Case Study

Point West Place - Framingham, MA

Picture of Point West Place

Point West Place is a five story multi-tenant office building located adjacent to the Massachusetts Turnpike in Framingham, Massachusetts.


The building's major mechanical systems included:

4 - 70 ton McQuay Roof Top Air Conditioning Units
2 - Heating/Ventilating Units
Pneumatic Controls

The initial project involved automating the existing mechanical systems to accomplish several goals:

  1. Provide more control than what was available through the existing pneumatic control system.
  2. Decrease operating expenses by optimizing system performance.
  3. Ease the workload of the mechanical maintenance department through automation.
  4. Improve tenant comfort.
  5. Track the building's mechanical performance.
  6. Provide HVAC system overtime operation capabilities by dividing each floor into 4 zones and having separate schedules for each zone.

The first phase of this multiphased project involved the installation of a Delta Controls Intelli-Sys Control System . Approximately 8 space temperature sensors were installed per floor that transmit tenant space temperatures to a Delta Intelli-Con Micro Panel located on each floor. Additionally, four Delta Intelli-Con Micro Panels were installed to control and monitor the four roof-top air conditioners.

The Micro Panels are all connected to a Delta Intelli-Con Turbo Panel located in the basement via a 38.4K RS-485 twisted pair trunk wire. The Micro Panels were selected over standard zone controllers because of their Trend Logging capabilities and free programming capabilities. The Micro Panels on each floor have programming to provide tenant overtime HVAC capabilities by controlling the 8 floor control dampers per floor. When any of these dampers are open, the Micro Panel will cause either one or two roof-top air conditioners to run, depending on the heating or cooling load. These panels also control the static pressure of the discharge air.

The Micro Panels that were used for the four air conditioners are starting and stopping the compressors as well as controlling the outside air dampers. One requirement that was unique to this project was the requirement that the old controllers, Honeywell W7100's, were to remain in place as a means of backup control.

The Delta Turbo is a multi-ported, memory enhanced, dual processor field panel. At Point West Place, the Turbo panel controls several air handling units in addition to the site lighting. The Turbo panel connects to the color host, a system printer, and a high speed modem. The modem is used for off-site diagnostics, data retrieval and operator paging. As the requirements at Point West Place grow, additional Turbo's (up to 250) could be linked together over a proprietary 1,000,000 baud network, Intelli-Net.

Special software was written by R. L. Shields Associates, Inc. to control the outside lighting for the building. Exterior lighting is controlled automatically based on calculated sunrise and sunset times. The software also automatically corrects for daylight savings time. The software and hardware are able to reestablish control of all aspects of operation following power failures without operator intervention.

Software programs are being used to accomplish the following:

Optimum System Start-up
Purge Cycle
Enthalpy Control
Sunrise/Sunset Time Calculation
Automatic Daylight Savings Time Correction
Temperature Prediction
Degree Day Tracking

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.

Future phases of this project will include automating the tenant Variable Air Volume (VAV) Boxes and interfacing to the building's electrical meter with the control system to provide Demand Side Management capabilities.

Links to additional graphics for this project

AIR HANDLER
VAV BOX
TYPICAL FLOOR PLAN

What do the Operators say about the project?

Picture of Ralph Bartlett - MT-2

When I first decided to have an energy management system installed, I was only interested in something other than a time clock starting and stopping my rooftop units.

When Bob Shields from R. L. Shields Associates, Inc. came in representing Delta Controls, he seemed to be the typical salesman with all kinds of promises, but surprisingly, everything he told me we could do with the Delta Controls system was true and then some.

I have floor dampers that I now control. By opening and closing them I can move air to where it is needed on hot days. I'm controlling all my lighting with the Delta System. With the control I have over the rooftop units and the graphical display, I can see a problem and fix it before my tenants even notice it. Before purchasing the Delta Controls system, I would get a call from an unhappy tenant complaining of a problem and then spend half the day trying to troubleshoot it.

I am still finding ways to save money. With this system I am now only running half of my units in the winter and still maintaining the system static pressure by controlling my floor dampers, which I couldn't do before. We just began monitoring Electrical Demand and profiling the building. Soon we'll be able to do some Demand Limiting, which should save some substantial money.

What do I say about Delta Controls... Just try to take it away from me!

Ralph Bartlett, MT-2 - Building Technology Engineers, Inc. - Boston, MA

For more information on this project or Delta Controls, contact:

R. L. Shields Associates, Inc.
27 Wentworth Drive
Bedford, NH 03110
603-472-7431 (Voice)
603-472-7395 (Fax)
rshields@rlshields.com (E-Mail)

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