Gas extractor fresh air intake device for gas heater - uses pressure temp. transducers to control vane which directs flow between gas extraction and air intake

摘要

The burnt gas extractor/fresh air admission device comprises a gas evacuation hood with an offset vertical chimney on which is mounted a distribution box of parallelepipedic shape having an air inlet in its lower face. A pressure transducer mounted near the air inlet monitors the flow rate and two transducers (23) made from silica resistances or positive temperature coefficient resistances are placed in the air tube (22). The transducers are mounted on a printed circuit board mounted in guides so as to be readily removable. The printed circuit has a central hole through which air passes. The transducers are used to control a vane (3) which directs the flow, driven by a fan (5), to either extract gases or draw in fresh air.