Large Ceiling Systems

DESIGN FEATURES

 

CABINET

The heliarc welded tubular steel frame provides maximum strength and ease of service access. Removable panels of galvanized steel are insulated with 1 inch thick, 1-1/2 pound density insulation for thermal protection and sound attenuation. All parts are easily accessible. The electrical panel is hinged and swings out for servicing.

 

COIL SECTION

Designed for draw through application, the computer selected coil offers greater efficiency in the cooling and dehumidification process. Air bypass is provided to prevent saturated air from being introduced into the controlled space. The coil section is provided with a stainless steel drain pan.

 

FAN SECTION

The centrifugal, forward curved, double width, double inlet blower configuration is engineered for quiet reliable operation. The belt driven variable pitch drive section provides adjustable air flow capability to match load requirements of the controlled space. The draw through design insures even air distribution across the coil and bypass, low internal cabinet losses, and static sealing of the filter section. Motors are mounted on an adjustable slide base and have internal overload protection.

 

FILTER SECTION

Units are provided with 4 inch deep pleated design, 30% efficient filters (based on ASHRAE Std. 52-76) MERV 8. The filter section is an integral part of the system and is accessible from either side.

 

REHEAT

Two stage electric reheat is standard. Low-watt density finned tubular sheathed coils are constructed of stainless steel and sized to maintain room dry bulb conditions during a call for dehumidification. Low-watt density coils eliminate ionization associated with open air electric resistance heating.

 

REFRIGERATION CIRCUIT

LCS™ is available with either a single or dual refrigeration circuit. The refrigeration circuit includes a hermetic scroll compressor. These durable, heavy duty, fully welded compressors have no gaskets or seals, eliminating the possibility of refrigerant or oil leaking into the controlled space or environment. Scroll compressors also bring a combination of reliability, efficiency, and improved system sound performance. The refrigeration circuit includes built-in compressor overload protection, crankcase heater, filter drier, sight-glass, adjustable expansion valve with external equalizer, low pressure override timer (air cooled units), manual reset high pressure control, and compressor short cycle timer.

 

Water/glycol cooled units include a plate fin condenser sized to provide the required capacity for heat rejection with minimum water/glycol flow and low total pressure drop. Head pressure regulating valves control the condensing temperature and maintain required capacity at various water/glycol flow rates and temperatures.

 

Air Cooled with Remote Outdoor Condenser

A wide range of outdoor condensers are available. Condensers are manufactured by Data Aire and sized to meet heat rejection and ambient conditions as required. The industrial duty design includes galvanized corrosion resistant housing, aluminum finned copper tube coils, coated fan guards, energy efficient thermally protected direct drive motors, and variable fan speed control on lead motor for proper control down to -20° F ambient temperatures. Additional fan motors are controlled with ambient thermostats.

 

Air Cooled with Outdoor Condensing Unit

When compressors are required to be out of the controlled space, LCS™ is available with a remote outdoor condensing unit. The condensing unit includes hermetic scroll compressor(s) with built-in overload protection, crankcase heater, filter drier, sight-glass, and condenser coil. The coil is constructed with copper tubes and aluminum fins. The housing is galvanized steel with vertical air discharge. The condenser fan motor is variable speed type for head pressure control down to -20° F ambient temperatures. Additional fan motors are controlled by ambient fan thermostats.

 

Water/Glycol Cooled with Remote Outdoor Dry Cooler

Remote outdoor dry coolers are available in a variety of sizes. Each dry cooler includes galvanized corrosion resistant housing, aluminum finned copper tube coil, coated fan guards, surge tank, pump contactor, and energy efficient thermally protected direct drive motors. Dry coolers with multiple motors have cycling control.

 

CHILLED WATER SYSTEMS

Chilled water systems include all the same features of the LCS™ product line. Designed for draw through application, the computer selected coil offers greater efficiency in the cooling and dehumidification process. Air bypass is provided to prevent saturated air from being introduced into the controlled space. Chilled water flow is controlled by a 3-way chilled water valve for accurate and economical temperature control and dehumidification.

