An acronym for Air Handling Unit. This piece of equipment is tied to a master HVAC system and is used to distribute conditioned air.

Ammonia is a very-efficient refrigerant and one of the most cost-effective refrigerants for commercial use. Businesses use ammonia refrigerant systems because they can save a lot of money on energy. Also, detecting leaks in an industrial setting is easy because it has a distinct odor. Ammonia is a good choice for eco-friendly businesses because it does not damage the ozone.

A refrigeration system that utilizes ammonia as the refrigerant. The ammonia absorbs heat from the cold areas and relocates it for heating or rejection to the atmosphere.

An acronym for American National Standards Institute, ANSI is a U.S. organization that recommends standards for many products in various industries.

Also known as record drawings and red-line drawings, as-built drawings are documents that allow compare and contrast between the designed versus final specifications and provide a detailed blueprint of the building and the land around it as actually constructed in the end. They are also a revised set of drawings submitted by a contractor upon completion of a project or a particular job. They reflect all changes made in the specifications and working drawings during the construction process, and show the exact dimensions, geometry, and location of all elements of the work completed under the contract.

An acronym for the American Society of Heating, Refrigeration, and Air Conditioning Engineers, ASHRAE’s mission is to serve humanity by advancing the arts and sciences of heating, ventilation, air conditioning, refrigeration, and their allied fields with a vision of a healthy and sustainable built environment for all.

The circumstance of water traveling from one system back into any part of the main distribution system, usually by siphoning.

A device to prevent backflow, especially into a potable water supply.

An acronym for Building Information Modeling, BIM is a digital representation of physical and functional characteristics of a facility. BIM software is used by to plan, design, construct, operate and maintain buildings and diverse physical infrastructures, such as water, refuse, electricity, gas, communication, utilities, roads, railways, bridges, ports and tunnels.

A boiler is a closed vessel in which a fluid (most often water) is heated and sometimes converted into steam through the application of heat.  This heated fluid is used for another process such as warming air or another fluid.

An acronym for British Thermal Unit, BTU is any of several units of energy (heat) in the HVAC industry, each slightly more than 1 kj. One BTU is the energy required to raise one pound of water one degree Fahrenheit, but the many different types of BTU are based on different interpretations of this “definition.” In the United States the power of HVAC systems (the rate of cooling and dehumidifying or heating) is sometimes expressed in BTU/hour instead of watts.

Building Automation System or BAS is an integration of digital, electronic, and/or pneumatic controls and devices to provide unattended and automatic operation of building systems. Systems may include HVAC, elevators, fire suppression, smoke control, security, lighting, and other subsystems.

The term “building services” refers to service needs for existing buildings. Examples could include ongoing maintenance, repair and upgrades to for mechanical, electrical or plumbing systems.

A recorded process that serves to provide a framework for an in-depth, detailed examination of a particular project or job. The research is used to generate a multi-faceted understanding of a complex issue in their real-life setting.

An acronym for Constant Air Volume, it is a system to provide a constant air flow. This term is applied to HVAC systems that have variable supply-air temperature but constant air flow rates. Most residential forced-air systems are small CAV systems with on/off control.

A chiller is a device that uses the refrigeration cycle to cool a fluid (water or glycol blend).  This cooled fluid serves as a heat sync to reject unwanted heat to the outdoors.

Chlorofluorocarbons (CFCs) are generally a mixture of chemicals commonly used as refrigerants. They are used as propellants in aerosol sprays too. CFCs generally contain different substances, including fluorine, carbon, chlorine, and hydrogen.

Chlorofluorocarbons (CFCs) are colorless and odorless, making them more challenging to detect. CFCs are generally quite volatile and start evaporating immediately when exposed to open air.

That is one of the main reasons why they can be inhaled so easily. Even though CFCs are considered non-toxic, exposure (commonly through inhalation) can result in respiratory issues and may even cause a person to lose consciousness.

This is the heart of an air conditioning or heat pump system. It is typically part of the outdoor unit and pumps refrigerant to meet the cooling requirements of the system.

Vapor that liquefies due to the lowering of its temperature to the saturation point.

A component in the basic refrigeration cycle that ejects or removes heat from the system. The condenser is the hot side of an air conditioner or heat pump. Condensers are heat exchangers and can transfer heat to air or to an intermediate fluid (such as water or an aqueous solution) to carry heat to a distant sink, such as ground (earth sink), a body of water, or air (as with cooling towers).

An acronym for Computer Room Air Conditioning Unit, CRAC’s are cooling units for computer rooms. They monitor and maintain the temperature, air distribution and humidity in a network room or data center.

