Abstract: Improved process permitting a vinyl chloride batch which is to undergo polymerization in suspension, to be additionally cooled. Gaseous matter formed in the gas chamber of a polymerization vessel is delivered through a pipe connection communicating with the gas chamber and a reflux condenser, to the reflux condenser and condensed therein, and the resulting condensate is returned to the polymerization vessel. In the improved process one or more nozzle structures are used to inject fully desalted water into the pipe connection over the entire polymerization period. The spray water has an approximate temperature of from 5.degree. to 45.degree. C and is used in a proportion of at least 10% by volume, based on the overall quantity of water necessary for effecting the polymerization.