Long Lineset Instructions

ManualsBrandsBlueridge Manualsair conditioning cooling14.3 SEER 70,000 BTU System Bundle Horizontal Air Conditioner Gas Furnace and Coil

Page 6

Table 7. BTUH Loss For Equivalent Length (HFC-410A)

Nominal

Tons

Tubing

Outside

Diameter

(Inches)

BTUH Loss For Equivalent Length (HFC-410A)

25' 50' 75' 100' 125' 150' 175' 200'

5/8 -100 -275 -460 -667 -846 -1014 -1268 -1487

3/4 0 -77 -169 -277 -384 -478 -602 -726

7/8 46 0 -57 -130 -196 -265 -360 -487

3/4 -89 -270 -452 -652 -839 -1071 -1354 -1564

7/8 0 -93 -167 -274 -407 -563 -742 -953

1 1/8 52 13 -11 -74 -188 -318 -441 -611

3/4 -208 -575 -918 -1356 -1613 -2026 -2429 -2824

7/8 0 -168 -320 -528 -726 -896 -1162 -1348

1 1/8 114 80 19 -58 -148 -266 -391 -537

7/8 -221 -598 -948 -1305 -1716 -2063 -2438 -2844

1 1/8 0 -109 -239 -398 -565 -741 -925 -1106

1 3/8 52 -33 -133 -239 -339 -478 -572 -775

Vapor Line Quick Select

Table 2 should be used to size the vapor line. Follow this

procedure for sizing the vapor line:

1. Find your unit on the left side of table 2 (for both

HCFC-22 and HFC-410A)

2. Start with the rated vapor line size on the outdoor unit

(refer to engineering handbook or installation

instructions)

3. You may consider increasing or decreasing the vapor

line size if a larger size is listed in table 2. Larger vapor

lines will reduce pressure drop and improve system

efficiency. For details see section Line Sizing in Detail.

Long Line Requirements

For systems with the outdoor unit 5-50 feet above the

indoor unit, one trap must be installed at the bottom of the

suction riser. For suction lifts between 50 and 100 feet

(cooling only units; vapor lifts over 50 feet not allowed on

heat pump), install a second trap halfway up the riser. For

suction lifts over 100 feet, install traps at 1/3 intervals.

For variable capacity systems see section Line Sizing in

Detail.

COMBINATION VAPOR LINES

Vapor risers must be sized to ensure adequate velocity for

oil return. In general, piping can be designed to ensure

adequate velocities for oil return even with two stage

systems. A good way to do this is to reduce the vapor riser

size. A combination vapor line can be constructed with the

larger diameter pipe in the horizontal runs to minimize

pressure drop, and smaller diameter pipe in the vertical to

increase velocities.

NOTE — Maximum vapor riser = 125 feet

Table 5 simplifies vapor/suction line selection by

incorporating all of the calculations involving vapor line

sizing, pressure drop, velocity range and tonnage. To

calculate capacity loss due to pressure drop in the vapor

line refer to the section Sizing Suction and Vapor Lines in

this document.

Assumptions: 2-4 elbows every 50 feet

EXAMPLE: VAPOR LINE SIZING

Given: 7-1/2 ton HCFC-22 A/C cooling only condensing

unit with evaporator lower than condenser, with 112 feet of

piping. The piping includes 20 feet of vertical lift and 92 feet

of horizontal run as illustrated in figure 2.

INDOOR COIL

SUCTION RISER

90 FT.

2 FT.

40 FT.

OIL TRAP

Figure 2. Indoor Coil Below Condenser

Find: Select vapor line size from table 5.

Solution: 1-3/8 inch outside diameter line is the rated

suction line size. It is listed on table 5 because it will provide

good refrigerant velocities for oil return.