Creating and Installing Proper Ventilation for Your Roof 

Insulate those lines if they are easily accessible. Then maybe more blownnin insulation.

Your interior walls aren’t air tight and conditioned living space is not airtight.

Through leaks between the 2 spaces like plumbing runs, sewer venting, electric runs etc. pulls air from those types of openings

What he said makes perfect sense. The theory behind attic ventilation is to draw air up from the soffit to cool the roof. Common sense says that a cooler roof means a cooler attic. By having a vent in the side of the gable, air will be drawn in from there. The roof will remain hot. While there will be some cooling in the attic it is not going to work nearly as well.

​@@mikem1436 i understand how soffit vent works. But how is the air drawn from gable vent any hotter than from the soffit? His short circuit concern is not applicable as the air movement is a continuous on going process. Not like the vent can only draw certain amount of air volume and it must be optimized. Correct, gable vent might not be effective compare to other methods, but it's definitely still better than no gable vent at all.

Soffit gable and ridge vents don't work well together. I had that configuration when they reroofed my house. Heavy rains leaked in through the ridge vent. Once I blocked off my gable vents never had issues. Plus the external baffle ridge vent with open soffits keep my attic less than 20 degrees hotter than ambient temperature year round. There's websites like green builders that explain the science behind venting. Took me a lot of research to figure out but I'm happy I didn't waste money on an attic fan. If I did, I'd still have a hot attic that gets "cooled off" Now, my attic doesn't even hit that temperature most of the time and in winter it's not 40 degrees hotter which wouldn't be high enough to trigger it in that instance. Pretty much everything this video is saying is correct.