The following article was published in ASHRAE Journal, November 2007. ©Copyright 2007 American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. It is presented for educational purposes only. This article may not be BACnet Today copied and/or distributed electronically or in paper form without permission of ASHRAE.

Aculight, a laser manufacturer in Washington, is using BACnet to provide precise temperature and controls to its cleanrooms. BACnet® for Cleanrooms By Terry W. Hoffmann (1858 m2) of additional space over its previous facilities. ACnet and open communications protocols have revolution- In the larger Bothell facility, Aculight wanted to install new building systems. Bized building systems. Facilities no longer need to choose However, the state-of-the-art industrial complex posed unique challenges. Labo- among single-vendor, proprietary packages that may or may not ratories had to be enclosed to contain po- tentially hazardous high-powered lasers. provide the desired functionality at an affordable price. They can Cleanrooms required continuous tuning to maintain pressure, temperature and select equipment from a variety of vendors to achieve the desired humidity. Facility managers requested level of control. All this can be done at a reasonable cost without centralized, remote monitoring and control so they would not have to adjust sacrificing interoperability. controls in these areas. Engineers designed a solution based on Aculight is a 13-year-old company single Bothell, Wash., complex. The new that develops and manufactures lasers building houses administrative offices, About the Author for industrial, military/aerospace and research laboratories and manufacturing Terry W. Hoffmann is director of marketing, medical applications. In 2006, Acu- space. Aculight renovated the facility, which Systems at Johnson Controls light consolidated two facilities into a provided the company with 20,000 ft2 in Milwaukee.

November 2007 B A C n e t ® Today | A Supplement to ASHRAE Journal B 1 5 the BACnet protocol and BACnet Testing Laboratory (BTL) certified devices. The solution effectively integrated new and legacy systems from multiple vendors. It allowed a relatively small but rapidly expanding company to incorporate interop- erable and expandable building systems without sacrificing advanced control technology.

A Demanding Facility Aculight, with 85 employees, is doing high profile work for the commercial and government sectors developing and manu- facturing four categories of laser technology: • Medical lasers; • Infrared countermeasures for use in defense; • High-powered lasers for industrial and military use; and • Active imaging lasers for use in developing three-dimen- sional maps. Ceiling-mounted HVAC equipment serving the production area. Aculight, originally focused on research and development, during the past four years transitioned its technology into prod- maintain comfortable and safe working conditions, Aculight had ucts and begun manufacturing. The move meant investing in a installed two rooftop units in the original facility. In the new manufacturing space. renovation, these had to be integrated into the overall solution. In 2006, Aculight began construction to expand its combined Since Aculight works on dozens of different laser projects and administrative and research facility with a manufacturing cen- the heat produced from each laser is highly variable, continuous ter. The expansion increased the facility’s total square footage adjustment is needed to keep temperatures within an accept- from 27,000 ft2 (2508 m2) to 47,000 ft2 (4366 m2). Contractors able range. Previously, this was a manual operation. Personnel took the opportunity to update obsolete building controls and adjusted in-room controls to maintain comfort. install systems that better supported the company’s operational Aculight wanted a system featuring continuous adaptive control needs. to maintain consistent indoor environments automatically. As project engineers began designing a solution for Aculight The inclusion of Class 1000 cleanrooms in the renovated on a BACnet backbone, facility operators had a variety of non- facility imposes special demands on building controls. Com- standard requirements and concerns. For laser safety reasons, mon in manufacturing and scientific research, cleanrooms have Aculight’s research, development and manufacturing floor is a controlled level of environmental pollutants. Special filters not one open space. Rather, it contains a number of enclosed remove dust and other particulate matter from outside air en- spaces including cleanrooms. Each space has separate climate tering the room. Inside air circulates through high-efficiency control requirements. Aculight requested a building manage- particulate air (HEPA) and ultra-low penetration air (ULPA) ment system that could reliably monitor and control a variety filters to remove contaminants. Cleanroom HVAC systems usu- of separate zones and enclosures simultaneously. ally also control humidity to low levels. “Class 1000” refers to Previously, laboratory spaces had in-suite climate controls, U.S. Federal Standard 209E, and denotes the number of particles requiring facility managers to “suit up” in lab coats, hairnets, of size 0.5 µm or larger permitted per cubic foot of air. booties and laser safety glasses prior to entering the laboratory; The rooms stay “clean” by maintaining higher atmospheric a time consuming practice. “Employees were always making pressure inside than out. When a door opens, it creates a vacuum their own adjustments to the controls,” said Ken Bean, Aculight’s that sucks particulate matter out of the cleanroom rather than director of manufacturing operations. “Just when we thought we allowing it to enter. Maintaining constant atmospheric pressure had a handle on a room’s environment, it would be out of whack also requires continuous adaptive tuning. Pre-renovation, the again.” To enable remote monitoring and control, Aculight asked facility did not have control systems capable of continuous for a centralized climate control system that allows adjustments monitoring and adaptive tuning. The addition of Class 1000 to be made from a single all-encompassing user interface. cleanrooms made installing advanced control technology in A number of other variables made maintaining internal the facility imperative. environments challenging in the prerenovation facility. Met- ropolitan Seattle’s climate is characterized by fluctuations Affordable, Customized Solution in outside temperature and humidity. Meanwhile, inside the Project engineers recognized that the manufacturing and facility high-powered lasers produce large amounts of heat. To research performed at Aculight made advanced control tech-

