Product Overview
Page ___________ of ______________
Form C-HU - Page 9
Example: Unit Reznor Model 23/33
Steam Pressure 10 psi
Entering Air Temperature (EAT) 40°F
The heating output of any particular installation is a function of many different factors. It is very seldom that any
installation will exactly match the conditions described in the tables on the previous page. For those installa-
tions, correction factors must be used to determine heating output and other values.
Below is an example of conditions different from those given in TABLE A and B on the previous page. Fol-
lowing are procedures for determining heating output and other values at conditions other than “cataloged”
conditions.
I. In TABLE B nd the Heating Capacity for “catalog” conditions
with High Speed Fan Setting
33,000 BTUH
II. Determine Heating Capacity for steam pressure of 10 psi and
EAT of 40°F
33,000 BUTH x 1.290 = 42,570 BTUH
Find the conversion factor in TABLE C that satises the
conditions listed. In this instance, it is 1.290. Multiply original
BTUH output by the conversion factor.
III. Determine Leaving Air Temperature (LAT) using the formula
shown (right):
LAT = EAT+ BTUH ÷ (CFM x 1.085)
In TABLE B nd the Air Volume (cfm) for “cataloged” model and
apply it conditions described in Step II above.
40°F + (42,570 BTUH ÷ (500 cfm x 1.085)) = 118°F
IV. Determine the condensate in pounds per hour (lbs/hr).
42,570 BTUH ÷ 952.5 = 44.7 lbs/hr of condensate
Divide the heating output by the Latent Heat of steam found in
TABLE D at 10psi. In this case it is 952.5.
V. Determine the Equivalent Direct Radiation (EDR) in square feet
based on conditions in step IV using the formula shown (right):
EDR = 4 x condensate (lbs/hr)
4 x 44.7 lbs/hr = 179 sq. ft. EDR
ENGINEERING DATA (cont’d)
STEAM CAPACITIES, CALCULATIONS AND CORRECTION FACTORS