They found themselves doing a lot of moonlighting as they tried to get mechanical systems operating effec­tively. In 1962 those efforts were tak­ing up so much of their time that they decided to do testing and balancing exclusively. Kahoe Air Balance Com­pany was formed in Eastlake, OH, just east of Cleveland.

According to Ralph L. Meacham, current president of Kahoe Air Bal­ance and an employee of the com­pany since 1965, Kahoe and Coultas were dedicated to establishing a to­tally independent testing and balanc­ing industry. Their intention was that TAB agencies would function without any affiliation with any contractors, manufacturers, or engineers.

In 1964, largely through the efforts of Kahoe, the Associated Air Balance Council (AABC) was formed. He served as the Council's president for a number of years after its formation. In the beginning, only a few firms were involved in the Council but, today, it's an international organization with 65 certified members.

The 1982 Fourth Edition of AABC's National Standards states, "The Associated Air Balance Council was established in 1964 to meet the needs for training and to establish acceptable total system balance techniques and standards." The AABC has four major functions.

• Promote training, develop, and dis­tribute technical data.
• Establish national standards for to­tal system balance.
• Conduct a certification program for testing and balancing agencies.
• Advance the state of the art of the industry.

Each AABC firm must have at least one certified Test and Balance En­gineer (TBE). In order to qualify for this position, the person must submit an education resume acceptable to AABC. He can have no less then ten years of TAB experience, five years of which must be continuous field ex­perience in actual TAB work. In ad­dition, he has to pass an AABC ex­amination for certification. An AABC-qualified Test and Balance Technician must have completed an apprenticeship program, have five years of experience, and pass a qualifying test. According to Meacham, from 60% to 70% of design engineers now specify TAB on their projects. "The travesty of that," he adds, "is that they don't always adhere to their specs. They specify it but it doesn't always happen because of budget cuts or, quote, 'to save money.' You might save it today and spend twice as much later, but that's a hard thing to deal with."

The Process

AABC describes the procedure as: "Total System Balance is the process of testing, adjusting, and balancing environmental and other systems to produce the design objectives.

"Air conditioning is defined by the American Society of Heating, Refrigerating and Air-Conditioning Engineers as 'The process of treating air to control simultaneously its temperature, humidity, cleanliness, and distribution to meet the comfort re­quirements of the conditioned space.'

"Each air treatment process in the conditioning system contributes a specific function to produce proper environmental conditions. However, it is the coordinated action of all of these processes in a system - each related to and influencing the others - that produces the desired conditions. If any one of these coordinated functions does not perform as designed, the final results will affect system performance.

"Total System Balance is the process of testing, adjusting, and balancing each system component so that the entire system produces results for which it was designed. It is a science that requires proper use of instruments, evaluation of readings, and adjusting the system to design condi­tions. The mere ability to use an in­strument does not qualify a person as a Test and Balance Engineer or Tech­nician. Qualification requires train­ing and years of field experience in applying proven techniques and in analyzing gathered data."

In an air and water balance, the process begins on the air side with the technician checking each piece of equipment to make sure they are functioning properly. In the course of balancing a system, he will have taken air measurements from every outlet in the building. He attempts to get the system into a maximum con­dition so he can simulate a loaded de­mand at which point he adjusts the components of the system. In the pro­cess he will also be dealing with re­turn air and exhaust from the space.

On the water side, he will be checking and adjusting pumps, chillers, circuit setters, and flow metering devices.

Meacham says, "What we really do is tune up the system, to make sure it is working to the best ability of the equipment and the installation. We're also trying to maximize its efficiency."

The efficiency they try to achieve is what the engineer envisioned. "We're really trying to set it up to the design engineer's specifications," says Meacham. "If he's trying to design an extremely energy-efficient system, we're in that pro­cess. We're not making a conscious effort to save energy. We're trying to set the system up to the design engineer's specs. If his goal was a high-efficiency system, then we help him achieve that goal. We are not designers and we are very careful to stay out of the design aspect of build­ings. That's because these are the people who specify us and who de­pend on us."

As acceptance of testing and balancing has grown among en­gineers, so has the realization that certain aids to the TAB process need to be specified in the original design. "Engineers today are much more aware of duct dampers. It wasn't too many years ago that there was always a fight to get dampers installed. But now most engineers are aware of the need for them, and the advantages of putting them in the original design."

Another item that is regularly seen in systems today are Pete's plugs, which provide a rubber gasketed ac­cess to piping systems. Through these outlets a technician can insert probes directly into the fluid to check tem­peratures and pressures. TAB tech­nicians also get involved in insuring that a building will be safe. They check stairwell pressurization under varying conditions. Digital equip­ment is available that will provide the technician with the differential pres­sure between two different locations such as outside and inside a stairwell. Technicians are also sometimes called upon to check the pounds of pressure it takes to open doors under fire conditions. This is to make sure occupants can get out in an emer­gency.

