Marcellus area spot natural gas trading points. Underground natural gas storage facilities. PDF Marketed production of natural gas in the United States and the Gulf of Mexico 2009. National Petroleum Reserve Alaska. Natural gas deliveries to the electric sector PDF natural gas market centers. Natural gas pipeline/transportation maps
Temporary air intakes such as open boiler room windows can be closed (and often are when persons in the boiler room are feeling cold) cutting off the boiler's air supply. When the combustion air supply is closed off the fire starts to smoke as the air supply is exhausted. Incomplete combustion occurs and carbon monoxide is generated.