Adding a gable fan, do they work well?

[infinkc]

Garage gets fairly hot in the summer. Has anyone had any experience with Gable fans? I have 2 gable vents on opposite ends of my garage. Just curious how well they work. I do have a closed ceiling, so not sure if it will do much especially with a 16' ceiling, would think it has to pull air from somewhere? so would it jut be pulling air from outside still?

Just looking for anyone with experience with them.

https://www.amazon.com/dp/B0718YDDG7/?tag=atomicindus08-20

Picture of the area, its all sheeted now.

 

[racecougar]

Yes, makeup air has to come from somewhere.

You don't have soffit and ridge venting?

 

[kaymccampbell]

Gable fans work fine, as long as you have someplace to get air. Or, you insulate the hell out of the attic. Or both.
If you don't have ridge or soffit vents, then you can only have one gable fan, so the other gable vent provides air.
Outside air, no matter how hot, is still cooler than what's in your attic.

 

[Hohn]

Don't waste your time with a gable fan. Unless you live and work in the gable, you won't notice a difference.

Think about the heat that comes in your work area. Where does it come from? How does a gable fan address the heat flow?

Put your hand on the surface of the sheetrock at your ceiling. How hot is it? If it's not hot, it can't radiate much heat down to you. And convection heating isn't really happening down to you either from a finished and enclosed attic. The heat is trapped in your attic and not coming down.

So you're left with essentially just conductive heating up through the slab and convective heating from hot summer air.

A gable fan is good for helping to dry out a wet attic if you had a roof leak and not much else.

 

[Hohn]

Gable fans work fine, as long as you have someplace to get air. Or, you insulate the hell out of the attic.

The more you insulate the attic, the more pointless the gable fan becomes. With more insulation up there, the heat cannot get down to the sheetrock and warm it. Thus, more insulation means less heat transmission into the conditioned space, making the supposed benefit of a gable fan even weaker.

My garage is hot in the summer, and the attic will soar past 140F. BRUTALLY hot. But the surface of the sheetrock on the conditioned side of the ceiling is basically ambient temperature of the garage. Which means the attic temp isn't driving the garage temp. And I only have 12ft ceilings.

Or both.
If you don't have ridge or soffit vents, then you can only have one gable fan, so the other gable vent provides air.
Outside air, no matter how hot, is still cooler than what's in your attic.

It's true that outside air is cooler than what's in the attic. But the purpose here isn't cooling the attic-- it's cooling the workspace.
So unless you can demonstrate that the attic heating is driving heat down to the workspace, there's no point to gable cooling if it doesn't translate to workspace cooling.

 

[Hohn]

If you feel the surface of the garage ceiling sheetrock and find that it *is* warm to the touch, then the solution smarter than a gable fan is more attic insulation on top of the sheet. This makes it both cooler in summer and warming in winter. Insulation is cheap. Install twice as much as you think you need and get on with life.

 

[Shiftless]

If you want to really move some air, assuming you have adequate gable vents, I suggest a small whole house fan with automatic closing louvers. Just open a window on the cool side of the garage, turn on the fan and enjoy a cool breeze sweeping the hot air from the garage and from there up to the attic to sweep out the superheated air up there.

 

[Innovate1]

insulation in the ceiling and good passive attic venting is about as good as you are going to get. Best is soffit and ridge vents. Adding a fan doesn't really do much more if anything for the space below. Where are you located?

 

[Zeke]

I disagree with those that say no fan is as good as a fan. Doesn't have to be high velocity. As mentioned, heat build up will be higher in temps than outside temps even if at 100º. You just want to close it off during the cold weather.

 

[mm08822]

What is missing is needing an opening from the workspace into the attic.
Many homes placed a screen into the attic hatchway and opened distant windows in the floor(s) below. The airflow from those windows pulled cooler air through the house through the hatchway and out from the fan. Air flow alone has a cooling effect on the body regardless of temp or humidity content.

