Setting up a temporary heating system to assure that work continues even on the coldest days requires close attention to safety guidelines. SAFE FUEL HANDLING Most heating systems for enclosures require mobility, so the use of 100-pound propane cylinders is common. A safe way to increase propane output from cylinders is to manifold three cylinders. This allows heaters of 200,000 to 400,000 Btu per hour to operate at full capacity. An alternative to manifolding is to use bulk storage propane in a 500- or 1,000-gallon tank. HEATING EQUIPMENT Use the following list of heating equipment recommendations to help ensure heaters are used safely and efficiently: 1. Make sure all gas-fired equipment is equipped with 100% fuel shutoff valves. 2. Never operate direct-fired heating equipment in an unventilated area. 3. Keep heating equipment away from combustible materials. 4. Make sure lines used on gas-fired equipment are approved for the designated fuel and rated for the pressure required to operate the equipment. 5. When using cylinders, protect against leakage due to broken lines or loose fittings by using an excess-flow valve at the cylinder valve outlet.