a condenser is a piece of apparatus or equipment that can be used to condense, that is, to change the physical state of a substance from its gaseous to its liquid state; in the laboratory, it is generally used in procedures done with liquids brought into gaseous state through heating or application of vacuum (lowered pressure); often a mixture with water or other substances. condensers can be applied at various scales, from micro-scale (very few microliters) to process-scale (many liters), using laboratory glassware and occasionally metalware that accomplishes the cooling of the vapor generated by boiling (through heating or application of vacuum).