CYA with combustion testing and analysis

A FELLOW BRAGGED, “I can tune up any oil burner by eye as good or better than anyone can using instruments!” The time was the early 1970s, the place was the local Sid Harvey branch where I was employed and where I had been placed in charge of all oil burner work. Jim and John Wilson were the branch managers and a deep well of knowledge on all things related to heating or air conditioning. I went to that well often.

As soon as the blustering “expert” left their store, Jim and John explained the importance of doing the job of tuning up an oil burner correctly. I left that day with a new Bacharach kit consisting of two dumbbell-shaped plastic containers that were for testing for the presence of excess CO2 and O2; a smoke tester; draft gauge; and a probe-style stack thermometer. Jim and John took the time to train me before I left the store.

As the years went by, my collection of Bacharach equipment grew to include several of those test kits and they have been an invaluable resource for fine-tuning not only oil-fired equipment, but also for gas-fired units – especially the new high-tech, high-efficiency units we see today that require precise set-up for proper combustion and performance.

But those Arnold Schwarzenegger-type dumbbell CO2 and O2 testing devices have given way to the electronics age. In addition to testing for all of the above, except for smoke, the new electronic units also look at carbon monoxide, nitric oxide and can include a printer to provide hard copies of the test results. A printed test result from properly calibrated testing equipment is a great CYA (cover your assets) way to prove you did the job correctly.

The Wilson brothers had strongly recommended the kit containing the excess oxygen tester because it was possible to obtain identical carbon dioxide tests with either too much or too little combustion air. Too little air and CO forms. The electronic test equipment registers CO in parts per million and is extremely accurate.

It might be helpful to understand a little more about CO. Carbon monoxide is a colorless, odorless, tasteless, toxic gas produced during incomplete combustion of fuel – natural gas, oil, coal, wood, kerosene, etc.

During normal combustion, each atom of carbon in the burning fuel joins with two atoms of oxygen, forming harmless carbon dioxide. When there is a lack of oxygen to ensure complete combustion of the fuel, each atom of carbon links up with only one atom of oxygen, forming carbon monoxide.

Carbon monoxide inhibits the blood’s capacity to carry oxygen. In your lungs, CO quickly passes into the bloodstream and attaches itself to hemoglobin, the oxygen carrying pigment in red blood cells.

Hemoglobin readily accepts carbon monoxide over the life-giving oxygen atoms – as much as 200 times as readily as oxygen – forming a toxic compound known as carboxyhemoglobin.

Low levels of carbon monoxide poisoning result in symptoms commonly mistaken for common flu and cold symptoms: shortness of breath on mild exertion, mild headaches and nausea.

With higher levels of poisoning, the symptoms become more severe: dizziness, mental confusion, severe headaches, nausea and/or fainting upon mild exertion. At high levels there may be unconsciousness and death.

Compounding the effects of the exposure is the long half-life of carboxyhemoglobin in the blood. Half-life is a measure of how quickly levels return to normal. The half-life of carboxyhemoglobin is about five hours. This means that for a given exposure level, it will take about five hours for the level of carboxyhemoglobin in the blood to drop to half its current level after the exposure is terminated.

So, the real question becomes how much is too much? Symptoms vary widely based on exposure level, duration, and the general health and age of an individual. The one recurrent theme that is most significant in the recognition of carbon monoxide poisoning is headache, dizziness and nausea.

These “flu-like” symptoms are often mistaken for a real case of the flu and can result in delayed or misdiagnosed treatment.

The chart on this page shows exposure limits.

The OSHA standard for exposure to carbon monoxide prohibits worker exposure to more than 35 PPM of CO, averaged over an eight-hour workday. There is also a ceiling limit of 200 PPM, as measured over a 15-minute period.

Work safe, work smart and CYA.

Dave Yates owns F.W. Behler Inc., a contracting company in York, Pa. He can be reached by phone at 717/843-4920 or by e-mail at [email protected].