Air conditioner

An air conditioner comprising:

• a refrigeration compressor, an external heat exchanger, an expansion device including first and second expansion means, and an internal heat exchanger to effect a refrigeration cycle, and a valve to direct the flow of refrigerant for heating and cooling operations,
• means for separately mounting said external and internal heat exchangers in respective external and internal units which are to be at spaced locations,
• means for connecting said compressor, valve, external and internal heat exchangers and expansion device to perform a refrigerant cycle, including refrigerant piping of some length for connecting said separated external and internal heat exchangers,
• said first expansion means of said expansion device maintaining a high-low pressure of the refrigeration cycle at a desired state when the length of said refrigerant piping is below a predetermined length and said second expansion means maintaining the high-low pressure at the desired state when said refrigerant piping is longer than said predetermined length, and
• control means for selectively activating one or both of said first and second expansion means according to the length of the said refrigerant piping and the state of the heating or cooling operation of the air conditioner for changing the volume of expansion produced by said expansion device to adjust the high-low pressure of the refrigeration cycle.