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Nobody’s perfect. As human beings, we’re bound to make mistakes. This is true in all aspects of life but especially so in the residential HVACR sector, which incorporates more than 141 million homes.

While most HVAC technicians aim to provide the best service possible, even the most skilled installers have missteps. When these errors do occur, what are the most likely causes? How often do they arise? Does the industry maintain data tracking these instances? And how exactly should a contractor proceed if such a mistake is detected?

Building America Program

The U.S. Department of Energy (DOE)’s Building America Program leverages building science research to develop the solutions and best practices needed to advance energy efficiency throughout America’s homes.

One ongoing Building America project is focused on tracking installation residential HVACR system faults. Through the program, surveyors plan to visit 300-400 homes across eight geographical regions, examining HVAC systems that have been in operation for one year or less, identifying and analyzing faulty operation. Each home will be visited twice — once during the heating season and again during the cooling season — through 2024.

Dr. David Yuill, P.E., associate professor, University of Nebraska, is one of the project’s facilitators. He believes the study will ultimately provide the industry some insight as to which residential HVAC installation faults are most common and impactful, which detection methods are most effective, how and why fault detection can be advantageous in conjunction with smart meters, and more.

“HVAC system faults are important because they reduce the capacity, efficiency, and life cycle of the unit,” said Yuill at the 2023 ASHRAE Winter Conference, while presenting on the topic. “A faulty system impacts the equipment’s energy usage, the environment, and end user comfort and cost.”

Preliminary results identify inadequate refrigerant charge, evaporator airflow, and liquid line restrictions as the leading causes of installation faults.

Researchers determined only 23% of systems tested were charged with the perfect amount of refrigerant, and approximately 60% of systems were within +/- 5% of charge.

“The good news is the majority of systems are within a close range, but the bad news is that 40% deviate more than 10%,” said Yuill.

Approximately 13% of systems showed the perfect amount of evaporator airflow — 350 cfm/ton — while approximately 45% were underperforming.

While the results are preliminary in nature, the study suggests there’s a lot of work to be done.

“There is a significant number of systems that are not operating as efficiently as they could be,” said Yuill.

Faults in the Industry

The National Comfort Institute (NCI) performed installation fault studies of its own in 2006 and 2013, which revealed only 57%-63% of the Btu promised by manufacturers were delivered to the occupied space. The most common faults cited include duct leakage, over- or undercharged units, cracked heat exchangers, and short cycling.

When it comes to detecting and authenticating faults, HVAC technicians must perform the proper tests, said John Puryear, instructor, NCI.

“How long would you go to a doctor who says, ‘I saw your name on the schedule today and took the liberty to write a prescription that I thought you needed?’” he asked. “Without testing and verifying pressure, temperature, and airflow, appropriate heat transfer does not take place.”

Contractors relying on rules of thumb, installation shortcuts, or sloppy processes generally pay the price in the long run, said Puryear.

“Callbacks should not be used as a company’s quality assurance program,” he said. “Not following protocol and verifying a customer’s satisfaction will almost always lead to callbacks and warranty issues, which eat away at a company’s bottom line.”

Wes Davis, technical service director, ACCA, is also a proponent of performance testing and visual inspections.

“Measuring and evaluating various HVAC system parameters help to identify deviations from expected performance,” he said. “This includes measuring airflow, refrigerant charge, electrical measurements, and combustion analysis. Measured values must be compared with the manufacturer's specifications and industry standards to ensure the equipment operates correctly. From there, any faults that have been identified can be corrected.”

A poorly executed install has the potential to hurt a contractor’s pocketbook as well as the occupant’s well-being.

“Nothing is more galling than to lose the profit on a new system installation to an unnecessary, time-sucking callback,” said Davis. “Once a company’s reputation is damaged by unnecessary callbacks, it takes a long time to rebuild a customer’s trust in your company. Even worse than a callback is to lose profit (and more) due to an installation-related problem that results in property damage or harm to the occupants. Those types of mistakes can put a company out of business.”

ACCA has undertaken a significant initiative to identify when and why systems fail through its ACCA 5 Quality Installation (QI) Standard. Partnering with measureQuick, the process reviews the elements of the system design and installation and helps to identify the steps and processes necessary to ensure installed and commissioned HVAC systems meet the QI standard.

“The QI certificate program focuses on installing new equipment in existing homes and will extend its scope to encompass retro-commissioning activities for previously installed equipment,” said Davis. “This inclusive approach allows for evaluating new and retrofit installations and may result in data that would contribute to the prevalence of faults that are corrected.”

Contractor Solutions

Vince DiFillipo, president and owner, DiFilippos Service Co., Paoli, Pennsylvania, said his company focuses heavily on workmanship before, during, and after the install to help minimize installation faults.

“We require our techs to complete a 42-point installation quality control sheet on-site and discuss the results with the client,” he said. “Clients sign the sheet and receive a copy so that they’re aware of any issues.” DiFilippos management reviews callbacks individually with each tech to prevent reoccurrences and verify the issue was due to a human error rather than faulty equipment.

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42-POINT INSPECTION: DiFilippos Service Co., Paoli, Pennsylvania, completes a 42-point inspection quality control sheet on-site and discusses the results with clients. (COURTESY OF DiFilippos Service Co.)

Regardless if it’s a human or equipment error or not, the contractor has to be the one to remedy the situation, DiFillipo said.

“Clients rarely blame the equipment manufacturer — it’s almost always the contractor,” he said. “Fewer callbacks increase client satisfaction, which ultimately builds confidence in the brand of equipment/parts we’ve installed. A job well done reassures we stand by our work and the products we sell.”

And a job well done deserves the proper notoriety.

“We provide positive feedback and photos from successful jobs through our social media platforms and via recognition at meetings,” he said. “We also ensure our technicians receive great pay. We’re committed to providing training and a steady process to ensure we’re providing customers with top-notch service.”

Martin Hoover, owner, Empire Heating & Air Conditioning, Decatur, Georgia, said his company experiences about a 3% rate of installs on service calls and just under 10% on installs. Improper airflow, charging issues, condensate drain concerns, over- or undersized equipment, poorly designed plenums, and manufacturer failure are the leading causes.

“We track faults by employee on a monthly basis,” Hoover said. “This is important because we want to make sure employees aren’t making the same mistake over and over again. If they are, we ensure that individual receives the training necessary to overcome those concerns.”

All of Empire’s field employees are NCI-certified and most have worked with the ACCA QI standard.

Hoover insists training is critical in delivering an exceptional home service product.

CONFINED SPACES: In the HVACR contracting realm, the quality of the service delivered ultimately dictates the level of success an HVACR contracting obtains. (Image courtesy of Empire Heating & Air Conditioning)

“We hold weekly meetings with our service and install teams, where we talk about the good and the bad,” he said. “Over the years, we’ve seen trends rise and fall. Some of those issues have been related to new technologies, but it usually comes down to training. The better trained a technician is, the better his callback rate is.”

In the HVACR contracting realm, the quality of the service delivered ultimately dictates the level of success an HVACR contracting obtains.

“Acknowledging and addressing issues in real time helps to maximize customer satisfaction and profitability,” said Hoover. “You must be profitable to hire quality people and be able to train and retain them. It's a competitive market, and every job matters.”