Lochinvar Copper-Fin CW 495, Designer'S Manual

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A manual main gas shutoff valve is
provided outside the jacket, upstream
of the main gas valve.
In Canada, derated10% from 2,000 -
4,500 ft., over 4,500 ft. derate
must be
in accordance with local authorities.
Consult factory for installations at
higher elevations.
High Altitude Applications
Atmospheric pressure decreases as the
height above sea level increases. At any
altitude above sea level, a cubic foot will
contain less gas than a cubic foot at sea
level. Thus, the heating value of a cubic foot
of fuel gas will decrease as height above
sea level increases.
Specific gravity of a gas with respect to sea
level also decreases with altitude. These
changes in heating value and specific
gravity tend to offset each other.
However, as elevation above sea level is
increased, there is less oxygen per cubic foot
of air. Therefore, heat input rate should be
reduced in an appliance above 2000 feet.
Ratings should be reduced at the rate of 4
percent for each 1000 feet above sea level.
WATER CONNECTIONS
Inlet and Outlet Water Connections
For ease of service, install unions on inlet and
outlet of the water heater.
The connection on the unit marked “Inlet”
should be used for return water from the
storage tank. The connection on the header
marked “Outlet” should be connected to the
inlet of the storage tank. (See Appendix A for
Water Heater Piping Diagrams).
L o c h i n v a r
D E S I G N E R
’
S G U I D E C O P P E R
-
F I N W A T E R H E A T E R
6 1 5 - 8 8 9 - 8 9 0 0
1 1
4.
5.
(TABLE D) – GAS SUPPLY PIPE SIZING
Length of Pipe In Straight Feet
Nominal Iron
Pipe Size, Inches
10 20 30 40 50 60 70 80 90 100 125 150 175 200
369 256 205 174 155 141 128 121 113 106 95 86 79 74
697 477 384 328 292 267 256 246 210 200 179 164 149 138
1,400 974 789 677 595 543 502 472 441 410 369 333 308 287
2,150 1,500 1,210 1,020 923 830 769 707 666 636 564 513 472 441
4,100 2,820 2,260 1,950 1,720 1,560 1,440 1,330 1,250 1,180 1,100 974 871 820
6,460 4,460 3,610 3,100 2,720 2,460 2,310 2,100 2,000 1,900 1,700 1,540 1,400 1,300
11,200 7,900 6,400 5,400 4,870 4,410 4,000 3,800 3,540 3,300 3,000 2,720 2,500 2,340
23,500 16,100 13,100 11,100 10,000 9,000 8,300 7,690 7,380 6,870 6,150 5,640 5,130 4,720
Maximum capacity of pipe in thousands of BTU’s per hour for gas pressures of 14” Inches Water Column (0.5 PSIG) or less and a total
system pressure drop of 0.05 Inch Water Column (Based on NAT GAS, 1025 BTU’s per Cubic Foot of Gas and 0.60 Specific Gravity).
1
1
/
4
3 /
4
1
1
/
2
1
2
1
/
2
3
1
/
2
3
2
(TABLE E) – INLET GAS PRESSURE
MODELS NAT. GAS
LP GAS
CW 495-745
Minimum Allowable 4
”
8
”
Maximum Allowable 10.5 ” 13 ”
CW 986-2066
Minimum Allowable 4.5 ” 8 ”
Maximum Allowable 10.5
”
13
”
EXAMPLE OF
HIGH ALTITUDE
APPLICATIONS
For example, if a unit’s
input is 100,000 Btu/hr
at sea level, the rated
input at 4000 feet of
elevation can be calculated
by derating input 4% per
1000 feet above sea
level.
[Btu/hr Input]
[1.00 - (Elevation/ 1000
ft. x 0.04)] = Btu/hr
Input at specified
elevation.
[100,000][1.00 - (4000
ft. /1000 ft. x 0.04)]
= Btu/hr Input 4000’
elevation.
[100,000][0.84] =
84,000 Btu/hr Input at
4000 ft. elevation.