9. Design vent system for sea level input.
10.Provide adequate ventilation of Boiler Room. See Section I:
11.Never pass any portion of vent system through a circulating air duct or plenum.
WARNING
When an existing boiler is removed from a common venting system, the common venting system is likely to be too large for proper venting of the appliances remaining connected to it.
G.If an Existing Boiler is Removed:
At the time of removal of an existing boiler, the following steps shall be followed with each appliance remaining connected to the common venting system placed in operation, while the other appliances remaining connected to the common venting system are not in operation:
1.Seal any unused openings in the common venting system.
2.Visually inspect the venting system for proper size and horizontal pitch and determine there is no blockage or restriction, leakage, corrosion, or other deficiencies which could cause an unsafe condition.
3.Insofar as is practical, close all building doors and windows and all doors between the space in which the appliances remaining connected to the common
venting system are located and other spaces of the building. Turn on clothes dryers and any appliance not connected to the common venting system.
Turn on any exhaust fans, such as
4.Place in operation the appliance being inspected. Follow the Lighting (or Operating) Instructions. Adjust thermostat so appliance will operate continuously.
5.Test for spillage at the draft hood relief opening after
5 minutes of main burner operation. Use the flame of a match or candle, or smoke from a cigarette, cigar or pipe.
6.After it has been determined that each appliance remaining connected to the common venting system properly vents when tested as outlined above, return doors, windows, exhaust fans, fireplace dampers and any other
7.Any improper operation of the common venting system should be corrected so the installation conforms with the National Fuel Gas Code, NFPA 54/ANSI Z223.1. When resizing any portion of the common venting system, the common venting system should be resized to approach the minimum size as determined using the appropriate tables in Part 7 and Part 11 in the National Fuel Gas Code, NFPA 54/ANSI Z223.1.
Figure 27: Typical Vent System
33
