Controls

Overview

Building controls have come to take many forms and are known by many names. One of the more basic but familiar building control devices is a thermostat. This simple device measures the temperature (input) and turns a switch (output) on or off depending on the temperature. This basic concept of controlling outputs based on the value of inputs has not changed and remains at the core of even the most advanced building control systems.

Modern building control systems are much more complicated than a simple thermostat but they achieve the same basic function. Building controls give facility operators a way to monitor, regulate, and automate the behavior of other mechanical or electrical systems in the building. The term building controls is often used in reference to HVAC system controls, but it can be applied more broadly to any controls on any building system.

Technologies

The technologies used in building controls has changed greatly with time and has allowed the capabilities of these systems to expand dramatically. These technologies include:

• Electro-Mechanical Control (Relay Control) - Devices (like the thermostat) open and close electrical circuits in response to measured changes such as temperature. These control devices can be wired together to accomplish more complex functionality but there are limitations to the scale and sophistication of control you can achieve.

• Pneumatic Controls - Pneumatic controls use compressed air in tubing that can be run long distances throughout a facility. This not only allows for information to be sent between devices (in the form of varying air pressure), but the compressed air can directly provide the pressure and force needed to open or close valves and dampers or modulate other mechanical devices on HVAC equipment. Early pneumatic control systems relied on electro-mechanical components to handle much of the logic and programming of the controls.

• Electronic Controls - In the 1960’s, electronic controllers and eventually programmable logic controllers (PLCs) were developed and began being used in building controls. These controllers still rely heavily on pneumatic control components and analog sensors to create a complete control system, but they replaced relay control designs.

• Direct Digital Controls (DDC) - Starting in the 1980’s, direct digital control became the new standard in building control systems and revolutionized the design and application of building controls. Direct digital control eliminates the need for pneumatic control components by directly using digital sensors and components to measure input signals. These signals would feed inputs on PLCs and greatly simplified the design and implementation of control systems. With digital communication technology rapidly developing at this time, network communication between controllers and control devices also became a standard feature of DDC systems.

  DDC control technology has continued to mature and improve significantly since it was first introduced, but it is still the core technology used in modern building control systems.

What do they Mean?
BAS, BCS, BMS, EMS, EIS

There are several facility/building system names which are all related to building controls and are often used interchangeably or incorrectly. Depending on who you talk to, you may still receive different definitions for the various terms. In our experience, here are the most common term definitions.

• Building Automation System (BAS) - An interconnected system which automates the control of various systems and equipment throughout a facility. In many facilities, the scope of control is limited to HVAC systems, but it can include other systems such as security, access control, fire & safety, and elevators. BAS is a more specific term than building controls since it is limited to systems that are interconnected and accessible from a central interface or location.

• Building Control System (BCS) - One or more HVAC control devices that may or may not be interconnected. This term is often used interchangeably with BAS but it often implies a more limited scope of functionality with few systems other than HVAC being integrated.

• Building Management System (BMS) - This term is often used interchangeably with BAS and has a very similar definition. Sometimes this term is used to denote the inclusion of features such as work order management or resource scheduling which are typically not considered features of BAS.

• Energy Management System (EMS) - A tool used to gather real-time energy and operational data about a facility for the purpose of tracking energy consumption and identifying wasteful or inefficient operation. EMS is often confused with BAS or BMS and regarded as an interchangeable term, but it is not. EMS is primarily a software system which relies on data collected by the BAS but does not replace the BAS or directly control equipment.

• Energy Information System (EIS) - A database of energy meter data and energy invoice data that is used to help manage an organizations energy cost and sustainability program. EIS systems are common with organizations who manage a larger portfolio of facilities and does not typically include operational data from the BAS.

Bringing Them Together | EMIS

As technologies mature, they often become more interconnected and allow for data to be easily shared and analyzed between them. The application of advanced data analytics to building systems has driven a shift away from the distinct and separate systems described above. Energy Management and Information Systems (EMIS) are the combination of BAS, EMS, and EIS with the addition of Fault Detection & Diagnostics (FDD) and Automated System Optimization (ASO). EMIS is rapidly transforming the way business manage their facilities and is the latest evolution of building controls technology.

LEARN MORE about our EMIS platform and how it can grow your facility management into the future.