A data center is a facility that houses an organization’s core information technology, (IT) and computing operations, equipment, and infrastructure for the purposes of remote storage, processing, or distribution of large amounts of data. Simply put, a data center is a physical place to store and compute data.

Design-assist is a project delivery method in which the construction team is engaged by the owner to collaborate with the architect or engineer during the design phase. It is intended to reduce the cost and time for construction, improve constructability and add value. Design-assist is part of the recent trend in delivery methods toward teamwork approaches to design and construction.

A method of project delivery in which one entity – the design-build team – works under a single contract with the project owner to provide design and construction services. One entity, one contract, one unified flow of work from initial concept through completion. Design-build is also known as design/construct and single-source responsibility. Design-build successfully delivers office buildings, schools, stadiums, transportation, and water infrastructure projects with superior results.

Specialized housing to contain, insulate and direct air flow in an HVAC system.

An acronym for Energy Efficiency Ratio, EER is an energy performance rating of an HVAC cooling device. An EER rating provides insight about how much cooling capacity a unit provides from a specific amount of energy used. It is expressed in values and numbers and is normally calculated with a 95° F outside temperature and an inside (return air) temperature of 80° F and 50% relative humidity.

Electrical systems or the “E” component of MEP incorporate everything from electrical power to data and telecommunication wiring. Solid electrical design and installation doesn’t just keep the lights on. It is also responsible for making the HVAC systems work and ensuring that any electricity-powered devices in the building is functioning and communicating as well.

Any device that removes impurities through a straining process.

An integral part of an HVAC system that transfers heat from one source to another.  For example, a gas heat exchanger transfers heat from combustion to condition/warm air that in turn heats a space.

An acronym for Heating, Ventilation, and Air Conditioning, the goal of a good HVAC design is to balance indoor environmental comfort with other factors such as installation cost, ease of maintenance, and energy efficiency.

An acronym for Indoor Air Quality, IAQ refers to the air quality within and around buildings and structures, especially as it relates to the health and comfort of building occupants. Understanding and controlling common pollutants indoors can help reduce your risk of indoor health concerns.

An acronym for Insulated Metal Panel, IMPs are lightweight, composite exterior wall and roof panels with metal skins and an insulating foam core. The outer skin serves as either metal wall siding or metal roofing using standard profiles, while the inner face serves as a metal interior finish or liner. The rigid insulation between the metal skins gives the panels their superior energy conservation properties and also provides a rigid core for extensive spanning capabilities across structural members.

The interconnection via the internet of computing devices embedded in everyday objects, enabling them to send and receive data.

An acronym for Light Emitting Diode, an LED is a light source that emits light when an electrical current flows through it. LED lighting products produce light up to 90% more efficiently that incandescent light bulbs.

An acronym for Leadership in Energy and Environmental Design, LEED is the most widely used green building rating system in the world. LEED certification is a globally recognized symbol of sustainability achievement and leadership.

A method used by HVAC professionals to determine the correct sizing of HVAC equipment. A load calculation considers many factors including space design conditions, building envelope, number of people, space usage and system type to determine the total BTU’s required for heating and cooling.

Mechanical systems or the “M” component of MEP incorporates the control of environmental factors, either for human comfort or for the operation of machines. Heating, cooling, ventilation, and exhaustion are all key areas of “mechanical.”

In the construction world, MEP is an acronym for Mechanical, Electrical, and Plumbing. These three technical trades cover the systems that make buildings habitable for humans. MEP systems are normally designed together, due to the high degree of interaction between them.

An acronym for Minimum Efficiency Reporting Values, MERV’s report a filter’s ability to capture particles between 0.3 and 10 microns. The higher the MERV rating the better the filter is at trapping specific types of particles. The rating is derived from a test method developed by the American Society of Heating, Refrigeration, and Air Conditioning Engineers (ASHRAE).

Negative air pressure occurs when the pressure of the air in one area is lower than it is in another. For example, in the HVAC world, this occurs when the air pressure is lower inside of the building than the pressure outside of the building. Whenever this happens, it will cause air to flow into the room from the outside, especially when a door or window is opened.

An acronym for Net Square Foot, NSF is the total usable square footage of a facility measured from the inside wall surfaces.

An acronym for Original Equipment Manufacturer, the OEM is generally perceived as a company that produces parts and equipment that may be marketed by another manufacturer.

A Building Automation System (BAS) mainly focuses on automation of indoor conditions like Heating, Ventilation, Lighting, and Air-Conditioning. At the same time, its motive is to provide cost and energy efficient solutions and thereby making the buildings intelligent. In making the building intelligent, the most important thing is the communication between the different devises. Building Automation Protocols are the rules and standards of which communication is possible between different devices. An Open Protocol allows vendors’ equipment to interoperate without the need for proprietary interfaces. The main advantage of using Open Protocols is ease of expanding and the ability to allow secure remote access to the system through any standard web browser.

