I-Tec Commercial Room Ventilator System; General Description; Control Wiring; Recommended Control Sequences - Bard I-TEC Series Installation Instructions Manual

I-TEC COMMERCIAL ROOM VENTILATOR SYSTEM

GENERAL DESCRIPTION

The I-TEC Commercial Room Ventilator (CRV) is
designed to be used with all Bard I-TEC models. The
only intent of this device is to provide the required
ventilation by delivering fresh air to meet IAQ (Indoor
Air Quality) requirements. In the installed application,
this system also includes exhaust provisions which
are balanced with the intake air to maintain building
pressurization requirements of ASHRAE 62.1 Standard.
Ventilation is accomplished with two blower/
motor assemblies for maximum ventilation at low
sound levels. The intake and exhaust blowers are
programmed independently and are balanced to
maintain a slight positive pressurization in accordance
to ASHRAE 62.1 Standard.
The I-TEC CRV is also provided with filters to reduce
the required service needed and to further improve the
IAQ. The exhaust air blowers and intake air blowers
are protected by two throw away filters. Both are
accessible without the need for tools.

CONTROL WIRING

The I-TEC CRV comes wired from the factory set to 450
CFM of ventilation. Care must be taken when deciding
how to control the operation of the ventilator. When
designing the control circuit for the ventilator, the
following requirements must be met.
1. The indoor blower must be run whenever the I-TEC
CRV is run.
2. Select and configure the correct CFM ventilation
level that the I-TEC CRV needs to operate and
configure the system to this level following later
instructions within this section. Over ventilating
serves no useful purpose and significantly affects
the overall efficiency of the heat pump system.
System operating costs would also increase.
3. Run the I-TEC CRV only during periods when
the conditioned space is occupied. Running the
ventilation during unoccupied periods wastes
energy, decreases the expected life of the CRV,
and can result in large moisture buildup in the
structure. Running the CRV when the structure
is unoccupied allows moisture to build up in the
structure because there is little or no cooling load.
Thus, the air conditioner is not running enough to
remove the excess moisture being brought in. Use
a control system that in some way can control the
system based upon occupancy.
Operating the I-TEC CRV during unoccupied periods can
result in a build up of excess moisture in the structure.

RECOMMENDED CONTROL SEQUENCES

Several possible scenarios are listed below:
1. Use a programmable electronic thermostat with
auxiliary terminal to control the CRV based on daily
programmed occupance periods. Bard markets and
recommends Bard Part #8403-060 programmable
electronic thermostat.
2. Use Bard CompleteStat™ that incorporates
temperature, humidity and occupancy control
with learning capability into a single device. No
programming required.
3. Use a DDC control system to control the CRV based
upon a room occupancy schedule to control the CRV.
4. Tie the operation of the CRV into the light switch. The
lights in a room are usually on only when occupied.
5. Use a manual timer that the occupants turn to
energize the CRV for a specific number of hours.
6. Use a programmable mechanical timer to energize
the CRV and indoor blower during occupied periods
of the day.
NOTE: The ventilation package comes with a
blower interlock function, but is disabled when it is
shipped from the factory in case a thermostat with an
occupancy output or occupancy sensor is not utilized
and "A" terminal to "G" terminal must be tied to drive
the ventilation package. If a thermostat or control
does drive occupancy output, remove the tape from the
orange wire located in the low voltage terminal box and
connect it to the "G" terminal to activate this function.
(See Figures 11-13.)

SETTING THE VENTILATION CFM LEVELS

The I-TEC CRV has four pre-set levels of ventilation
CFM available. These are 300, 375, 450 and 525 CFM
of ventilation air. The I-TEC CRV is shipped from the
factory set on the 450 CFM ventilation level. To change
between these four different levels of provided ventilation
CFM, first refer to Figure 15 to look up the corresponding
CFM needed for the intake and exhaust blowers to meet
the design criteria and determine which "speed/wire
color" is needed. Then, perform the following steps.
Manual 2100-578L
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