Plate Heat Exchanger Sizing Guide for Heating Systems
Brazed plate heat exchangers are widely used to transfer heat between two separate water circuits while keeping them hydraulically separated. They are essential in heat pump systems, boiler installations, underfloor heating circuits, and thermal stores.
Choosing the right exchanger ensures efficient heat transfer, stable system operation, and reliable performance. This guide focuses on inlet and outlet temperatures (ΔT) and provides a simple overview for selecting the correct plate heat exchanger.
Temperature Difference (ΔT)
The most important factor when selecting a plate heat exchanger is the temperature difference between the flow and return temperatures (ΔT).
Typical heating systems operate with:
Heat pump systems:
5–10°C ΔT
Example:
Flow 45°C / Return 40°C
Boiler systems:
10–20°C ΔT
Example:
Flow 70°C / Return 55°C
A larger ΔT allows more heat transfer, while smaller ΔT systems may require a larger plate heat exchanger to achieve the same output.
Quick Plate Heat Exchanger Guide
The table below shows typical plate exchanger sizes commonly used in heating systems.
These are typical selections used for boilers, heat pumps and hydraulic separation applications.
Actual sizing may vary depending on:
-
system flow rates
-
inlet and outlet temperatures
-
pressure drop requirements
-
heat load
Example: Gas Boiler System
Example system:
Boiler: 26 kW
Primary circuit: 75°C flow / 55°C return
Secondary circuit: 45°C flow / 65°C return
Typical exchanger used:
This provides sufficient heat transfer while maintaining low pressure drop.
Typical Applications
Plate heat exchangers are commonly used for:
• Heat pump hydraulic separation
• Boiler system separation
• Underfloor heating circuits
• Thermal store connections
• Domestic hot water heat transfer
Why Use This Guide
This guide helps heating engineers and installers select the correct plate heat exchanger for their system. Proper selection ensures efficient heat transfer, stable circulation, and reliable operation.
At B.E.E. – The SMART Heating Merchant, we supply hundreds of SWEP plate heat exchanger options for residential and commercial heating installations. The E8TH and B10TH plates shown here are the most commonly stocked models, but additional configurations are available to suit different system requirements.
Still Not Sure Which Heat Exchanger You Need?
Use our Heat Exchanger Selection Form and send us your system details. Our team will review the information and help identify a suitable plate heat exchanger for your installation.