A package or packaged unit is a self-contained/single piece of equipment that has the means to condition air.

These are the construction contract documents and supporting engineering documents prepared in sufficient detail and include documents describing the scope of work.

Proactive or schedule-based activity required to keep something in good working order.

Plumbing systems or the “P” component of MEP systems any system that allows the movement of fluids, typically involving pipes, valves, plumbing fixtures, tanks, and other apparatuses. Today, plumbing systems can be used for heating and cooling, waste removal, potable cold and hot.

Positive air pressure occurs when the pressure of the air in one area is higher than it is in another. For example, in the HVAC world, this occurs when the air pressure is higher inside of the building than the pressure outside of the building. This is what is desirable when installing and maintaining HVAC systems in buildings.

Water suitable for drinking.

This is the gathering and monitoring of data points from equipment in order to keep it from failing and to ensure efficiency. Based on this information, contractors can leverage insight that wasn’t available in the past.

Process Safety Management, or PSM, is an OSHA regulation that is concerned with processes at your facility that use highly hazardous chemicals.  PSM provides a compliance framework to evaluate each process with the end goal of no spills, fires, explosions, reactions, releases, or other incidents arising from their use. The development, implementation, and ongoing maintenance of a PSM program is not only required for governmental compliance but is critical for employee safety, protection of the environment, and reducing costly downtime.

A Closed or Proprietary Building Automation System is a stand-alone system where all elements are produced by the same manufacturer and these elements will not be compatible with any other manufacturer’s equipment. The drawback of Closed Protocol systems come in the form of restrictions. By being bound to one manufacturer, you will also be restricted in where you can go for repairs. Additionally, it means that a decision to migrate to another manufacturer will need a complete change of system.

This is unplanned maintenance to fix an asset or piece of equipment after an unexpected breakdown. In most cases, maintenance teams want to minimize the amount of reactive maintenance in their facilities.

A compressor whose piston or pistons move back and forth in the cylinders.

In construction, this is the process of modifying something after it has been manufactured. Retrofitting a building involves changing its systems or structure after its initial construction and occupation. This work can improve amenities for the building’s occupants and improve the performance of the building. As technology develops, building retrofits can significantly reduce energy and water usage.

A Risk Management Program (RMP) identifies potential risks which could result in the emission of refrigerant into the atmosphere and outline measures to minimize the possibility of those risks occurring.

In plumbing, a rough-in is the installation of the drain, waste, vent, and supply lines in a structure to the proposed location of each fixture.

Shell space refers to a suite or floor within in a building that has a floor, walls, windows, and a roof, but no interior improvements. It may also have some basic HVAC, plumbing, and electrical. The space may be converted into usable space later. Shell space is typically found in new construction but can also be found in older buildings.

Solar energy begins with the sun. Solar panels (also known as “PV panels”) are used to convert light from the sun, which is composed of particles of energy called “photons,” into electricity that can be used to power electrical loads.

Substantial completion is a legal term found in construction contracts to define that stage of a contractor’s work that is sufficiently complete in accordance with the applicable construction agreement. And when used in relation to a project, substantial completion is that point where what was constructed is fit for occupancy and ready to be used for its intended purpose.

An acronym for Uninterrupted Power Supply, UPS provides an alternative to “no-break” electrical supply that can be required in situations where it is important there is no loss of electrical supply, even if the primary supply fails. Typically, this is necessary where a loss of power could result in a risk to health or disruption to business.

An acronym for Variable Air Volume, it is an HVAC system that has a stable supply-air temperature and varies the air flow rate to meet the temperature requirements. Compared to Constant Air Volume systems, these systems conserve energy through lower fan speeds during times of lower temperature control demand. Most new commercial buildings have VAV systems.

An acronym for Variable Refrigerant Flow, VRF is a type of HVAC system that allows for effective HVAC zone control. VRF systems can simultaneously heat some zones while cooling others. They allow for precise temperature control in every room of a building and contribute to higher temperature consistency in buildings.

Water hammer is a pressure surge that occurs in a plumbing system when the flow velocity of water changes rapidly. It’s also known as hydraulic shock. The pressure increase is often caused by suddenly closing a valve, faucet, or water appliance. As the water changes direction, it slams into the closed valve or pipe walls, creating a hydraulic shock wave reverberating through the pipeline. This can cause a loud pounding noise, which is where the term “water hammer” comes from.