Capillary Tube for 12,000 BTU Compressor

The capillary tube for a 12,000 BTU compressor depends on the type of refrigerant gas and the evaporator temperature.

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Before Selecting a Capillary Tube for 12,000 BTU Compressors

The performance of capillary tubes is determined by both their length and diameter, which together define the total restriction:

1. Impact of Diameter Changes: A percentage change in diameter has a more significant effect on flow than an equivalent change in length.
2. Adjusting Restriction:
   • Lengthening the tube increases restriction and slows the flow.
   • Excessively long tubes may become uneconomical and often ineffective.
   • Shortening the tube gradually increases flow until reaching a critical point where flow increases more rapidly with each reduction in length.
   • Extremely short tubes can result in large flow increases with minor length reductions. At this stage, the tube acts more like an orifice than a capillary tube.

General Recommendation: Keep the tube between 5′ and 16′ in length. While exceptions exist, adhering to this range avoids many operational issues.

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Capillary Tubes for 12,000 BTU Compressors Using R134a

Evaporator Temp.	Length (m)	Diameter (mm)
5°C	1.09	2
7.2°C	1.10	2

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Capillary Tube for Air Conditioning with R410A

Diameter (in)	0.047	0.049	0.055	0.059	0.063	0.071	0.079	0.087
Length (m)	0.2033	0.2438	0.4583	0.6953	1.025	2.041	3.646	6.012

Capillary Tube for 12,000 BTU Window Air Conditioner with R410A

Evaporator Temp.	Capillary Tube Dimensions
45°F	0.064 in, 94″

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Capillary Tube for 12,000 BTU Compressor Using R404A

Evaporator Temp.	Dimensions
-10°F	0.064″ – 5½ ft (2 tubes)
25°F	0.064″ – 6 ft (2 tubes)
45°F	0.064″ – 6½ ft (2 tubes)

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Capillary Tubes for 12,000 BTU Compressor Using R22

Evaporator Temp.	Dimensions
-10°F	0.064″ – 4 ft
25°F	0.052″ – 5 ft (2 tubes)
45°F	0.052″ – 5 ft (2 tubes)

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