Venmar 600 cfm, 1200 cfm, 700 cfm User Manual

Light Commercial

Heat Recovery Ventilators

Installation, Operation and Service Instructions

VB0002

VB0003

600 cfm 700 cfm

VB0001

1200 cfm

06/00 04597

Contents

1 Safety Considerations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2 Installation

2.1 Inspection . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.2 Mounting Location Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.3 Mounting Options . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.4 Ductwork . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3

2.5 Internal Grilles and Diffusers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.6 Exterior Hoods . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.7 Drains . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

2.8 Electrical Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3 Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.1 General Information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.2 Sequence of Operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.3 Defrost . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

3.4 Remote Wall Control (Optional) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4 Airflow Measurement and Balancing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.1 Flow Station Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

4.2 Balancing Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5 Maintenance and Service . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5.1 Bi-Monthly Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

5.2 Annual Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Appendix A - Mounting Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Appendix B - Unit Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Appendix C - Flow Station Positions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Appendix D - Drain Connections . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Appendix E - Terminal Control Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

Appendix F - Electrical Connection Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19

Appendix G - Make-up Heat Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Appendix H - Wiring Diagrams . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

Appendix I - Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24

Page 2

1 Safety Considerations

2.3 Mounting Options

Hazards may exist within this equipment because it
contains electrical and powerful moving components.
Only qualified service personnel should install or
service this equipment. Untrained personnel can perform
basic maintenance such as maintaining filters.
Observe precautions marked in literature and on
labels attached to unit. Follow all safety codes.

WARNING

Disconnect main power switches to unit before
performing service or maintenance. Electric shock
can cause personal injury or death.

2 Installation

2.1 Inspection

Inspect the exterior of the unit for shipping
damage by ensuring that there is no damage to the
door, door latches, door hinges, damper, duct collars,
cabinet, etc. Inspect the interior of the unit for damage
by ensuring that the fan motors and housings, heat
exchange cores, insulation, dampers, actuators and
drain pans are all intact.

If transportation damage is found, file a claim
immediately with the transportation agency. Remove
all packaging, tape, etc. from the cabinet.

2.2 Mounting Location Requirements

When determining an installation location, the
unit must be mounted in a heated area to prevent
condensate drain lines from freezing. The mounting
location should be away from occupied areas to provide
quiet operation. The area should also be easily accessible
for maintenance.

There are several options for hanging or floor

mounting the unit.

NOTE:

In all cases, the unit must be level. Consult
local building code for restrictions in your area
regarding installation.

Hang the unit with the reinforced rubber straps
provided as shown in Appendix A. Check with local
building codes regarding the use of rubber straps in
commercial buildings. Attach the straps to the unit
with two #8 screws provided. Then attach the other
end of the strap to the ceiling joists, trusses, custom
frame, etc.

The unit can also be hung with 3/8" (10mm)
threaded rod and U channels or angles (not supplied)
as shown in Appendix A.

When installing the unit, keep in mind that access to
the control panel may be required. Supply and exhaust
ducts to outside may have 1" to 2" (25 to 51mm) of
insulation on them. Rubber vibration isolation may
be required and is recommended for quiet operation.

The unit can also be mounted on a metal or wooden
curb (not supplied) bolted to the floor as shown in
Appendix A. Space must be left under the unit to
allow connection of drain lines. A gradual slope is
required for the condensate water to drain by gravity
(minimum 1/4"/foot) (6mm/305mm). If this is not
possible, a pump should be used. If attachment of the
unit to the curb is required, ensure that screws, bolts
and mounting hardware do not interfere with moving
parts or that the integrity of the cabinet insulation is
not affected.

2.4 Ductwork

NOTE:

These Heat Recovery Ventilators have minimum
clearance requirements when mounting. See Appendix B
for specific clearance requirements. Mounting options
must allow 6" (152mm) clearance in front of control
cover for access.

A mounting location close to an exterior partition
will minimize the length of insulated duct. The unit
should be close to a drain and 120 volt, 60 Hz power
supply. The unit should be mounted away from hot
chimneys, electrical panels and other hazards. The
area should also be easily accessible for maintenance.

