Installation and Operation Manual
For Models:
IH and WC Series Industrial Dehumidifiers
PD and PDW Series Residential Dehumidifiers
RC Series Remote Condensers
CAUTION
CAUTION - ONLY TRAINED, QUALIFIED PERSONNEL SHOULD INSTALL AND/OR
SERVICE DESERT AIRE EQUIPMENT. SERIOUS INJURY, DEATH AND PROPERTY
DAMAGE CAN RESULT FROM IMPROPER INSTALLATION/SERVICE OF THIS
EQUIPMENT. HIGH VOLTAGE ELECTRICAL COMPONENTS AND REFRIGERANT
UNDER PRESSURE ARE PRESENT.
LIMITED WARRANTY. The goods manufactured by seller are warranted to be free from all
latent defects in material and workmanship which may be disclosed under normal use and
service within two years from date of shipment. In order for warranty to be valid, a START-UP
REPORT must be completed and returned to the factory. If the report is not sent back,
warranty will be voided on the equipment. If it is found that the goods contained defects at the
time such goods were furnished by the seller, seller will either repair or replace the defective
part or parts at sellers option. This warranty to repair or replace is the exclusive remedy and is
expressly limited to the materials furnished by the seller. All replacements or repairs shall be
F.O.B. Milwaukee, WI. The seller shall not be liable for labor cost incurred in diagnosing the
problem, in removal or replacement of the part or parts so repaired or replaced. Accordingly,
seller shall not be liable for any consequential damages, whether to person or property, caused
by defects in goods. This warranty does not apply to any goods which may have been repaired
or altered in any way outside of our factory, so as to affect its stability in our judgment, nor
does this warranty apply to any goods which have been subjected to misuse, negligence or
accident. This warranty is in lieu of all other warranties, expressed or implied, including any
implied warranty of merchantability, and extends only to the original purchaser.
Additional copies of this manual can be purchased for $5. Contact Desert Aire by
mail or phone to order:
Desert Aire Corp.
c/o Service Department
8300 West Sleske Court
Milwaukee, WI 53223
ph: 414-357-7400
fax: 414-357-8501
TABLE OF CONTENTS
Installation ..........................................................................................5
1.
1.1.
Unpacking and Inspecting ........................................................................................ 5
1.2.
Location of Dehumidifier........................................................................................... 5
1.3.
High Voltage Electrical Connections......................................................................... 6
1.4.
1.3.1
Wire and Fuse Sizing ...................................................................................... 6
1.3.2
High Voltage Connections ............................................................................... 7
Controls Wiring and Set-up ...................................................................................... 7
1.4.1
CA2300 Controller Package ............................................................................ 7
1.4.2
Johnson Controls UNT Controller Package................................................... 8
1.4.3
Honeywell
1.4.4
Johnson Controls Aquastat........................................................................... 9
1.4.5
Nonstandard Control Package ........................................................................ 9
®
®
Snap Action Humidistat and Thermostat Controller Packages ... 8
®
1.5.
Condensate Drain..................................................................................................... 9
1.6.
Duct Installation...................................................................................................... 10
1.7.
Outside Air Applications ......................................................................................... 13
1.8.
1.9.
2.
1.7.1
Outdoor Air Option Equipped Units ............................................................... 13
1.7.2
Standard Systems in Conjunction with Outside Air........................................ 15
Water Heating Applications (PDW and WC Models Only) ...................................... 16
1.8.1
Water Piping Connections ............................................................................. 16
1.8.2
Low Water Flow Protection............................................................................ 18
Remote Condenser Installation .............................................................................. 18
1.9.1
Refrigerant Piping of Remote Condensers .................................................... 19
1.9.2
Evacuation and Charging of Remote Condensers ........................................ 20
Start-up Procedures ........................................................................21
2.1.
Prior to Start-up ...................................................................................................... 21
2.2.
Start-up Procedure ................................................................................................. 22
2.3.
System Operation Modes ....................................................................................... 22
2.3.1
Dehumidification / Air Reheat ........................................................................ 23
2.3.2
Dehumidification / Air Cooling ....................................................................... 23
2.3.3
Dehumidification / Water Heating (PDW and WC Models Only)................... 23
2.3.4
Blower Operation........................................................................................... 24
2.3.5
Air Heat (Optional)......................................................................................... 24
2.3.6
Outside Air (Outside Air Equipped Models Only)........................................... 24
3.
Service and Maintenance................................................................ 25
3.1.
