AutomatedBuildings.com Article - Defining a Smart Building: Part Four

Smart buildings will change over time based on the evolution of technology and the increased interest in the smart building approach by designers, contractors and manufacturers. This may mean new building control systems (i.e. indoor positioning systems), but it is more likely be advances in the “foundational systems” such as security, electrical distribution or HVAC. We continue to define and provide key details to describe the attributes of a smart building by addressing electrical, metering, and video surveillance systems.

Given water is our most precious resource; something we can’t survive without, electricity is also integral and critical to our lives and functioning of our communities. Without stable, high quality electricity our world would be radically and negatively impacted. We rely on safe and reliable electricity from our utilities and within our buildings.

A smart building has an electrical infrastructure that is dependable, adaptable and cost-effective to maintain and operate. In addition to the electrical infrastructure building owners also must have a relationship with their supplier for two-way communication with the utility grid, demand response notifications and optimal rate structures. Furthermore, building owners may address the use of renewable sources or a microgrid for a building or development that can that locally generate electricity, possibly integrate the utilization of DC current in buildings given that much of the equipment in a building runs on DC. The smart building aspects of electrical distribution involve:

Power Monitoring Systems - A prerequisite for electrical distribution is a power monitoring control system, able to examine the quantity and quality of power being supplied and consumed. Measurement produces data, and data is the underpinning or basis of control and management.

Emergency Power – Electrical backup capabilities are also a requirement for the smart building, especially in critical facilities such as healthcare and data centers, also for conventional buildings where lack of power halts activity and affects building and business operations. This would typically involve generators, automatic transfer switches and UPS systems, as well as regularly scheduled testing of the backup systems.

Demand Response - Buildings must dynamically interact with the utility grid and they do so best by participating in Demand Response (DR). DR is the most visible of numerous strategies where the utility grid and a building with its related assets (such as on-site power generation or storage) are in communication to optimize the supply, demand, costs and prices of energy.

DR compels building owners to think about how exactly they can reduce energy consumption, which is beneficial even when there isn’t a demand response event. To take advantage of demand response building owners need to:

(a)    develop a detailed energy curtailment plan or more likely an array of plans based on different levels of energy reduction
(b)    provide the means to measure and verify the plan results or performance through metering and sound M&V practices
(c)    automate the building’s response to a curtailment event using the building control systems

Plug Loads - Plug loads, or what the USGBC calls process energy are somewhat overlooked because they are not as large as HVAC and lighting energy consumption. The plug load involves all the equipment in a building using typical AC outlets such as computers, monitors, refrigeration, washers, dryers, office equipment, or other appliances. The percentage of energy consumption in a building by plug loads is approximately 19% and growing despite the advances in newer equipment which has lower power consumption. A secondary effect of the plug load is that much of the plug load equipment emits heat, thus requiring additional HVAC cooling. Thus, a double whammy: a situation in which the energy consumption of the plug load requires more energy consumption of the HVAC system.

Standby power or “vampire power” is electrical power consumed from electronic devices turned off or in standby mode. Studies show the consumption of electrical power due to standby power is between 7-13%. One way of addressing plug load is a power strip that can sense the electrical current and manage the plug load. Some outlets on the power strip may be able to turn devices on or off by sensing whether the device is in use or in a prolonged idle state.

Building Metering

Smart meters gather data in real-time or near real time and can provide not just usage data but information on outages, malfunctions, and quality.

Power Meters - There are generally two types of power meters for buildings. One is for monitoring and measuring power to the whole building. The others are sub meters, meant to measure usage for specific spaces, tenants or electrical circuits, primarily to allocate or bill-back the cost of electric power to those who consumed it.

The sub meters typically have a current transformer or “CT” that senses and gathers data on voltage, wattage and amperage on the circuit in real-time or near real-time. Multiple CTs will connect to a processor or a server/controller with the processor having a connection to an IP or BAS control network. Sub meters are generally meant to provide information on energy consumption based on kilowatt hours (kWh).

Metering and sub metering provides data to improve the management of energy consumption. For example, if the data provided by a meter shows that a large electric load exists when a building is unoccupied, this may indicated there is equipment running that needs to be shut off. The data may also show that shifting certain equipment schedules will reduce charges from the utility companies by reducing demand during peak periods. Energy use indices (EUIs), such as kilowatt-hours used per square foot (kWh/SF), can be compared between similar buildings to determine if a building is using more energy than it should. EUIs can also be compared to previous data to see if the building’s energy usage has increased. Since equipment efficiency tends to decrease over time, observations in energy usage can indicate when equipment is in need of service or replacement.

Flow Meters - A major thrust of water efficiency is the reduction or elimination of the use of potable water. Techniques such as rainwater capture, advanced wastewater treatment, greywater “harvesting”, and water-conserving plumbing fixtures are all tools that can be used to reduce the use of potable water.

From the smart building perspective, the interest is in the water monitoring and management systems consisting of water meters, sensor-operator water fixtures such as faucets, urinals, water closets, occupancy sensors, automated ball valves and water valves. Some of these devices can be monitored and managed and others may only be able to be monitored. These types of management systems are also applicable to greywater, wastewater and recycled rainwater systems. For example, a greywater system will need to monitor ultraviolet lamps (used to disinfect), filters, system pressure, UV lamp life and failure, and pumps,.

In most buildings we deal with an internal plumbing system and an external irrigation system for the building’s landscape. Reducing the use of potable water for landscaping can be done with recycled wastewater, captured rainwater and careful selection of the plants and trees.

Irrigation control systems may have a preset schedule and sensors which can adjust the watering schedule as needed. These devices consist of moisture sensors, flow sensors, rain shut-offs and “evapotranspiration” controllers (devices that measure the evaporation of water into the air and the loss of water by the plants, used in precisely calculating specific water need of the plants). The result is watering the right areas with the right amount of water and avoiding over or under watering and runoff.

The benefits of monitoring and managing water systems in buildings have several advantages:

It’s a given that any sizable building will have a video surveillance system. Video surveillance systems, also known as closed-circuit television systems (CCTV), are one part of a facility's larger security and life safety plan. The larger plan may include physical and operational aspects of security as well as other security or life safety systems, such as access control and intrusion detection. Much like the broader electronics marketplace, the technology for video surveillance has changed from legacy analog to digital technology.

IP-Based video surveillance leverages existing IT infrastructure and contributes to lower cost of installation. The IT infrastructure allows for improved network security, remote access to the systems, remote notification of events and alarms and use of Power-over-Ethernet. Most importantly it allows for the integration of the video surveillance systems into other building technology systems allowing for greater functionality between the systems.

[an error occurred while processing this directive] While the video surveillance system is a mainstay of building security, it serves many purposes. The analysis of digital images addresses aspects of physical security but goes way beyond that to provide data and information for building life safety, energy management and overall building performance. If you assume that the video camera is an extension of the human eye, the related analytical software is the extension of the human brain.

Cameras can detect smoke or fire, identify specific individuals, detect motion, determine if objects have been moved and provide occupancy data including the actual number of people in a given space. Generally, if you can develop a pixel template of the event or condition you are trying to track, the video analytic software can detect the event or condition.

One of the greatest benefits of using analytics in a typical video surveillance security system is improved detection and identification of threats, conditions and events. The software is working 24/7 with a level of accuracy.

The array of consistent analytic tools related to video cameras is extensive. They include:

The next installment of “Defining a Smart Building” will address communication and data infrastructure, HVAC and access control systems.

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