Friedrich 9 - Manual (Page 23)

21
The Vert-I-Pak A series units must be installed with a free
return air configuration. The table below lists the indoor
airflow at corresponding static pressures. All units are rarted
at low speed.
The Vert-I-Pak units are designed for either single speed or
two fan speed operation. For single speed operation refer to
the airflow table below and select the most appropriate CFM
based on the ESP level. Connect the fan output from the
thermostat to the unit on either the GL terminal for low speed
or to the GH terminal for high speed operation.
For thermostats with two-speed fan outputs connect the low
speed output to the unit GL terminal and the high speed
output to the GH terminal.
Ductwork Preparation
Ductwork Preparation
Duct ESP:
Indoor Airflow Data
Pull the fl ex duct tight. Extra fl ex duct slack can greatly
increase static pressure
Explanation of charts
Fresh Air Door
Chart A is the nominal dry coil VERT-I-PAK CFMs. Chart
B is the correction factors beyond nominal conditions.
To determine your system's indoor external static pressure
(ESP, in inches of water) use a duct calculator (as provided
by your duct supplier). Include all flex duct transitions and
discharge grille(s). If flex duct is used, be sure all the slack
is pulled out of the flex duct. Flex duct ESP can increase
considerably when not fully extended. DO NOT EXCEED a
total of .30 ESP, as this is the MAXIMUM design limit for the
VERT-I-PAK A-Series unit.
The Fresh Air Door is an “intake” system. The fresh air door
opened via a slide on the front of the chassis located just
above the indoor coil. Move the slide left to open and right
to close the fresh air door. The system is capable of up to 60
CFM of fresh air @ ~.3” H20 internal static pressure.
Determining the Indoor CFM: Chart A – CFM
Correct CFM (if needed):
Chart B – Correction Multipli ers
Model
VEA12/VHA12 VEA18/VHA18 VEA09/VHA09
ESP (")
.00"
.10"
.20"
.30”
Low
340
300
230
140
High
385
340
280
190
Low
420
350 *
290
250
High
470
420 **
350
300
Low
430
400
340
290
High
480
450
400
330
Highlighted values indicate rated performance point.
Rated performance for
* VEA12
Rated Performance for
** VHA12
ESP (") Low High
.00" 690 740
.10" 610 700
.20" 560 640
.30" 510 580
.40" 450 520
Model
VEA24/VHA24
Highlighted values indicate rated performance point.
IMPORTANT: FLEX DUCT CAN COLLAPSE AND
CAUSE AIRFLOW RESTRICTIONS. DO NOT
USE FLEX DUCT FOR: 90 DEGREE BENDS, OR
UNSUPPORTED RUNS OF 5 FT. OR MORE.
EXAMPLE: Measured voltage to unit (heaters) is 230 volts.
Measured Current Draw of strip heaters is 11.0 amps.
230 x 11.0 = 2530
2530/1000 = 2.53 Kilowatts
2.53 x 3413 = 8635
Supply Air 95 ° F
Return Air 75 ° F
Temperature Rise 20 °
20 x 1.08 = 21.6
8635
= 400 CFM
21.6