Case Studies

Case Study: Refrigeration and HVAC Electronic Monitoring and Controls system, Emergency Back-Up Generator and Utility Rebates.

Dairyland, U.S.A.
Hunts Point, Bronx, NY

Dairyland, U.S.A. Finds ‘Greener’ Pastures

In the year 2001, as it is today, Dairyland, U.S.A. was a successful and growing, wholesale food distribution company that serves virtually all of New York City’s and the northeast’s finest restaurants. Based in the Hunts Point section of the Bronx, the company employs 280 people in the food service industry. To meet its customers needs for high quality, good tasting food, Dairyland, U.S.A. operates a 110,000 Ft.2 warehouse with over 22,000 Ft.2 of refrigerated or freezer space. To move the food in and out of these chilled and unchilled spaces, Dairyland, U.S.A. uses battery-powered, electric fork lifts. The good news for Dairyland, U.S.A. back in 2001 was that their business was growing so fast, they were going to need to expand their warehouse space.

The Problem with Success

As the point person for day-to-day operations, Dairyland, U.S.A.’s Brian Adair is keenly aware of what it takes to keep the operation in ‘ship-shape’. One thing that stood out on his radar screen was the company’s cost of electricity. “I saw the bills going up each month, for both demand and usage. I also knew we needed more space and was afraid of the impact energy costs would have on our growth”, said Mr. Adair. “Plus, I read the newspaper and I knew 3 years ago that NYC was facing severe shortages of electricity. With our freezer and refrigeration load, a black-out could be devastating to our business.” Hence, Dairyland, U.S.A. began to seek out a comprehensive energy solution.

Working with the Pros

Bob Bradley is the President of 1st Rochdale’s fuel oil subsidiary, Twin Pines Fuels. Based in the Bronx, Bob made a sales call to Dairyland U.S.A. When he discovered their needs were with electricity, he called in Tom Thompson of 1st Rochdale’s Green Apple Sustainable Energy Group. “The first thing we do when we get a call for high energy costs is to take a look at the billing history and develop a usage profile.” According to Thompson, that analysis confirmed what Brian Adair told him – Dairyland U.S.A.’s usage, demand and costs were rising.

A walk-thru energy audit of the facility with 1st Rochdale’s refrigeration consultant Jack Davidoff of Energy Consulting Services revealed that the performance of the control system as well as the compressors for the chilled spaces was not operating as efficiently as possible. This gave the 1st Rochdale team the information it needed to develop an energy plan that would save money, strengthen reliability and help clean the air.

Developing an Effective Energy Action Plan

Energy Consulting Services developed an action plan that put real time energy information in the hands of Dairyland U.S.A.’s operations chief, Brian Adair. The plan included:
  1. Mechanical improvements to the operation of the compressors,
  2. Electrical and operational improvements to allow ‘off-peak’ battery charging,
  3. Installation of a Danfoss electronic refrigeration control system that more efficiently monitors the temperature in the chilled spaces and the operation of the compressors,
  4. Installation of more efficient lighting and lighting controls that took advantage of natural daylighting available at the site, and;
  5. A ‘Smart Metering System’ that includes a computerized energy management system (manufactured by Danfoss) and a electricity usage data logger that give Dairyland U.S.A. the ability to isolate, monitor and curtail pre-selected loads at critical times of the year.
Further, 1st Rochdale applied for and received incentive funding from the NYSERDA to install the computerized energy management system and worked out a financial arrangement that provided Dairyland U.S.A. with a favorable without limiting existing lines of credit.

The Proof is in the Pudding

At the time this project began, Dairyland, USA had a peak load of approximately 460 kW and annual consumption of 2.5 million kWh. Business growth has resulted in the need for additional cooling, battery charging and lighting capacity. As a result, the facility load was expected to grow at the time 1st Rochdale was called in.

After installation of the energy improvements, Dairyland, U.S.A. has been able to reduce demand by almost 200 KW/month while their ability to control their energy usage and bills has dramatically increased. The installation of the system also gave them the ability to curtail predetermined loads when electric supplies are constrained in NYC. These load reductions are identified in the table below.

