Calculating ESP of a duct system

[tsf31]

Hi..

What should be the Factor of Safety to be considered to arrive at the final External Static Pressure of a duct system after adding up the the losses through every straight run and fittings of the critical path?

Is it enough to take into account the pressure drop for the LAST air outlet in the critical path or should I consider ALL air outlets on the critical path?

[frank]

On the index run you only allow for the resistance of the last outlet......ignoring all other outlets.

[tsf31]

Thank you for the response..

What about the factor of safety?

Any help is appreciated..

[Brian_UK]

The factor of safety is surely the accuracy of your calculations.

However, are you asking about the Factor of Safety required when ventilating toxic atmospheres?

[B G Scott]

If this is an application in an industrial environment, get a copy of "Industrial Ventilation" published by the
American Conference of Governmental Industrial Hygienists.
You will find all the recommendations for most applications with design criteria for most fittings you may come across, including most specialist industrial processes.
Duct design is dealt with in detail.