The supply and exhaust duct connections on the

unit are as follows:

UNIT DUCT SIZE

600 cfm/700 cfm 14" x 8" (356 x 203mm)

1200 cfm 20" x 8" (508 x 203mm)

NOTE:

Duct sizes are for connection purposes only.
Ducts should be sized to keep noise and pressure drop
to a minimum.

Page 3

The supply and exhaust ducts connected to
outside, as well as any ducts passing through an
unconditioned space, must have a minimum insulation
value of R5. In addition, a continuous integral vapor
barrier over the duct insulation must be used.

Air balancing dampers are recommended for both
supply and exhaust ducts to allow for adjustment of
airflow. Also, flexible canvas connectors should be
installed close to the unit in the supply duct to the
building and the exhaust duct from the building to
reduce noise transmission from the unit to the
building, see Appendix C.

All ports on the 600 cfm and 1200 cfm units have
1" (25mm) flanges to facilitate the installation of the
ductwork. Please note that the "Fresh Air from
Outside" port has a defrost damper incorporated with it.
Ensure that any mechanical fasteners used to connect
the duct do not interfere with the operation of the
damper. Screws can be installed on the side of the

cabinet rather than the flange for this port only.

For port locations see Appendix B.

All ports on the 700 cfm unit have 2" (51mm)
flanges to facilitate the installation of the ductwork.
Please note the "Fresh Air From Outside" connection
is factory set to be the left side upper port. It is
possible to reverse the operation of the defrost
damper in order to use the port on top of the
cabinet for "Fresh Air From Outside" connection.

To change the "Fresh Air From Outside" from the
side to the top use the following directions. For port
locations see Appendix B.

The duct system should be designed according to
the high speed flow rate of the unit. In order to keep
the noise and pressure drop to a minimum, a maximum
air velocity of 1100 ft/min (5.6 m/sec) should be used
in calculations in duct design. The duct runs should
be kept as short as possible with the minimum
amount of elbows and transitions.

The manufacturer recommends the use of smooth
radius elbows or square elbows with turning vanes to
achieve maximum performance.

2.6 Exterior Hoods

It is important that the fresh air intake hood be
positioned well away from any source of contamination.
The exterior supply and exhaust hoods must be
separated enough to prevent cross-contamination
and at an elevation that will prevent blockage by
snow, dirt and leaves.

NOTE:

Consult local building code for restrictions in
your area.

A rodent screen with 1/4" (6mm) mesh must be
installed to prevent the intake of large debris and
animals. A backdraft damper may need to be
installed in the exhaust duct to prevent cold air entering
the building if the unit is to be shut off for a long
period of time.

To maintain optimum airflow performance,
exterior hood selection must be such that the
minimum free area of opening is as follows:
140 inches

2

(0.09m2).

Remove the cover of the damper motor with a flat
screwdriver. Reverse the Orange and Red wires by
moving the Orange from terminal #2 to terminal #3 and
moving the Red wire from terminal #3 to terminal #2.
The end result in order to have the "Fresh Air From
Outside" connection to the top port will be:
#1 - White, #2 - Red, #3 - Orange.

2.5 Internal Grilles and Diffusers

Locate exhaust grilles and supply diffusers to provide
effective ventilation and avoid short circuiting of airflows.
Adjustable dampers should be provided at every
grille and diffuser location to make balancing of the
system possible.

A proper selection of style and size of grilles and
diffusers is required to minimize pressure drop. The
velocity of the airflow should not exceed 400 ft/min
(2 m/sec) for normal applications.

Page 4

2.7 Drains

The drain fittings provided with the unit will
accept a 3/4" (19mm) NPT coupler (supplied by others).
The drain line for the unit must be fabricated
on-site and connected to the building main. A loop in
the hose or trap in the copper or plastic pipe must be
provided to prevent sewer gases from entering the
unit when connecting to a drain as illustrated in
Appendix D.

NOTE:

Consult local building code for plumbing requirements
in your area. If copper pipe is to be used, ensure not
to solder to the 3/4" (19mm) coupler while it is
attached to the plastic drain fitting as deformation may
occur. Ensure adequate slope is present to allow good
drainage (minimum 1/4" per foot or 6mm per 305mm).