Dairyland, USA: Where the Savings Come From

Source of Savings Demand Savings kWh Savings Annual $$Value
Refrigeration 200 kW 295,000 kWh/year $81,000
Battery Charging 120 kW N/a $7,000
Lighting 15 kW 50,000 kWh/year $6,000
Tax Benefits N/a N/a $26,000

Financial Performance

The EMS paid for itself in just over 1 year while saving Dairyland, USA more than $1,000,000 over 10 years while providing Dairyland, USA’s management team with the ability to monitor and control their refrigeration systems from remote locations and receive a security call if temperatures in the space are outside normal operating ranges. This reduces the likelihood of food spoilage, increasing the value of inventory and improving Dairyland, USA’s bottom line. As a result, 1st Rochdale Cooperative Group Inc. used new, ‘energy smart’ technology to help its customer, Dairyland, USA, reduce its energy costs and improve the quality of their product while improving grid reliability and reducing emissions from their operations.

Danfoss Electronic Monitoring & Control EMS Specification Information

This system provides for:
  • Electrical Demand Limiting
  • Refrigerated Temperature Control
  • Refrigeration Defrost Monitoring & Control
  • Refrigeration System Evaporator Control & Monitoring
  • Refrigeration System Compressor Status & Pressure Monitoring (all compressors)
  • Zoned Demand Limiting (i.e., Office HVAC)
  • Time of Day Control and Battery Charger Demand Limiting
  • Partial Lighting Control
  • Monitoring & Alarming
Detailed System Specification and Narrative – Dairyland, USA Inc.
  1. Limiting the amount of Electricity being used in a 15 minute Electrical Demand Window: The Danfoss system monitors electrical demand through the primary utility service meter, located at the service entrance to the building. The Danfoss system instantaneously measures incoming electrical demand and predicts electrical demand for the coming 15 minutes to facilitate a pro-active response that allows the controller to maximize electrical demand savings in real time.
  2. More Accurate Refrigerated Space Temperature Control: The Danfoss electronic space temperature sensors are highly accurate and self-calibrating. The Danfoss electronic temperature control provides a 2-degree, ‘start & stop’ temperature range for refrigeration systems. This eliminates overcooling of the space and increases the refrigeration system efficiency. The existing mechanical refrigeration thermostats typically have a ‘turn on/turn off’ range of up to six degrees Fahrenheit. This wide spread in temperature causes the existing mechanical space thermostats to be set lower than the Danfoss electronic space temperature controller must be set at. This means that more energy is required to assure the same temperature, due to the fact that that the refrigeration system must operate longer than it needs to with a more precise means of establishing and regulating the required temperature that is provided by the Danfoss. Further, when the refrigeration system over cools a space, it accelerates the transfer of cool air to the outside spaces through the walls and ceiling. Finally, as the refrigerated space temperature decreases, so does the efficiency of the compressor(s), which cause even greater, wasteful energy use.
  3. Limiting the Evaporator Fan Motor Run Time: The evaporator fan motors consume large amounts of electricity in two ways. When the fans are operating, the motors use electricity. They also produce heat that the refrigeration system must ultimately remove. The Danfoss controller program turns the evaporator fans ‘on and off’ with the refrigeration system. An electronic ‘off delay’ allows the Danfoss controller to take advantage of all of the refrigerated air within the evaporator before turning off the evaporator. Another Danfoss control program prevents stratification of the air within the refrigerated box by monitoring the run time of the evaporators and turning the fans on to mix the air if the fans did not run in the previous 30 minutes.
  4. Compressor Status Monitor: Allows the user to see the status of the compressor from a PC.
  5. Monitoring Refrigeration Compressor Head Pressure: Higher than normal refrigeration compressor head pressure causes the compressor to work harder, increasing wear and tear as well as electricity consumption. Electronic head pressure transducers constantly monitor the refrigeration system head pressure and send an alarm signal when the pressures are outside of the normal operating range. This informs the EMS service provider &/or the facility management of a minor refrigeration problem (e.g., condenser fan motor failure, dirty condenser coil) before it causes excessive compressor wear, increased electrical consumption, safety limit trips, and/or compressor failure. Any of these events could result in a catastrophic product loss. This is a major liability for most customers and serves as the primary motivation for the installation of this system.
  6. HVAC Demand Load Control/Time of Day Savings: The HVAC controls offer time of day temperature control with demand load control. This reduces energy usage when the offices are not being used and when peak electrical usage periods are detected by the Danfoss system.
  7. Battery Charger Demand and Time of Day Control: This allows the forklift battery chargers to be automatically turned off when peak electrical usage periods are detected by the Danfoss system.
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