The selection of the right condenser is crucial to be able to perform the required application. Depending on the required condensation level a different cooling capacity needs to be chosen.

The easiest way for finding the right conditions is by applying the “delta 20 rule”:

• Heating bath temperature should be 20 degrees higher than the boiling point of the solvent to be evaporated at the vacuum chosen
• Cooling temperature should be at least 20 degrees lower than the boiling temperature of the solvent

A bath temperature of 50 °C is recommended for many applications.

Example:

• 50 °C heating bath temperature
• 30 °C boiling temperature (by adjusting the vacuum)
• < 10 °C cooling temperature

There are many advantages of heating the bath to a maximum of 50 °C:

• No risk of scalding when handling the evaporation flask
• Lower evaporation of heating liquid (e.g. water)
• Higher energy efficiency compared to other heating bath temperatures

The transparent plastic coating (P+G) improves the durability and stability of the glass. It also protects the operator from broken bits of glass as well as chemicals in case of glass breakage.

Tap water is the most common used fluid. When using distilled water, 0.5 g of Borax should be added. Distilled water without any additionally added ions will corrode the bath. For heating temperatures higher than 95 °C we recommend polyethyleneglycol (PEG).