Ruud UGPL - High Altitude Installations

22
80+ HIGH ALTITUDE
INSTRUCTIONS
THE NATIONAL FUEL GAS CODE
(NFGC) GUIDELINES SHOULD BE
FOLLOWED WHEN CONVERTING
THESE FURNACES FOR HIGH
ALTITUDE OPERATION.
-GPL/-GLL HIGH ALTITUDE
KITS
All -GPL/-GLL models can be converted
for high altitude using the following kits:
High Altitude Kit Models
RXGY-F13 . . . . . . . . . . . ALL -GPL models
RXGY-F28 . . . . . . . . . . . -GLL-05, GLL-07(all),
-GLL-10
RXGY-F27 . . . . . . . . . . . -GLL-12
The kits include pressure switches and
instructions for converting the furnace
for elevations above 5,000 ft. These kits
should never be used at elevations
below 5,000 ft. In addition, the kit
instructions detail how to re-calculate
burner orifice size based on gas heating
value and elevation. The instructions
are based on a required 4% per
thousand feet reduction in input as
specified by the
National Fuel Gas
Code
(NFGC). Specific orifices should
always
be recalculated for all high
altitude installations as outlined below.
Orifices should be changed, if
necessary, based on gas heating value
and elevation.
-GPL/-GLL -HIGH ALTITUDE
OPTION #278
Furnaces can be ordered from the
factory already converted for high
altitude elevations. The factory option
for high altitude elevations would be
ordered as a 278 option (example: a
100k BTU upflow furnace which is
factory converted for high altitude
elevations would have the model
number -GPL-10EBRMR278
). These
factory converted furnaces come with
pressure switches for high-altitude
elevations already attached. Also,
different burner orifices are installed at
the factory which are one drill size
smaller (#43 DMS) than standard -GPL/-
GLL gas furnaces (#42 DMS). The
smaller orifice is installed to
accommodate for average heating
values expected in most high altitude
areas and a required 4% per thousand
feet reduction in input as specified by
the
National Fuel Gas Code (NFGC).
Specific orifices should always
be
recalculated for all high altitude
installatons as outlined below. Orifices
should be changed, if necessary, based
on gas heating value and elevation.
ELEVATIONS ABOVE 2000 FT
REQUIRE THAT THE FURNACE
INPUT RATING BE ADJUSTED AND
THAT THE SIZE OF THE BURNER
ORIFICES BE RE-CALCULATED
BASED ON ELEVATION AND GAS
HEATING VALUE. THE BURNER
ORIFICES MAY (OR MAY NOT)
NEED TO BE CHANGED. THE
FOLLOWING EXAMPLES SHOW
HOW TO DETERMINE IF AN ORIFICE
CHANGE WILL BE NECESSARY AND
HOW TO DETERMINE THE NEW
ORIFICE SIZE.
IN CANADA, AS AN ALTERNATE TO
ADJUSTING THE BURNER ORIFICE
SIZE, THE MANIFOLD GAS
PRESSURE MAY BE ADJUSTED.
THIS METHOD IS COVERED LATER
IN THIS SECTION. THIS METHOD OF
ADJUSTING MANIFOLD PRESSURE
MAY ONLY BE USED IN CANADIAN
INSTALLATIONS.
34 80 Plus furnaces installed above
2,000 ft. require the furnace to be de-
rated 4% per thousand feet.
IMPORTANT: Factory installed orifices
are calculated and sized based on a
sea level Natural Gas heating value of
1075 BTU per cubic ft.
NOTE: Orifices are available through
your local distributor.
The following are examples of orifice
sizing using the National fuel Gas Code
Appendix F. For a simplified estimation
of orifice size based on altitude and fuel
heating value, Tables 5 and 8 can be
used. However, calculations are the
best method.
Example: 900 BTU/ft
3
Regional
Natural Gas Heating Value
I / H = Q
25000 / 900 = 27.78 ft
3
I = Sea Level input (per burner): 25000
H = Sea Level Heating Value: 900
Q = 27.78 ft.
3
Natural Gas per hour.
From Table F.1 of
National Fuel Gas
Code Handbook, 2002
(3.5 w.c.
column).
Orifice required at Sea Level: #40
From Table F.4 of
National Fuel Gas
Code Handbook, 2002
Orifice required at 5000 ft. elevation
(4% de-rate per thousand ft.): #42
Orifice required at 8000 ft. elevation
(4% de-rate per thousand ft.): #44
Example: 1050 BTU/ft
3
Regional
Natural Gas Heating Value
I / H = Q
25000 / 1050 = 23.81 ft
3
I = Sea Level input (per burner): 25000
H = Sea Level Heating Value: 1050
Q = 23.81 ft.
3
Natural Gas per hour.
From Table F.1 of
National Fuel Gas
code Handbook, 2002
(3.5 w.c.
column).
Orifice required at Sea Level: #43
From Table F.4 of
National Fuel Gas
code Handbook, 2002
Orifice required at 5000 ft. elevation
(4% de-rate per thousand ft.): #45
Orifice required at 8000 ft. elevation
(4% de-rate per thousand ft.): #47
TABLE 5
NATURAL GAS ORIFICE DRILL SIZE (4% PER 1000 FT. DE-RATE)
IMPORTANT: 80+ MODELS ONLY. DO NOT
USE THIS CHART WITH ANY 90+ MODELS.
BURNER INPUT (PER BURNER) 25,000 BTU @ SEA LEVEL
Annual Avg. Heat
Value (btu per ft
3
)
850
900
975
1075
1170
38 39 40 41 41 42 42 43
40 41 42 42 42 43 43 44
41 42 42 42 43 43 44 44
42 42 43 43 43 44 44 45
43 44 44 44 45 45 46 47
Sea level
to 1999 ft
2000 to
2999 ft
3000 to
3999 ft
4000 to
4999 ft
5000 to
5999 ft
6000 to
6999 ft
7000 to
7999 ft
8000 to
8999 ft
!
CAUTION
!
CAUTION