I have had a problem with ice build up on my roof. This happens where there is a valley on the roof with a skylight near the valley. I have installed 2 whirlybird vents but the problem still exists. The roof has soffit venting all around as well as vents on the gables. I read an article on Solar powered roof vent, Solar Star. Are these vents beneficial and would they stop the ice from building up during winter?