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I learned HVAC and IAQ from this

April 2013

Fluke 62 MAX

The Fluke 62 MAX mini infrared (IR) thermometer takes the dust, the water, and the 3-meter drop.

Some critical issues face the technicians and engineers who care for the heating, ventilation, air conditioning and refrigeration (HVAC/R) systems we all depend on.

When they set out to solve problems - from bad system design to neglected air filters and accumulations of potentially sickening mold - these pros rely on their brains…and their test tools.

Fluke recently conducted an informal survey of HVAC/R and indoor air quality (IAQ) professionals to learn more about their challenges on the job, the mistakes they see (and their lessons learned), and any advice they would like to pass along. Here's a roundup of who answered our survey, and what they said.

HVAC/R techs, engineers…and more

Our seventeen survey participants hail primarily from the United States, with one engineer from Belgium joining the group. Seven work under the title of HVAC technician, with five others serving as engineers. Others work as electrical technicians, installers, service technician, or in HVAC service and design. One signed in as a director of real estate management.

Seven of the group operate in a plant or industrial setting; another five participants work in both commercial and residential challenges. Two specialize in residential systems, while two others focus on schools.

Problems, problems…

Asked what's the most common HVAC or IAQ problem they see, respondents described a variety of troubles. Several mentioned system design issues. "Not properly sizing capacity for room, application and heat load," said Wess, who works in HVAC service and design. "Undersized duct and oversize equipment," said HVAC tech Anthony. "Air flow issues," said Dan, another HVAC tech, "both indoors and across condenser coils outside."

Another common issue: poor system maintenance. "Lack of filter cleaning/replacement," said Donald, a senior project engineer, "this reduces cooling air flow and contaminates any open type controls - relays, contactors, etc." Alfred, a service technician, agreed. The problem is "techs thinking the compressor has failed when filters are dirty," he said. "In my situation," added William, another HVAC tech, "it's extreme dirt."

The issue of mold was also mentioned. "A lot of technicians will troubleshoot an air conditioning system and overlook the mold that is created from condensation of the evaporator coils," said Rick, an industrial maintenance technician. "I have worked on units after someone else and discovered mold collecting on the vents and found it inside the ductwork." But HVAC tech Robert expressed caution on mold. "People think they have mold when they don't," he said. "Mildew on outside of unit, yes, but not mold inside the unit."

Learning the hard way

Though a few said they had nothing to offer, most survey participants admitted they've learned lessons from mistakes they've made. "Cheap high-efficiency air filters can be very costly," said HVAC tech Anthony. "Turn off breaker and/or fusen before opening service panel," advised electrician and installer Manuel Alberto. "Hot wire was corroded and loose." Similarly, project engineer Donald advised "never assume that everything is properly wired, even when previously tested by others."

And remember Rick, who talked about mold problems? "I learned the hard way about mold and mildew," he said. "A worker started getting sick and made several trips to a doctor, and found she was getting sick from the mold in the ductwork. I felt bad because I take pride in my work, and I did not realize there was a health issue in the office."

Tips, tricks and advice

What do these pros consider the most interesting or surprising HVAC/IAQ measurement or testing practice they have discovered? The learning was as varied as their situations.

"Use a PVC frame, with a matrix of crisscrossed monofilament fish line, with a length of 1/4 inch cassette tape tied to each intersection," said Donald. "Holding this in the air stream from a diffuser allows one to easily track the air flow patterns without resorting to smoke pens and the like, avoid inadvertent triggering of smoke detectors or causing personnel discomfort."

"I found that using an infrared meter to monitor the temperature makes it faster to troubleshoot a system," said Rick. "I also use a humidity meter because it helps me determine if the drain pan has water build-up."

Wess, an HVAC service and design pro, said system testing is often missing. "I see a large number of installations that just put them in and never do any test and balancing, even when required within the statement of work," he said. "Some systems don't even have dampers in them so something can be adjusted later!! And it's never a good idea to completely take the drawings as accurate or calculated."

Others kept their lessons brief. "Allowing time before settling on the temp recorded by the meter," said Alberto. "Most complicated issues are a result of multiple basic issues," was Anthony's diagnosis. And Manuel just said, "I'm still learning. Can't get enough of it."

"Listen to the tenant in the space," advised Tom, a chief engineer. "They don't always know what is wrong but a lot of the time you can find the problem faster by listening." "Always check, never assume," said Wess. "If in doubt, ask." And Donald added, "always check the basics first, and isolate sections of the system to avoid wasted effort."

Fluke 289 True-rms Industrial Logging Multimeter

The Fluke 289 True-rms Industrial Logging Multimeter helps you find little problems before they become big ones.

Tooling up

On the job, survey respondents reported using a wide range of Fluke tools, from basic instruments like the Fluke 62 MAX+ Infrared Thermometer and the Fluke T5 Voltage, Continuity and Current Tester to such advanced test tools as the Fluke 787 ProcessMeter™ and the Fluke ScopeMeter® 125 Series Oscilloscope.

It was no surprise that Fluke multimeters were mentioned most frequently: 14 respondents said they use Fluke DMMs like the tough Fluke 27 II/Fluke 28 II Industrial Multimeters, the Fluke 77 IV Series Digital Multimeter or the advanced Fluke 289 True RMS Industrial Logging Multimeter with TrendCapture.

Some 10 respondents mentioned that their kits include amp meters, including the Fluke T5 Voltage, Continuity and Current Testers and the Fluke 336 Clamp Meter.

Another popular tool was the infrared non-contact thermometer, like the Fluke 561 Infrared and Contact Thermometer (which has both infrared and contact functions).

And yes, the pros had time for some final advice.

"Always use quality tools," said Gene, a plant industrial engineer. "A wrong measurement can cost you hours."

"Only one thing," concluded Bruce, aka the Voice of Experience.

"Always use Fluke equipment. I say this with over 30 years, doing so."

Find out about the new Fluke VT02 Visual IR Thermometer »