A few years ago I purchased a 1928 brick home with a pyramid hip roof. It has a power vent near the peak. Soffit venting appears to be limited. The soffit was replaced with aluminum which includes some foot long lengths of vents, two each on the north, east, and west sides, and three on the south side. The house is 28x28. Some of the soffit vents had been covered by loose insulation which I corrected. But it is my sense there is not enough air flow in the summer. Is there a formula for determining the proper amount of soffit vent area?