Johnson’s Small Stainless Steel LP Gas CO2 Generator is a ceiling‑hung unit built for longevity and simple greenhouse integration. The LP model uses a 24 V gas valve with automatic flame‑failure shutoff and includes a pressure gauge; a 115V/24V transformer is required, and an optional controller is available. At full fire it delivers up to 60,000 BTU/h and about 72 cubic feet of CO2 per hour (approximately 8.25 lb/h) at 60°F, suitable to enrich roughly 4,800 ft² at one air change per hour. Typical installation dimensions are 18 in diameter by 20 in height, with a weight around 21 lb. The unit hangs from the rafters to save floor space and is manufactured in the U.S. by Johnson Gas Appliance Co.