Worked perfectly except when trees were pollinating. (Pollen is like joint compound dust!)
In the cooler months, close the hatchway to keep heat in.

A 36x36 gable mount easily cooled 1500sqft. Gable vent opened due to air flow from fan when running.

All you need is a variable speed controller. Gable vent opened due to air flow from fan when running.

A house with many windows is much easier to strategically control the air flow through the house. In the case of a garage with large o/h doors, they probably will need to closed most of the way and/or keep the furthest door open.

 

[rsparks64]

I disagree with those that say no fan is as good as a fan. Doesn't have to be high velocity. As mentioned, heat build up will be higher in temps than outside temps even if at 100º. You just want to close it off during the cold weather.

We added a gable to the attic of our last house. It got extremely hot in the attic in the summer and, even with 2 gables and some vents there was not much air movement. We had insulation above the ceilings but in August it seemed to get hot upstairs. We added the Gable fan and it worked quite well and our A/C bills went down too.

 

[N_Jay]

If your ceiling is one or two degrees above the room temp you want, every bit of cooling above is worth while.

 

[The Bean]

A dry, well-ventilated attic prevents mold from developing both inside the attic and in the living areas below. Attic ventilation helps draw hot air outside during the warmer months of the year, and reduces ice sheeting and ice dam build-up during the winter months.
If you don't like the appearance of gable vents, think about wind powered turbine vents or static cupolas.

 

[mm08822]

We added a gable to the attic of our last house. It got extremely hot in the attic in the summer and, even with 2 gables and some vents there was not much air movement. We had insulation above the ceilings but in August it seemed to get hot upstairs. We added the Gable fan and it worked quite well and our A/C bills went down too.

Before my parents got ac, the attic fan/screen in the attic hatch saved us in the summer from all but the worst dog days.

Even after we got central air, we still used the attic fan quite a bit instead of running $$ac all summer.

 

[bb29510]

if your ceiling is insulated, who care how hot the air above the insulate is. the attic doesnt create heat it just store the heat, so stay away from the black and dark color roofs

 

[N_Jay]

if your ceiling is insulated, who care how hot the air above the insulate is. the attic doesnt create heat it just store the heat, so stay away from the black and dark color roofs

Its not how hot the air is, its how hot the ceiling is.

 

[Coasterbuilder]

Noticed attic fans on sale at home depot a coupe of weeks and and picked one up to replace the one died years ago. Top brand with Bluetooth, temp sensors and programmable operation based on attic temp.

Turned out that it wasn't a direct replacement fit, so I plugged it in and set up the app to show me temps, but not turn on for a few days until I could get up there in the morning to work on it. Freaking hot in So. Cal. that week.

Wrote down the temps every hour for a few days and the attic ran about 20 degrees hotter than the outside temp. Installed the fan, and turns out that with the fan running, the attic ran.......about 20 degrees hotter than outside temp.

 

[Pen & Wrench]

I was always told that if you have your attic well insulated, that will help with thermal efficiency in the living space, but along with that, adequate ventilation is needed to keep the attic temps nearly the same as the outdoor temps. If you don't have enough ventilation to keep the attic temps in control, and you cannot easily achieve adequate natural ventilation, then I think an attic fan would make sense, but to me natural ventilation seems like a better choice.

 

[dcg9381]

Don't waste your time with a gable fan. Unless you live and work in the gable, you won't notice a difference.

I've got an "attic fan" in the garage on a thermostat. It turns on when heat soaked cars get in there and vents through the soffit. But I've got living space over the garage, so that's why I do it.

I agree you won't notice a difference, but where their might be a difference is a case where you've got air handlers (and HVAC duct work) in the ceiling... Seems like that's a good candidate for a gable fan if you can get a 20 degree or so drop in temperature. No HVAC up there? I wouldn't vent it either. Looks like that construction is traditional bat insulation. Just insulate the hell out of it.