摘要 |
The conduit circuit (5) incorporates a second circulation pump (11) and a by-pass conduit (12) coupled between the two pumps. When the first pump is cut out all the heat carrying medium is fed from the input air heat recovery battery (1) back to it, i.e. without the heat carrying medium passing through the output air recovery battery (2). A source (14) for peak heat feeds when required further heat to the conduit circuit. A cool source (16) also when required feeds cold to the conduit circuit when the first pump (6a) is cut out. |