Normally, it only takes one techni­cian to balance a building unless he has an apprentice or a helper with him. Meacham says that's the most cost effective way. If more than two journeyman are used in a building, it's usually because there is more than one system.

At the completion of a system bal­ance, the contractor is presented with a report on the process. Ultimately, the report goes to the engineer and to the owner unless the owner is the client.

AABC's definition of the report: "A report is a record of actual test and balance results. This report shall re­flect actual, tested, and observed conditions of all systems and compo­nents during Total System Balance. The report shall be certified, dated, and signed by the certified Test and Balance Engineer."

A report also contains design data as well as the normal operating con­ditions of the building systems that are specified for Total System Bal­ance. It provides sufficient data per­taining to the instruments used and system operating modes during balancing to allow any reported data to be repeated.

"A Total System Balance project shall not be considered complete un­til the owner's representative has been provided with a final Test and Balance Report that thoroughly describes the operation of the sys­tems," according to AABC.

Although most of the buildings companies like Kahoe deal with have large central systems, Meacham says they do get involved with smaller spilt systems, computer room units, and heat pumps.

"The more complex jobs are obvi­ously the central systems, especially those that involve variable air vol­ume," he says. "These systems have become very sophisticated and really need attention because there are so many variables. Someone really has to come in and get them set up and working properly."

Increasingly, the technicians at Ka­hoe are encountering floor-by-floor hvac systems. Especially in specula­tive buildings, the balancing agency balances on a floor-by-floor basis as the space is leased. Meacham's peo­ple are also encountering more build­ings with energy management and building management systems, and those that employ direct digital con­trol (DDC).

The technicians haven't encoun­tered any particular problems with these systems with the exception of keeping up with the technology. Says Meacham, "A lot of them are differ­ent. Each time you run into a new sys­tem, it has its own idiosyncrasies. It's hard to keep your people up to speed with the technology. We work hard at it, but it's difficult because the tech­nology is changing very rapidly."

Although Meacham is quick to point out that his company does not get involved in any way in hvac sys­tem design, that doesn't mean they won't help an engineer.

"We'll go in during the design stage and go over the drawings," he says. "We want to make sure the sys­tem can be balanced - that there are dampers in air systems and balanc­ing valves in water systems. Our ob­ject is not design but the ability to balance. "

Do Kahoe technicians run across buildings that just won't work? The answer is yes, but Meacham says it's a rarity. "There are some out there that just won't work," he adds. "We try to make them as efficient as we can given what's installed, or we make recommendations concerning what we feel would help improve the situ­ation, such as changing dampers or motors.

The tools of balancing

Because instruments and test equipment are the lifeblood of a TAB agency, and because many of them are extremely expensive, they are handled with extreme care. AABC requires that they be recalibrated within six months of a TAB job.

Some instruments are more deli­cate and can't even last the six months, according to Meacham. He says, "If the technician senses that there is a problem, then we just re­place the instrument and get it back in for calibration or repair.

Kahoe also has a 40-point recorder called a data logger that can profile a building, or a fan, and record 40 different points almost instantly. It can be used to record temperatures, humidity, pressures, and differential pressures.

The Ohio firm has specialized equipment for scanning HEPA filters used in clean rooms and surgical suites. The company also has a parti­cle counter used to certify the clas­sification of clean rooms.

"The equipment isn't used daily," says Meacham, "but when you need it, it's nice to have it and be able to provide the service. We see this as kind of a side service for our cus­tomers, and feel it complements our ser­vice, as does the sound testing we do."

Meacham says the biggest im­provement in testing he's seen in the last decade is the use of flow hoods and the improvements that have been made in them. "They've become very sophisticated," he says, "more dura­ble, more reliable. They are an asset and we rely on them."

While new flow hood designs pro­vide a digital readout, Meacham prefers those with analog readouts. That's be­cause, as the digital numbers fly by, it's hard for the technician to get a handle on what's actually happening. They claim the digital equipment is also sometimes slower to provide a readout than the analog equipment.

Digital thermometers, on the other hand, are quite popular at Kahoe and each of the firm's four offices has at least one or two of the devices for use by field technicians.

The old standby for measuring air pressure - and one that is still heavily relied on, according to Meacham - is the air manometer that uses Pitot tubes to traverse a duct. While Meacham says the hoods are very helpful and reliable, Kahoe insists that its technicians use a manometer to cross-reference the hood readings they get. "We strongly encourage cross-references," he says, "testing by more than one method provides a comparison."

Just as auto mechanics armed with the latest computerized test equip­ment can make an automobile sing, highly skilled TAB technicians armed with an arsenal of properly calibrated instruments can make a building's mechanical system live up to its potential.

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All Pictures and text are supplied and updated by Kahoe Air Balance