Appendix A. Instructions For High Altitude Installations (Us Only) - Crown Boiler AWR Series Installation Instructions Manual

Appendix A:
As with most gas appliances, special consideration must be given when this boiler is installed at altitudes
above 2000 ft:
• AWR Series boilers is not certified for installation above 2000ft in Canada.
• Do not install the AWR038B at altitudes above 2000ft anywhere.
• When installed above 2000ft, input ratings for the AWR070B – AWR280B are derated by 4%
for each 1000 ft above sea level in accordance with The National Fuel Gas Code (NPA-54
ANSI Z223.1). For example, a boiler that is to be installed at 4000 ft must be derated by 16%.
This input derate is accomplished through the use of smaller main burner orifice. This reduc-
tion in input results in a correspondingly lower output and must be considered when sizing the
boiler. Approximate inputs as a function of altitude are shown in Table A1.
• Safe operation of this boiler depends upon the use of the correct burner orifice. See the tables below for
the correct configuration. Failure to properly configure this boiler for the installation altitude could cause
personal injury or death due to Carbon Monoxide (CO) poisoning.
• Orifice for this boiler cannot be drilled in the field. Obtain orifice for the proper altitude from the local
distributor (see Service Parts). Part Numbers for the correct size and style orifice are shown in Table A2.
Boilers that are factory configured for high altitudes have the altitude (or range of altitudes) for which the
boiler is configured marked on the packaging. Since it is possible for the orifice to be changed between the
factory and the end user, always verify that the correct orifice is in place for the installation altitude before
placing the boiler in operation. The size of the orifice may be found on one of its wrench flats.
Manifold pressures, as well as minimum and maximum inlet pressures, are the same as at sea level.
• When orificing a boiler for an "odd" altitude, select the orifice for the higher altitude shown in the tables
below. For example, orifice a boiler being installed at 4100ft as though it were being installed at 5000ft.
• When sizing a vent system for this boiler in accordance with the National Fuel Gas Code (NFPA-54/ANSI
Z223.1), use the sea level input ratings to determine the maximum capacity of a given vent system. Use
the high altitude input ratings in Table 1 to determine the minimum capacity of the vent system.
Model Sea Level
AWR070 70000
AWR105 105000
AWR140 140000
AWR175 175000
AWR210 210000
AWR245 245000
AWR280 280000
* Based on the following Higher Heating Values: Natural Gas - 1020 BTU/scf, Propane - 2516 BTU/scf
Instructions for High Altitude Installations (US Only)
Table A1: Approximate Input (BTU/hr) at Various Altitudes*
2000 3000
64400 61600 58800
96600 92400 88200
128800 123200 117600
161000 154000 147000
193200 184800 176400
225400 215600 205800
257600 246400 235200
!
WARNING
!
CAUTION
Altitude (ft)
4000 5000 6000
56000 53200
84000 79800
112000 106400
140000 133000
168000 159600
196000 186200
224000 212800
54
7000 8000 9000
50400 47600 44800
75600 71400 67200
100800 95200 89600
126000 119000 112000
151200 142800 134400
176400 166600 156800
201600 190400 179200
10000
42000
63000
84000
105000
126000
147000
168000