If you got that much mildew I suspect you have leak or a/C drain not draining and holding moisture? Something causing the mildew and IMO it not normal? You can look outside see if the A/C drain is draining some where should seed PVC pipe sticking up and draining? You can take panel off you unit and look in at the A coils. Look along walls of garage for any signs of moisture?

Insulating the garage door will only slow down the heat transfer from the outside to the garage interior. The garage will still get just as hot, but it may take a little longer. But, in the evening, the garage will actually take longer to cool down because the heat transfer will flow from the garage to the outside, and the insulation will slow it down.

My garage has no insulation or ventilation. Right now, the outside air temperature is 96 degrees, but my garage temperature is only 91 degrees. My garage never get above about 96 degrees, even when the outside air temperature is 100 degrees.

There is one in my house in front of furnace closet, vents to attic, built in 2004, Sumter county.

I think the attic vent is a code violation of the current building code (see Post No. 26). I have also read several expert opinions that say an attached garage should be isolated from the living section of the house and the attic to contain a fire that starts in the garage. If you have a fire with smoke that occurs in the garage, the attic vent will allow the attic to fill up with smoke and permeate the rest of the house. This is my opinion, but maybe a home inspector could provide another opinion.

If the home has a gas furnace, could that ceiling vent be a vent from the outside to provide the required air for combustion? I seriously doubt that the building inspector would miss such an obvious violation.

Yeah but that's when we are in the garage, right? Don't really care about the night.

Did the material installed make the door movement any less noisy????

The posts on this thread that claim to reduce the garage temperature by 20 or 30 degrees by installing foam insulation on the garage door are not believable. Right now, at 1PM, the outside temperature at my house is 95 degrees and the interior temperature of my garage is 96 degrees. My garage door faces west and has no insulation on the door. Adding insulation to the door wouldn't change anything. Yet, some posters are claiming that adding an inch of foam board to my garage door will magically reduce the garage temperature to 65 or 75 degrees. I would suggest that, before you insulate your garage door, monitor your garage and outside temperatures during the daytime. If the temperature difference is less than about 5 degrees, the door insulation will be a total waste of money.

The insulation and radiant barrier prevent the heat from getting in, thus cooler. The inside of the radiant barrier is 15 degrees cooler than the hot side. You can check it out for yourself on the internet just search radiant barrier.

The attic insulation prevents the heat from the attic radiating into the garage.

I agree with this because most of the heat is coming from the attic. If the temperature is 95 outside the attic is over 140. Just insulating the door will not help.

How is it going to reduce it below ambient temperature when everything in, around, and above it is ambient at least temperature? IMO it Will NOT reduce temperature below ambient temperature. The garage is not sealed air tight.

It is correct that no matter what you do to the garage, short of installing an air conditioner, you will never get the garage temperature below the outside air temperature.

Thank-you,
 

:mademyday:

Dreamer!!

Thanks for the reply! There are no leaks or A/C drain issues. The problem is likely that the garage door is often not opened/closed for up to a couple months at a time when I am traveling. Therefore, no air movement.

I have installed a dehumidifier, and it dropped the humidity to my set 55% level and cycles on/off as expected. Also got a 20" box fan to move air when I am working in the garage.