Performing a smoke test prior to evaluating the combustion process is one way to ensure that the combustion testing equipment remains in good working order.

Dateline: Chicago, Oct. 16, 2006. Story lead: “Carbon monoxide [CO] poisonings kept firefighters busy Sunday as furnaces were fired up for the first cold-weather weekend of the year. Fumes sickened several people, but nobody was critically ill after three cases - two in Chicago and one in the west suburbs.”

Not only are firefighters busy responding to CO calls, but so are HVAC contractors, making sure that their customers’ heating equipment is in good working order and does not pose any dangers of incomplete combustion - the source of CO production.

But are contractors making sure their employees are protected each time they enter a home or building, and do they make sure their customers are educated on the origins of CO and the dangers associated with it? That’s what The NEWS wanted to know, so we recently ran an online survey on our Website (

137 respondents answered the following questions.

1. Does your company include combustion analysis as part of your HVAC equipment inspection? Why or why not?
2. Do your technicians carry CO analyzers to test the indoor air on every service call? Why or why not?
3. Does your company attempt to educate consumers about CO? Why or why not?
4. Do you consider CO education a priority for your employees and customers?
5. Do you feel you and your techs know enough about testing HVAC equipment for incomplete combustion?
The results from each question are shown in Figures 1-5. Some respondents were also asked to expand on their answers in follow-up interviews.
The majority of respondents said they did conduct combustion analysis and carry analyzers on service calls. And overwhelmingly, respondents said they believed in educating customers on the dangers of CO poisoning and the importance of education among their employees and co-workers. Most felt they know enough about testing and combustion analysis.

One respondent saw the need for continued education. “We have provided this education to our employees and are doing so again this year,” he said. “We will provide these courses at least once a year to attempt to convey the right information.”

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The goal of the process called combustion analysis is to improve fuel economy, reduce undesirable exhaust emissions, and improve the safety of fuel-burning equipment. Combustion analysis begins with the measurement of flue gas concentrations and gas temperature, but it can also include the measurement of draft pressure and soot level. Not all HVAC contractors include combustion analysis as part of their equipment checkup. However, the survey showed that 78 percent of respondents performed combustion analysis (Figure 1).

Some respondents said that a cracked heat exchanger, a major source of CO, is not always easy to spot. “A hole in a heat exchanger may not be apparent,” said one person. Another noted, “The new-style furnaces are now next to impossible to view a crack in the exchanger with the human eye.”

Another popular reason for conducting combustion analysis is to protect the customer and to ensure future business.

“It is the only true way to be sure the furnace is operating properly and at top efficiency safely,” was one answer. “While our service techs are out there, we want them to do an analysis for the safety of the homeowner.”

One respondent said, “It gives us something to compare to the following year and maybe see a problem before it develops.”

Fuel efficiency, an important reason for testing, was on the mind of this respondent who said, “It is the only way we can tune the appliance to maximum efficiency. We find 95 percent of all gas furnaces we tune up for the first time are underfired and using more gas than necessary. The combustion analyzer also allows us to find other problems - problems with venting, combustion air, flame impingement, overfired, excess CO production.”

But despite all of the reasons to perform combustion analysis, there are still some naysayers: 22 percent of the survey respondents. One person said that his customers have never asked for it and his competition doesn’t do it. Another said that he couldn’t afford the necessary equipment to perform the analysis.

And this respondent said, “On a gas furnace it is not needed. Most gas furnaces do not even have a way of changing the air to or going through the burners.”

Some people said that such a procedure was only necessary if they “suspected” a problem.

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CO analyzers, hand-held test equipment to determine CO levels in the air, have become standard in most HVAC service techs’ toolboxes, at least according to our survey. The results were very close, however. A total of 52 percent of respondents said they or their techs carry CO analyzers on every service call (Figure 2).

“You never know what you are walking into,” said one respondent. “Low levels of CO in a home are an indicator of a problem. Without testing for it, the issue may go unnoticed until someone is sick or dead.”

