It seems like the summers just keep getting hotter and hotter. Perhaps it’s global warming? Whatever the reason, it takes me a lot of effort and money to keep my house cool during the summer months. In the hottest part of the day, I used to run my air-cons all the time. That’s why I installed solar attic fans to help keep my house cool.
Are you wondering how my attic fans can cool my home and reduce my energy bills? Here’s how it works. In the hot summer months, my attic heats to over 120° Fahrenheit, and this pocket of hot air transfers heat through my ceiling into my house, heating it. By running attic fans, I can vent this heated air outside and bring cooler air back in, cooling my attic space and home.
I’ve been so impressed with the results of my solar attic fans that I want to share what I’ve learned with you and recommend some of the best products on the market. I’ll review the seven best solar attic fans from Lowe’s so that you can choose one that best fits your needs.
Solar attic fans can help you in winter too
You might think a solar attic fan only works in the hot months, but this is untrue. In winter, your attic and home can suffer from ice and water damage if you don’t remove the humid air.
Some solar attic fans feature humidistats, which turn the fan on when the air in your attic reaches a specific humidity level. Thermostats are also a common feature. They trigger the fan when your attic heats to a particular temperature.
How many solar attic fans do you need?
What is your roof area?
It’s easy to work out the area of your attic by multiplying its length by its width. If you have your house plans, this saves you the trouble of measuring.
What is your roof slope?
Perhaps you already know the slope of your roof; it is measured in twelfths. A shallow sloping roof is 2/12 and a steep one might be 12/12. The first number is the height and the second is the width.
Once you have the area and pitch of your roof, then you can work out how many solar attic fans you need using these tables.
Guide for roofs with a low slope
| Attic Slope | Attic Size | Attic Fan Size in Watts |
| 1/12 – 4/12 | 800 ft² | 1 Solar Attic Fan |
| 1/12 – 4/12 | 1,200 ft² | 1 Solar Attic Fans |
| 1/12 – 4/12 | 1,600 ft² | 2 Solar Attic Fans |
| 1/12 – 4/12 | 2,000 ft² | 2 Solar Attic Fans |
| 1/12 – 4/12 | 2,400 ft² | 3 Solar Attic Fans |
Guide for roofs with medium slope
| Attic Slope | Attic Size | Attic Fan Size in Watts |
| 5/12 – 8/12 | 800 ft² | 1 Solar Attic Fan |
| 5/12 – 8/12 | 1,200 ft² | 2 Solar Attic Fans |
| 5/12 – 8/12 | 1,600 ft² | 2 Solar Attic Fans |
| 5/12 – 8/12 | 2,000 ft² | 3 Solar Attic Fans |
| 5/12 – 8/12 | 2,400 ft² | 4 Solar Attic Fans |
Guide for roofs with a high slope
| Attic Slope | Attic Size | Attic Fan Size in Watts |
| 9/12 – 12/12 | 800 ft² | 2 Solar Attic Fans |
| 9/12 – 12/12 | 1,200 ft² | 2 Solar Attic Fans |
| 9/12 – 12/12 | 1,600 ft² | 3 Solar Attic Fans |
| 9/12 – 12/12 | 2,000 ft² | 4 Solar Attic Fans |
| 9/12 – 12/12 | 2,400 ft² | 5 Solar Attic Fans |
Note that these numbers are guidelines based on 20W fans in regular attic conditions.
7 Best Solar Attic Fans On Lowes
1. MasterFlow 500 CFM Silver Galvanized Steel Solar Power Roof Vent
This is a 10 W solar attic fan that probably won’t have enough power to cool your whole attic on its own, but you could install two or three units. It’s handy that you have a mains connection so that you’re not dependent wholly on sunlight, but the drawback is that it adds to your fuel bills.
The adjustable thermostat gives you plenty of control, and the tiltable solar panel allows you to position it for maximum solar energy collection.
Key Features
- Roof-mounted attic vent and thermostat
- Solar panel dimensions 11 1/4-in x 16 in
- Dual solar and mains power adjust automatically
- Adjustable thermostat
- Tilt-and-swivel design for optimal performance
- 10-watt solar panel
Pros
- This combination of mains/solar products is perfect for northern states that don’t get much sunshine
- The tiltable solar panel is handy, especially if you aren’t installing the unit on a south-facing roof.
- Rugged and durable galvanized steel design
Cons
- Not very powerful as a stand-alone fan but a convenient and affordable second fan
2. US Sunlight 10 Watt Solar Attic Fan
This is a fully automatic stand-alone solar attic fan. Since it has a built-in thermostat and humidistat, you can just leave it to do its job knowing that it won’t incur any costs from your mains power. The adjustable solar panel is mounted on a galvanized steel dome, which isn’t the prettiest design ever but is certainly tough and durable looking.
