Hi, I'm new. I'm High Desert Man from NM. I just installed a vent hood in kitchen that has about 13 feet of 5 inch ducting; it's a straight run. I placed a vent cap on that is round and has horizontally cuts around the perimeter. This morning we have high east canyon winds (normal) and I hear the roar of the wind throughout the house. Any suggestions on a special type vent cap or anything else that might reduce the windy noise? Many thanks to all y'all professionals out there that take time to answer these type questions!!
Do both the hood vent and the roof vent have dampers installed? They should. While a stiff wind might lift the roof damper, the hood damper generally stays closed. If both dampers are indeed in place, I would call the hood manufacturer and ask for recommendations.
If the ducting runs through an attic you might install an inverted "Y" piece with it's own damper gasketed on the attic side. When the wind draws across the roof vent the "Y" damper would pull open and draw attic air instead of hood air. When the fan was operating the damper would be pressed closed by the air pressure of the fan.