2.8 Electrical Connections

Power

A terminal block and strain relief bushing or a
junction box is provided for line voltage to make the
necessary power connections.

The electrical requirements are as follows:

600 cfm 700 cfm 1200 cfm

The 700 cfm unit is two speed. Low speed can be
initiated by creating a closure across LOW - COM or
high speed can be initiated by creating a closure
across HIGH - COM.

Unit Check points:

___ Power connected, no ventilation call - Both fans

are off, defrost damper (if equipped) closes off
fresh air from outside.

VOLTAGE 115V 115V 115V
MCA 8.65 6.63 13.4
MOP 12.5 9.13 20

Control Box Access For Low Speed Setting
(600 cfm/1200 cfm only)

Disconnect power to the unit. Remove the four
screws securing the cover plate as shown in
Appendix F. Lift off the control cover plate and
switch the red wire as shown in Appendix F.

3 Controls

3.1 General Information

Fan Interlock Relay Output (FF)

External fan control can be achieved by connecting an
external 24 volts fan control through dry contacts (FF).
These contacts are closed on a call for ventilation or
defrost. See wiring diagram shown in Appendix E-5.

___ Power connected, low speed call - Both fans on

low speed internal defrost damper (if equipped)
opens fresh air from outside. If equipped with
recirculation module, the internal defrost
damper closes recirculation opening.

___ Power connected, high speed call - Both fans on

high speed, defrost damper opens fresh air from
outside. If equipped with recirculation module,
the internal defrost damper closes recirculation
opening.

___ Power connected, occupied timer/sensor connection

open (unoccupied mode) - Both fans are off, defrost
damper closes fresh air from outside. If equipped
with recirculation module, the internal defrost
damper opens recirculation opening.

___ Power connected, FF control contacts close

during unit ventilation or defrost cycle.

3.3 Defrost

Speed Selection (600 cfm/1200 cfm only)

There are three speed settings available with the
controls, only two of which can be functional at any one
time. The units are factory set to use the low and high
speed taps on the blower motors. If necessary, the
medium speed tap can be used instead of the low
speed tap. See Appendix E-2 for instructions on how to
make this change. Units without the remote wall control
option can be shut off by opening the contact
between LOW - COM or HIGH - COM as shown in
Appendix E-2.

3.2 Sequence of Operation

Before start-up, check the unit for obstructive
packaging, objects near or in blowers, dampers, heat
exchangers, etc. Once installation is complete, check all
modes of operation to ensure that the unit is working
properly. Close the doors and check for operation on
LOW, COM and HIGH. Use a wall control or the dry
contact switching to run fan speeds as shown in
Appendix E-2.

The unit functions are controlled by integrated
controls in the unit which may include Exhaust Only
Defrost or Recirculation Defrost (via the recirculation
module - 600 cfm and 1200 cfm units only). In cold
temperatures, defrost cycles will remove frost from
the heat exchanger to maintain good operation.

Exhaust Only Defrost (Optional)

Frost removal occurs when the supply blower
de-energizes, the supply air damper and the core
damper close and the exhaust fan continues to circulate
only warm inside air through the heat recovery core
to maintain ventilation. This process prevents the build
up of ice in the core. Defrost is temperature initiated
at 23°F to -22°F (-5°C to -30°C) and time based.

WARNING

A negative building pressure may develop during
the defrost cycle with possible backdrafting fumes
from combustion equipment.

Page 5

Recirculation Defrost Module
(Optional - Factory Installed)

The Recirculation Defrost Module is only available
with the 600 cfm and 1200 cfm units. The defrost
cycle is electronically controlled in response to the
outside temperature 23°F to -22°F (-5°C to -30°C).
On a call for defrost, the supply air damper in the
recirculation module closes, exhaust fan is de-energized
and the supply fan continues to recirculate warm air
through the heat recovery core. It is possible to extend
the defrost times during very cold weather by removing
the jumper JU1-F on the circuit board as shown in
Appendix F. For dimension and weight changes to
the 600 cfm and 1200 cfm models with recirculation
defrost, see Appendix B-2 and B-4.

