# How do you calculate friction loss in a duct?

**duct**. The

**friction loss**is customarily given as

**pressure loss**for a given

**duct**length, Δp / L, in units of (US) inches of water for 100 feet or (SI) kg / m

^{2}/ s

^{2}.

Subsequently, one may also ask, what is friction rate of duct?

**Friction rate** (FR) is the pressure drop between two points in a **duct** system that are separated by a specific distance. **Duct** calculators use 100′ as a reference distance. So, if you were to set the **friction rate** at .

Similarly, how do you calculate static duct pressure loss? Add total elbow equivalents to the length of straight **duct** to arrive at the total system **duct** length. Multiply the **static pressure** for 100 feet of **duct** by the percentage of 100 feet that you have. This will be the **static pressure** caused by the **ductwork**.

Similarly, you may ask, how do you calculate the airflow of a duct?

Traverse the **Airflow** in the Exhaust **Duct** An anemometer, a test instrument that measures air velocity is used to **determine** the average air speed in the **duct**. Then the average feet per minute is multiplied by the area of the **duct** in square feet to **determine the airflow** moving through the **duct**.

How do I calculate friction?

**How to find force of friction**

- Choose the normal force acting between the object and the ground. Let's assume a normal force of 250 N.
- Determine the friction coefficient.
- Multiply these values by each other: 250 N * 0.13 = 32.5 N .
- You just found the force of friction!