| CH-RCH COOLING/HEATING
SYSTEMS CH-RCH indirect gas-fired cooling and heating
systems are a logical alternative to the conventional rooftop package units or expensive
field built systems. The standard rooftop package offers a limited choice of cooling and
heating combinations and is available only for outdoor installation.
CH-RCH systems are available with a broad range of heating
selections for each cooling capacity.
CH-RCH systems feature low gas furnace air resistance which
permits high air volumes without by-pass duct work or dampers.
CH-RCH systems offer air handling and heating sections for
ceiling suspended, floor mounted or rooftop installation.
CH-RCH systems have the flexibility to satisfy special
damper, filter, cooling coil or control requirements.
CH-RCH systems provide a deferred cooling option. The
remote air cooled condensing unit and cooling coil can be installed at a future time.
CH-RCH systems are backed by a nation wide factory service
organization.
CH-RCH Operating Sequence
The "On" position of the "On-Auto" fan
switch located in the cooling/heating subbase provides continuous blower. The
"Auto" leg allows blower operation whenever the room thermostat calls for
cooling or heating.
The "Cool" position of the
"Cool-Off-Heat" system switch in the subbase energizes the air cooled condensing
unit and opens the liquid line solenoid valve, allowing refrigerant to flow to the DX
cooling coil. When the room thermostat indicates that the space is too cool, the liquid
line solenoid closes and the condensing unit is pumped down, shutting off on low head
pressure.
The gas furnace(s) is turned on in the "Heat"
position of the system switch and, in turn, is controlled by the room thermostat.
Equipment Selection
- Determine the total system cooling and heating loads, either
from job specifications or by conventional calculations.
- Select the CH-RCH model number in the performance tables
under the nominal tonnage column and opposite the required heating MBH input.
- Total Static Pressure (TSP) is the sum of all system
component pressure drops external of the MB blower including plenums, intake hood,
dampers, filters, DX coil, transitions, furnaces, system ductwork and registers. See
Bulletin RD-1 or SD-1 for pressure drops thru duct furnaces.
- CH-RCH cooling capacities and air cooled condensing unit
performance data are found on page 8. The total cooling MBH and leaving air dry bulb and
wet bulb temperatures of standard 4-row DX coils for each CH-RCH model are listed matched
with equivalent air cooled condensing units. 6-row cooling coil capacities are also shown
with comparable condensing units. Computer matched components are available for other
cooling requirements.
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