Routine Maintenance..............................................................................................25
3.1.1
Service Every Month .....................................................................................25
3.1.2
Service Every Six Months..............................................................................25
3.1.3
Pool Water Chemistry....................................................................................26
3.2.
4.
Compressor Failure ................................................................................................26
3.2.1
Mild Burnouts ................................................................................................26
3.2.2
Severe Burnouts............................................................................................27
Appendix .......................................................................................... 29
4.1.
System Rating Plate ...............................................................................................29
4.2.
Model Numbering Matrix.........................................................................................30
4.2.1
System Serial Number Code .........................................................................30
4.2.2
Dehumidifier Model Number ..........................................................................31
4.2.3
Remote Condenser Model Number ...............................................................32
4.3.
Troubleshooting......................................................................................................33
4.3.1
Supply Blower Will Not Run...........................................................................33
4.3.2
Compressor Will Not Run ..............................................................................33
4.3.3
Evaporator Coil Ices Up (Suction Pressure Below 58 psig) ...........................34
4.3.4
Head Pressure is Too High (Above 270 psig)................................................35
4.3.5
Unit Runs But Walls and Windows Drip.........................................................36
4.3.6
Pool Water Heating Problems (WC and PDW Models Only) .........................36
4.4.
System Start Up Report..........................................................................................37
4.5.
System Guidelines - Unit Air Flow ..........................................................................39
4.5.1
Determining System Air Flow ........................................................................39
4.5.2
Blower Adjustment Procedure .......................................................................39
4.6.
System Guidelines - Unit Operation........................................................................40
4.6.1
Controller Set Points......................................................................................40
4.6.2
Refrigeration System Pressures ....................................................................41
4.6.3
Temperature Rise or Drop Across Unit..........................................................41
4.7.
Outside Air Supplemental Information ....................................................................42
4.7.1
PDW and PD Operation Mode .....................................................................42
4.7.2
IH and WC Operation Modes ........................................................................42
4.8.
SMACNA Duct Designs ..........................................................................................43
4.9.
Determining if Outside Air Pre-Heating is Required................................................44
4.10.
Approximating Outside Air Volume .......................................................................45
4.11.
Start-up Supervision Supplemental Information (Optional)...................................46
1.
Installation
1.1.
Unpacking and Inspecting
Desert Aire inspects and tests each dehumidifier before it leaves the factory so that
you receive a quality piece of equipment. However, the dehumidifier may have been
damaged in transit. Check the equipment thoroughly for both visible and concealed
damage before you sign the receiving papers. Document any damage in writing on
the carrier’s bill of lading to ensure that damage claims are handled promptly. If the
unit has been damaged, obtain a claim form from the carrier. Promptly fill out and
return the form, and notify Desert Aire of any damage. DAMAGE CLAIMS OR
SHORTAGES MUST NORMALLY BE FILED WITH THE FREIGHT CARRIER WITHIN 5
WORKING DAYS AFTER YOU RECEIVE THE EQUIPMENT.
1.2.
Location of Dehumidifier
Allow a minimum of 36 inches of clearance around all sides of the dehumidifier for
piping, duct connections, and service access. Install the unit on a sturdy, level
mounting base or a platform that will prevent vibration and sound transmission.
Never install the dehumidifier on a wooden platform. Do not install the unit near
occupied rooms such as bedrooms. Never suspend the unit above a swimming pool
or a spa. Do not attempt to conserve installation space by fabricating restrictive
ductwork with abrupt bends. You may reduce the operating efficiency and the
moisture removal capacity of the dehumidifier. See Section 1.6 for detailed duct
installation instructions.
Figure 1.
IH/WC/PD/PDW Installation & Operation Manual
Typical Floor Installation
5
Figure 2.
Typical Suspended Installation
YOU MUST NOT INSTALL A STANDARD DEHUMIDIFIER IN AN UNCONDITIONED SPACE
OR WHERE AMBIENT TEMPERATURES CAN FALL BELOW 45°F. If you must install
the dehumidifier outside or in an unconditioned space, such as an attic, you must use
an outdoor-rated dehumidifier. Desert Aire equips outdoor-rated dehumidifiers with
weatherproofing and thicker insulation. You can determine whether your
dehumidifier is outdoor-rated by inspecting the unit rating plate (see Section 4.1 for
details).
1.3.
High Voltage Electrical Connections
THE INSTALLING CONTRACTOR MUST VERIFY THAT ALL THE ELECTRICAL WIRING
TO THE DEHUMIDIFIER AND ITS ACCESSORIES COMPLIES WITH NATIONAL, STATE
AND LOCAL CODES.
