Commissioning could save 25% – ASHRAE

USA: ASHRAE has produced a new commissioning guide that it says could result in energy savings of up to 25% in supermarket refrigeration systems. 

With studies showing that refrigeration accounts for 60% of the energy use in US supermarkets, the new guide – Refrigeration Commissioning Guide for Commercial and Industrial Systems – provides help in commissioning custom-engineered commercial and industrial refrigeration systems.

“Custom refrigeration systems are complex and individually designed for each facility,” says Richard Royal, who served as chair of the committee that wrote the guide.

“Deficiencies in the system design found at start-up are not easily resolved and, as a result, maintenance managers or operators deal with unnecessary shortcomings and expenses over the life of a facility. The value of commissioning is to establish a consistent stepwise process that helps ‘get it right the first time,’ resulting in refrigeration systems that ‘work right’ and minimize maintenance and energy costs,” he added.

The US Environmental Protection Agency estimates that supermarkets typically use approximately 3,000,000kWh of electricity per year, with 60% of that energy use attributed to refrigeration. It is estimated that commissioning in existing grocery stores would result in energy savings of 7-25% per year.

“Thousands of refrigeration systems are installed every year in facilities ranging from convenience stores to large, sophisticated frozen food distribution centres,” Royal said. “Properly commissioned systems reduce energy cost, are easier to maintain, help minimise liabilities from refrigeration leaks and reduce loss of product to system failures or unreliable performance.”

Royal noted that commissioning of refrigeration systems is uncommon in the industry. One reason is a belief that commissioning results in added cost and time without sufficient or measureable value.

“Certainly, commissioning is an investment, but it provides significant financial value in several ways,” he said. “First, systems operate more reliably with lower maintenance cost and lower energy cost when commissioning is applied as described in this guide. Second, incorporating commissioning can reduce first cost through improved understanding of system performance and lead to better equipment design and installation methods.”

Also included in the guide is information on commissioning during planning and design; construction and installation; and system start-up and first-year operation. A matrix helps delineate roles and responsibilities. Examples of commissioning checklists and acceptance plans can be used for reference or template.

The book is available for free download at www.ashrae.org/freeRefCxGuidance.