| 摘要 |
<p>Space heating apparatus 10 comprises a fresh air inlet 14 communicating with heating chamber 16 which has a first opening 20 connecting to mixing chamber 22. A gas burner 24 is located near to first opening 20 so as to heat air passing therethrough. Second and third openings 38, 40 are provided above and below first opening 20 into the mixing chamber 22, each communicating with a common recirculated air inlet 42. Gate means in the form of two plates 52, 54 are mounted so as to be slideably displaceable in unison such as to open or close the first, second and third openings 20, 38, 40 whilst maintaining a constant cross-sectional area for air flow into the mixing chamber 22. A fan 28 is mounted in an outlet 26 so as to draw cold air through the apparatus 10 and discharge heated air into an interior building environment through an air delivery outlet 30. <IMAGE></p> |
