Solar Water Heater Flat Plate Heat Exchanger

 

Heat Exchangers

The most critical component of a solar water heater is the heat exchanger.  It greatly effects performance and is the heart of scaling or corrosion in a system.  Our system utilizes a 14 plate 316 stainless steel heat exchanger from Swep of Sweden.  Flat plate exchangers have better thermal transfer than any other heat exchanger available today.  Because of its 316 stainless steel composition, compact size and turbulent flows it is easy to periodically clean by flushing with an acidic solution.  It is critically important to keep the heat exchanger clean of  scale buildup which greatly reduces effeciency.

 

How Does a Flat Plate Heat Exchanger Work?

These unique heat exchangers are made from 316 stainless steel sheets and stamped with herringbone pattern of grooves.  Identical sheets are stacked in alternating directions, forming separate flow channels for the two liquid streams. The ridges of adjacent plates touch one another in a matrix of contact points. This assembly is then brazed at the contact points and edges to create a rugged, compact, counter-flow heat exchanger.


After the cold tap water enters port 1) it will travel through every other plate and exit port 4) slightly warmer.  The warm collector loop fluid will enter port 2) and travel through every other plate and exit port 3) slightly cooler.  This process continues until the pumps are stopped by the system controller.

 

 

Plate Heat Exchangers Compared to all Other Heat Exchangers

  • 3 to 5 Times Higher Heat Transfer Efficiency

  • Cheaper in Cost

  • Easy to Dismantle, Inspect and Maintain

  • Easy to Clean

  • Space Savings of up to 90%

 

Performance

 

Below is a solar system temperature over time performance chart with the Swep heat exchanger.  The initial storage tank water temperature is 70 degrees and the collector fluid temperature is 87 degrees.  As shown via the graph the temperature difference between the collector loop and storage tank over the course of the day is between 5 to 10 degrees.  The overall performance loss due to an exchanger is only around 5 to 8%.


 

International Certifications

Underwriters Laboratories Inc.

International Organization for Standardization

Canadian Standards Association