reportrter: older aiair condiong units use hyhydroflurocarbrbo, greenhouse gases that are bad for thenvironment. they're now being replaced by a new system. marion: it's energy efficient, itit's climate friendly. meaning that i it's using nanal refrigigerants whichch don't m the enviroronment. so t they have a v very, very,y low w globalarmingng pentiala. reporter: the new refrigerant is propane, a highly flammable gas. there arare strict safafety regugulations goveverning its . itit a new challenge for technianans in gnadada. dedennis: hope a all of you ha nicece weekend. porter: at this workshshop, paicicipantsearnrn abo the n new systems. dedennis: hope a all of you ha the training is orninized by polocal professionals,s, with te paicicsupport ofof the germannew corporatioion for internationl cooperatio dedennis: there e aren't really ririsks associatated with norl use.e. the only ririsks are en tenicicians me intnto ntact withth it. when trere's aroblem, and theyn. reporter: every st is discussed inetetail. these pipes e being g sembled to transport the fmmmmable propopane. they n