Mr Fix It Plumbing 4320 Atlantic Ave #230, Long Beach, CA 90807 (562) 988-2454 http://www.mrfixitplumbing.com/ A combustion air opening within an exterior wall of 1-square-inch for every 4000 Btu ranking of water heater is needed inside the higher and reduced twelve inches of the enclosure. With our in depth https://www.google.com/maps?cid=4067949459714107514