GS110 DIRECT VENT BOILER INSTALLATION AND OPERATION INSTRUCTIONS | Page 7 |
All joints in metal intake air systems must be secured using corrosion resistant fasteners and sealed using a suitable Silicone caulk. If PVC or CPVC is used, the joints must be cleaned with a suitable solvent and connected using a solvent based PVC cement. The intake air system MUST be supported by the building structure not the boiler/water heater.
Intake Air Option - Vertical Guidelines
A listed, nonrestrictive intake air cap must be used. The intake air cap must terminate as shown in Figure 6. The penetration point in the roof must be properly flashed and sealed.
Intake Air Optional - Horizontal Guidelines
The maximum equivalent length for the horizontal intake air pipe is listed in Table 2. The intake air system must be pitched down, toward the terminal, 1/4" per foot (21 mm per meter).
If horizontal runs exceed 5 feet (1.5 m) they must be supported at 3 foot (0.98 m) intervals with overhead hangers. Figures 7 through 10 show the four horizontal air intake options. The intake terminations certified for use the GS110 are listed in Table 5.
Figure 6 - Vertical Positive Pressure Venting with Outdoor Combustion Air (Cat. III)