 

CONTROL SYSTEM

Unit control is maintained with the microprocessor based Mini Data Alarm Processor-II. The Mini Data Alarm Processor-IIis a wall mounted, one row, 16 character control that not only monitors the controlled environment’s humidity, air flow, and cleanliness, but also provides alarm history and an automatic self-test of the microprocessor on system start-up. Multiple messages are displayed by automatically scrolling from each message to the next. All messages are presented in a clear vernacular format on the liquid crystal display (LCD). Multiple alarms are displayed sequentially in order of occurrence.

 

OPERATION - A slide switch allows unit on/off operation: push buttons allow menu selection for programming, operational information, diagnostics, and historical data. The two-level password feature prevents unauthorized access. Menu programmed information for basic system operation and alarm parameters is non-volatile.

 

PROGRAMMABLE FUNCTIONS - The user friendly MENU and SELECT push buttons permit step-by-step programming of the following selections:

Temperature Setpoint: 65-85° F/18.3-29.4° C

Humidity Setpoint: 30-70% RH

Temperature Deadband: ±1-5° F/C in 0.1° Increments

Humidity Deadband: ±1-15% RH in 0.1% increments

Temperature Alarm Points

Humidity Alarm Points

Calibrate Temperature Sensor

Calibrate Humidity Sensor

Unit Start Time Delay

Interstage Time Delay

Password – 1st Level

Password 2nd Level

Audio Alarm Level

Restart Mode

Firestat Trip Temperature

Local Alarm

 

DISPLAYED CONDITIONS, DATA, and FUNCTIONS - The Mini Data Alarm Processor-II displays and monitors the following conditions, data, and functions:

Temperature Setpoints

Humidity Setpoint

Current Temperature

Current Humidity

Cooling 1, 2 (as applicable)

Reheat

Humidification

Dehumidification

 

ALARMS - Alarm conditions are displayed and monitored on the microprocessor LCD along with an audible alarm. The alarm silence switch will quiet the audible alarm but the display will continue to indicate the alarm condition until it is corrected. The following alarms are displayed:

High Temperature Warning

High Humidity Warning

Low Temperature Warning

Low Humidity Warning

Compressor High Pressure

High Condensate Water

Firestat Tripped

No Air Flow

Compressor Short Cycle

Low Voltage Warning

Temperature Sensor Failure

Humidity Sensor Failure

 

HISTORICAL DATA - Temperature and humidity, with the minimum and maximum readings since the last power on can be recalled and displayed. Alarm history is maintained in sequential order (up to 5 alarms).

 

DIAGNOSTICS - Automatic and manual diagnostics sequences simplify troubleshooting.

In addition, the Mini Data Alarm Processor-II has an inclusive seven-day programming format for unoccupied (low demand) periods. This secondary schedule can minimize equipment run times, reducing energy consumption and provide user cost savings.

 

The following selections can be adjusted to match the requirements needed for unoccupied (low demand) periods.

• Cooling Setpoint for Secondary Schedule

Adjustment Range: 1 – 30° F above the “occupied” Temperature Setpoint

• Reheat Setpoint for Secondary Schedule

Adjustment Range: 1 – 30° F below the “occupied” Temperature Setpoint

• Dehumidification Setpoint for Secondary Schedule

Adjustment Range: 1 – 30% RH above the “occupied” Humidity Setpoint

• Humidification Setpoint for Secondary Schedule

Adjustment Range: 1 – 30% RH below the “occupied” Humidity Setpoint

• Day Schedule

Scheduling for each day of the week or any combination of days

“Unoccupied” Adjusted Setpoint Operation

Adjusts to Temperature and Humidity Setpoints to Secondary Schedule

“Unoccupied” ON/OFF Operation

During “unoccupied” schedule:

cooling – off

heating – off

humidification – off

dehumidification – off

fan – off

• Override Request

Override Secondary Schedule

Adjustment Range: 1 – 12 hours

 

OPTIONS

 