B 1 6 B A C n e t ® Today | A Supplement to ASHRAE Journal November 2007 nology compulsory. As a small company, maintains optimal indoor environments Aculight did not have the financial re- with continuous adaptive tuning. If a sources for a building project on the scale laser begins to radiate large amounts of larger industrial facilities or large-scale of heat, sensors detect the temperature projects in the commercial, health-care or change and controls notify the chiller education sectors. It would be difficult to and air handling system to pump in find a proprietary, single-vendor solution chilled air. When a cleanroom door that fit Aculight’s demands for advanced opens, releasing some of the pressure control and interoperability at an afford- built up within, controls compensate to able cost. bring air pressure back to the desired BACnet gave Aculight the freedom psi. All of this is accomplished through to customize a solution using equip- intelligent data exchange between ment from a variety of vendors. They BACnet sensors, the building man- were able to select the right amount of agement system and field equipment control technology to suit their unique controllers. requirements and did not have to sacrifice As an added benefit, interoperability Advertisement formerly in this space. interoperability for robust monitoring means the building management system and control. can collect trend data from sensors and Previously, building automation con- controls throughout the facility. The data trols communicated with building sys- helps facility managers identify equip- tems and equipment using a proprietary ment that needs maintenance or replace- protocol. The new solution made data ment. It also enables regular recommis- available as BACnet information. As sioning. Systems can be reprogrammed a result, Aculight was able to ensure to take advantage of observed trends. For seamless integration between third-party, example, the rooftop and other multivendor equipment including: equipment may idle during times when • New and legacy rooftop units; manufacturing activities are typically • A new air-handling system; and on hold. • Equipment for cleanrooms includ- When systems share data via the ing split-system , BACnet protocol, they operate more and supply fans. intelligently and efficiently. Aculight The solution devised for Aculight was estimates that it is saving 23% on energy also a building management system that costs thanks to intelligent, interoperable is capable of monitoring and controlling a building systems. BACnet technology large number of unique climate zones. “If helps buildings contribute to business I get a call from an employee saying his outcomes in three ways: by making workspace is a little chilly, I can call up a buildings “smart,” reducing energy and floor plan, get a precise temperature reading other operating costs, by enabling invest- from the workspace and make adjustments ments in the best and most cost-effective without affecting any other zone within the equipment regardless of vendor and by facility,” said Bean. enhancing operations. The system also delivers single-session Aculight’s new facility has been in monitoring and control for cleanrooms, operation since January 2007. Company overheated manufacturing spaces, labo- leaders are pleased with how well BAC- ratories and offices. The user interface is net systems and devices operate as an Web-based and can be accessed from any integrated whole. Open data protocols computer with an Internet connection. enabled a solution customized enough for Aculight benefits by having single-ses- the facility’s unique demands and cost- sion access to monitor and control all effective enough for its budget. Aculight building systems and equipment. got the precise level of control technology The system monitors temperature, pres- it needed, at a reasonable cost, without sure, humidity and overall air quality. It sacrificing interoperability.

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