Venting terminations and sizing |
| shown in Figure 8. The appropriate screen is to be | ||||
• Refer to Figure 8 and Table 2 for vent pipe materials | installed into the end of the termination elbow and | |||||
and sizing. Examples of the vent terminations are | secured with a small amount of silicone sealant. This | |||||
shown in Figures 9 and 10. If the installation requires a | will allow for easy removal for inspection and cleaning. | |||||
vent riser, suitable drainage must be provided to ensure | For installations using 76mm (3 in.) venting, use the | |||||
condensation does not accumulate. Termination | 76mm (3 in.) termination elbow and screen (not sup- | |||||
through a roof is shown Figure 11. |
| plied). |
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• G/JW 40, 50 and | • G/JW5065 high input models are supplied with a 76mm | |||||
50mm (2 in.) termination elbow and (2) plastic "rodent | (3 in.) termination elbow that includes a steel mesh | |||||
screens" (see Figure.7). The screen is required to keep | rodent screen. |
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foreign objects, rodents and small birds from entering |
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the venting system and only one (1) screen is to be |
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installed in the termination elbow. These screens have |
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been sized to ensure maximum energy efficiency of the |
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venting system based on the "equivalent length" of the |
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vent piping. How to determine the equivalent length is |
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WATER | SUFFIX | VENT PIPE | * VENT | MAXIMUM EQUIVALENT | MINIMUM EQUIVALENT | |
HEATER | MATERIAL | |||||
MODEL |
| SIZE | (SCHEDULE 40) |
| VENT LENGTH | VENT LENGTH |
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G/JW40, | NVH, | 50mm (2 in.) | PVC**, CPVC | 12.3m (40 ft.) + termination elbow | 0.76m (2.5 ft.) + one 90° elbow + | |
PVH |
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| termination elbow | |
50, 60 | NVH, | 76mm (3 in.) | PVC**, CPVC | 24.4m (80 ft.) + termination elbow | 12.3m (40 ft.) + termination elbow | |
| PVH | |||||
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G/JW5065 | SNV, | 76mm (3 in.) | PVC, CPVC | 12.3m (40 ft.) + termination elbow | 0.91m (3 ft.) + one 90° elbow + | |
| SPV |
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| termination elbow |
G/JW5065 | LNV | 76mm (3 in.) | PVC, CPVC | 19.8m (65 ft.) + termination elbow | 6.9m (20 ft.) + termination elbow | |
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Equivalent lengths of straight pipe for various elbows using Schedule 40 PVC and CPVC.
| Size | Type | Short Sweep/ | Long Sweep/ |
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| Short Radius | Long Radius |
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| 50mm (2 in.) | 90° elbow | 2.44m (8 ft.) | 1.52m (5 ft.) |
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| 76mm (3 in.) | 90° elbow | 2.44m (8 ft.) | 1.52m (5 ft.) |
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| 50mm (2 in.) | 45° elbow | 0.91m (3 ft.) | 0.76m (2.5 ft.) |
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| 76mm (3 in.) | 45° elbow | 1.22m (4 ft.) | 1.07m (3.5 ft.) |
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Notes:
1.Use long radius elbows where possible. Minimum dis- tance between 90º elbows should be 150mm (6 in.).
2.*Check local codes to determine which materials are allowed in your area.
3.**Pipe assembly adapter must be used with PVC venting material (see Figures 13, 14 & 15).
Table 2 Allowable Vent Lengths and Materials (Vert. and Horiz.).
NOTE: VENT PIPE MUST BE SUPPORTED EVERY 1.2m (4 ft.). TO PREVENT VIBRATION, USE ISOLATION
PADS WHEN ATTACHING STRAPS TO FLOOR JOISTS, WALLS OR CEILINGS.
TERMINATION
ELBOW
RODENT SCREEN (INSTALL INTO ELBOW)
GROUND LEVEL OR
MAXIMUM SNOW
LINE*
Example for calculating equivalent feet. |
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STRAP | |||
Section “A” . . . . | . .0.15m | (0.5 ft.) |
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90° elbow | 1.83m . . | (6.0 ft.) |
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Section B | 0.31m . . | (1.0 ft.) |
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45° elbow | 0.91m . . | (3.0 ft.) |
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Section C | 0.46m . . | (1.5 ft.) |
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45° elbow | 0.91m . . | (3.0 ft.) |
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Section D | 4.57m . (15.0 ft.) |
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Total Equivalent | 9.14m . (30.0 ft.) |
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Based on this example use the (fully open) rodent screen for vent length greater than 6.1 equivalent metres (20 equivalent ft.) (see Figure 7).
45°
ELBOW
90°
ELBOW
PVC ADAPTER 
(SUPPLIED)150mm (6 in.) MIN.
Figure 8 General Venting Layout
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