Energy Saver Coil - An Energy Saver Coil can be provided integral to the unit matching the nominal capacity. Energy Saver cooling is available whenever the incoming water/glycol temperature is below the setpoint of the water sensing changeover thermostat. The water sensing changeover thermostat is factory set at 45° F/7.2° C. The water sensing changeover thermostat is field adjustable. The Energy Saver> operates during a need for cooling. The Energy Saver valve will open at setpoint plus deadband. When the space temperature falls to setpoint, the valve will close and the space is considered satisfied. While in Energy Saver mode with the valve open, if the incoming water/glycol temperature rises 3° F above the setpoint (of the water sensing thermostat), the Energy Saver valve will close and DX (mechanical) cooling will begin. Option includes a 3-way pressure control valve on the condenser water circuit(s) and a 3-way valve for the economy coil. Common piping for the coil and condensers is provided.

 

Auxiliary Chilled Water Coil - Where an existing chilled water loop is available, units can be fitted with an auxiliary chilled water coil. Units will operate using the chilled water for cooling. Upon a loss of water flow or an increase in room temperature the system will bring on compressor (DX) cooling. The Auxiliary Chilled Water Coil option includes the next size motor. Separate piping is provided for the chilled water coil and refrigeration connections on air cooled units or water circuit(s) on water/glycol cooled units.

 

Unit Mounted Temperature And Humidity Sensors - Temperature and humidity sensors may be ordered for unit mounting in the return air.

 

Unit Mounted Disconnect - A unit mounted non-automatic disconnect switch is installed in the high voltage electrical section. The operating mechanism prevents access to the high voltage electrical components until switched to the “OFF” position. The operating mechanism (handle) protrudes through the exterior unit panel.

 

Hot Water Reheat - Where hot water is available, a water coil for reheat is offered. The coil is designed for 150 psi maximum water pressure and includes a 2-way valve (a 3-way is also available). Units with the hot water reheat do not include electric reheat.

 

Hot Gas Reheat - The unit’s hot gas discharge may be used for reheat for maximum system efficiency.

 

Steam Generator Humidifier - Units may be furnished with an electric steam generator humidifier with “quick change” disposable cylinders and auto-flush cycle. The steam generator humidifier with its patented control system optimizes cylinder life by concentrating incoming water to a predetermined conductivity much higher than that of any entering water. The control system continuously monitors the conductivity in the cylinder through its electronics which allows water to be flushed as often as is necessary to maintain the level at this design conductivity. The high design conductivity results in a minimum flushing of heated water which saves energy. The humidifier is designed to allow all units at any voltage to produce full rated steam output at an optimum low water level. Available in 10 and 30 pound per hour capacities.

 

Hot Gas Bypass - Hot gas bypass may be ordered for changing load conditions. The hot gas bypass valve is installed between the compressor discharge line and the leaving side of the expansion valve through a side outlet distributor. The system with the evaporator under full load will maintain pressure on the leaving side of the hot gas bypass valve to keep the valve port closed. Should the load on the evaporator decrease to the point where the coil is below the desired setting, the pressure on the discharge of the hot gas bypass will put pressure on the diaphragm overcoming the spring pressure of the seat and allowing some hot gas to mix with the normal liquid discharge of the expansion valve raising the evaporator pressure. This reduces the cooling capacity of the unit to match the load. The hot gas bypass valve can be adjusted to “fine tune” the unit to room conditions.

 

3-Way Water Regulating Valve - A 3-way water regulating valve for pressure control may be ordered to replace standard 2-way valve installed in the unit. The 3-way valve controls the water/glycol flow rate to maintain the required capacity under varying conditions.

 

Condensate Pump - Condensate pumps may be ordered as factory installed or for field installation. Condensate pumps are complete with sump, motor, and automatic control. The pumps are rated for 130 GPM at 20 foot maximum or 40 GPH at 20 feet with check valve. Pumps shipped loose are available in 115, 230, or 460 volt.

 

Extended Compressor Warranties - Extended compressor warranties are available for periods of twenty-four (24) or forty-two (42) months in addition to the standard factory eighteen (18) month warranty. These warranties are for the replacement of compressors and do not include labor.