Application Notes for
Combustible Gas Detection
(Application Note # HV-13-0516)

In recent years, combustible gas leak detection has grown in importance because of increased safety concerns, performances of products/systems, liability concerns, health concerns, & warranties.

Gas leak detection is a way of nondestructive testing of dangerous combustible gases from sealed components or systems. Leaks can easily result from poor seals and connections, as well as from inadequate welds. Slow gas leaks from small defects or vibrations can be dangerous, expensive, frustrating, time consuming, and a potential for sickness, death or explosions. For years, contractors and other personnel used the OLD soap & water method which has been proven to be ineffective in detecting the precise location of particularly small gas leaks. Recently, gas leak detectors & gas sniffers have become much more popular & useful.
The Most Common Reasons for Gas Leak Detection are:

1. Protect Personnel and Property: Gas leaks can potentially create serious personnel hazards as well as destroy material and property.
2. Contamination and Safety: With stricter OSHA and environmental regulations, the reasons for gas leak detectors are growing.
3. Reliability: Equipment reliability has always been a major reason for gas leak detectors & gas sniffers.
4. Energy Loss: With the high cost of energy, losses are increasingly important. By gas leak detection, energy can be saved by conserving the amount of fuel used in a system such as natural gas or propane from leaking out

Most Common Users of Gas Leak Detectors & Gas Sniffers:
• Gas Utilities
• Building Owners (Office, Apartments, etc)
• Plumbers
• Refrigeration
• HVAC Contractors
• Pipelines
• Home Owners

Most Common Gas Leak Detector & Gas Sniffer Applications:
• Fittings
• Furnaces
• Pipes (metal or plastic)
• Water Heaters
• Valves
• Gas Appliances
• Canisters
• Tanks
Most Common Gases Being Tested for Leaks in
Residential, Commercial and Industrial Applicaitons:
• Propane
• Butane
• Natural Gas
• Other Combustible Gases
Portable Combustion
Analyzers as Safety Devices (Application Note #HV-13-0602)

Portable Combustion Analyzers Can Be Used as Safety Tools for Technicians in Residential or Commercial HVAC Applications. With all residential & commercial boilers, furnaces, & heaters, there is an inherent risk that cracks in the heat exchanger, improperly maintained ducting systems, or other malfunctions can cause combustion gases to leak into the living or working environment of a building. During the combustion process, an inadequate supply of oxygen can result in the production of higher than normal concentrations of carbon monoxide. Thus, if a combustion system is not properly maintained, the occupants of the building or any HVAC contractors working in the boiler room may be at risk of exposure to dangerous levels of carbon monoxide

Carbon monoxide (CO) is a colorless, odorless, tasteless, flammable and highly toxic gas that can cause adverse health effects if inhaled at certain concentrations. The table below describes the effects of different levels of exposure.

Combustion gas analyzers can be used to measure the levels of ambient CO present in a boiler room and throughout the building to ensure the safety of all occupants.

Measuring Combustion Efficiency Properly on 90%+ Condensing Equipment

Combustion efficiency is a measurement of how well any given fuel is being burned and converted into useful energy (heat, hot water, steam). The calculations are based on 3 major factors:

1. Chemistry of the burned fuel (propane, natural gas, oil, etc)
2. The CO2 percentage by volume after the combustion process
3. The NET temperature difference between the Stack Gas and the Primary

Condensing furnaces, boilers, and tankless water heaters use a different method of measuring ▲T because condensing systems use outdoor air as the primary temperature (not the amient room air temp). Furthermore, the stack temperatures of condensing systems are MUCH lower than atmospheric systems, so the importance of properly measuring the correct ▲T is much greature for accurate combustion efficiency calculations using your combustion analyzer.

High efficiency, condensing furnaces/boilers/water heaters need to be tested properly by driller a hole in the incoming air plastic/ PVC vent pipe (most manufacturers have dual testing ports already for both incoming air and exhaust, please refer to their specifications of where to test.) In order to botain an accurate combustion efficiency reading, the Smart Incoming Air Temp Probe must be inserted in the combustion air intake (while simultaneously the standard 12” probe is inserted into the Flue Exhaust Stack) so that a True NET Stack Temperature is used in the eciency calculation of the analyzer.


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