Return Air Duct Sizing Chart

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.

Return air duct sizing chart.

Table 4 2 return air duct installation sizes based on 05 inches of pressure drop per 100 ft round duct rectangular duct cfm dia. Hvac ductwork sizing is critical for proper heating and cooling in every room. Calculate the return duct size based on the air conditioner s size and the type of duct you are using. It involves the heat output of the unit measured in british thermal units the air flow from its blower the number of vents and their location and the length of ducts needed to reach those vents.

4 tons x 144 square inches return air duct in square inches. Tees split but do not reduce and an appropriate reducer must be added. Dampers on take off duct runs allow for adjustments of air distribution. Return air cfm must be equal or greater than supply air cfm.

While this may be true in most cases for a metal supply air duct it is not for a metal return nor a 6 flexible duct on supply or return. Air intakes and outlets ventilation systems air intakes and outlets rules of thumbs. 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. Particle diameter strainers and filters mesh size vs.

These ductwork tips will help balance your air conditioning and heating system. Have to get the air back to the furnace. Size of air conditioner example. Duct system sizes and airflow quick chart created date.

Never locate ducts at the end of the trunk line run. Particle diameter opening size. Return air ducting is necessary in almost every room. In order to maintain velocity reduce duct size.

Wxh wxh wxh wxh wxh wxh wxh wxh 80 6x6 7x5 9x4 90 7x6 8x5 10x4 100 7 8x6 9x5 11x4 125 7x7 9x6 11x5 13x4 150 8x7 9x6 12x5 15x4 175 8 8x8 9x7 10x6 13x5 17x4.