Evaporators and Cascades


The versatility of Vahterus Plate & Shell Heat Exchanger is particularly demonstrable in evaporator applications. Our product can be used as highly efficient Flooded or Direct Expansion (DX) evaporators, due to low pressure drop and high heat transfer. Fully welded circular plates and a protective outer shell guarantee safety, high integrity and durability for our customers.

In particular, since the droplet separation system is integrated with the flooded evaporator, Vahterus PSHE Combined is an efficient and compact solution for evaporators.


The cascade unit combines both a condenser and an evaporator (flooded or DX). Vahterus Plate & Shell Heat Exchangers are ideal for cascade operations, based on their high thermal efficiency, a minimum difference in temperature between the evaporative and condensing media, and low running costs. Our fully welded construction ensures that there is no leakage or cross-contamination. The unit is easy to install, as well as to insulate. In refrigeration, cascade heat exchangers are used to transfer heat between two refrigerants. They are used especially with CO2.

The media can be the same e.g. NH3 / NH3 is often used in heat pumps, or different e.g NH3 evaporating against CO2 condensing in cooling or freezing systems.

In process industries, the cascades can be used as highly efficient steam transformers where there is black steam condensing in the plate pack and clean steam generated in the shell. Capacity range varies between 5–10,000 kW.

Key benefits:

  • Compact size
  • Small refrigerant charge in refrigeration applications
  • Efficient heat transfer
  • Low pressure drop
  • Availability of multiple materials
  • Easy to install and insulate