Home Improvement

3000CFM is probably too much. Your exhaust needs to match your soffit intake in terms of how much air they move. You can't just exhaust air without replacing that air. Find a roofing contractor and not a handy man. If you're forcing 3000CFM out and your soffit vents combined allow for 1000CFM, there are still 2000CFM that need to come from somewhere and it could start coming from your conditioned space through air leaks from things like light fixtures and drywall gaps.

It sounds like you're wanting to vent the attic to cool the house? If so, insulation is your best bet. Yes it may also prevent you from gaining heat in the winter from the sun, but it will also keep the heat from your HVAC inside which is way more efficient than relying on an insignificant amount of heat from a winter sun. We recently increased our insulation to R50 and it has helped lower our bills and equal out the temperature of the house