Filter Performance - Pressure Drop Inches W.c; Filter Sizes; Applying Filter Pressure Drop To Determine System Airflow; Unit Clearances To Combustibles - York Affinity PC9 Technical Manual

036-21671-001 Rev. A (0106)
FILTER PERFORMANCE
The airflow capacity data published in the "Blower Perfor-
mance" table listed above represents blower performance
WITHOUT filters. To determine the approximate blower per-
formance of the system, apply the filter drop value for the fil-
ter being used or select an appropriate value from the "Filter
Performance" table shown.
NOTE: The filter pressure drop values in the "Filter Perfor-
mance" table shown are typical values for the type of filter
listed and should only be used as a guideline. Actual pres-
sure drop ratings for each filter type vary between filter manu-
facturer.

FILTER PERFORMANCE - PRESSURE DROP INCHES W.C.

MINIMUM OPENING
AIRFLOW RANGE
0 - 750
751 - 1000
1001 - 1250
1251 - 1500
1501 - 1750
1751 - 2000
2001 & Above
APPLYING FILTER PRESSURE DROP TO
DETERMINE SYSTEM AIRFLOW
To determine the approximate airflow of the unit with a filter in
place, follow the steps below:
1. Select the filter type.
2. Determine the External System Static Pressure (ESP)
without the filter.
3. Select a filter pressure drop from the table based upon
the number of return air openings or return air opening
size and add to the ESP from Step 3 to determine the
total system static.
4. If total system static matches a ESP value in the airflow
table (i.e. 0.20, 0.60, etc,) the system airflow corre-
sponds to the intersection of the ESP column and Model/
Blower Speed row.
5. If the total system static falls between ESP values in the
table (i.e. 0.58, 0.75, etc.), the static pressure may be
rounded to the nearest value in the table determining the
airflow using Step 5 or calculate the airflow by using the
following example.

UNIT CLEARANCES TO COMBUSTIBLES

Top Front Rear
Application
In.
Downflow 1
Horizontal 0
* Combustible floor base or air conditioning coil required for use on combustible floor.
† Line contact only permitted between lines formed by the intersection of the rear panel (top in horizontal position) of the furnace jacket and building
joists, studs or framing.
4
SIZE
DISPOSABLE
1 Opening 1 Opening
Sq. in.
230
330
330
330
380
380
463
Left Side Right Side
In. In. In.
3 0 0
3 0 1

FILTER SIZES

CFM
1200
1600
2000
2000
NOTE: All filters must be high velocity cleanable type.
FILTER TYPE
WASHABLE FIBER
1 Opening
In w.c. In w.c.
0.01 0.01
0.04 0.03
0.08 0.07
0.08 0.07
0.14 0.13
0.17 0.15
0.17 0.15
Example: For a 120,000 Btuh furnace operating on high
speed blower, it is found that total system static is 0.58" w.c.
To determine the system airflow, complete the following
steps:
1. Obtain the airflow values at 0.50" & 0.60" ESP.
Airflow @ 0.50": 2220CFM
Airflow @ 0.60": 2135 CFM
2. Subtract the airflow @ 0.50" from the airflow @ 0.60" to
obtain airflow difference.
2135 - 2220 = -85 CFM
Subtract the total system static from 0.50" and divide this
difference by the difference in ESP values in the table,
0.60" - 0.50", to obtain a percentage.
(0.58 - 0.50) / (0.60 - 0.50) = 0.8
3. Multiply percentage by airflow difference to obtain airflow
reduction.
(0.8) x (-85) = -68
4. Subtract airflow reduction value to airflow @ 0.50" to
obtain actual airflow @ 0.58" ESP.
2120 - 68 = 2152
Flue Floor/Bottom
In. In. In.
*
0 0
1
†
1 0
0
Cabinet Top Return
Size Filter in
B (2) 14 x 20
C (2) 14 x 20
C (2) 14 x 20
D (2) 14 x 20
PLEATED
1 Opening
In w.c.
0.15
0.20
0.20
0.25
0.30
0.30
0.30
Closet Alcove Attic
Yes Yes Yes
Yes Yes Yes
Unitary Products Group
Line Contact
NA
†
Yes