Why are Positive Air Transients harmful to a DWV system?
A. They can result in the loss of water seals or, at a minimum, contribute to the depletion of the traps. Positive air transients ave been proven to resonate inside of conventionally designed systems up to three days. In addition they can be the source of bubble through; a condition that allows sewer gases as well as pathogens to be introduced in to the living space without loss to the trap seal.
