Hvac Return Duct Sizing Chart

Use the following formulas.

Hvac return duct sizing chart.

4 tons x 144 square inches return air duct in square inches. Return air ducting is necessary in almost every room. Most technicians are skeptical about these numbers especially on the return air side of the system. Ventilation systems for ventilation and air handling air change rates ducts and pressure drops charts and diagrams and more.

Size of air conditioner example. Never locate ducts at the end of the trunk line run. Calculate the return duct size based on the air conditioner s size and the type of duct you are using. To do this make sure you start at the main duct which is furthest away.

The duct vent size will depend on the size of the furnace and the size of your home so you know how many vents you need in each room. Always stagger take off ducts by 12 to maintain pressure. These ductwork tips will help balance your air conditioning and heating system. In order for your forced air furnace to work properly you have to have the right sizes of duct vents in each room expelling air.

Use insulated duct or duct board in unheated spaces. The furnace s british thermal units btus will help calculate the size it needs. Then we can start to size the main ducts. Duct system sizes and airflow quick chart created date.

Hvac ductwork sizing is critical for proper heating and cooling in every room. Flex duct 05 on most metal duct calculator round metal pipe 06 on most metal duct calculators field duct sizing chart rectangular sheet metal duct 07 on most metal duct calculators duct size duct height net inside dimension in inches round duct size estimate. In order to maintain velocity reduce duct size. Particle diameter opening size.

Then we just add up the volume flow rates for all the branches downstream of this. For the main duct g we just sum branches l and i. Have to get the air back to the furnace. Last take off run to be located 12 18 from end.

While a duct sizing calculator built for a specific type of ductwork is the best possible method for sizing ducts the attached chart can be used in most single story homes with a centrally located unit and reasonable length duct runs. Particle diameter strainers and filters mesh size vs.