Hvac Return Air Duct Sizing

Particle diameter opening size.

Hvac return air duct sizing. Have to get the air back to the furnace. Air volume equivalent round air volume cfm 4 6 8 10 12 duct inches cfm 50 6 x 4 550 75 6 x 4 675 100 8 x 4 6 x. Particle diameter strainers and filters mesh size vs. Larger volumes or higher static pressures should be dealt with on an individual job basis.

Ventilation systems for ventilation and air handling air change rates ducts and pressure drops charts and diagrams and more. This equal friction method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. 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.

A furnace return system must collect all the air being put out by that system. One thing to remember is that you must have enough supply vents vents blowing air out and return vents vent sucking warm air back in the air conditioner. 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. Properly sizing and installing your air conditioning system are important in making sure your air conditioner operates efficiently according to the u s.

These ductwork tips will help balance your air conditioning and heating system. If the furnace is putting out 1 000 cubic feet per minute of air flow the return system must collect 1 000 cubic feet and take it back to the unit.