Bryan Boilers Forced Draft Steam Boilers, Service Manual

Page: 9 / 37

TABLE 1.8.1C: ESTIMATING FLUE GAS EMISSIONS
Estimated Emissions (Volumetric Flow Rate Per Million Btu/hr Input)
(Multiply PPH listed times boiler input divided by 1,000,000)
BOILER
TYPE
PARTICULATES NOx CO SOx Hydrocarbons
PPH per
MMBH
PPM PPH per
MMBH
PPM PPH per
MMBH
PPM PPH per
MMBH
PPM PPH per
MMBH
PPM
Gas Fired
Oil Fired
N/A
0.020
N/A
20
0.049
0.068
50
70
0.194
0.018
200
18
N/A
0.286
N/A
290
0.010
0.004
10
4
1.8.2 CLEARANCES
The vent system and draft control devices must
be installed so as to achieve the clearances to
surfaces outlined in Table 1.2.1, Minimum
Clearances chart, in this manual. See also Table
1.8.9 for vent clearances. All clearances must
comply with the National Fuel Gas Code
(NFPA54), and with all
local and state building codes. The clearances
described in this manual are intended to be
general guidelines only, additional requirements
may occur because of local building design
regulations.
1.8.3 BOILER ROOM PRESSURIZATION
The boiler room must be supplied with adequate
air for combustion and for proper operation of
draft control devices (barometric dampers or draft
diverters) as outlined in "Combustion Air Supply",
Section 1.7 of this manual.
WARNING
THE BOILER ROOM MUST BE MAINTAINED
AT A POSITIVE OR NEUTRAL PRESSURE
(RELATIVE TO OUTDOORS) AT ALL TIMES.
EXHAUST FANS OR CONNECTIONS FROM
THE BOILER ROOM TO ZONES OF NEGATIVE
PRESSURE (AIR DUCTS, NEGATIVE
PRESSURE ROOMS, ETC.) WILL CAUSE
NEGATIVE PRESSURE IN THE BOILER
ROOM. SUCH CONDITIONS WILL CAUSE
HAZARDOUS OPERATION OF THE BOILER
AND INTRODUCTION OF COMBUSTION
PRODUCTS INTO THE BUILDING AIR.
IF THE BOILER ROOM MUST BE UNDER A
NEGATIVE PRESSURE AT ANY TIME, AN INDUCED DRAFT FAN WILL BE REQUIRED.
FURTHER, THE BOILER MUST BE PROVIDED
WITH A BAROMETRIC DRAFT CONTROL -
NOT WITH A DRAFT DIVERTER. THE FAN
MUST BE INTERLOCKED WITH THE BOILER
AND A DRAFT PROVING SWITCH MUST BE
INSTALLED TO PREVENT OPERATION OF
THE BOILER IF THE FAN SHOULD FAIL TO
OPERATE.
IT ALSO MAY BE ADVISABLE TO INSTALL AN
AUTOMATIC VENT DAMPER IN THE VENT
SYSTEM TO PREVENT BACKFLOW
THROUGH THE VENT SYSTEM DURING
BOILER OFF CYCLES. SEE FOLLOWING
SECTION ON AUTOMATIC VENT DAMPERS.