A trap (drip leg) should be provided in the
inlet gas connection to the water heater.
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).
LOW WATER
TEMPERATURE DELIVERY
A number of water heating applications may
require delivered water temperature in a
system below 140°F. Systems such as nursing
homes and hospitals would be examples of
this type of system.
A water heating system that will be operated
at less than 140°F
must
use a mixing valve
on the outlet side of the storage tank in order
to ensure that the products of combustion do
not condense inside the combustion chamber
of the water heater.
The mixing valve allows the water heater to
operate above 140°F to protect from
condensation, while still allowing a delivery of
colder water to the system fixtures. Also
inherent in this design is the protection of
occupants from water containing bacteria
such as Legionella. Legionella can be
significantly reduced in the water storage
vessel by heating the water to a minimum of
140°F. See Appendix A for piping details.
18
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
I I
W A T E R
H E A T E R
6 1 5 - 8 8 9 - 8 9 0 0
Lochinvar
(TABLE K) – INLET GAS PRESSURE
MODELS
NAT. GAS
LPG
CF 401-751
Maximum Allowable
10.5
”
13
”
Minimum Allowable
4.5
”
8
”
CF 991-2071
Maximum Allowable
10.5
”
13
”
Minimum Allowable
4.5
”
8
”
4.
5.
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’
x 0.04)] = Btu/hr Input
at specified elevation.
[100,000][1.00 -
(4000’/1000’ x 0.04)] =
Btu/hr Input 4000’
elevation.
[100,000][0.84] =
84,000 Btu/hr Input at
4000’ elevation.
3.
