99% of people don’t even realize that the plenum is what actually makes your home feel comfortable 💡 In this video, we’re assembling a plenum — but what exactly is a plenum? A plenum is an essential part of a ventilation or air conditioning system that helps direct airflow properly throughout your home. Simply put, it’s a box or chamber inside the duct system where air is either distributed or mixed. For example, when your air conditioner cools the air, that air first goes into the plenum. From