My friend needs a new roof on her home. One side of the roof has standard ashalt shingles and the other side, where an addition was built, has a flat roof. Her roofer wants to put in a power ventillator with no ridge vent but I feel that the combination of soffit vents plus a ridge vent is the better way to go. Since he is a professional his opinion has a great deal of weight. What do you think? I will print the responses and show them to her to suggest the best way of dealing with this.