Return Air Duct Design

6 tips for good ductwork design.

Return air duct design.

This is the best configuration and mandatory if the unit has a 5 ton blower. The third example shows a return air base beneath the air handler furnace. An hvac return air duct should be in every room except a bathroom and kitchen. Rounded throats on ells drastically improve airflow especially a rounded inside throat.

They should be on interior walls across the room from the supply ducts that should be washing exterior walls with conditioned air the red arrow points to a large wall mounted return air vent. 8 7 rules of duct design acca manual d residential duct systems 9 0. The unico return duct upc 04 xxxx is an acoustical flex duct 10 ft 3 m long. Duct fittings and terminal units.

9 1 distributed return. The return air ducts in an hvac system are especially liable to get taken for granted even though their part in heating and cooling your home is just as essential as supply ducts. And δt being the temperature difference between the designed air temperature and the design return temperature. Square ells return or supply are a bad idea.

Just to note that we will use a cp of 1 026 kj kg k as standard and the delta t should be less than 10 c so we ll use 8 c. It plays a vital role in the home s forced air heating and cooling system performing its job quietly and without much attention. The furnace or air handler ahu in the drawing below pulls air through the return ducts conditions that air and then sends it through the supply ducts back into the house. 10 3 fire and smoke dampers.

9 3 pressure balancing. 10 2 volume control dampers. The furnace or air handler is probably on the other side of the wall. Not providing enough returns is a common ductwork design flaw that leads to comfort complaints.

The problem with bedrooms occurs in houses where the hvac design did not include return vents in each bedroom. A person can be forgiven for not knowing much about their home s air duct system. Duct sizing duct calculation duct design energy efficient ductwork design. To maintain balanced air pressure and air movement your duct system needs return vents for air in the room to be pulled back into the hvac system.

Each one in a system can add as much as 80 to the tel. 9 2 central return. Return duct systems. This duct does an excellent job of absorbing sound from the blower.