According to Emerson, benefits besides the potential for greater energy efficiency include a lower refrigerant requirement, less piping and insulation, and fewer hangers. Distributed systems can also mean shorter installation times, with about a 25-percent reduction in labor associated with piping installation. Commissioning and phasing are more efficient due to smaller dedicated systems, the report states, and the systems offer the potential for lower pressure loss.

Distributed HVAC Systems

To look at the HVAC side of the equation, one also needs to look at the typical approach.

In such a case, a store either has large, central units or traditional packaged rooftop units. Both designs feature significant air distribution (ductwork) to deliver conditioned and return air throughout the store. The fresh air is blended with the return air, and conditioning is based on inside conditions.

Distributed HVAC systems provide a dedicated unit for fresh air, and multiple conventional rooftop units for return air. This design features minimal ductwork and strives for “optimal environmental control throughout the store.”

Benefits listed in the report include lower overall installation costs, improved zone control, reduced ductwork, and reduced structural support requirements. It also cited the greater availability of conventional HVAC units, the potential for reduced construction costs and refrigerant use, and the potential for enhanced performance and energy efficiency.

The Smart Store

In conventional design, said Emerson, “PC-based remote access software provides a direct interface for the energy management system (EMS), which provides a data link to the store. The EMS gathers a limited amount of data on select store components and controllers concerning lighting and HVACR. This design features many isolated components and controllers, which means a large amount of valuable information is inaccessible. This design also requires multiple front ends (interfaces) and underutilizes the EMS.

“A truly integrated store provides browser-based access to an offsite facility-monitoring center, which provides a centralized data warehouse by collecting and mining data from all EMS, chain-wide. The EMS provides wired and wireless connection to all store components and controllers, including compressors, valves, ovens, doors, lighting, HVAC and more. Web-based user interface provides alarm, maintenance, asset and food quality management, as well as energy analysis.”

Features noted include intelligent system diagnostics; preventive and predictive maintenance; centralized dispatch and maintenance services; centralized energy management; and facility-wide data mining.

Benefits cited include better monitoring and measurement capabilities, improved quality of information, chain-wide application of intelligent data analysis, improved maintenance decisions, and wireless networks to reduce installation costs.

Food Quality And Security

According to the Emerson report, in conventional design food quality initiatives and energy and maintenance services are not integrated, nor is the data from these isolated components brought together by a monitoring command center. “This means valuable information is inaccessible and there is limited understanding of how these programs affect each other. Very little attention is also placed on possible food security threats such as terrorism and sabotage.”

The new direction is for “more focus on a total solution for the retail industry. The result is an Integrated Food Quality Program that connects all food quality initiatives and energy and maintenance services technologies to a 24-hour, remote monitoring command center. There is also a greater awareness of and attention to how all these programs are intertwined and affect each other. There is also an increased focus on preventing food security threats such as terrorism and sabotage.”

Features noted include energy commissioning, energy and equipment monitoring, maintenance performance reports, dispatch services, analysis of historical energy usage, food auditing, bacterial growth-based alarming, wireless temperature sensors, 24-hour Web-based monitoring of critical temperatures, and asset management.

Benefits, according to Emerson, include improved product temperature control, increased product shelf life, reduced shrink loss, better food presentation, and decreased maintenance and training costs. According to the report, an integrated plan can provide quick, cost-efficient data retrieval with multiple access points, enhanced decision support for management, and increased accountability for contractors, OEMs, and store personnel. It could also better enable a store to meet FDA and USDA food code requirements and HACCP guidelines.

Advanced Controls

In a conventional design, a distributed control system requires separate modules to manage each store system application. “Low processing power restricts the amount of applications and data that can be managed and gathered. This prevents the stores from acting quickly to improve equipment performance. It is also very difficult to see the ‘big picture.’”

By contrast, new directions provide “technologically advanced controls that manage the entire store system, including lighting and HVACR, from one central location. Enhanced processing power allows a larger quantity of data to be gathered, while onboard Ethernet communications adds the ability to communicate remotely through a variety of configurations. Intuitive user interfaces allow users to navigate screens quickly and easily. Greater emphasis is placed on maintaining a comfortable, healthy indoor environment. These advanced controls are the foundation of integrating store electronics.”

Here the benefits cited include system readings that are more precise, improved performance, user-friendly interface design, and improved communication. Critical information can be relayed more quickly, and the flexible platform is designed to allow for easy expansion.

Publication date: 09/01/2003