PRODUCT DESIGN
3
G
ENERAL
I
NFORMATION
The MBVC Blower Cabinets are used in combination with a
casedevaporatorcoilfor a two-piece blower and coilcombi-
nation. Thiscombination of blower andcoil functions as the
indoor part of a split air-conditioning system, and may be
matched with a remote condensing or heat pump unit and
allowsfor a variety ofmix-matching possibilities.
The blower cabinet can also function as an electric furnace
whenused with an electric heater.
NOTE: The electric heating elements for electric furnace
installation are not shipped with the cabinet and are field-
installed. Electric heater kits (HKR) are available as sales
accessoriesfor supplemental electric heat.
Systems should be properly sized by heat gain and loss
calculations made according to methods of the Air Condi-
tioning Contractors Association (ACCA) or equivalent. It is
the contractor’s responsibility to ensure the system has ad-
equate capacity to heat or cool the conditioned space.
TheMBVC blower cabinet uses avariable speed motor that
maintains a constant airflow with a higher duct static. It is
approvedforapplicationswithcoolingcoilsofupto0.8inches
W.C. external static pressure and includes a feature that
allows airflow to be changed to + 10%.
The MBVC blower cabinets, with proper coil matches, can
bepositioned for upflow, counterflow, horizontal right or hori-
zontal left operation. All units are constructed with R-4.2
insulation. In areas of extreme humidity (greater than 80%
consistently), insulate the exterior of the blower with insula-
tionhavingavaporbarrierequivalenttoductwork insulation,
providinglocalcodespermit.
TheCAPX/CHPXcoilsare equipped with a thermostaticex-
pansionvalvethathasabuilt-ininternalcheck valveforrefrig-
erantmetering. TheCACF/CAPF/CHPF coils are equipped
with a fixed restrictor orifice.
Thecoilsare designed for upflow,counterflow,or horizontal
application, using ECM motors on the MBVC models.
FEATURES
This modular blower is a part of the ComfortNet™ family of
products. It may be installed as part of a “legacy” system
using a standard 24 VAC thermostat. However, with the
CTK01AAComfortNet™thermostatkit, this modular blower
may be installed as part of a digitally communicating sys-
tem. The ComfortNet™ system provides automatic airflow
configuration,enhanced setup features, and enhanceddiag-
nostics. Italso reduces the number of thermostat wiresto a
maximumoffour.
C
OMFORT
N
ET
™S
YSTEM
OVERVIEW
TheComfortNet™system(orCT™system)isasystemthat
includesaComfortNet™compatiblemodular blower and air
conditioner or heat pump with a CTK01AA thermostat. Any
other system configurations are considered invalid
ComfortNet™ systems and must be connected as a tradi-
tional (or legacy) system. The table below compares the
validCT™systems.
CT™ compatible
Modular Blower CT™ compatible
Air Conditioner Full CT™ system
benefits & features
CT™ compatible
Modular Blower CT™ compatible
Heat Pump Full CT™ system
benefits & features
AComfortNet™heating/airconditioning system differs from
alegacy/traditionalsystemin the manner in which the indoor
unit, outdoor unit and thermostat interact with one another.
In a traditional system, the thermostat sends commands to
theindoorandoutdoor units via analog 24 VACsignals. Itis
a one-way communication path in that the indoor and out-
door units typically do not return information to the thermo-
stat.
Ontheotherhand,theindoorunit, outdoor unit, and thermo-
statcomprisingaComfortNet™system“communicate”digi-
tally with one another. It is now a two-way communications
path. The thermostat still sends commands to the indoor
and outdoor units. However, the thermostat may also re-
questand receive informationfrom both theindoor and out-
door units. This information may be displayed on the CT™
thermostat. The indoor and outdoor units also interact with
one another. The outdoor unit may send commands to or
requestinformation from theindoorunit. Thistwo-waydigital
communications between the thermostat and subsystems
(indoor/outdoor unit) and between subsystems is the key to
unlockingthe benefits and features of the ComfortNet™ sys-
tem.
Two-waydigital communications is accomplished using only
twowires. Thethermostatandsubsystemcontrolsarepow-
eredwith 24 VAC Thus, amaximum of 4 wiresbetween the
equipment and thermostat is all that is required to operate
the system.
