I’ve wondered about this too, especially since I’m trying to keep costs down but still want the attic to stay reasonable in summer. My house is a 70s ranch with a low slope and decent soffit vents, but it still gets crazy hot up there. I looked into both roof and gable fans—roof fans seem more effective at pulling air straight up and out, but installation’s pricier and you’re cutting another hole in the roof (which makes me nervous about leaks long-term). Gable fans are cheaper and easier to swap out if they die, but I’ve read they can short-circuit airflow if your intake isn’t solid.
I’m leaning toward a solar roof fan just because of the energy savings, but I keep second-guessing if it’s worth the extra upfront cost. Anyone else notice a real difference in attic temps after adding one?
I’m leaning toward a solar roof fan just because of the energy savings, but I keep second-guessing if it’s worth the extra upfront cost.
I’ve inspected a bunch of 70s ranches with setups like yours. Solar roof fans do drop attic temps—usually by 10-15 degrees in peak summer—but only if your soffit vents are clear and there’s enough intake. I’ve seen a few installs where folks skimped on intake, and the fan just pulled conditioned air from the house instead. Personally, I’d rather patch a gable than a roof if something leaks down the line, but if you’re set on solar, just double-check your venting first.
Solar roof fans do drop attic temps—usually by 10-15 degrees in peak summer—but only if your soffit vents are clear and there’s enough intake.
That’s exactly the key. I’ve seen a lot of people skip the intake math, and then wonder why the fan isn’t helping or, worse, is pulling AC air up through ceiling gaps. I’d say if you go solar on the roof, make sure your intake vent area matches or exceeds the exhaust. I use the 1:1 ratio as a baseline, but more intake is usually better.
One thing I’d add—solar fans have come a long way in terms of reliability and leak prevention, but roof penetrations are always a risk point. If you’re in a region with freeze/thaw cycles or heavy rain, flashing details matter. I’ve retrofitted a few where the original installer just slapped some mastic around the base... not great.
Gable fans are easier to swap out or patch up, but they don’t always move air as effectively unless your attic layout cooperates. If your roofline is low-pitch and there’s not much vertical space, gable fans can struggle.
Personally, I lean solar for energy savings, but only after double-checking vent sizing and making sure my roof’s in good shape before cutting anything.
If you’re in a region with freeze/thaw cycles or heavy rain, flashing details matter.
This is spot on. I manage a few older properties and learned the hard way that even a tiny flashing miss can cause headaches—one winter, a “quick” solar fan install turned into a slow ceiling stain that took months to trace. I do like gable fans for easy maintenance, but in houses with chopped-up attic spaces, they just don’t move air evenly. Intake vents are the silent MVPs here... I’ve seen folks double their exhaust and forget the soffits, then wonder why nothing changes.
That thing about intake vents being the real MVP is so true. I helped my uncle with his attic fan setup last summer—he was convinced adding a second roof fan would fix his heat issues, but we barely saw a difference. Turns out, his soffit vents were clogged with old insulation and dust... basically useless. Once we cleared those out, the temp dropped way more than with just the extra exhaust.
I’m still not sure if roof fans are worth the extra risk for leaks, though. The gable fans seem easier to swap or service, but like you said, they don’t always pull air from every corner—especially in weirdly shaped attics. Has anyone tried running both types together? Or is that just asking for trouble with pressure imbalances? I keep hearing mixed things from different folks on jobsites.
Also, flashing details stress me out every time. Even when you follow the instructions, it feels like there’s always some spot water wants to sneak through...
