Hvac Return Duct Sizing Chart

Then we can start to size the main ducts.

Hvac return duct sizing chart.

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 opening size. Last take off run to be located 12 18 from end. 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.

The furnace s british thermal units btus will help calculate the size it needs. Use insulated duct or duct board in unheated spaces. Flexible duct work must be stretched tightly for maximum air flow. Return air ducting is necessary in almost every room.

Duct system sizes and airflow quick chart created date. Particle diameter strainers and filters mesh size vs. Calculate the return duct size based on the air conditioner s size and the type of duct you are using. These ductwork tips will help balance your air conditioning and heating system.

Air intakes and outlets ventilation systems air intakes and outlets rules of thumbs. Ventilation systems for ventilation and air handling air change rates ducts and pressure drops charts and diagrams and more. 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 for your forced air furnace to work properly you have to have the right sizes of duct vents in each room expelling air.

Always stagger take off ducts by 12 to maintain pressure. For the main duct g we just sum branches l and i. Hvac ductwork sizing is critical for proper heating and cooling in every room. Use the following formulas.

Ductwork chart main duct flow rates. Never locate ducts at the end of the trunk line run. Most technicians are skeptical about these numbers especially on the return air side of the system. In order to maintain velocity reduce duct size.

4 tons x 144 square inches return air duct in square inches. Have to get the air back to the furnace.