Johnson Controls YORK YPC Series, Installation Manual

Page: 57 / 114

JOHNSON CONTROLS
57
18
FORM 155.17-N1
ISSUE DATE: 4/1/2013
SECTION 18 – SEALED COMBUSTION
(BURNER FRESH AIR INTAKE DUCT SIZING)
Many codes and regulations stipulate a fresh air in take
ductwork sys tem for burners. It is the ultimate re spon-
si bil i ty of the customer to make sure all national, local
and other applicable codes, restrictions and regula-
tions are satisfied in regards to the burner’s fresh air
intake ductwork.
Due to the many various job-site conditions, materi-
als of construction, and fi nal ductwork design/installa-
tion, this section will not ad dress the ac tu al design and
details of the ductwork.
If a fresh air intake duct is required for the chiller in-
stal la tion, a burner intake adapter flange kit can be
pur chased through a Power Flame representative.
The data found in the “Com bus tion Air Re quire ments”
table (See Appendix A - Tables ), will offer the field
engineer the air intake re quire ments for his burn er at
the proper operating conditions.
For combustion air design temperatures other than
what’s listed in the “Combustion Air Requirements”
ta ble, use the ad just ment pro ce dure in the following
formula:
ACFM = SCFM x 460 + T
AIR
°F
537
where:
ACFM – Actual Cubic Feet/Minute (corrected for
pressure and temperature)
SCFM – Standard Cubic Feet/Minute (based at 77°F)
An undersized fresh air intake duct will
sig nifi cant ly reduce the capacity of the
burn er and the chiller. If in doubt regard-
ing the air flow capabilities of a chosen
duct size, the next largest size duct is
recommended.