Section 18 - Sealed Combustion; (Burner Fresh Air Intake Duct Sizing); Acfm = Scfm X; Air - Johnson Controls YORK YPC Series Installation Manual

FORM 155.17-N1
ISSUE DATE: 4/1/2013

(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.
JOHNSON CONTROLS
SECTION 18 – SEALED COMBUSTION
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
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.
°F

AIR

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