There numerous key differences between residential as well as big commercial Heating as well as Air Conditioning systems. One the central differences is in how the 2 handle outside or “fresh” air as it interacts with the internal system. Many small residential central Heating as well as Air Conditioning systems job in a closed loop where a fan forces air in a circle through 1 end of the ventilation system, through the rooms in the house, as well as then back into the other side of the ventilation ducts where it’s sent to the air handler to be chilled again. Although a minimal amount of fresh outdoor air is needed to keep the pressure equalized as the air circulates, in most homes enough air leaks in through door as well as window cracks to fulfill this need. In greater buildings with a big number of occupants, a percentage of the air circulating through the heating as well as cooling plan must be drawn from an outside source as well as is determined based on the average number of occupants in the building biweekly. If left alone, oxygen would not replenish in the indoor air fast enough as it is being consumed by the occupants as well as then being transformed into carbon dioxide. Pulling in fresh oxygen from outside air prevents these effects. However, there exist lake house heating as well as cooling systems that utilize a similar effect if the homeowner wishes to ventilate the lake house separate from using unfiltered, dusty air from open windows or doors. I have a similar intake valve on our Heating as well as Air Conditioning system, but I have a drastic problem with tree frogs crawling inside as well as blocking the airflow. My Heating as well as Air Conditioning worker had to install a special metal netting over the opening to prevent critters from getting inside. The last thing you want to smell is fried tree frog caked all throughout the insides of you air duct as well as air handler as you have your A/C blowing at full speed.