MORE: With school out, Philly teens say they need more places to build community and stay safeOuyang has, essentially, pardoned all that dust, because Philadelphia’s Kensington High School now has air conditioning. Around 50 Philadelphia schools — or nearly one quarter of district schools — still won't have what the district considers to be adequate cooling when the school year begins later this month. In the last four years, the number of Philly schools without air conditioning has fallen from 118 to 52. Still, the district seems unlikely to meet its previous goal of air conditioning all its buildings by 2027. Adding AC to old schools can take yearsKensington High School’s HVAC upgrades included replacing aging heating, ventilation, and air conditioning systems, along with updating ductwork.