Cold Air Return In Attic

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 return in attic.

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. 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. Condensation forms when warm humid air comes into contact with a colder surface like your air conditioner s ductwork. They can be placed into staircase cavities stacked closets that run one on top of the other or in stud cavities in the wall.

This pulls the air across your body. 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. 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. 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.

To explain the components of a forced air system. During cold weather gas burners create heat in the heat exchanger image 2 which in turn heats the air. If the supply ducts are in the floor then the return air should be located up high. 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.

At 21c i d guess you have a lot of leaks on the return side. If the supply ducts are high or in the ceiling then the return air ducts or grills should be low on. Cold air returns are sized 1 5 times above the supply capacity to prevent negative pressure in the system. Most of the openings which allow air to escape into the attic can easily be overlooked.

Unlike supply vents return vents do not need to be cased in metal. 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. 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. Do not return air from bathrooms and kitchens.

A fan draws air from the house into the system through return air vents image 1.