Installation manual

035-19599-001 Rev. A (1103)
22 Unitary Products Group
In the USA use the following formula to calculate the furnace
input.
For natural gas multiply the heat content of the gas BTU/SCF (or
Default 1030 BTU/SCF, times 2 cubic ft. of gas measured at the gas
meter, times a barometric pressure and temperature correction factor of
0.960; times 3600, then divided by the time (In seconds) it took to mea-
sure 2 cubic ft. of gas from the gas meter.
For propane (LP) gas multiply the heat content of the gas BTU/SCF (or
Default 2500 BTU/SCF, times 1 cubic ft. of gas measured at the gas
meter, times a barometric pressure and temperature correction factor of
0.960; times 3600, then divided by the time (In seconds) it took to mea-
sure 1 cubic ft. of gas from the gas meter.
The formula for US input calculation using a cubic foot gas meter:The formula for US input calculation using a cubic foot gas meter:
In Canada you will use the following formula to calculate the fur-
nace input if you are using a cubic foot gas meter.
For Natural Gas multiply the Heat content of the gas MJ/m
3
(or Default
39.2), times 2 cu. ft. of gas x 0.02831 to convert from cubic feet to cubic
meters measured at the gas meter, times a barometric pressure and
temperature correction factor of 0.960; times 3600, then divided by the
time it took to measure 2 cu.ft. of gas from the gas meter.
For Propane (LP) Gas multiply the Heat content of the gas MJ/m
3
(or
Default 93.14), times 1 cu. ft. of gas x 0.02831 to convert from cubic
feet to cubic meters measured at the gas meter, times a barometric
pressure and temperature correction factor of 0.960; times 3600, then
divided by the time it took to measure 1 cu.ft. of gas from the gas meter.
The formula for metric input calculation using a cubic foot gas meter:
In Canada use the following formula to calculate the furnace input
if you are using a gas meter that measures cubic meters.
For Natural Gas multiply the Heat content of the gas MJ/m
3
(or Default
39.2), times 0.0566 m
3
of gas measured at the gas meter, times a baro-
metric pressure and temperature correction factor of 0.960; times 3600,
then divided by the time it took to measure 0.0566 m
3
of gas from the
gas meter.
For Propane (LP) Gas multiply the Heat content of the gas MJ/m
3
(or
Default 93.14), times 0.00283 m
3
of gas measured at the gas meter,
times a barometric pressure and temperature correction factor of 0.960;
times 3600, then divided by the time it took to measure 0.0283 cm of
gas from the gas meter.
The formula for metric input calculation using a cubic foot gas meter:
BTU/f
3
x 2 cu.ft. x 0.960 x 3600
=BTUH/H
BTU/f
3
x 2 cu.ft. x 0.960 x 3600
= BTUH/H
Seconds it took to measure the 2 cu.ft. of gas Seconds it took to measure the 2 cu.ft. of gas
NATURAL GAS INPUT CALCULATION PROPANE (LP) GAS INPUT CALCULATION
EXAMPLE: EXAMPLE:
1030 x 2 x 0.960 x 3600
= 79,997.38
2500 x 1 x 0.960 x 3600
= 80,000.00
90.5 108
Natural Gas Propane Gas
BTU/SCF 1030 BTU/SCF 2500
MJ/m
3
x (2 cu.ft. x Conv) x 0.960 x 3600
= MJ/H x 0.2777 = kW x 3412.14 = BTUH/H
Seconds it took to measure the 2 cu.ft. of gas
NATURAL GAS INPUT CALCULATION
EXAMPLE:
39.2 x 2 x 0.960 x 3600
= 84.76 x 0.2777 = 23.54 x 3412.14 = 80,312.62
90.5
Natural Gas
BTU/SCF 1030 = 39.2 MJ/m
3
PROPANE (LP) GAS INPUT CALCULATION
EXAMPLE:
93.15 x 1 x 0.960 x 3600
= 84.41 x 0.2777 = 23.45 x 3412.14 = 80,000.00
108
Propane Gas
BTU/SCF 2500+93.15 MJ/m
3
MJ/m
3
x (2 cu.ft. x Conv) x 0.960 x 3600
= MJ/H x 0.2777 = kW x 3412.14 = BTUH/H
Seconds it took to measure the 2 cu.ft. of gas
NATURAL GAS INPUT CALCULATION
EXAMPLE:
39.2 x 2 x 0.960 x 3600
= 84.76 x 0.2777 = 23.54 x 3412.14 = 80,312.62
90.5
Natural Gas
BTU/SCF 1030 = 39.2 MJ/m
3
PROPANE (LP) GAS INPUT CALCULATION
EXAMPLE:
93.15 x 1 x 0.960 x 3600
= 84.41 x 0.2777 = 23.45 x 3412.14 = 80,000.00
108
Propane Gas
BTU/SCF 2500+93.15 MJ/m
3