Table 7—R-22 System Suction Pressure Drop

Nominal

 

Line

Pressure

Suction

 

 

 

R---22 Suction Line Pressure Drop (psig)

 

 

Size

 

OD

Drop

Velocity

 

 

 

Total Equivalent Line Length (ft)

 

 

 

(Btuh)

 

(in.)

(psi/100 ft)

Fpm

20

50

80

100

125

150

175

 

200

225

250

 

5/8

13.6

2563

3

7

11

14

17

20

24

 

27

31

34

18000

5/8

4.0

1539

1

2

3

4

5

6

7

 

8

9

10

 

3/4

1.5

1025

0

1

1

1

2

2

3

 

3

3

4

 

 

7/8

0.8

769

0

0

1

1

1

1

1

 

2

2

2

 

 

5/8

6.7

2052

1

3

5

7

8

10

12

 

13

15

17

24000

3/4

2.5

1367

1

1

2

3

3

4

4

 

5

6

6

 

7/8

1.3

1026

0

1

1

1

2

2

2

 

3

3

3

 

5/8

10.1

2565

2

5

8

10

13

15

18

 

20

23

25

30000

3/4

3.8

1708

1

2

3

4

5

6

7

 

8

9

9

 

7/8

1.9

1282

0

1

2

2

2

3

3

 

4

4

5

 

3/4

5.3

2050

1

3

4

5

7

8

9

 

11

12

13

36000

7/8

2.6

1538

1

1

2

3

3

4

5

 

5

6

7

 

 

1 1/8

0.7

902

0

0

1

1

1

1

1

 

1

2

2

 

 

3/4

7.0

2392

1

3

6

7

9

10

12

 

14

16

17

42000

7/8

3.5

1795

1

2

3

3

4

5

6

 

7

8

9

 

1 1/8

1.0

1053

0

0

1

1

1

1

2

 

2

2

2

 

3/4

8.9

2733

2

4

7

9

11

13

16

 

18

20

22

48000

7/8

4.4

2051

1

2

4

4

6

7

8

 

9

10

11

 

1 1/8

1.2

1203

0

1

1

1

2

2

2

 

2

3

3

 

7/8

6.7

2564

1

3

5

7

8

10

12

 

13

15

17

60000

1 1/8

1.8

1504

0

1

1

2

2

3

3

 

4

4

5

 

1 3/8

0.7

987

0

0

1

1

1

1

1

 

1

2

2

Line set application not recommended

Example 2

Jason is servicing a 5-ton R-22 air conditioner with 7/8” suction line. As part of his basic inspection he believes he has normal airflow because the air filters are clean, ductwork appears to be properly sized and in good shape and the evaporator coil is clean. He then checks the superheat and subcooling at the outdoor unit service valves. Taking pressures and temperatures he finds the following:

SLiquid line pressure = 260 psig S Liquid line temperature = 110°F S Suction line pressure = 60 psig

SSuction line temperature = 65°F

Using an R-22 PT relationship, Jason calculates the subcooling to be approximately 10°F with 30°F superheat. Because the subcooling is correct but the superheat appears to be high, he is concerned and decides to perform the Pseudo Evaporator Superheat check.

Examining the lineset, Jason finds approximately 145 ft of suction line with 4 long radius elbows. Per Fig. 33 and Table 7, each fitting has an equivalent length of 1.4 ft. The total equivalent length of the suction line is (145’ + (4 * 1.4’) ≈) 150 ft. Based on Table 9, Jason determines there should be 10-psig pressure-drop in the suction line.

Jason now takes the suction line temperature at the outlet of the evaporator and obtains 51°F. Per the instructions, Jason adds the 10-psig pressure-drop to the 60-psig pressure at the outdoor unit to get 70-psig at the evaporator. Saturated pressure of 70-psig equates to approximately 41°F. Jason determines the Evaporator superheat to be (51°F - 41°F =) 10°F. Jason concludes the TXV is functioning properly.

NOTE: In this situation, both the pressure drop and the heat gain in the suction line are significant contributions to the superheat at the service valve. The pressure drop contributes approximately 7°F superheat and the heat gain in the suction line contributes 13°F.

Fig. 33 – Pseudo Evaporator Superheat Pressure and Temperature Measurement Locations

37

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Image 37
Bryant R-22 service manual System Suction Pressure Drop
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R-22 specifications

The Bryant R-22 stands out in the landscape of residential heating and cooling systems with its combination of efficiency, durability, and modern technology. Designed primarily for homeowners seeking comfortable climate control solutions, the R-22 model delivers consistent performance throughout varying seasonal extremes.

One of the main features of the Bryant R-22 is its high energy efficiency. Rated with a SEER (Seasonal Energy Efficiency Ratio) that meets or exceeds industry standards, this air conditioning unit is designed to reduce energy consumption while providing optimal cooling. This not only helps in lowering monthly utility bills but also promotes environmentally responsible usage.

Another notable characteristic is the unit's durability. Constructed with a robust cabinet and high-quality components, the R-22 is built to withstand the rigors of daily use, with protective features that enhance its longevity. The cabinet comes with a powder-coated finish that resists corrosion and harsh weather conditions, ensuring that the unit stays functional and aesthetically pleasing for years.

The Bryant R-22 also incorporates advanced technology to improve user experience. One such innovation is the SmartSet technology, which allows homeowners to program their unit to optimize comfort levels according to their specific needs. This programmable capability enhances energy savings and ensures that the home remains at the desired temperature when residents are present.

Moreover, the unit features a Quiet Operating System that significantly reduces noise levels, making it suitable for residential areas where noise might be a concern. The design minimizes vibrations and optimizes airflow, creating a comfortable environment without disruptive sounds.

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Finally, the Bryant R-22 is backed by a solid warranty, providing peace of mind for homeowners. This commitment to quality and customer satisfaction is a testament to Bryant’s dedication to producing reliable and efficient HVAC solutions. Overall, the Bryant R-22 is an exemplary choice for those looking to enhance their home comfort with the latest in HVAC technology.
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