The assembly comprises a housing 14 generally containing {HEAD ~ a propane or natural gas fired furnace} 16 with {TAIL ~ supply duct} 18 
with
The assembly comprises a housing 14 generally containing { HEAD ~ a propane or natural gas fired furnace } 16 with { TAIL ~ supply duct } 18
OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH REL TAIL TAIL TAIL TAIL TAIL TAIL OTH