1.3.1
Wire and Fuse Sizing
The field-installed power supply wires and overcurrent devices must be sized to
handle the minimum ampacity of the dehumidifier without exceeding the maximum
fuse size rating. Both the minimum ampacity and the maximum fuse size are printed
on the unit rating plate. FAILURE TO PROPERLY WIRE THE DEHUMIDIFIER WILL
CREATE THE POSSIBILITY OF SHOCK AND MAY LEAD TO PREMATURE SYSTEM
FAILURE.
6
Desert Aire
1.3.2
High Voltage Connections
On single phase units the power supply must have 3 connections (2 power, 1
ground). On three phase units the power supply must have 4 connections (3 power,
1 ground). Connect the power supply wires to the main power block located in the
upper section of the electrical compartment.
Figure 3. Single-Phase and Three-Phase System Power Connection.
1.4.
Controls Wiring and Set-up
The optional controls provided with your system are delicate instruments. You must
handle them carefully. Installation requirements depend on your controller package.
1.4.1
CA2300 Controller Package
The CA2300 controller is a digital controller used with Desert Aire Dehumidifiers. It
includes pool water (if applicable) and air sensors which have been factory wired and
mounted inside the unit. No sensor field wiring is required and the controller need
not be mounted in the conditioned environment. Mount the controller in a convenient
place and run the provided ribbon cable back to the unit’s electrical box. NOTE: Do
not run the ribbon cable adjacent to or in the same conduit as wires higher than 30
volts. Refer to the CA2300 instruction manual for complete documentation.
The CA2300 controller is designed to work with a variety of Desert Aire systems. As
part of the installation you must perform a setup procedure so that the controller
knows which type of system it is controlling. The INSTALL “AIR HEAT” OR “WATER
SENSOR” section of controller manual will show you how to do this. Which steps you
install depends upon which system you have:
•
IH and PD Models: If your application includes the installation of an air heater
you can control it with the CA2300 by installing AIR HEAT. Utilize dry contacts H1
and H2 located on the system’s terminal strip for this purpose.
IH/WC/PD/PDW Installation & Operation Manual
7
•
WC and PDW Models; For these units you must install WATER SENSOR. Once
again, install AIR HEAT if your application includes an air heater. See Section
4.6.1 for recommended set points. NOTE: The CA2300 series controller is
capable of controlling a field-supplied auxiliary water heater. Utilize dry contacts
W1 and W2 located on the system’s terminal strip for this purpose.
1.4.2
®
Johnson Controls UNT Controller Package
The Johnson Controls UNT controller is a more powerful digital controller used with
Desert Aire dehumidifiers. For maximum flexibility, the air temperature and humidity
sensor and the digital display are shipped loose for field-installation. This controller
is capable of energizing auxiliary air and water heaters, as well as outdoor intake
dampers, depending on the model and options of your dehumidifier.
The blowers in dehumidifiers with a UNT controller can operate either continuously or
intermittently. With intermittent blower operation, the blower will run only when there
is a demand for air heating, air cooling, or dehumidification. You can select the
blower operating mode by adding or removing a wire jumper from the terminal strip
on the electrical panel of the dehumidifier.
Refer to the separate UNT instruction manual for detailed instructions on installing
the sensors, using the controller, and choosing the ideal blower mode for your
application.
1.4.3
®
Honeywell
Snap Action Humidistat and Thermostat Controller Packages
These controllers have the sensors built-in. You must mount the controllers in the
conditioned environment approximately 5 feet above ground level. Avoid locations
where sensor readings may be influenced by sunlight, air vents, stagnant areas, etc.
Run standard thermostat wire back to the terminal strip located inside the unit’s
electrical box. Refer to your unit’s low voltage diagram located on the inside of the
electrical box door for necessary terminal connection points. If you choose to control
an air heater with the thermostat, use the isolated contacts provided on the
dehumidifier’s terminal strip. Do not connect the heater directly to the thermostat
unless you are certain that the heater is equipped with an isolation relay.
NOTE: Leave the thermostat set in the ‘AUTO’ position. This will allow automatic
cycling of the unit between cooling and heating modes. If you leave the thermostat
set to ‘HEAT,’ the air cooling mode will be locked out and vice versa.
8
Desert Aire
NOTE: If you control your system with a humidistat only, you will have to add a wire
jumper to the unit’s terminal strip. Refer to the electrical diagram for details.
