| A heat exchanger is a device designed to efficiently | | | | Shell and tube heat exchangers are available in |
| transfer the heat from one medium to another. In | | | | dozens of tube configurations and sizes ranging from |
| the case of an outdoor corn boiler, these media | | | | a few feet long to 50 feet or more for power plant |
| would be air and water. | | | | steam generation. |
| A typical domestic setup would include a | | | | A variation on the shell and tube design is shell and |
| water-to-water heat exchanger for hot water and a | | | | coil where a helical (spiraling) coil replaces the tubes. |
| water-to-air heat exchanger for forced air home | | | | No matter what the design or application, the basic |
| heat. Water-to-water exchangers are also used to | | | | principle is the same. The water to be heated flows |
| heat hot tubs, swimming pools and the water for | | | | through tubes, and the heated boiler water encased |
| radiant baseboard or radiant in floor heating systems. | | | | by the shell flows around the tubes. |
| Water-to-Water Heat Exchangers | | | | Turbulence is created by the baffles holding the |
| The three most common types of water-to-water | | | | tubes together in what is called a tube bundle. |
| heat exchangers used with outdoorcorn boilers are: | | | | Shell and tube exchangers for non-chlorinated water |
| Sidearm, Shell and Tube, and Brazed Plate. What | | | | applications, such as domestic hot water and hydronic |
| differentiates one from the other besides the cost is | | | | heating, are usually constructed with a brass shell and |
| the way they're designed to transfer heat from one | | | | copper tubes. |
| medium to another, and the method used to create | | | | For swimming pools and spas the shell should be PVC |
| turbulence. | | | | or stainless steel with stainless steel tubes. 316L |
| A key component in the efficient transfer of heat | | | | grade stainless steel is commonly used for this |
| between liquids is turbulence. The more turbulent the | | | | application. |
| flow of water, the more efficiently heat is | | | | Cost: $200-$600 depending on copper or stainless |
| transferred. | | | | construction and the overall size based on the |
| Sidearm Heat Exchanger | | | | volume of water to be heated. |
| The sidearm exchanger is a popular and inexpensive | | | | Brazed Plate Heat Exchanger |
| choice for heating domestic hot water. It | | | | The third type combines compact size with a highly |
| incorporates a pipe within a pipe design where the | | | | efficient design to produce a device for heat transfer |
| water in the inner pipe (your hot water) is heated by | | | | that is up to six times smaller than a shell and tube |
| hot water from the boiler circulating through the | | | | heat exchanger of similar capacity. |
| outside pipe. | | | | The key to this efficiency lies in their unique |
| Turbulence is created by scrolling on the outer | | | | construction. Corrugated stainless steel plates are |
| surface of the inside pipe. | | | | brazed together (eliminates gaskets) with every |
| This straightforward design prevents clogging by | | | | second plate turned 180 degrees. This design creates |
| sediment and resists scaling. One drawback of the | | | | two highly turbulent fluid channels that flow in |
| sidearm type is reported slow recovery under heavy | | | | opposite directions (counter flow) over a massive |
| use. Cost: $130-$150. | | | | surface area. |
| Shell and Tube Heat Exchanger | | | | Cost: $100-$500 depending on capacity. |