Ridge vents in combination with soffit vents are the most effective passive system available. Power vents can move more air but consume energy. It's your call

Have the contractor show you he is installing/making sure the soffit vents that are necessary for a ridge vent to operate properly are being done.

Then relax, knowing the new system will be the best possible solution.

Either ridge/soffit vent combo, or powered roof vent -- not both. Also, if your house/attic space is small (like in an older house) the available sizes of power vents might be too much -- sucking conditioned air from your living space (I was told this by the manufacturer of the power vent)

raee and others

I don't agree..
why??
in 18yrs our power roof vent fan...runs just about all the time from
mid april to mid october.. yes just passed sunup to after sun down..daily

we have ridge vents and soffit vents(100%)..all installed when the house was built..
the powered vent fan was at my request from the builder..its set at 115F..
so soffit/ridge vents don't work as claimed..the build thought it was a dumb idea!
please provide at least one research document from a non ridge vent maker
to backup your claim..fyi I have looked into this matter and have found none!
soffit vents don't help! ridge vents don't either! more insulation in the attic helped more!

think i'm joking..
we installed reflextex($500) insulation on the roof rafters to help the ridge vents..
yet the fan still runs..even when it 75 outside..no I haven't change its temp setting to 15yrs..

so..back your claim with facts..i'd like to see them..prove me wrong..

-dkenny