Refrigerant charge status indication method and device
First Claim
1. A method of determining the sufficiency of refrigerant charge in an air conditioning system having a compressor, a condenser coil, an expansion device and an evaporator coil connected in serial refrigerant flow relationship, comprising the steps of:
- sensing the temperature of the refrigerant leaving the condenser coil and generating a first electrical signal representative thereof;
sensing the outdoor temperature and generating a second electrical signal representative thereof;
converting said first and second electrical signals to first and second digital values; and
comparing said first and second digital values to obtain an approach temperature difference; and
comparing said approach temperature difference with predetermined optimal values to determine whether a proper refrigerant charge condition exists.
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Accused Products
Abstract
A method and apparatus for determining the sufficiency of the refrigerant charge in an air conditioning system by use of temperature measurements. The temperature of the liquid refrigerant leaving the condenser coil and the outdoor temperature are sensed and representative electrical signals are generated. The electrical signals are converted to digital values that are than compared to predetermined optimal values to determine whether the system is properly charged with refrigerant. An appropriate LED is lighted to indicate that the system is undercharged, overcharged or properly charged. For non-TXV/EXV systems a third parameter i.e. the return air wet bulb temperature is also sensed and a representative digital value thereof is included in the comparison with the predetermined known values to determine if the charge is proper.
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Citations
17 Claims
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1. A method of determining the sufficiency of refrigerant charge in an air conditioning system having a compressor, a condenser coil, an expansion device and an evaporator coil connected in serial refrigerant flow relationship, comprising the steps of:
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sensing the temperature of the refrigerant leaving the condenser coil and generating a first electrical signal representative thereof; sensing the outdoor temperature and generating a second electrical signal representative thereof; converting said first and second electrical signals to first and second digital values; and comparing said first and second digital values to obtain an approach temperature difference; and comparing said approach temperature difference with predetermined optimal values to determine whether a proper refrigerant charge condition exists. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Apparatus for determining the sufficiency of refrigerant charge in an air conditioning system having a compressor, condenser coil, an expansion device and an evaporator coil interconnected in serial refrigerant flow relationship comprising:
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a temperature sensor for sensing the temperature of the liquid refrigerant leaving the condenser; a first signal generator for generating an electrical signal representative of said sensed liquid refrigerant temperature; a second signal generator for generating a second electrical signal representative of a sensed outdoor temperature; an analog-to-digital converter for converting said first and second electrical signals to first and second digital values, respectively; a first comparator for comparing said first and second digital values to obtain an approach temperature difference; and a second comparator for comparing said approach temperature difference with predetermined optimal values to determine whether a proper refrigerant charge condition exists. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17)
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Specification