One respondent said having test equipment makes good business sense. “It keeps my techs safe and helps with the customer because they see we are serious about CO,” he said.

One contractor said it is all a matter of routine. “It takes no extra time; we just turn the analyzer on outside and read it when we enter the structure,” he said. “CO is dangerous, and the analyzer makes it so easy to check.”

In place of analyzers, some contractors and techs carry CO monitors on every job. One said, “Our techs are equipped with the National Comfort Institute (NCI) monitor that they carry on their persons. In addition, all our service and installation techs are NCI CO-certified.”

But since the percentage of respondents (48 percent) who don’t carry analyzers was so high, it is obvious that a lot of contractors don’t see the need for carrying test equipment. Some stated that the cost of the equipment didn’t justify the expense, while others said they had the equipment but didn’t always use it.

One respondent said that a CO alarm works in place of an analyzer. “We recommend carbon monoxide detectors,” he said. “Analyzers are very expensive and require constant calibration to be reliable.”

One person noted that it is risky to have “expensive” equipment lying around. “Analyzers are too expensive and can’t be left in a service truck overnight,” he said.

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Even if some contractors don’t conduct combustion analysis, or require techs to carry test equipment, they are part of the larger majority who believe in educating customers about the dangers of CO poisoning. In The NEWS’ survey, 82 percent of respondents felt it is important to talk to consumers about CO (Figure 3). Most respondents have “leave behind” material about CO, some of which is available from manufacturers and distributors. Others use direct mail and brochures to tell the CO story. It simply makes good business sense to educate.

“We feel it is our responsibility to educate,” one person said. “We do it to protect our customers and to reduce liability. We have found problems with CO on systems that were looked at by other contractors not using them, resulting in thankful, happy customers who tell their friends about us.”

One respondent said that there are many venues for educating consumers, including the mass media. “We use articles in newspapers and other publications,” he said. “We make television and radio appearances, appear at schools, service organizations, and chamber of commerce seminars. We try to get the word out on our safety training to various groups and attend their meetings as either members or guests doing these sessions.”

To some contractors, a good face-to-face discussion is as effective as anything else. As one respondent said, “If customers have a problem, we discuss the issues with them. In addition, we encourage them to purchase a CO detector.”

Another added, “Lots of boilers and furnaces are located inside the residence in the living space such as a laundry room or closet. We explain to them the importance of keeping the combustion air opening open. Because of the cold winters many people have a tendency to plug their outside air opening because of the cold air seeping into the room, thinking they are correcting a problem when they are actually creating one.”

Other contractors encourage their service techs to make a point of talking with customers, while armed with industry data, Website information, and updated news about CO monitors. As one person put it, “CO is the No. 1 cause of accidental poisoning deaths in North America. We simply give customers the truth about CO, how it is formed, and how it can enter a home.”

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In a follow-up interview, several contractors explained why they felt that CO education was a priority for their employees as well as their customers. They were among the 87 percent that believe in the importance of CO education (Figure 4).

“CO is an issue that is not well understood by most residential contractors,” said Gary Richardson of Rare Service Heating and Air Conditioning Inc., Clovis, Calif. “In my area, CO is not even in their vocabulary. My foreman and I have been through the NCI class by Jim Davis on combustion analysis and have taught our techs from this knowledge base how to tune up a gas furnace.

“They have been absolutely amazed at the improvement in performance of the equipment as well as the reduction of CO production of a well-tuned furnace - and they feel as though they have made a huge contribution to the comfort and health of the residents of the home.”

Scott Robinson of Apple Heating & Cooling, Ashtabula, Ohio, said that his techs can never get enough training. “I have learned that the subject matter is not easy to assimilate,” he said.

“I feel after having been to the sessions many times (eight or more) I still need more training. I have found that even after as much as 24 hours of training on the subject, some technicians still don’t quite get it.

“My feeling is we need to train on these subjects at least annually. Like all knowledge, we lose some with disuse. And commonly we do not use our training as much during the warmer months.”

