mrkool wrote:

So why do you want to add ridge vents? for ventilation? if so, why
don't you use powered thermostatic controlled vent fans inside the
gable vents, that's just what I did, I can't believe the temperature
drop in my attic of 3000 sq ft, from 160+ to now, around 100,
will save on the shingles, keep the insulation from absorbing heat,
moisture control, and save on my compressors run time also put foil
backed ductwarp
over my insulation leaving some space between for moisture to escape.

But, if it's for another reason, please excuse my interuption, didn't
mean to but in.

mrkool

Do you run your thermostatic fan in winter? How much power does it use?
Where do you measure the temperature?

I'm about to add ridge vents because they are the most cost-effective
method. They vent the hottest air all along the roof, and that air
tends to sweeps the underside of the decking.

I have a complex hip roof with no soffit vents. I have a north gable
and a west gable. I could put an exhaust fan in the west gable, which
has a single louvered vent. If I ran it, air would enter through the
vents in the north gable. Most of the attic would be dead air. So
ridge vents will be worthwhile if I get an exhaust fan one day. Before
I bought a fan, I'd install soffit vents.