<strong>Yahoo Message Number: 13649</strong>JH,<br/><br/>The bungs may just be for positioning of tubing while in tube bending machine. Temperatures in intake & exhaust sysems are used to evaluate efficiencies of heat exchangers, turbo sections, cylinders & more. The test data is evalutaed by the engineer, not me.<br/><br/>Bob Kumza,<br/><br/>Your question of exterior vent for range hood (or microwave oven) is well...