3.4 Remote Wall Control (Optional)

Remote mounted wall control options can be used
to control the ventilators from a location remote to
the installed unit location. The connection from the
ventilator to the control is low voltage and requires a
4 conductor (24 ga. minimum) LVT cable. Models
are available with either a dehumidistat control or
gas sensor. The following four options are available.

Slide Switch Type

Dehumidistat to engage high speed exchange.
Slide switch operation supporting continuous low
exchange and continuous high exchange.

Push Button Electronic Type

Dehumidistat to engage high speed exchange.
Push-button operation supporting: intermittent
(stand-by) ventilation, continuous low exchange,
continuous high exchange, maintenance indicator
light and exchange indicator light.

Pool Electronic Type

Ideal for pool dehumidification. Dehumidistat to
engage high speed exchange. Push-button operation
supporting: intermittent (stand-by) ventilation, continuous
low exchange, continuous high exchange, maintenance
indicator light and exchange indicator light.

Pollutant Detector Type

Pollutant monitor to engage low/high exchange.
Push-button operation supporting: intermittent
(stand-by) ventilation, continuous low exchange,
continuous high exchange, maintenance indicator
light and exchange indicator light.

4 Airflow Measurement

and Balancing

Once installation is complete, the supply and
exhaust airflows should be balanced. This will
ensure proper operation and a good quality installation.

A well designed duct system with properly sized
duct runs and equal static pressure losses of both the
supply and exhaust will aid in balancing the unit.
However, it will be necessary to take flow
measurements with the proper equipment to ensure a
balanced system.

Magnehelic gauges and Flow Measuring Stations
(FMS) are available for 14" x 8" (356 x 203mm) or
20" x 8" (508 x 203mm) rectangular duct and a range
of round duct sizes. Please ask your supplier for
more information.

4.1 Flow Station Positions

Whether flow stations are permanently installed or
used temporarily, the position they are placed in is very
important to ensure accuracy as shown in Appendix C.
The best locations for mounting the FMS is in the
long straight sections of ducting where airflow has
stabilized across the area of the duct. This position
will provide the most accurate measurements.

The next best location for the FMS is immediately
before or after a 90 degree elbow and 12" (305mm)
from any damper. In straight sections of pipe,
the FMS should be installed at least 30" (762mm)
from any fan outlet. This applies to the "Supply Air
Opening" connection on the heat recovery ventilator
and the "Exhaust Air Opening" connection.

With airflow measuring stations permanently
installed, balancing is done by measuring airflow on
one side of the heat recovery ventilator and then the
other. Adjustments can then be made to the damper
to equalize airflows.

When using the temporary method, an FMS is
installed in one air duct of the heat recovery
ventilator and the flow recorded. The FMS is then
relocated to the other air duct and the airflow is
recorded again. Dampers can then be adjusted to
equalize airflow. This procedure should be repeated
to ensure that the unit is balanced properly.

Page 6

4.2 Balancing Procedure

Before proceeding with balancing, all windows,
overhead doors and walk-in doors should be closed
and exhaust systems should be turned off.

The connections between the flow stations and the
ducts must be sealed with tape. Mount the magnehelic
gauge in a convenient location where it is level and
will not vibrate or be bumped. Zero the gauge.
Measure the exhaust air first as it is often the lowest
due to a longer duct system.

With the fan speed at maximum, connect the hoses
from the FMS to the magnehelic gauge. If the needle falls
below zero, reverse the hose connections. Ensure that
the damper is wide open. Take a reading from the
magnehelic gauge and record it. Remove the FMS
and place it in the supply duct. This process is not
necessary if the FMS is to be permanently mounted.

Repeat the procedure. If the reading is higher in
the supply duct, adjust the damper until the reading
is the same. If the reading is lower, return the FMS
to the exhaust duct and adjust the damper to obtain
the same reading as the supply duct.

5 Maintenance and Service

5.1 Bi-Monthly Maintenance

WARNING

Disconnect power before maintaining unit.