1.4.4
®
Johnson Controls Aquastat
If you application includes water heating with snap action controls provided by Desert
Aire, the field installation of an aquastat is required. Mount the sensor on the water
circuit in an area where continuous water flow will be experienced before any heater.
Mount the thermostat in a convenient place assuring that the sensor capillary tube
remains protected by wrapping excess length. Run standard thermostat wire back to
the terminal strip located inside the unit’s electrical box. Refer to your unit’s low
voltage diagram located on the inside of the electrical box door for necessary
terminal connection points. The controller is equipped with an isolated contact
closure for second stage water heat. Control auxiliary water heaters by connecting
them directly to the second stage contacts on the aquastat.
NOTE: An aquastat is not used in cooling tower applications where water heating
occurs on call for air cooling.
1.4.5
Nonstandard Control Package
If your application does not utilize the standard controller, refer to the documentation
which accompanied your control package. The low voltage wiring diagram located
on the inside of the electrical box door shows how to connect sensors and auxiliary
heaters to your non-standard controller. NOTE: If you use a non-standard controller
to energize an auxiliary heater, you may need to install one or more isolation relays
between the heater and the controller. FAILURE TO ISOLATE ELECTRICAL CIRCUITS
CAN RESULT IN DAMAGE TO THE DEHUMIDIFIER AND THE ACCESSORY DEVICE.
1.5.
Condensate Drain
You must raise the dehumidifier at least 12 inches above the floor to provide
clearance for the condensate drain connection. You must supply and install a p-trap
on the 1” MPT drain line. Pitch the condensate drain line a minimum of 1/4” per
linear foot, and support the pipe with code-approved hangers at least every 5 feet. If
the drain runs through an unconditioned space, you must install heat tracing to
prevent the moisture in the drain from freezing. When gravity disposal is not
possible, you may use a condensate pump. Follow the pump manufacturer’s
installation instructions.
IH/WC/PD/PDW Installation & Operation Manual
9
NOTE: While its supply blower runs, the inside of the dehumidifier operates at a
negative pressure. If you do not trap the drain, condensate will be drawn into the
cabinet of the dehumidifier, which may lead to premature corrosion and property
damage.
Figure 4. Condensate Piping
1.6.
Duct Installation
Duct design and installations should conform to the latest ASHRAE and SMACNA
low velocity duct standards (see Section 4.8 for details). Undersized, restrictive
ductwork with abrupt turns or transitions can decrease the efficiency and the
moisture removal capacity of your dehumidifier. Size the ductwork for an acceptable
air pressure drop at the air flow volume of your dehumidifier.
Model Size
Air Flow Rate
(CFM)
0100/0125
0200
0300
0400
0500
0750 / 0800
0950 / 1000
1200
1500
540
950
1400
1900
2300
3500
4100
5500
6900
External Static Pressure
(Resistance of Ductwork
and Grilles)
0.5” Water Column (WC)
0.5” WC
0.5” WC
0.5” WC
0.5” WC
0.5” WC
0.5” WC
0.5” WC
0.5” WC
Table 1. Standard Unit Air Flow Specifications.
Use neoprene flex connectors when you attach ductwork to the dehumidifier to
prevent excess vibration noise. Duct the supply air from the dehumidifier to all
exterior walls and glass surfaces. Pay particular attention to skylights to avoid air
10
Desert Aire
stagnation and condensation on their surfaces. NOTE: Never direct air toward the
surface of a pool or spa. Do not install ceiling fans over the water surface. Air
movement above a pool can significantly increase its evaporation rate.
Figure 5. Basic Pool Room Layout.
Install the return air grilles or openings as high as possible in the room. In most
cases one centrally-located return air grille will be adequate. To prevent air shortcycling, do not install the return air grille too close to a supply grille. Grille sizing is
also important.
Select the grilles, registers and diffusers on the basis of low static pressure loss,
required throw distance, and the specified CFM rating. You can find this information
in most grille manufacturer’s catalogs. If you are installing the grilles in a corrosive
environment, such as an indoor swimming pool, choose components made from
anodized aluminum.
IH/WC/PD/PDW Installation & Operation Manual
11
Figure 6. Soffit Duct Layout.
Due to the elevated humidity conditions in a pool or spa enclosure, you should avoid
the use of fiberglass duct board or duct liner to prevent mold and bacteria growth. If
you must install ductwork in an unconditioned area, use two-inch fiberglass duct
wrap with a vapor barrier facing. If you install a below-grade duct system, use PVC
or plastic-coated galvanized spiral pipe to avoid deterioration.
