HASTINGS, MI — To complement its state-of-the-art medical facility here, Pennock Medical Center selected a state-of-the-art building automation system (BAS) that incorporates a LonWorks®-based solution from Echelon.

The 88-bed hospital presents a highly demanding environment for HVAC and lighting, ranging from operating rooms to a near Olympic-sized pool and fitness center.

Managing such a complex infrastructure, and managing it within a tight budget, is an ongoing challenge. What the facility needed was a BAS that could simplify maintenance and minimize costs.


The hospital had upgraded an aging pneumatic building control system to a “Metasys” direct digital control (DDC) system from Johnson Controls in 1993. While an improvement over the old pneumatic BAS, relying on a closed proprietary system concerned Mike Strimback, the maintenance supervisor at Pennock.

“With a proprietary system, we were tied to one supplier for all parts and technical support,” he commented. “Response was sometimes a problem, because Pennock is not the largest hospital, and we’re not always at the top of the supplier’s to-do list.”

System reliability was also a concern, said Strimback. “The DDC had a single dedicated PC that distributed all the data. If we had a software glitch or a power interruption, which happened on occasion, the whole system would go down. Without that head-end, it wouldn’t operate.”

In 1997, Strimback took advantage of a planned retrofit of several hot water heating converters in the surgery penthouse of the main hospital building to introduce LonWorks technology, a nonproprietary architecture designed to provide an open network to which many systems can be integrated.

The maintenance supervisor turned to Johnston Services Inc. of Alto, MI, which had a working relationship with the hospital dating from 1990. Johnston Services, an Echelon-authorized network integrator and member of the Open Systems Alliance, has integrated more than two dozen LonWorks-based systems since 1997.

A year later, a major expansion of the Professional Office Building (POB) across the parking lot from the adjoined hospital and physician’s building provided an opportunity to expand the open network. The POB would be doubled in size, adding a fitness center, gymnasium, and 21- by 75-foot, 55,000-gallon pool to the existing office space.

The energy-intense needs of this mixed-use facility would truly test the capabilities of the controls system. The office space would be a snap, but the fitness center had to be kept very cool, the pool water warm, and the air around the pool cool and dry. “The equipment has to run hard to maintain a comfort level,” said Bill Johnston of Johnston Services.

Prior to installation, the hospital projected that the new controls system would pay for itself within 15 months. There is no doubt that the system has met and surpassed its goal. Although the POB facility expanded from 22,000 to 43,000 square feet, the cost of utilities has remained the same, dropping from 30 cents per square foot per month to just 15 cents. Additional conservation opportunities are also being explored.


Since completing the POB expansion, Johnston Services and the hospital have taken evolutionary steps to convert the remainder of the campus to LonWorks. The open system piggybacks on the existing data network used by the hospital’s IT group.

This eliminates the need to install a costly, complicated, dedicated network found in traditional DDC systems. Technicians simply tap into the nearest point on the existing Category-5 data network.

The controls network is fully distributed. An Echelon i.LON™ 1000 Internet server manages each of the three major areas of the campus and provides authorized access to the building automation network from any computer with a Web browser. Routers manage traffic among the more than 100 nodes on the network, consisting of LonWorks-enabled equipment from various manufacturers, such as Honey-well variable air volume (VAV) controllers and Leviton occupancy controllers.

Occupancy controllers regulate not only lighting in the operating rooms, for example, but also airflow. Regulations prescribe the amount of fresh air per person that must be circulated in a surgical area, as well as the temperature. Cooling very warm outside air, or heating very cold outside air, can be expensive. The new network monitors both temperature and airflow, adjusting the temperature and increasing airflow only when the room is occupied.


Strimback and his staff have streamlined their daily routines. They complete what they call a daily rounds sheet, collecting data from any workstation in the maintenance office and identifying actual or potential trouble points.

“If there are no major problems, we perform a physical point check, but we spend a lot less time doing that than we used to,” said Strimback. “With the old DDC system, for example, we would have a technician over at the POB building every day collecting data and making corrections on site. Now we can do most of that from here.

“We’ve cut our labor in half. We’re actually able to stay ahead of the curve, performing preventive maintenance.”

Trouble calls have dropped substantially, said Strimback. “We used to get one or two calls a day. The beauty of the LonWorks system is that now we catch little things every day. Sometimes they’re not even a problem yet, but something just seems a little abnormal. We can usually determine whether it’s a problem and correct it before anyone knows about it.”

The ability to monitor the BAS from any Web-equipped computer has been a tremendous time saver for Strimback, who can even log onto the system from his PC at home. “It has not only saved me from coming into the office, but enabled me to resolve problems faster.”

Publication date: 12/09/2002