Key Features
- 800 CFM (Cubic Feet Per Minute)
- The solar panel tilts and rotates for maximum sun exposure
- No solar controller needed
- The solar panel is mounted directly on the dome
Pros
- 800 ft³ per minute is an excellent performance from a ten-watt solar panel
- The adjustable solar panel can be positioned to maximize exposure to the sun.
- This is a well-priced entry-level solar loft fan
Cons
- You will probably need two more of these fans since 10 W is quite a small power output.
3. QuietCool 30 Watt Solar Powered Roof Mount Attic Fan
I like the attractive matte black design of this powerful attic fan. The top-mounted solar panel can be adjusted to almost any angle ensuring maximum power input. The preset thermostat will control heat automatically.
I recommend this fan to anyone not living in a sunny place since the dual mains/solar power supply means that you are not entirely reliant on solar power. It also means that you can run this fan outside sunlight hours giving it more time to cool your house.
Key Features
- Powerful 30 Watt solar panel
- Ultra-energy efficient DC motor
- Preset thermostat
- Included AC/DC inverter for 24/7 runtime
- Heavy-duty steel housing
- Fully adjustable solar panel
- 15-Year warranty
Pros
- The dual solar/mains power supply means that this stand-alone unit will probably be the only solar attic fan you need to cool your attic space.
- An attractive design you’ll be happy to have on your roof.
- Excellent warranty terms mean that this is a long-lasting investment
Cons
- The lack of humidistat means that this panel won’t be as effective in winter unless you control it manually.
4. QuietCool 40 Watt Solar Powered Gable Mount Attic Fan
Key Features
- 40 Watt solar panel
- Ultra-energy efficient DC motor
- Preset thermostat
- AC/DC inverter for 24/7 runtime
- Heavy-duty steel housing
- Fully adjustable solar panel with a 60-degree tilt
- 15-year warranty
This is another attractive QuietCool fan with a potent forty-watt solar power capacity. It gives you lots of control with a customizable thermostat and the option of mains power. This is a more expensive fan but the degree of control it offers is unparalleled, and unless you have an enormous attic space, then this one fan should give you all the cooling you need.
Pros
- A plug-and-play product that runs in the background and keeps your life simple
- The powerful 40W solar panel gives you lots of energy, and you have the option of a mains connection as a fallback.
- Combination power means that the fan runs whenever it is needed.
Cons
- If you power this fan from your mains supply, you will incur electricity costs.
5. iLiving 20W Smart Solar Attic Exhaust Fan
This is a smartly designed midrange attic solar fan. It comes with a customizable thermostat that offers you plenty of control over when the unit starts cooling your attic. The waterproof brushless motor ensures smooth and fault-free running over an excellent fifteen-year warranty period. Despite this being only a twenty-watt model, it’s a well-designed and good-value mid-range fan.
Key Features
- Smart thermostat control 65-130F
- Waterproof brushless motor, 15-year limited warranty
- Adjustable solar panel with 1750 CFM capacity
Pros
- The customizable thermostat gives you total control over the fan.
- An attractive design with an easy to angle solar panel.
- The brushless motor offers longer life and quiet operation.
Cons
- The 20W solar panel isn’t very powerful.
6. Air Vent 800-CFM Weatherwood Galvanized Steel Solar-Power Roof Vent
This solar-only attic fan is a good no-nonsense unit for small homes. It offers reasonable airflow, and since the solar panel can be mounted separately to the fan unit, you can place the panel on a south-facing slope for maximum exposure to the sun.
There’s no mains backup, so this is a fan best suited for homes in the sunnier southern states.
Key Features
- Solar-powered; solar panel mounts separately on the roof
- 800 CFM airflow
Pros
- This is a simple product to install.
- You can install the fan and solar panel separately to ensure the best performance.
- Solar only so this fan won’t impact your electricity bill.
Cons
- Quite expensive for a fan with just 800 ft³ per minute airflow
7. Air Vent Black Gable Power Ventilation
This is a decent mid-range solar attic fan but the maximum 800 CFM is unlikely to cool your whole attic. It’s a light and compact unit but doesn’t have an automatic thermostat or humidistat so you’re sacrificing some valuable features for a lower price.
Key Features
- 30% quieter and 35% more efficient
- UL Listed with thermal overload protection
- The fan blade is housed within a patented innovative series of rings
Pros
- Rugged galvanized steel design
- Gable-vent design means you don’t need to install the fan on the roof, just a solar panel.
- This fan has a quiet and unobtrusive motor.
Cons
- Only a five-year warranty
If you have any comments or questions about this review of the seven best solar attic fans, then please share them with us below.