Table of Contents

## What size duct do I need for 3000 CFM?

The biggest 42×12 ducts with 504 sq inch crosssection can handle 3000+ CFM airflow.

### How do you calculate air flow in a duct?

Calculate the duct air flow, or “q,” using the formula: q = v x A. For example, if v is 15 m/s and the A is 8 square meters, q is 120 cubic meters per second or 120 m^3/s.

**What happens if ducts are too small?**

Ducts that are undersized will increase the static pressure, which will result in excessive noise as air moves through the system. It is often loud enough to be distracting, so it will not be difficult to overlook and should be addressed, as undersized ducts overwork the heating unit.

**What size duct do I need for 6000 CFM?**

USING THE CFM/FPM CHART:

Air Volume in Ducts in Cubic Feet per Minute (CFM) | ||
---|---|---|

2000 | 6000 | |

6 | 395 | 1180 |

7 | 535 | 1605 |

8 | 700 | 2095 |

## How do you calculate CFM for a rectangular duct?

Calculating CFM

- CFM = FPM x Duct Cross Sectional Area.
- FPM = 4005 x √.45.
- FPM = 2,686.
- CFM = 2,686 x Duct Cross Sectional Area.
- A (Duct Cross Sectional Area) = X (height in feet) x Y (width in feet)
- A = 1.07 sq. feet.
- CFM = FPM x Duct Cross Sectional Area.
- CFM = 2,686 x 1.07 sq. feet.

### What size heat duct do I need?

The size of your duct work depends not just on the size of your entire house but also on the size of each individual room. Thus, one needs to gauge the square footage of the entire house as well as that of all the different rooms in order to decide duct work sizing.

**How many CFM is a 1.5 ton unit?**

600 CFM

How Many CFM For 1 – 6 Ton Units? (Chart)

Unit Tonnage: | CFMs Required: |
---|---|

1.5 Ton Unit | 600 CFM |

2 Ton Unit | 800 CFM |

2.5 Ton Unit | 1,000 CFM |

3 Ton Unit | 1,200 CFM |

https://www.youtube.com/watch?v=g5NRq8CbAYw