Ducting calculator (Metric)




A complete calculator for determining duct sizes, velocities and pressure losses for large or small ducting systems passing either warm or cold air. It is double sided and divided into sections which handle all aspects of duct sizing calculations. It gives answers for either round, square or rectangular ducts.

One section of the calculator gives the velocity in the duct or sizes the duct from any specific velocity requirement.

Pressure Loss
A separate section deals with the pressure loss in the straight portions of the duct.

Pressure Loss in Fittings
On many installations a large proportion of the pressure loss occurs in the various bends, branches and other fittings and a section deals specifically with this giving the loss in velocity heads for a wide variety of fittings and providing scales to convert this to actual pressure loss.

Warm Air Heating
This section gives the volume of air required for warm air heating according to the heat requirements and the temperature differential between warm air and the room. In addition a further section gives the heat loss from the surface of the ducting carrying the warm air.

Duct sizes-up to 100″ diameter and the equivalent rectangular or square.

Imperial or Metric

7-5/8″ diameter

Single sided, 3 colour
Complete in case with full instructions


Start typing and press Enter to search