Alerton, click here...

4  FM quick reads on controls

1. With Building Controls, Age May or May Not Be the Reason for Problems


Today's tip from Building Operating Management comes from Rita Tatum, contributing editor for the magazine: Facility managers should recognize common problems with older controls, but also recognize that the age of controls may not be the real issue.

One widely recognized problem with older controls is getting repair parts and service on older controls. Another common issue tied to the age of controls is greater difficulty integrating one control system into other systems. "Older controls generally have proprietary protocols," says Jim Sinopoli, managing principal for Smart Buildings.

Another issue is that older controls just don't have the capabilities to meet the needs of the organization. "The problem of aging controls is not always a functional problem, as much as a need for improvement to meet the wants of a tenant, the inability to control the use of energy or the ability to reduce labor costs associated with operating less dependable equipment," says Jack Althoff, owner representative, ProJX Inc.

Many older control systems do not offer capabilities like load-shedding or point-of-use zone control, says Althoff. With pneumatic or analog controls, tighter operating parameters are not possible because of the large swings in actuator travel inherent in such designs.

But when a facility manager is experiencing controls problems, it's important to remember that aging controls are not always the culprit, according to Jack McGowan, CEO of Energy Control Inc. The building control problems that McGowan typically encounters are not technical issues or control-failure issues. "The biggest issue is that over time a variety of staff interfere with, circumvent and bypass systems," McGowan says. "This is a symptom of the real problem, which is that there is rarely a disciplined long-term program to leverage controls, ensuring that they remain operational."

This has been a Building Operating Management Tip of the Day. Thanks for listening.


2.  Reduce IAQ Complaints Through Communication

In the past, the prevailing characteristic of new and more sophisticated controls was to reduce the influence of the occupants. Thermostats controlling individual spaces and operable windows were removed. The result was that customer needs were reduced to standards. The customer was left with other no means to control his or her environment than to complain.

In the absence of individual controls, facility managers should try to create ways for occupants to still influence their environment. Providing opportunities for occupants to set the quality agenda for their work environment through surveys, focus groups or interviews will go a long way to minimizing indoor air quality complaints. They are ways to replace individual controls with communications.

Facility managers can show a link between what the customer wants in the way of environmental quality and the operating strategies they employ. This gives control back to the occupants, reduces complaints and creates a partnership in environmental quality management. It is a no cost way to improve satisfaction and complements any planned capital improvements over time you may have in place that will return some control to occupants over their environment.

3.  Retrocommissioning Building Automation Can Reduce Energy Costs

Today's tip from Building Operating Management: Retrocommissioning can reduce energy costs significantly.

There are plenty of reasons that building automation systems benefit from retrocommissioning. One is that well-meaning operating staff can make changes to the system that have the unintended consequence of increasing energy consumption, Bert Gumeringer, director of facilities operations and security services at Texas Childrens Hospital in Houston.

"What happens is that our good maintenance people come in and they make adjustments based on 'tribal knowledge,' he says. "Some of those practices aren't in synch with good engineering practice." Retrocommissioning can rectify those mistakes.

One common problem, says Gumeringer, is that operating staff tend to put devices in the manual mode, rather than the automatic mode, so the building automation system is not running the equipment. Another issue is sensors that have been bypassed or sensors that haven't been calibrated properly.

A third problem is sensors that were disconnected. That may happen if a technician goes to do a preventive maintenance item and leaves a key sensing device disconnected. "Putting everything back together the way it's supposed to be really yields good results," Gumeringer says. If all of the sensors are in good working order, the building automation system gives the facility manager a window into the system.

He has found that retrocommissioning can bring a substantial payoff. His team has retrocommissioned several buildings that are more than 15 plus years old. "We're starting to see some very nice savings in the two to three to four hundred thousand dollar annual range by doing retrocommissioning," he says. Savings from retrocommissioning have enabled the hospital to keep energy costs essentially flat even as the amount of space was increased. "If we had not done that, our costs would have continued to trend upward," Gumeringer says.

This has been a Building Operating Management Tip of the Day. Thanks for listening.

4.  Occupancy Sensors Need Not Leave Occupants in the Dark, Shorten Lamp Life

Today's tip comes from James Piper, contributing editor for Building Operating Management magazine: Properly installed occupancy sensors won't leave occupants in the dark or reduce lamp life.

One of the biggest complaints concerning the occupancy sensor is that it can leave occupants in the dark if it falsely believes that the space is unoccupied. Most occupancy sensors work by detecting motion. Once detected, the sensor turns the lights on for a preset amount of time. Each time that motion is detected, the sensor's timer is reset. If no motion is sensed and the timer reaches its preset interval, the lights are turned off. If the space is still in use, the occupants can be left in the dark.

In most cases, the failure to detect occupants is the result of installation or application errors. To be effective the sensor needs to be able to see all or most of the space. Sensors have a limited viewing range and angle. Objects within the space or unusual room configurations can partially block the view of sensors, resulting in false readings. By selecting the right type of occupancy control and by properly placing that control, most false readings can be eliminated. If there still are concerns about leaving occupants in the dark, a single, low wattage fixture can be left switched on at all times to provide backup lighting.

A related concern is that, as a result of their frequent on off cycles, occupancy sensors kill lamp life. While there is no question that this frequent cycling does reduce lamp life as measured by total operating hours, it can actually extend the calendar life of the lamps, particularly in applications where light is only needed a small fraction of the time.

This has been a Building Operating Management Tip of the Day. Thanks for listening.


RELATED CONTENT:


controls , building automation , energy efficiency

Reliable Controls, click here.
Delta Controls, click here.


QUICK Sign-up - Membership Includes:

New Content and Magazine Article Updates
Educational Webcast Alerts
Building Products/Technology Notices
Complete Library of Reports, Webcasts, Salary and Exclusive Member Content



click here for more member info.