| 摘要 |
PURPOSE:To improve a thermal efficiency by a method wherein secondary heat exchangers are provided at a hot-water supplying side and a room heating side respectively so as to be located in the after streams of primary heat exchangers. CONSTITUTION:Primary heat exchangers 4, 14 are provided at the upper part of the cylinders 3, 13 of the room heating side and the hot-water supplying side heat exchangers equipped with burners 2, 12 penetrating therethrough while secondary heat exchangers 6, 16 are provided respectively in the after streams thereof at the communicating part with an exhaust gas assembling part 19. The primary heat exchangers 4, 14 are consisting of water tubes with fins. |