1

1

2

VL0001

600 cfm and 1200 cfm

1. Washable foam filter

2. MEF filter - optional

1 or 2

1

VL0002A

700 cfm

Drain Pans and Interior of Unit

With the filters removed from the unit, the foil
faced insulation surfaces and the drain pans should
be wiped clean with a soft cloth and mild cleaning
solution. Also ensure that the drain fittings are free
from dirt and are draining freely.

5.2 Annual Maintenance

Bi-monthly maintenance should include:

Air Filters

The standard foam filters are washable. Under
normal conditions it is recommended that they be
cleaned every two months. More frequent cleaning
may be required under extremely dirty operating
conditions. Use a vacuum cleaner to remove the
heaviest portion of accumulated dirt, then wash with
warm water.

A medium efficiency filter for the supply air
stream is available from your supplier. This filter
is disposable and should be replaced when it
becomes dirty.

WARNING

Disconnect power before maintaining unit.

Annual service should include:

Air Filters

Vacuum and wash standard foam filters. Replace

medium efficiency filter if present.

Drain Pans and Interior of Unit

Wash the foil faced insulation surfaces and wipe
the drain pans with a soft cloth and mild cleaning
solution. Check the drain fittings to ensure they are
draining freely.

Heat Recovery Core

The heat recovery core must be handled with care.
It is recommended that it be washed once a year
following the season of most intense use, in order to
ensure maximum efficiency of the partitions.

Page 7

Allow the heat recovery core to soak for three
hours in warm water and mild soap. Rinse under a
heavy stream of water.

WARNING

Hot water and a strong cleaning agent could
damage the polypropylene core. Ensure the core is
returned to the unit in the correct orientation. Use
the sticker as a guide.

Fans

Blower wheels and fan housing should be checked
for dirt build-up. If they appear dirty, it may be
necessary to remove the blower assembly and then
vacuum the dust out through the fan mouth. See the
following page for instructions on removing the
blower assembly.

System Operation Check

Verification of all control modes should be
checked to ensure proper operation. Refer to the
Controls Section, Sequence of Operation.

Testing and Replacement of the Damper Actuator

Check damper operation by switching between
LOW - COM or HIGH - COM on the dry contact
terminal or by switching through the modes on the
optional remote wall control. If the damper does not
respond in one or both directions, check all connections.

Motor and Blower Removal and Installation

Disconnect power from the unit. To determine if
the fan motor is burned out, disconnect the four-wire
service connector between the motor and cabinet.
Connect the motor directly to a 115 volt power
source with an electrical cable, as follows:

RED + WHITE Low speed

BLUE + WHITE Medium speed

BLACK + WHITE High speed

If the motor functions normally, there is a problem
with the wiring connections or the main circuit
board. Check all wiring and replace main circuit
board if necessary.

If the blower does not run, it must be replaced. To
replace the motor, remove the heat recovery core
from the unit. Disconnect the four-wire service connector
from the unit. Remove the fasteners holding the
motor assembly in place. Lift the assembly up and
out, using one hand under the motor and one hand to
steady it. Remove the assembly carefully from the
unit to avoid damage to the insulation, shelf, etc.
Install the repaired motor assembly by following
these instructions in reverse.

REMOVE THESE
2 SCREWS

LOCKING PLATE

CAPACITOR

700 cfm ONLY: Check for 24 volt output between the
White/Red and the White/Orange wires at the damper
motor. If 24 volts can be measured at the damper
motor, the problem is either in the connections, the
defrost relay or the main circuit board.

600/1200 cfm ONLY: (CAUTION: 120VAC) Check
for 120 volt output across the White/Black wires. If
120 volt can be measured at the motor, replace the
motor. If 120 volt cannot be measured at the motor,
check pins J1-9 at the printed circuit board.

Main Circuit Board Replacement

The main circuit board must be replaced if an
electronic problem arises. For example, the unit
suddenly stops, the unit stays in defrost all of the
time or if control functions are not working properly.

Ensure that power is reaching the board. Test the
blower motors and damper actuators for operation
when directly connected to the appropriate power
voltage. If the motor and damper actuators function
normally, replace the main circuit board.

VD0004A

600 cfm and 1200 cfm

THUMBSCREW

SERVICE CONNECTOR

VD0001A

700 cfm

Page 8