Cold Air Return In Attic

Any water vapor in the warm air rises until it reaches the cold roof deck area at which point it cools and condenses back to a liquid phase.

Cold air return in attic.

A fan draws air from the house into the system through return air vents image 1. Metal and flexible ductwork need to be sealed to guarantee that it is reasonably air tight for maximum efficiency use an approved foil tape or duct sealant. To explain the components of a forced air system. If the supply ducts are high or in the ceiling then the return air ducts or grills should be low on.

The flexible design allows for connection of a new or existing side air return on either side based on the placement of the reinforced sheet metal panel of the return air box assembly. A cold air return is a vent that sucks cold air into a furnace so that it can be heated and brought back to a room through a furnace register. These vents are seen in many types of furnace systems although there are alternatives such as drawing air from the outside or from the area around the furnace. If that return duct is pulling in any outside air then the opposite has to be happening somewhere else in the system ie it is pushing out an equal amount of heated air.

Condensation forms when warm humid air comes into contact with a colder surface like your air conditioner s ductwork. The return vent pulls cold air from the bottom of the room and returns it to the furnace to be reheated and returned as warm air. This colder surface then chills the surrounding air to a temperature below it s dew point which causes the water vapor to condense into a liquid just like on the outside of a glass of iced teas sitting outside on a hot day. A return air temp b outside air temp c airflow across evaporator coil d return air leaks from attic if you measure supply and return temperatures at the grille and at the air handler you can get an good idea of where your biggest losses are occurring.

At 21c i d guess you have a lot of leaks on the return side. Unlike supply vents return vents do not need to be cased in metal. If the supply ducts are in the floor then the return air should be located up high. They can be placed into staircase cavities stacked closets that run one on top of the other or in stud cavities in the wall.

The return air vent openings need to be on the opposite side of the room so the conditioned air is pulled across the room. Cold air returns are sized 1 5 times above the supply capacity to prevent negative pressure in the system. During cold weather gas burners create heat in the heat exchanger image 2 which in turn heats the air. Ensure proper return air flow for your 17 5 ensure proper return air flow for your 17 5 in winchester residential electric furnace application with this easy to assemble return air box.

This pulls the air across your body.