You can use galvanized sheet metal ducts for most applications. However, you
should use aluminum or stainless steel ducts for extreme applications such as
chemical laden environments.
12
Desert Aire
Figure 7. Under-Floor Duct Layout.
1.7.
Outside Air Applications
1.7.1
Outdoor Air Option Equipped Units
Construction codes often require you to introduce outdoor air into a commercial
building while it is occupied. Desert Aire dehumidifiers can be factory-configured to
help you comply with these codes. Several factory-installed options, which are
available by special order, can include flanging for an outdoor air duct connection
and a fresh air intake box with air filters and a damper. See Section 4.2.2 to
determine if your system is equipped with any of these options.
The CA2300 Series and the UNT controller have a 7-day programmable timer which
can be used to set occupied times on IH and WC model dehumidifiers. These
models are built with an electronic evaporator damper. When the occupancy timer
opens (or closes) the outdoor air damper, the airflow volume through the evaporator
coil changes, affecting the moisture removal rate of the dehumidifier. The internal
electronic damper will automatically modulate to maintain the optimum airflow volume
across the evaporator.
IH/WC/PD/PDW Installation & Operation Manual
13
The Desert Aire PD and PDW Series dehumidifiers are designed for residential
swimming pool applications. These dehumidifiers are not provided with an electronic
evaporator damper. You must not connect an occupancy-controlled outdoor air
damper to a PD or a PDW system. The airflow volume changes which occur can
cause condensate carryover and can reduce the service life of the equipment. You
must either interlock the outdoor air damper with the blower of the dehumidifier
(using contacts provided) or use a separate outdoor air intake and fan which are not
physically connected to the ductwork of the dehumidifier. When you interlock the
outdoor air damper and the blower, you do not need an occupancy timer. The
outside air damper must be open whenever the blower is running. If you use a
physically separate outdoor air intake, then you may use the occupancy timer on the
CA2300 Series or UNT controller to turn it on and off.
NOTE: If your PD or PDW was ordered with an outside air option which will not be
utilized in the field, a minor adjustment is necessary to assure proper air flow through
the evaporator coil. Call the Desert Aire Service department at 414-357-7400 for
further information.
Desert Aire dehumidifiers ordered with the outdoor air intake option are built with
additional electrical terminals. These terminals should be utilized to control an
exhaust fan and outside air duct damper. See the system’s low voltage wiring
diagram for details.
NOTE: You must provide a transformer or a power source for
the outdoor air damper and the exhaust blower contactor.
You must install an exhaust blower or “gravity dampers” whenever you bring outdoor
air into a dehumidified room. Without the exhaust fan, the room would be at a
positive pressure. This increased room pressure can drive moisture and chlorine
odors into insulation, building materials, and adjacent rooms. Size the exhaust
blower to maintain the dehumidified room at a neutral or slightly negative pressure. If
you do not use the exhaust fan dry contacts provided by Desert Aire, you must make
sure that the exhaust blower shuts off whenever the outdoor air damper closes.
You must install the outdoor air intake away from any sources of airborne
contamination such as exhaust fans or plumbing vents. You must also filter the
outdoor air before it comes in contact with any coils. Insects and debris in the
unfiltered air will rapidly clog the dehumidifier’s reheat condenser coil, which will lead
to repeated service calls and eventual equipment damage.
If mixed air temperatures in the system’s blower compartment fall below 45°F an
internal safety thermostat will de-energize and override a call for outside air on IH
14
Desert Aire
and WC models. In PD and PDW models this thermostat will lock out the
compressor. This safety mode will remain active until mixed air temperatures in the
blower compartment rise above 55°F. IF OUTDOOR TEMPERATURES IN CONJUNCTION
WITH YOUR OUTSIDE AIR FLOW RATE ARE CAPABLE OF TRIPPING THE SAFETY THERMOSTAT,
YOU MUST INSTALL AN OUTSIDE AIR PREHEATING COIL.
Refer to Section 4.9. to
determine if the pre-heating of outside air is required for your application. An
example of a proper outdoor air installation is shown in Figure 8.
Figure 8. Proper Installation for an Outside Air Application.
NOTE: Desert Aire systems are designed to handle a range of external static
pressures. In applications where strict outside air code compliance is required,
proper system airflow must be determined by a professional balancing contractor.
When an approximation of outside air volume is all that is necessary, the procedures
detailed in Section 4.10. can be used.
