Some pre drilled holes are too small for supplied hardware
Remington Solar Attic FanCheck on Amazon
Remington Solar make some excellent solar powered appliances, including this 30 watt attic fan.--break--It boasts both thermostat and humidistat automation, keeping control of both temperature and humidity without any intervention.--break--The fan is equipped with a long lasting brushless motor, which has the added benefit of boing whisper quiet.--break--The overall design is simple, but unobtrusive, so if you’re concerned about an eyesore on your roof, those concerns are unwarranted with this Remington Solar attic fan.
- Efficient operation--break--Adjustable solar panel
- Does not perform well on cloudy days--break--AC/DC inverter requires additional purchase
Remington Solar 20 Watt Solar Attic FanCheck on Amazon
If your attic is smaller, you might find that you only need a 20 watt solar attic fan.--break--Boasting almost identical features to its 30 watt big brother, this 20 watt solar attic fan from Remington solar offers excellent construction, backed by a 15 year warranty and a 30 day money back guarantee.--break--The motor is hail and weather resistant, and its brushless technology ensures quiet operation.--break--The solar panel is nice and compact, and is actually Texas windstorm certified.--break--It’s suitable for attics up to 2000 square feet, and will comfortably move 1280 CFM.
- Includes humidistat and thermostat--break--Weather resistant
- Requires additional purchase to make WIFI ready--break--Mounting screws strip easily
Final Thoughts On The Best Solar Attic Fans
Going solar when it comes to attic fans makes a lot of sense. Not only are you saving money on powering the fan, but the fan is also helping to cool your home and reducing the strain on your air conditioning, a double plus.
Not to mention the other factors such as extended roof life, impact on the environment, and reduced fire risk.
For all of these reasons and more, solar attic fans make a smart choice for any homeowner, particularly in sunnier states.