Water to Water Heat Exchanger
Definition:
A water-to-water heat exchanger is a device used to transfer heat between two water streams (one hot and one cold) without mixing them.

Structure:

• Shell & Tube Type: Hot water flows inside the tubes, and cold water flows around them.

• Plate Heat Exchanger: Water flows in separate channels between metal plates, providing a large heat transfer area and high efficiency.

Operation:

• Hot water (e.g., from a boiler or absorption chiller) enters the exchanger.

• It transfers its heat through the metal surface to the cold water.

• Cold water is heated, and hot water loses part of its heat.

• The two water streams never come into direct contact.

Applications:

• Heating and cooling in HVAC systems

• Food and pharmaceutical industries for temperature control without cross-contamination

• Energy recovery in production lines (e.g., using hot outlet water to preheat inlet water)

• Underfloor or radiator heating systems

Advantages:

• Prevents contamination of clean (potable) water

• High heat transfer efficiency

• Reduces energy consumption and costs

• Flexible installation and usage

Steam to Water Heat Exchanger
Definition:
This type of exchanger transfers thermal energy from hot steam to cold water. During the process, steam condenses into water, releasing heat to the cold water.

Structure:

• Often constructed as shell & tube or plate type.

• Steam usually flows on the shell side, and cold water flows through tubes or adjacent plates.

• Significant energy is released when steam condenses on the metal surface.

Operation:

• Hot steam enters the exchanger.

• Steam transfers its temperature and energy indirectly to the cold water.

• Steam condenses into water (condensate).

• Cold water becomes hot water, ready for use (e.g., in heating or industrial processes).

Applications:

• Production of sanitary hot water (hotels, hospitals, buildings)

• Central heating (radiators, underfloor systems)

• Food industry (cooking, sterilization, cleaning)

• Preheating boiler feed water to improve boiler efficiency

Advantages:

• Very high efficiency (due to latent heat released during condensation)

• Fast and effective heat transfer

• Suitable for producing large volumes of hot water

• Reduces energy consumption and extends boiler life