1.7.2
Standard Systems in Conjunction with Outside Air
THE INTRODUCTION OF OUTSIDE AIR INTO THE RETURN AIR DUCT CAN LEAD TO A HOST OF
PROBLEMS.
Contact the Desert Aire service department before proceeding with such an
installation. If outside air must be added to satisfy code requirements on a non outside
air equipped system it is advised that the intake and exhaust be connected directly to the
space being conditioned. SYSTEM FAILURES CAUSED BY IMPROPER OUTSIDE AIR
INSTALLATIONS ARE NOT COVERED BY WARRANTY.
IH/WC/PD/PDW Installation & Operation Manual
15
1.8.
Water Heating Applications (PDW and WC Models Only)
1.8.1
Water Piping Connections
Desert Aire PDW and WC Series dehumidifiers are equipped with water heating
condensers. You must connect pool water circulating lines to these units so that they
operate as intended. The dehumidifier water supply circuit must tap into the main
pool water line downstream from the main filter. If the main pool circulating pump is
large enough, you can use a manual throttling valve to divert a portion of the water to
the dehumidifier. Normally, you must size and install an auxiliary water pump which
can handle the unit’s required water flow rate, which is listed in Table 2. If you are
using a water source other than a pool or a spa (such as a chilled water loop), the
required flow rate has been printed on a label affixed near the water line stubs of the
dehumidifier.
Model Size
0100/0125
0200
0300
0400
0500
0750 / 0800
0950 / 1000
1200
1500
Water Flow Rate and
Pressure Drop
Pool Application
2 GPM @ 7.8 ft H2O
4 GPM @ 7.8 ft H2O
6 GPM @ 9.2 ft H2O
8 GPM @ 6.1 ft H2O
10 GPM @ 8.0 ft H2O
14 GPM @ 10.6 ft H2O
20 GPM @ 15.7 ft H2O
24 GPM @ 20.1 ft H2O
30 GPM @ 23.1 ft H2O
Water Flow Rate and
Pressure Drop
Spa Application
3 GPM @ 12.9 ft H2O
5 GPM @ 10.2 ft H2O
8 GPM @ 13.6 ft H2O
11 GPM @ 9.1 ft H2O
13 GPM @ 11.5 ft H2O
18 GPM @ 13.1 ft H2O
26 GPM @ 20.1 ft H2O
31 GPM @ 26.3 ft H2O
39 GPM @ 30.0 ft H2O
Table 2. Standard Unit Water Flow Rates (PDW/WC models only).
A typical water circuit arrangement is shown in Figure 9. To simplify the
commissioning and servicing of this job, you should install a flow meter and isolation
valves in the pool water lines which feed the dehumidifier.
16
Desert Aire
Figure 9. Proper Pool Water Heating Installation.
Legend
1
2
3
4
5
6
7
8
9
10
Supply Air
Duct Heater (Gas, Electric, Steam,
Hot Water)
Flex Duct Connector
Refrigerant Piping to Remote
Condenser
Desert Aire Water Cooled
Dehumidifier
Filter Rack Assembly with Filters
Return Air
3 x 3 x 1 Rubber Vibration Isolators
P-Trap
Base
IH/WC/PD/PDW Installation & Operation Manual
11
12
Check Valve
Ball Valve
13
14
Flow Meter
Main Pool Heater
15
Auxiliary Pump
16
17
18
19
20
Filter Assembly
Main Pool Pump
Aquastat Sensor (Dry Well)
Water Inlet
Water Outlet
17
1.8.2
Low Water Flow Protection
Desert Aire WC Series dehumidifiers are equipped with a factory-installed water flow
switch. This switch prevents the unit from running in the water heating mode if there
is a lack of water flow. Desert Aire PDW Series dehumidifiers do not have a water
flow switch. The flow switch must be field-supplied and installed. Check the wiring
schematic of the dehumidifier for electrical connection details. PDW MODELS WILL
NOT RUN IN THE WATER HEATING MODE UNTIL YOU INSTALL THIS FLOW SWITCH.
1.9.
Remote Condenser Installation
When you add a Desert Aire remote condenser to a “remote-ready” dehumidifier, the
dehumidifier can reject unneeded heat to the outdoors. This option allows the
dehumidifier to provide space cooling during warm summer months. A “remoteready” dehumidifier has been factory-piped and wired to accept a remote condenser.
