What size duct does a 5-ton unit need to operate properly?

Using this approach, two 20-in. x 25-in. return grilles will be the right choice for a five-ton HVAC system in order to actually deliver 2,000 cfm back to the blower without causing the return to hemorrhage. Since the conventional wisdom of designing return grilles at 144 sq.in.

How do you know what size ductwork to use?

To calculate CFM, you need to know the size of your heating or cooling unit in tons. Multiply this number by 400, which is the average output of an HVAC unit. Then divide by the total square footage of your home. This will give you the multiplier for all your rooms’ CFM.

How many CFM does a 5-ton unit put out?

The rule of thumb about air conditioning was quoted in our opening statement. The basis for rating self-contained air conditioners is usually this value. We have a 2-ton unit handling 800 CFM, a 3-ton 1,200, a 5-ton 2,000, and a 10-ton 4,000.

How do you calculate duct size for airflow?

To calculate duct sizes use the equation Quantity = Area X Velocity. By calculating duct sizes with this equation it is possible to change duct sizes and maintain the same quantity (CFM) and velocity (FPM) in the duct. However, the pressure loss changes each time the duct size changes.

How many CFM can a 6 duct handle?

A rectangular 6×6-inch duct has an airflow of 110 CFM. Bigger 6×12-inch ducts can handle 270 CFM airflow.

What size duct do I need for 2000 cfm?

Equivalent diameter for rectangular and circular ducts – air flows between 100 – 50000 cfm

How do I know what size flex duct I need?

Measure the length and width of the room where the flex duct will be supplying the air. Multiply the length and width together to get the square footage of the room. For example, a 10-by-10 room will be 100 square feet.

How many CFM can a 6 round duct handle?

How many CFM is a 2.5 ton unit?

For instance a 2.5 ton system (Approximately 400 CFM per ton) would require (2) 14” flexible return ducts or (1) very short flexible 18” duct to move the 1000 CFM required by the 2.5 ton system.

How many CFM is a 6 round duct?

100 CFM
“For example, most techs will tell you that a 6” duct will provide about 100 CFM.”

How many CFM do I need for 4 duct?

What is the minimum duct size for a range hood? The minimum duct size for a range hood is 4”, which is ideal for range hoods 400 CFM and under.

How big should an air conditioning duct be?

A rule of thumb says ducts should carry 400 cubic feet per minute (CFM) of air for every one ton of cooling. So if you have a two-ton system, you need ductwork that will carry 800 CFM. One six-inch round duct is good for about 120 CFM, a six-inch duct carries about 150 CFM, and eight-inch carries about 200 CFM of cool air.

Where can I find a sizing chart for ductwork?

To size the ducts you’re going to need a duct sizing chart. You can obtain these from ductwork manufacturers or from industry bodies such as CIBSE and ASHRAE. If you don’t have one, you can find them in the following links.

How tall should a take off duct be?

Always stagger take-off ducts by 12″ to maintain pressure. Use insulated duct or duct board in unheated spaces. Flexible duct work must be stretched tightly for maximum air flow. Information provided is to be used as a guideline only. Rectangular and Round Duct Rectangular Duct Height (inches) Title Duct Sizing Chart.xls Author Owner

How tall is a Round Round duct in inches?

Duct Size Duct Height – Net inside dimension in inches ROUND DUCT SIZE ESTIMATE RECTANGULAR DUCT SIZE ESTIMATE 14″ 5″ 6″ 7″ 8″ 16″ 18″ 20″ Design Airflow 50 75 110 9″ 10″ 12″ 1300 1700 160 225 300 480 700 1000 Duct Size 5″ 6″ 7″ 8″ 18″ 20″ 9″ 10″ 12″ Flexible Duct Round Metal Pipe 750 1200 14″ 16″ Design Airflow