Engineering tool

Air Velocity Calculator

Calculate air velocity in m/s for your cold storage or refrigeration room. Enter room dimensions, fan flow rate, and airflow direction β€” get the velocity in seconds.

Open the calculator How it works

Overview

The air velocity calculator computes the airflow speed across the cross-section of a refrigeration or cold storage room. It takes the fan flow rate (mΒ³/h) and divides it by the cross-sectional area (chosen based on airflow direction) to give the velocity in m/s.

Correct air velocity matters: too low and you get warm spots and uneven cooling; too high and you risk dehydrating perishables or oversizing the fan. For blast and ultra-rapid freezing, high velocities are required to drop product temperature fast enough to control ice-crystal size.

How it works

  1. 1Enter the room dimensions: length, width, height (in meters).
  2. 2Enter the total fan flow rate in mΒ³/h.
  3. 3Pick the airflow direction (length-wise or width-wise) β€” this selects which face of the room is the cross-section.
  4. 4Submit. The tool returns the average air velocity in m/s.

Inputs explained

  • Room dimensions. Length, width, and height of the conditioned space in meters. Use internal dimensions, not external structural dimensions.
  • Fan flow rate. Total airflow delivered by the fan(s) in cubic meters per hour. Sum all evaporator fans serving the same space.
  • Fan direction. Choose Length if airflow runs along the long axis of the room (cross-section = width Γ— height); choose Width if airflow runs across the short axis (cross-section = length Γ— height).

Limitations & disclaimer

The tool gives an average bulk velocity for an empty room. Real installations have product, racking, evaporators, and ducting that perturb the airflow locally. Use this as a sizing starting point and verify with field measurement or CFD where critical.