Not all Desert Aire dehumidifiers are remote-ready. If in doubt, refer to Section 4.2 in
the appendix to determine if your dehumidifier is equipped with this option.
Install the remote condenser on a level, hard surface. Do not install the condenser
directly on soil or within three feet of any major obstructions. If either the air inlet or
outlet is blocked by walls, shrubs, or debris; the service life of the equipment will be
reduced. CONSULT WITH DESERT AIRE IF YOU MUST INSTALL THE REMOTE
CONDENSER MORE THAN 10 FEET BELOW OR 50 FEET AWAY FROM THE
DEHUMIDIFIER.
NOTE: Pitch refrigerant lines in the direction of flow a minimum of ½” every 5 ft. of horizontal run.
Figure 10. Refrigerant Piping Examples, with Remote Condenser Above and Below Dehumidifier.
18
Desert Aire
1.9.1
Refrigerant Piping of Remote Condensers
1. Desert Aire remote condensers and remote-ready dehumidifiers have capped
refrigerant pipe stubs for the line set connection. The caps have been softsoldered in place. To remove the caps, heat them with a torch and then twist
them loose with a pliers. Do not overheat the caps or pipe stubs. NOTE: The
remote condensers are shipped from the factory with a holding charge of dry
nitrogen. RELEASE THIS CHARGE BEFORE REMOVING THE CAPS!
2. Remove the caps from the dehumidifier pipe stubs. NOTE: Desert Aire
dehumidifiers are equipped with remote condenser service valves located in the
blower compartment. The dehumidifier pipe stubs have been pressurized with
refrigerant for factory leak-checking. RELIEVE THIS PRESSURE BEFORE
REMOVING THE CAPS!
3. Fabricate the refrigeration piping between the dehumidifier and the remote
condenser using dehydrated ACR-type copper. Refer to the Table 3 at the end
of this section for the proper line sizes for your system. Use standard
refrigeration piping practices when you install the remote condenser above the
dehumidifier. Install a trap in the hot gas discharge line (labeled “A”) at every 15
feet of vertical lift as shown in Figure 10. Pitch horizontal runs a minimum of 1/2”
every 5 feet in the direction of flow. When you install the condenser piping, clean
and de-burr all the connection points. Take care to keep copper chips and
foreign materials out of the tubing. Solder or braze the joints together with 45%,
15% or Stay-Brite® solder.
4. After you braze the joints, check the lines for leaks by pressurizing the remote
condenser and line set with dry nitrogen or refrigerant vapor. CAUTION: Do
NOT EXCEED 80 PSIG NITROGEN CHARGE!
EXCESSIVE NITROGEN PRESSURE
CAN INTRODUCE NONCONDENSABLES INTO THE DEHUMIDIFIER AND
CONTAMINATE THE REFRIGERATION SYSTEM.
If the piping is free from leaks, release the pressure from the condenser. You
may charge and evacuate the lines by using the schrader ports on the remote
condenser service valves located in the blower compartment.
IH/WC/PD/PDW Installation & Operation Manual
19
LINE SIZE REQUIRED FOR UNITS (INCHES)
UNIT SIZE
0100 / 0125 / 0200
0300 / 0400
0500 / 0750 / 0800
0950 / 1000 / 1200
1500
SUPPLY (A)
5/8” OD
5/8” OD
7/8” OD
1-1/8” OD
1-3/8” OD
RETURN (B)
3/8” OD
1/2” OD
5/8” OD
7/8” OD
7/8” OD
Table 3. Remote Condenser Line Size Summary.
1.9.2
Evacuation and Charging of Remote Condensers
1. Evacuate the condenser and the piping to 400 microns. Isolate the piping for at
least ten minutes to verify that the system is free from leaks, moisture, and noncondensables.
2. When you add a remote condenser to a Desert Aire dehumidifier, you must add
more refrigerant to the system. The amount you add depends on the size of the
condenser and the length of the piping you installed. See Table 4 to determine
the necessary charge for your application. You can add this charge rapidly by
first heating your refrigerant cylinder, and then charging liquid refrigerant into the
condenser.
Example: You install an IH0500RR dehumidifier and an RC050 condenser 20
feet apart. The total lineset length is 30 feet. From Table 4, you must add 26
pounds of additional refrigerant to the system.
3. Once you have filled and checked the condenser and lineset for leaks, open the
lineset service valves located in the blower compartment of the dehumidifier.
4. Add the remote condenser jumper wire to the terminal contacts provided inside
the electrical compartment of the dehumidifier. Refer to the low voltage wiring
schematic for details. This dehumidifier will not operate in remote condenser
mode until this jumper is added.
