Feature Story

HVAC&R Engineers: Engineering the World We Live In
By Dave Meredith — ASHRAE Member & Student Branch Advisor

It was used in ancient Greece and by the Apollo crews on the moon. It is available in every city in the world and on the international space station orbiting overhead. It is as simple as a campfire and as complex as the space shuttle. Without it, there would be no fast food restaurants — without it there would be no ice cream except in the middle of winter. It is responsible for 30 percent of the energy used in the U.S., and you rely on it daily — almost as many times as you use computers. In fact without it, there would be no computers. So what is this career that is so ubiquitous, flexible, and wide ranging? It is heating, ventilating, air conditioning, and refrigeration engineering (HVAC&R).

Our industry's mission is simple: maintain desired conditions within the built environment under all types of weather, no matter how many people are occupying the space or how many lights or how much equipment is running. Do it safely, with the least impact on the occupants and the environment and provide the highest indoor air quality at the lowest operating cost to the owner.

To accomplish this amazing balancing act, HVAC&R engineers must be familiar with all fields of engineering, from electrical and controls to structural and lighting. The chemical combustion process in the boiler and the corrosion in the cooling tower are part of our vocabulary. If we fail in our mission, people can die.

Heating has been around since the first cave dwellers built a fire to keep warm in winter. Today we use every type of fossil fuel to heat buildings — gas, petroleum, and coal — as well as high tech sources such as solar energy. A geothermal system draws heat out of the ground to heat a building. Not only do we heat your home, school, shopping mall, and sports complex, we also provide the heat to bake bread, dry lumber, and make paper products.

Ventilation is required to remove odors and other gases produced by occupants and processes. Even carpet gives off chemicals that must be removed. We can provide this fresh air without being noticed by the occupants. In a concert hall, we provide a design that keeps people comfortable without any noise to interfere with the performance on stage. In an operating room, the doctor uses a laser to seal a leaking blood vessel. It would be bad if the smoke from the surgical procedure falls back into the open wound. Our precisely-controlled air movement prevents that from happening. The patient with the highly contagious tuberculosis is just down the hall from the organ transplant recipient with a suppressed immune system. Our pressure control of the ventilation system ensures that both patients are protected from each other.

Air conditioning does more than just keep you cool on those hot summer days. It also controls the humidity, keeping it at the proper levels. When you use a credit card or log on to an Internet search engine, you are connecting to a room with literally hundreds of computers. The energy density in that room is equivalent to having a person standing in every square foot of the room. But if any of those computers overheats, the company can loose millions of dollars of information. The system must run continuously — 24/7/365 — without ever missing a beat. We design these facilities for every possibility — hurricane, lightning strikes, utility outages, even terrorist threats.

You probably associate refrigeration as that big metal box in the kitchen that keeps your milk cold and your ice cream frozen. But move back into the food chain a few steps. In the supermarket you find refrigerated cases for everything from fresh fruits and vegetables to fresh and frozen meats. The flower display case and dairy case must be maintained at different conditions to maximize their products' shelf life. And think about bananas. About once a month, a shipment of bananas is delivered to the grocer's supply warehouse, where they are divided into three storage rooms. The first room is shipped out immediately. When it is empty a few days later, they start shipping out of the second room. When those bananas are finally gone, the third room is open and used to fill orders. For several weeks, those bananas arrive at the store just a day or two before their peak quality. But they arrived at the warehouse on the same day. The magic is in the special conditions that we provide to the storeroom to suspend the ripening of the bananas until we want it to occur.

If you are a fast food lover, on your next trip take a look at the other side of the counter. You will see the HVAC&R industry many times over. The hot food is stored under an infrared lamp to keep it warm. The fries are cooked in hot grease that is vented out through the hood above. Same thing for the making burgers — the grease and odors are vented away. If you think about the breakfast sausage patty, it is partially cooked right after it is formed. Before it is packaged for shipping, it is dipped into liquid nitrogen to quench the cooking process and fast freeze the meat. It only thaws when it hits the frying bucket. Even the ice-making machine for your soft drink is part of the refrigeration industry.

Modern buildings use computers and the Internet to control the operation of these complex and integrated systems. An airport terminal control room must monitor and control over 10,000 data points continuously to ensure that all areas are maintained within precise limits. When a component fails, a repairperson can be dispatched with a replacement part within minutes. Today's designers build systems that provide comfortable spaces with the least impact on the environment. These "green design" structures stand on the shoulders of giants who developed the concepts over many years.

To understand the basics of this industry requires at least a two-year degree from an ABET accredited college or university. To understand every aspect of this industry takes a lifetime of study — and by then much of what you learned will have become obsolete and replaced with new methods and concepts.

Check out the links related to HVAC&R engineering:

For more information on this engineering specialty, contact the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). ASHRAE is the world's leading technical society in the fields of HVAC&R. Through its meetings, research, standards writing, publishing and continuing education, the society helps keep indoor environments comfortable and productive, deliver healthy food to consumers, and preserve the outdoor environment.