Solar Attic Fans

Before deciding to install a solar attic fan on your home, you need to make sure that your roof and your attic are both a good fit.

Here are the main three considerations we make when determining whether your home would benefit from a solar attic fan:

Sun Exposure

Since they’re powered by an integrated solar panel, solar attic fans need to be facing the sun to be effective. You’ll want to make sure one of your roof decks faces South or West and isn’t in the shade in the afternoon.

Attic Volume

Any active attic ventilation is most effective when there’s at least a few feet of space between your roof deck and the ceiling inside of your home. If you have a low-slope roof with very little attic volume then most of the heat being transferred to your ceiling is via radiation from the underside of the roof deck, which attic ventilation doesn’t do much to reduce.

Attic Air Sealing

Active attic ventilation depressurizes your attic via the Bernoulli effect. If your attic isn’t air sealed (most aren’t in homes built in the Boise area before 2006), this lower pressure will pull your indoor air up into your attic. While this will cool down your attic, it does so with the air you’re paying to keep cool with your AC.

The best solution to this is removing your old insulation and air sealing your attic floor, a more cost-effective option is air sealing your home from the interior (which doesn’t require insulation removal). Either way, you’ll want to make sure your home is properly air sealed before installing any active attic ventilation.

All solar attic fans are not created equal.

We did hands-on testing with 7 different solar attic fans and researched dozens more before deciding which we were going to offer to the homeowners we work with, and we’re confident that the one we’ve chosen is the best solar attic fan on the market.

We exclusively install solar attic fans manufactured in the US by Natural Light Energy Systems. Our preferred unit and the one we install most often is the 35 Watt, Ultra Low Profile model. Here’s what sets their fans apart:

Lifetime Warranty

Natural Light’s solar attic fans come with an industry-best lifetime warranty.

All Metal, Heavy-Duty Construction

Most other solar attic fans are either made of flimsy metal that can be bent by hand or have plastic parts to cut costs. Natural Light solar attic fans are made of commercial-grade aluminum, making them the most durable thing on your roof.

Curb Appeal

Let’s face it – most attic fans are ugly. Natural Light’s solar attic fans are low profile and one color, giving them a clean, inconspicuous appearance on your home.

Learn more about Natural Light Solar Attic Fans on their website here, or see what sets them apart from the competition here.

Once you’ve determined that your home would benefit from a solar attic fan, it’s time to decide where on your roof you’re going to put it. There are a few considerations that need to be made here:

1. West or South Facing Roof Deck (for full afternoon sun exposure)
2. Center of Attic Air Volume (to make sure your entire attic is being ventilated evenly)
3. Between Trusses (to ensure maximum airflow)
4. 1-2 Feet Down from Ridge of Roof (to maximize the distance from your attic’s intake vents and make sure the hottest air in your attic being pulled out)
5. Aligned with Shingles to Allow Proper Overlay (to help ensure the fan never leaks and looks natural on the roof)

For your solar attic fan to function at its full capacity, the opening cut into your roof must match the size of the fan’s intake. This may seem obvious, but you’d be surprised by how often we find attic fans and roof vents installed onto holes that don’t match the size of the vent opening.

We use a template to mark the hole we’re going to cut into your roof to make sure we cut it’s big enough to maximize your solar attic fan’s airflow, but small enough to be completely covered by the fan’s flashing.

Most attic fan installers will use a saw to cut the nails holding your roof’s shingles down to clear a path for the fan. This is the simplest way to install a fan and doesn’t require much attention to detail, but risks damaging your roof’s shingles and underlayment.

We have a lot of experience working on roofs (Jacob used to install them in a past life), so we prefer to do things the right way. We take time to gently lift your shingles and remove nails where we need to and re-install them when we’re done, leaving your roof in just as good of shape as it was when we arrived.

If you’re going to be installing anything on your roof, you want to make sure that it stays in place and never leaks. That’s why we secure your solar attic fan with specialized screws meant for this exact purpose and caulk each screwhead before sealing the fan to your roof with a lifetime rated sealant that’s guaranteed to stay watertight longer than your roof itself will last.

To make sure your entire attic is being ventilated, we block off any vents within 6 feet of your solar attic fan. This forces the fan to pull air from the intake vents at your roof’s soffit or gables instead of pulling from an adjacent passive exhaust vent.