Ron asks: We installed a ridge-shaped ventilation grille and a solar-powered ventilation fan on our roof. I noticed that you said that these two systems should not be combined. Our contractor installed a ridge-shaped ventilation duct on our roof. A significant amount of heat was still accumulating in the attic, so he installed a solar fan on the roof that moves 500 CFM (cubic feet per minute). Should we remove the solar fan? -Rum.
Ask your professional roofer about local building codes related to installation requirements in your area. If a gable vent seems like too big of a task to you, consider installing smaller ventilation grilles in the shape of eyebrows that are slowly mounted to the bottom of the roof so that they can act as entrance holes. We have a garage from the 1940s (650 square feet) that was converted into an apartment with a cathedral-like roof by 26% without ventilation ducts. I think my best bet is to place eyebrow holes in the ceiling, at the bottom, and then, eyebrow or gable holes at the top.
The original design had an attic above the roof; the attic was ventilated with passive gable vents at each end. Currently, the house has 1 rectangular gable vent of 12 × 15 on each side of the house and a pair of small ventilation grilles on the mushroom roof. One of them says that they would simply add a single solar fan in the attic installed on the roof to increase air circulation mechanically. Roof vents work by expelling warm air from the attic, reducing both temperature and relative humidity in the attic space.
In warm climates, an electric fan is usually placed behind a gable ventilation grille or cut into the roof near the top to facilitate this process, as it forcibly expels more warm air from the attic. Upon inspection, there are 3 or 4 rectangular ceiling lights that feed the vaulted ceiling from the outside, but the roof doesn't seem to have an escape (the two eyebrows of this roof come from the attic that was sealed).