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About Building Controls

To fully understand the advantages of our building automation  and monitoring systems, you should first become familiar with the purpose and applications of the technology.

Building automation is a programmed, computerized, "intelligent" network of electronic devices that monitor and control the HVAC, security, fire, or lighting systems in a building. The intent is to create an intelligent building and reduce energy and maintenance costs.
Controllers in a range of sizes and capabilities control common building devices.

 

The operation of a building is typically based on occupancy. Occupancy is defined by time of day schedules to show when the building's systems are most likely in need of operation. Override is possible through different means.
Lighting is another automated service that can be turned on and off with a building automation system based on time of day. Operating times can be set by individual tenants within the building.

 

On the HVAC side, air handlers mix return and outside air in an effort to minimize temperature change. This saves money by using less chilled or heated water. Some external air is included in the circulation to keep the quality of the building's air healthy.
Temperature sensors are installed in rooms, the return and supply air ducts, and sometimes an external air location. Actuators are placed on the hot and chilled water valves, along with the outside air and return air dampers. The supply fan (and return if applicable) is started and stopped based on programmed time of day, temperature setpoints, or a combination. We control all of these devices together in an efficient process using the BAS building automation system.

A central plant is needed to supply the air-handling units with water. It may supply a chilled water system, hot water system and a condenser water system, as well as transformers and emergency power. If well managed, these can often help each other. For example, some plants generate electric power at period with peak demand, using a gas turbine, and then use the turbine's hot exhaust to heat water or power an absorptive chiller.

Chilled water is often used to cool a building's air and equipment. The chilled water system will have chillers and pumps. Temperature sensors measure the chilled water supply and return lines. Chillers are sequenced on and off to chill the chilled water supply.
The BAS building automation system has alarm capabilities. It can be programmed to notify someone if an alarm is detected. Notification can be through a computer, pager/Mobile phone or audible alarm.

  • Differential pressure switches can be placed on the filter to determine if it is dirty.
  • Status alarms are common. If a mechanical device like a pump is requested to start, and the status input indicates it is off. This can indicate a mechanical failure.
  • Some valve actuators have end switches to indicate if the valve has opened or not.
  • Carbon monoxide and carbon dioxide sensors can be used to alarm if levels are too high.
  • Refrigerant sensors can be used to indicate a possible refrigerant leak.
  • Amperage sensors can be used to detect low amperage conditions caused by slipping fan belts, or clogging strainers at pumps.

At sites with several buildings, momentary power failures can cause hundreds or thousands of alarms from equipment that has shutdown. Some sites are programmed so that critical alarms are automatically re-sent at varying intervals. For example, a repeating critical alarm (of a uninterruptible power supply in 'by pass') might resound at 10 minutes, 30 minutes, and every 2 to 4 hours thereafter until the alarms are resolved.

Security systems access control can also be interlocked to a building automation system. If occupancy sensors are present, they can also be used as burglar alarms.

Fire, flood, carbon monoxide and smoke alarm systems can detect activation of a number of alarms that can signal the presence of a serious safety event.