Abstract: An air conditioning unit is capable of preventing a liquid absorbent from crystallizing, thereby enhancing reliability of the operation thereof. A given amount of refrigerant is supplied to dilute the liquid absorbent when the air conditioning unit stops in operation, and it is circulated in lines and components of the air conditioning unit, thereby cleansing the liquid absorbent remaining in the components or lines, and the liquid absorbent is returned to the liquid tank, so that the liquid absorbent is prevented from crystallizing, whereby reliability of the operation is enhanced.

Abstract: A fuel-lean mixture burns in rows of flame ports each located between a pair of rows of flame ports burning a fuel-rich mixture. The fuel-rich flames support and stabilize the fuel-lean flames to stabilize combustion and to avoid flame liftoff and noise. The fuel-lean flames reduce the temperature of the overall flame, and thereby reduce the production of No.sub.x compounds produced by the burner. Stepwise and proportional burner control techniques are disclosed.

Abstract: A small combustion apparatus for domestic or commercial use, wherein the quantity of combustion is increased by enhancing the mounting density of the burner units and to stabilize combustion using a lean fuel mixture resulting in a decreased generation of nitrogen oxides and noise. The burner has first and second burner units, arranged alternatively adjacently to one another. Each of the burner units has a flame port portion at the top of the burner body vertical and flat, has an inlet for fuel gas and air at the bottom of the burner body, has a mixing channel extending from the inlet to the flame port portion; and has inlets of the first burner units located below the inlets of the second burner units fuel gas spouts, are provided to correspond to the respective inlets of the first and second burner units.