## What size duct is needed for 600 cfm?

6-inch
A 401 to 600 CFM fan requires a 6-inch minimum duct size, with an 8-inch duct recommended. A 601 to 900 CFM fan requires a 7-inch minimum, but an 8- to 10-inch duct is recommended. A 901 to 1200 CFM fan requires an 8-inch minimum, and a 10- to 12-inch duct is recommended.

How do you calculate CFM for duct size?

Duct CFM Calculation Formula

2. 24,000 BTUs ÷ 12,000 BTUs in 1 ton = 2 tons ✕ 400 CFM per ton = 800 CFM.
3. Room A = (2,000 BTUs ÷ 24,000 BTUs) ✕ 800 CFM.
4. Room A = 66.67 CFM.

### How many CFM is a 6 round duct?

CFM Sizing Chart For Flex Round Ducts (50-1,700 CFM)

Duct Size (Inches) Flex Duct Airflow (CFM)
5 inches 50 CFM
6 inches 75 CFM
7 inches 110 CFM
8 inches 160 CFM

What size air duct do I need?

The size of the HVAC unit you’ll need for the whole house can be found using the unit’s average output and the square footage of your home. As a rule of thumb, you’ll need 400 CFM of airflow per ton of air conditioning; it takes about 1 CFM of air to heat or cool 1 to 1.25 square feet of floor area.

## What size duct do I need for 2000 CFM?

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

Air flow – q – (Cubic Feet per Minute, cfm) (m3/s) Rectangular Duct Sizes (inches) (mm) x (mm)
1700 (0.77) 10 x 22 14 x 15
1900 (0.86) 12 x 19 14 x 16
2000 (0.9) 10 x 25 12 x 20 15 x 16
2500 (1.13) 14 x 20 15 x 18

How big does a flex duct need to be?

Flex duct has a higher pressure drop and as such may require the size shown on this guide be increased by 1 round size for up to 800 CFM and 2 round sizes above 800 CFM to insure proper airflow.

### How big is an AC duct sizing table?

ac duct sizing table grille cfm size cfm size cfm size cfm size 50 4” dia 900 3800 20×21 50 6×6 100 4×6 925 3900 75 10×6 150 950 4000 20×22 100 10×8 175 6×6 975 10×15 4100 125 12×8 200 6×8 1000 10×16 4200 20×23 150 225 6×10 1100 12×14 4300 175 12×10

How big is a D duct in HVAC?

not present Duct Size D Design Airflow 5 14″ 7 750 1 16″ 1 1200 1 18″ 1 1500 2 20″ 2 2000

## Which is the correct method of duct sizing?

This “Equal-Friction” method of duct sizing should be adequate for normal residential furnace heating and air conditioning applications. Larger volumes or higher static pressures should be dealt with on an individual job basis. Air Volume Equivalent Round Air Volume CFM 4″ 6″ 8″ 10″ 12″ Duct (inches) CFM.