Case Study

125 Cambridge Park Drive - Cambridge, MA

125 Cambridge Park Drive is a six story multi-tenant office building located adjacent to Rt. 2  in Cambridge, Massachusetts, near the Alewife MBTA Station.

The building's major mechanical systems include:

The initial project involved replacing the old EMS system since it was approximately 10 years old and parts were very hard, if not impossible to obtain. While updating the equipment, management put forth a list of goals that they wanted to accomplish during the replacement. These included:

1. Minimize operating and energy expenses.
2. Track the buildings mechanical performance.
3. Automate the present zone control system.
4. Maintain the integrity of the pneumatic control system for back-up control.
5. Install a Graphical Operator Interface.
6. Reduce the operator workload in the day-to-day operations of the HVAC system.

The first phase of this multi-phase project involved the installation of a Delta Controls Intelli-Sys Control System to replace the old EMS systems. Two space temperature sensors were installed per floor that transmit space temperatures to the Delta Intelli-Con Turbo Panel located in the Mechanical Penthouse.

The two Delta Turbo Panels control the following:

Each Delta Turbo Panel is a multi-ported, memory enhanced, dual processor field panel. At 125 Cambridge Park Drive, Turbo #1 connects to a printer and color host computer located in the Maintenance Office on the First Floor. Turbo #2 is connected to high-speed modem located in the Mechanical Penthouse. The modem is used for off-site diagnostics, data retrieval and operator paging. The two Delta Turbo Panels share information over a proprietary 1,000,000 baud network, Intelli-Net.

Special software was written by R. L. Shields Associates, Inc. to accomplish several of the tasks designated as goals. Custom software included:

1. Demand Side Management Software - This software is used to calculate the electrical demand, consumption and projects demand based on a minute by minute calculation. This enables the computer and operator to make changes in operation to avoid setting demand peaks. At 125 Cambridge Park Drive, demand is approximately $10.00 per kilo watt in the winter months and approximately $27.00 per kilo watt in the summer months. A reduction in the peak kilowatts of 100 in the summer can result in a monthly savings of $2,700.00. This software also unloads the static pressure in the building while starting the chillers. This reduces the initial demand spike. To better understand Electric Demand, click here.
2. Building Performance Tracking Software - Software was written take the trended information and store it on the hard drive located on the PC in the Maintenance Office. This includes electrical demand and consumption information, temperature data and other items that the maintenance personnel thought was important and storing it in a database. This database has some custom software that allows for automatic creation of management reports using the standard spread sheet programs.
3. Sunrise/Sunset Time Calculation - This controls the parking lot and building exterior lighting based on Sunrise and Sunset. The eliminates the problems associated with power failures skewing the time clocks and provides for the adjustment to Daylight Savings Time and Daylight Standard Time.

As previously mentioned, the Delta Turbo Panel is connected to a color host PC. The host system features Delta's IGRAPHW software. This "state-of-the-art" software package provides the user with both text information as well as providing a graphical interface. This software is also installed on the mechanical staff's personal computers to be used for off-site, after hours, operating changes. This helps the management company resolve problems and avoid some of the after hours call-ins. The maintenance staff has the ability to view all data and graphics from their home computers as they would see from their on-site computers.

Phase 2 was installed in 1997 to control the exterior lighting using custom software the calculates the times of Sunrise and Sunset.

Future phases of this project will include automating the tenant Variable Air Volume (VAV) Boxes, adding DDC to the chillers and Air Handlers, and adding Carbon Dioxide sensors to monitor indoor air quality.

What do the Operators say about the project?

"The Delta Controls system installed by R. L. Shields Associates made my life much easier.  I managed 3 buildings that had Delta systems in them.  The information and control that the system provided reduced dispatches and allowed us to correct potential problems before the tenants called us to complain.

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Intelli-Sys, Intelli-Con, Intelli-Net, and Intelli-Stat are trademarks of Delta Controls, Inc.