Indoor Airflow Data

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

863521.6 = 400 CFM

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.

Determining the Indoor CFM: Chart A – CFM

			Model
	VEA09/VHA09		VEA12/VHA12		VEA18/VHA18
ESP (")	Low	High	Low	High	Low	High
.00"	340	385	420	470	430	480
.10"	300	340	350 *	420 **	400	450
.20"	230	280	290	350	340	400
.30”	140	190	250	300	290	330

Highlighted values indicate rated performance point.

Rated performance for

*VEA12

Rated Performance for

**VHA12

		Model
	VEA24/VHA24
ESP (")	Low		High
.00"	690		740
.10"	610		700
.20"	560		640
.30"	510		580
.40"	450		520

Highlighted values indicate rated performance point.

Correct CFM (if needed):

Chart B – Correction Multipliers

Ductwork Preparation

Duct ESP:

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.

Ductwork Preparation

Pull the ﬂex duct tight. Extra ﬂex duct slack can greatly increase static pressure

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.

Explanation of charts

Chart A is the nominal dry coil VERT-I-PAK CFMs. Chart B is the correction factors beyond nominal conditions.

Fresh Air Door

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.