Application Sizing

Determine Performance Characteristics

The effectiveness of a heat exchanger is a measure of how well heat is transferred from the hot medium to the cold medium. Effectiveness is the ratio of an ideal heat-exchange process (without any losses) to the actual exchange and is expressed as a percentage. This ratio is strongly dependent on the flow rates of the gases, dimensions of the heat-exchanger core, and thermal properties of the transfer matrix. The Wilson Heat Exchanger IR Series is currently offered in three model sizes that maintain high effectiveness across a wide range of flow rates to accommodate a variety of heat-transfer applications.

Use the chart below to compare and evaluate the effectiveness and pressure loss of these representative IR Series heat exchangers for your application. The performance curves were calculated for various equal flow rates of air and combustion gas near atmospheric pressure. Locate a representative flow rate on the horizontal axis and read the range of performance characteristics for the applicable model on the vertical axis. For larger capacities, the relatively small size of the Wilson Heat Exchanger™ allows multiple units to be combined. Please contact Wilson TurboPower for specific performance curves relative to the optimization of your application.

Calculate Preheat Temperature

The outlet temperature of the cold flow (the preheat temperature) can be calculated using known hot and cold inlet temperatures plus the effectiveness percentage shown in the performance chart.

TPREHEAT = EFFECTIVENESS (THOT – TCOLD) + TCOLD

For example, in a preheat application for a natural-gas furnace, ambient cold-flow combustion air enters the Wilson Heat Exchanger at 40°C (104°F) (TCOLD), and the hot-flow exhaust temperature is 1,000°C (1,832°F)(THOT). With an effectiveness rating of 90% (0.9), the preheat temperature of the combustion air exiting the heat exchanger (TPREHEAT) will be 904°C (1,659°F). Calculations assume both hot and cold flows are equal.

TPREHEAT = 0.90 (1,000°C - 40°C) + 40°C = 904°C

TPREHEAT = 0.90 (1,832°F - 104°F) + 104°F = 1,659°F