Not sure of the pitch of the roof, but it's a ranch style house with a metal roof over asphalt shingles. TVA Energy Survey says it needs a ridge vent. Installer thought it had been done but after inspection does not think so. Questions: What could go wrong with doing it now? Does it need to be done? Installer says actic gets vented from old holes where wind turbins were and air coming up through the "V" of the panel.???