Specifications

PRO-C Series
2
The PRO-C Series has supply and return connections
located on the side of the unit and is designed to mate up
to the selected Carrier rooftop air-conditioner. The PRO-C
is designed for outdoor installation, has a high level of total
recovery effectiveness and includes a single-point electrical
connection.
In a typical application, the PRO-C pulls exhaust air
directly from the return air section of the Carrier unit.
Preconditioned outdoor air is then provided directly to the
cooling coil, mixing with the recirculated airstream. The
PRO-C unit and Carrier’s supply fans run continuously
while occupants are in the conditioned space, even when the
heating or cooling coils are off. This provides a continuous
supply of outdoor air, therefore meeting the ASHRAE
Standard 62 guidelines.
A key advantage to this approach is that no additional
ductwork is required beyond that which is already provided
for the Carrier unit. This simplifi es the installation process
and minimizes project first cost. This approach also
simplifi es retrofi t applications where it is desirable to increase
the amount of outdoor air supplied to a space without
replacing the existing HVAC system.
Applying the PRO-C Series Unit
Figure 2. PRO-C Series typical installation.
Exhaust Air
Supply Air
to Carrier
Return Air
to be Exhausted
Outdoor Air
Improves the Comfort
of Occupied Spaces
As outdoor air is supplied to the space, the heating/
cooling source is cycled on and off to maintain temperature.
When it is cycled off, very cold or very warm/humid air can
be “dumped” on the occupants, causing wide temperature
fluctuations, which makes for a very uncomfortable
environment. The PRO-C solves this problem by providing
moderated supply air conditions, even as the Carrier unit is
cycled on and off.
Helps Reduce Humidification
Requirements During the Heating Season
Supplying 15 to 20 cfm/person of cold, dry outdoor
air to a facility during the heating season can result in
unacceptably low indoor relative humidity. Most facilities
require humidification, which is costly to operate and
maintain. The PRO-C unit captures the moisture generated
within the space to provide free humidifi cation during the
heating season, therefore maintaining a healthier indoor
environment.
In moderate climates with short heating seasons, this
may be suffi cient to completely eliminate the need for any
humidifi cation equipment.
Economical Compliance
with ASHRAE Standard 62
To achieve acceptable indoor air quality, ASHRAE
Standard 62 recommends a three-to-four-fold increase in
the amount of outdoor air provided to most facilities. In
addition, the ASHRAE Standard recommends that this
increased outdoor air quantity be introduced continuously
while spaces are occupied. By recovering up to 80 percent of
the total energy normally exhausted from occupied spaces,
the PRO-C enables the Carrier unit to effectively handle this
increase in outdoor air load without the need for a larger
sized package and without increasing energy consumption.
Improved Cooling
Season Humidity Control
Operation of conventional HVAC systems is governed
by a thermostat, i.e., in response only to the conditioned
space temperature. When the cooling coil is cycled off,
the outside air fan is typically shut-off as well. Thus, no
ventilation is provided to the conditioned space until the
thermostat calls for cooling. If the outside air fan is allowed
to run while the cooling coil is off, then warm, humid air is
directed to the space. In both of these cases, indoor space
humidity levels will increase above guideline levels, i.e., 60
percent relative humidity.
Since the PRO-C unit dehumidifi es and cools the
incoming outdoor air, the supply air conditions are close to
the return air conditions. This effectively produces a buffer
against high outdoor latent loads resulting in acceptable
indoor humidity levels.
Without the addition of effective energy recovery, the
capacity of HVAC systems must be increased greatly to
handle the greater outdoor air loads. Increasing equipment
size often requires the addition of reheat and sophisticated
control sequences to control both humidity and temperature.
The PRO-C often reduces project fi rst cost by allowing a
smaller Carrier unit and duct system to be used, without the
need for reheat or complex controls.
Reduced Equipment First Cost
Benefits