Abstract:The fan-coil uni t is an air handing equipment w hich deals wi th the exho ust ai r f rom the ai r conditioning sy stem. Due to i ts low price, co nv enient installatio n a nd easy di stribution, it is applied w idely among the ai r conditio ning of of fice bui lding, guestho use and hotel. The selection of a fan-coil uni t only based o n the coo ling load o f ten result s in unsa tisfacto ry ef fects of the ai r conditioning. Due at tention should be paid fo r selecting the uni t on the perfo rmance properties of surplus pressure at the out let w ith proper supply ai r v olume, so as to ensure a ppropria te supply ai r temperature dif ference and ai r changes. Wi thin the allow able noise sta nda rd in th e using situa tion, the product s wi th big ger surplus pressure at the out let a nd supply ai r v olume sho uld be chosen, so as to achiev e g ood resul ts of the ai r condi tio ning.