such as pvc used in the plumbing trades because of its low cost durability and ease of assembly with a quick drying adhesive and a wide range of fittings pvc tubing having a 7 8 34 od and 3 4 34 id is preferred the manifold has an inlet 16 supplied with water from any convenient service such as a high pressure garden hose 17 a manual shutoff valve 18 is added for maintenance purposes as an optional feature a mineral filter 19 may be installed at the inlet when conditions warrant its use a number of tee fittings 20 are provided in the manifold 15 at substantially equally spaced intervals to roughly demarcate the condenser into approximately equal sections a vertical tube 21 is secured in the stem of each tee to overlie the condenser from bottom to top the open branch of the tee at the manifold end is capped off each vertical tube carries spaced nozzles 22 which direct a spray toward the condenser the vertical tubes here shown as eight in number are divided into four spray stages numbered a b c and d in fig3 and 4 stage a closest to the inlet is designated as the lead stage manifold 15 is supplied with a number of electrically operated solenoid valves 23 in series flow relationship a solenoid valve is installed at the inlet of each stage and is accordingly designated 23a 23b 23c and 23d on the drawings when solenoid valve 23a is energized stage a is activated.