There remains one area of continued uncertainty in system modeling--the determination of the usage pattern of any system.
Issue: 7/01
In previous columns, I have described the advances that we have been able to make in the modeling of the water and entrained air flows in building drainage and vent systems. These advances are reliant on a better understanding of the mechanisms of drainage flow and the availability of fast and accessible computing. However, any model predictions are only as good as the data that defines both the system and its operational regime. Defining the system is generally not a problem. Pipe sizes and appliance data are either readily available or measurable. Problems may arise in confirming installed pipe gradients against those defined by the system designer; however, these difficulties may be overcome by the system analyst, or the sensitivity of any prediction to these parameters may be determined.