Hayward H Series For Above Ground Pool Heater Low NOx Induced Draft Propane Gas 100.000 BTU P/N: H100IDP1 High performance. Low NOx. All Hayward Low NOx IDL heaters are dual voltage. The new Hayward H-Series Low NOx Induced Draft Heaters feature a patent pending Finn Plate heat exchanger for constant heat dispersement, state-of-the-art pre-mix burners for environmentally friendly Low NOx outputs, hot surface ignition for instant and reliable fire up, and an advanced L.E.D. digital control panel for simple programming of pool temperatures. It also includes an induced draft system that constantly moves air through the combustion chamber at a precise flow rate. As a result, all outside weather variables that can affect the heating performance, such as wind conditions, are eliminated without having to install a high-wind stack. NOTE: The Hayward IDL Series of heaters meet the NOx Emission standards set by the California South Coast Quality Air Management Commission for 2001 and the Texas Natural Resource Conservation Commission Code.