Case Study: Carbon Monoxide Incident

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Allegedly, sustained exposure to carbon monoxide occurred during the operation of a building unit’s rooftop unit with a natural gas heating section. The heating section's heat exchanger was described as having a "hole" or being "cracked in half." Omnitek Engineering, Inc. was assigned to determine if the air conditioner had been a likely source of carbon monoxide in the unit during the time it had been occupied.

The laboratory testing conducted included operating a similar rooftop unit under various operating conditions to investigate air flow between the flue gas side of the heat exchanger and supply air side of the heat exchanger with holes of varying sizes, cracks of varying lengths, and the complete separation (“cracked in half”) of a heat exchanger tube. The data collected included collection of combustion analysis data; visualization of heat exchanger air flow using test smoke; carbon monoxide monitoring and data collection of the return air and supply air during the varying heat exchanger conditions; flue side heat exchanger pressure measurement during ventor operation; and observing burner operation.

Based on findings from examination, testing and research, Omnitek Engineering, Inc. determined it is unlikely that sustained exposure to carbon monoxide occurred due to a failure in the heat exchanger of the rooftop unit.