A new research project, recently implemented by the International Institute of Ammonia Refrigeration, will revisit the economic sizing methodology the industry uses to determine optimum pipe sizing.
The project, expected to be completed in the next year, will provide a computer tool that will allow end users to determine optimum pipe sizing based on input data that includes the initial cost of a piping system, energy cost, life expectancy and refrigeration system operating efficiency.
The concept of economic pipe sizing was introduced to the ammonia refrigeration industry in 1984 by Bill Richards, one of the founding members of IIAR. Richards initially established the capital cost of piping by looking at diameter and length, and provided corrective factors for piping systems with varied costs relative to a baseline value, while also making adjustments for energy costs and hours of usage.
“This project is intended as an update of Richards’ methods,” said Bruce Nelson, IIAR Research Committee Chair and President of Colmac Coil Manufacturing, Inc. “It is a balancing of the initial cost for a facility with the operating costs.”
For example, a facility could use a small pipe that is cheap to install but has a high pressure drop, so operating costs are higher, or they might go to a large pipe with low pressure drops that is more expensive to install but has lower operating costs.
“This computer tool will help facilities make the decision on how much to spend initially and what the return will be on that investment,” said Nelson.