And it isn’t just the technicians and owners that have a lot at stake - it is the homeowners, too. Contractors like Roger Fouche of Schaal Heating & Cooling, Des Moines, Iowa, are happy to educate them about carbon monoxide detectors.

“We often find that by the time a tech arrives at a house, the CO has dissipated substantially.

“We have concerns that the CO detectors being sold for less than $100 will only go off after being exposed to CO at a rate of 70 ppm for eight hours. You could theoretically have a CO detector at 69 ppm forever and it would never go off! This is a real issue and consumers need to be made aware of this.

“I have had, on more than one occasion, my low-level detector go off while in my bag at a customer’s house for a sales call just because of candles. After pulling it out of my bag, I find it reading in excess of 30 ppm. Most homeowners don’t want to hear that their candles are bad for them. Constant exposure to this on a daily basis is some of the chronic health issues people have but don’t know why.”

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Contractors like Robinson said it is not possible to ever know enough about CO. But according to the survey, 66 percent of respondents know enough about testing HVAC equipment for incomplete combustion (Figure 5).

One contractor, Aaron York, NEWS’ contractor consultant and owner of Aaron York’s Quality Air Conditioning, Indianapolis, noted that the education process could always use some tweaking. “In my opinion, most technicians understand the combustion process and the ramifications of CO,” he said. “This does not mean that they are experts on CO or the combustion process, but they understand it well enough to perform their jobs.

“As the new furnaces have come down the pike from the manufacturers, the techs have attended many schools to stay up to speed on product. This includes the combustion process and CO issues. They have been trained on the use of CO detectors and prove repeatedly that they are competent in this realm. There is always more to learn, but all techs need is basic, fundamental knowledge as opposed to being experts.”

Jason Williams, technician for AirWorks Inc., Kalispell, Mont., uses a Bacharach combustion analyzer on a furnace maintenance.

Peter Wolfe of B. Wolle Associates Ltd., Bethlehem, Pa., thinks there is a lot of education out there but that people all need to share a basic knowledge. “There are many good articles and manuals on the subject but not everyone is on the same page,” he said. “We need to properly test after every service call to make the customer safe and keep us out of the courtroom.”

Jeff Wright of Jeff Wright Heating & A/C Services, Richmond, Va., summed up the reasons for CO testing and education: all affect the bottom line. “When someone ventures into the HVAC trade as a contractor, technician, or installer, this leap requires an unusually large investment in tools, test instruments, and continuing educational programs.

“As a professional, we should be glad to offer our services and expertise at a premium considering our investment of knowledge and ability. This is a solid value for what can be achieved. Therefore, if we are using these skills correctly we should get paid accordingly. I am careful to take the time I need to get the task done correctly. CO training can be used for great rewards financially and consumer protection, this is a win-win for everyone.”

Sidebar: ACCA Promotes Safety

The Air Conditioning Contractors of America (ACCA) participated with the U.S. Centers for Disease Control and Prevention (CDC) and the Consumer Product Safety Commission (CPSC) in a joint public announcement regarding the dangers of carbon monoxide (CO) poisoning for America’s homeowners. The three organizations also outlined steps homeowners can take to prevent possible poisoning during the heating season.

CO is an odorless, colorless gas produced by burning fossil fuels. Sometimes concentrations reach dangerous levels, but because you can’t sense it, homeowners must take precautions to protect themselves and their families.

Homeowners should engage the services of qualified licensed contractors to annually inspect and adjust all fossil fuel heating devices (any gas-, oil-, coal-, or wood-burning appliances or equipment within the home). To make sure that the technicians do the proper check, ACCA has prepared a list of actions that should be undertaken by qualified technicians and made it available on their Website at:

Each home should have at least one carbon monoxide detector, and preferably one on each floor and/or placed outside of any sleeping areas. Much like smoke detectors, batteries should be replaced twice a year, and the monitors themselves retired and replaced according to manufacturer specifications.

Publication date:12/18/2006