Installing a Solar-Powered Attic Fan

Eco-friendly products have created a big buzz lately, especially in the home-improvements arena. Solar-powered attic fans, for instance, help ventilate your attic through the rooftop panels that capture the sun’s energy.

The question, however, is whether this environmentally friendly ventilation system is worth the hype. Can it keep your attic cool during hot summer days and address winter-related condensation problems?

Installation Process

Having the right tools and skills is essential for any installation project. The process may also be overwhelming for rookies, considering efficiency and safety.

While installing a solar-powered attic fan may be pretty straightforward, it’s still pretty risky since you will be drilling holes in moisture-prone areas. To avoid any installation problems, it’s best to let the pros do the work for you.

Here’s how to install your solar attic fans in 8 steps:

1. Pick the Right Fan

Allowing fresh air to enter your attic through solar-powered fans may help solve your gable moisture problems. Typically, this system has separate units for control, collection, and ventilation, making it a versatile feature of your home.

It also often has at least a 40-watt solar panel, thermostat, and a 12-volt fan. Consider investing in a solar attic fan with double the output to get the best results.

2. Figure Out Installation Angle

Solar attic fans are best installed in the south-facing corner of your roof. If you have a flat-pitched roof, all you will need is a flush-mount unit. Once you have determined the perfect angle, connect the wires to the terminal box, which can be found on the panel’s underside.

Follow the wiring diagram often printed on the panels’ bottom part for smooth-sailing do-it-yourself solar attic fan installation.

3. Make Sure to Tighten the Connectors

In your solar attic fan kit, you will find a water-tight connector to the outer junction or terminal box to prevent moisture from seeping through the gaps. Next, strip the gauge wire and then thread it through the opening of the junction box.

Attach the red wire to the positive terminal and the black one to the negative terminal. You’ll then need to secure the water-tight lid of the box, as well as the connector.

4. Find the Rafters and Drill the Brackets

For the tricky part, use a hammer to find the rafters, where the panel will be installed to the roof using Z-bracket mounts. You’ll need to drill the brackets to the rafters to keep the panel away from the warm roof surface.

However, it’s necessary to use stainless-steel hardware to fasten the Z-bracket mounts to the panels’ inside edges. Before drilling them to the roof, use butyl sealant under the brackets.

5. Secure the Electrical Cable

Stretch the electrical cable from the panel throughout the roofline’s length to the near-end of the attic vent. Bolt the wire to the roof, following an 18-inch interval, and then run the wire through the gable opening.

6. Cut a Brace

After securing the solar panel on your roof, you may now install the fan inside your attic. Pick and mark the area where you want to add the fan. Measure and cut the brace. Drill and screw the brace in the vent opening.

7. Fix the Wires

Using wood screws, attach the fan to the brace to the gable surrounding the area. Get the previously inserted gauge cable and connect it to the fan wires. If there is enough power generated, you should not have a problem turning on the fan.

8. Add the Temperature Controller

If you want to add a thermal switch, use an ordinary plastic electrical box near the attic fan. Secure it into place and then insert the cable into the box from the solar panels. You may need a wire nut to tighten them all together.

Lastly, bolt the controller to the electrical box and adjust the temperature to activate the fan.


DIY attic fan installation projects may seem easy, but they may be critical to your roof’s health. It’s still best to hire professional installers to make the most of your investment.

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