When an ejector vent is connected to the building venting system, how is the additional load on the vent pipe calculated?

The correct answer, which involves converting the gallons per minute (gpm) discharge rate into fixture units, is based on the principles of plumbing design and vent systems. In plumbing, the venting system is designed to equalize pressure within the drainage system and prevent siphoning, which can lead to drainage issues.

When an ejector vent is connected to the building's venting system, the additional load imposed by the ejector pump must be considered to ensure that the venting system can adequately manage both the air and the liquid waste it will carry. Each plumbing fixture has a defined load in terms of fixture units, which represents the demand on the drainage system.

By converting the gpm discharge rate of the ejector pump to fixture units, you can assess how much additional capacity is required in the venting system. This conversion is essential for maintaining proper ventilation and preventing any potential backpressure that may affect system performance.

The other options do not directly address the question of how to quantify the additional load that an ejector vent adds to the vent system:

• Measuring the diameter of the vent pipe does not account for the flow characteristics or the load requirements of the ejector.

• Assessing the total volume of the ejector basin is not