Can too much ridge ventilation be detrimental

atticventventilation

At my house in central Texas, where temperatures can persist at 86 – 110 degrees Fahrenheit, one side is always hot, no matter how long the A/C runs. That attic space is considerably hotter than other locations.

Attic ventilation includes:

  1. twenty-two 16×8 soffit vents
  2. two 10' runs of plastic ridge vent
  3. three stack vents

For better or worse, the ridge vents do not have a filter underneath and are covered with shingles.

According to the web, such as this website, 20' is the minimum requirement and the 22 soffit vents balance appropriately.

Will it help to install additional ridge and soffit vent? or will that disrupt current circulation?


UPDATE:
The ridge vents are actually 8 ft. long (not 10') and only 5 ft. of that are actually exposed. 1.5 ft. on either side of the ridge vents are covered over by shingles.

house top view
ridge vent photo
house elevation

Best Answer

With the solar-powered vent and two static vents being so close together, I wouldn't be surprised if the the solar-powered vent (because it's powered) is pulling most of it's air from the two static vents. You might be able to check this by using toilet tissue, feather, incense smoke or something to determine air-flow direction through the static vents while the solar-powered vent is running.

If the net effect is that air is being pulled in, then none of those vents are doing as much as they should to cool the attic. Some of the air through the soffit vents is being exhausted through the solar-power vent, to be sure, but the static vents aren't helping.

If I were going to make changes, I would consider the following, in order of preference...

  • Remove and seal up the two static vents. This alone would cause the solar-powered vent intake to come completely from the soffits and thus pull hot air out of the entire attic area underneath.
  • Remove the solar-powered vent and install a ridge vent the entire length of the ridge next to it. As this makes venting totally passive, it might not be enough for your climate. Depending on size and efficiency, the solar-powered vent without the static vents may move more air. If still not enough, I would think more CFMs of air could be vented using a line-powered unit, but haven't researched it.