AIR CONDITIONING INSTALLATIONS AND APPARATUS, NAMELY, [ EVAPORATIVE AIR COOLERS, ] CENTRAL AIR CONDITIONING UNITS [, THRU-WALL AIR CONDITIONING UNITS, HEAT PUMPS, AIR HUMIDIFIERS, AIR DEHUMIDIFIERS, ELECTRIC, GAS AND KEROSENE AIR SPACE HEATERS, AIR PURIFIERS, AIR FILTERS FOR NON-RESIDENTIAL, INDUSTRIAL AND HOME INSTALLATIONS, AND REPLACEMENT PARTS THEREFORE; AIR HANDLERS FOR CIRCULATING CONDITIONED AIR THROUGHOUT A HOME, OFFICE OR COMMERCIAL BUILDING; HEAT EXCHANGERS FOR HEAT RECOVERY; SWIMM...