ADDITIONAL REFRIGERANT CHARGE REQUIRED
FOR LINE SETS (R-22)
UNIT SIZE
(UP TO 25’)
(26’ TO 50’)
0100 / 0125
8 LBS
9 LBS
0200
11 LBS
12 LBS
0300
15 LBS
17 LBS
0400
21 LBS
24 LBS
0500
23 LBS
26 LBS
0750 / 0800 / 0950 / 1000
36 LBS
40 LBS
1200 / 1500
30 LBS
38 LBS
Table 4. Additional Charge Summary for Remote Condensers
20
Desert Aire
2.
Start-up Procedures
2.1.
Prior to Start-up
A complete startup will minimize operational problems and expensive callbacks. The
startup will be quicker and easier if the space to be dehumidified is at its design
temperature and humidity. You may need to use auxiliary or portable air heaters to
heat the room. Read this section thoroughly before attempting to commission the
Desert Aire dehumidifier. Always disconnect the power before servicing the
equipment!
NOTE: If you purchased a factory supervised start-up with your system, refer to
Section 4.11. in the appendix for important information.
1. LEAK TEST ALL FIELD AND FACTORY PIPING. Shipping and handling may have
caused refrigerant leaks inside the dehumidifier. Dehumidifiers with a large
refrigerant charge are equipped with rotalock shutoff valves on their receivers.
Their operating charge is pumped down and locked into the receiver prior to
shipping, leaving a residual vapor charge in the system piping. DO NOT OPEN
THE RECEIVER ISOLATION VALVES UNTIL THE SYSTEM HAS BEEN LEAK
TESTED.
DESERT AIRE WILL NOT REIMBURSE YOU FOR REFRIGERANT LOST
IN THIS MANNER.
2. Check the rating plate for power requirements. The available power supply
voltage must be within ±10% of the voltage printed on the rating plate.
3. Verify that all field wiring matches the Desert Aire wiring schematics. Inspect and
tighten all field and factory wiring.
4. Check and adjust the belt tension for 1 inch deflection at the mid-point of the
blower belt(s).
5. Check the drain pan and the condensate piping. Test the drain and prime the ptrap by pouring water into the drain pan.
6. If you installed a supplemental air heater, make sure you installed it in the air
discharge (or “supply”) duct and not the return duct.
IH/WC/PD/PDW Installation & Operation Manual
21
7. If your dehumidifier has a water heating condenser, turn on the circulating pump
to run water through the system. Inspect the piping and repair any water leaks
you find. If your dehumidifier is a Desert Aire PDW Series, verify that a water
flow proving switch has been installed and properly wired to the electrical panel
of the dehumidifier.
8. If you installed a remote condenser, verify that a jumper wire has been added to
the system’s control circuit.
9. Verify that all service valves in the refrigeration lines are fully open.
10. Inspect the air filters and coils to assure they are clean. If necessary, clean the
coils and install new air filters.
11. Make sure that the neoprene blocks (vibration isolators) are placed under the
dehumidifier at each corner and that unit is level.
2.2.
Start-up Procedure
First, read and understand the “Start-Up Report” which was shipped with the
dehumidifier. Desert Aire uses the start-up report to verify the integrity of each
installation. A thorough start-up can reduce callbacks and can help increase
customer satisfaction. Carefully follow the process detailed in the start-up report.
Mail or fax the completed start-up report back to Desert Aire to validate your unit’s
warranty. Be sure to keep a copy for future reference. If you do not have a start-up
report, call the Desert Aire Service Department at (414) 357-7400 for a new copy.
Please be prepared with the model and serial number of the dehumidifier. THE
START-UP REPORT IS REQUIRED FOR WARRANTY VALIDATION.
2.3.
System Operation Modes
The standard sequence of operation for a Desert Aire dehumidifier is relatively
simple. Whenever the compressor runs, refrigerant flows through the evaporator
coil, where it absorbs heat from the warm, humid airstream. This heat must be
rejected to one of three heat sinks; room air, pool water (PDW and WC models) or a
separate air stream (remote condenser). The dehumidifier will direct the heat where
it is needed (or not wanted) as determined by the controller setpoints.
22
Desert Aire
In the case of PDW and WC models with remote condensers, if both the water and
the air need heat, the dehumidifier heats the air first. If neither the water nor the air
need heat, then the dehumidifier rejects the heat to the remote outdoor condenser.
PDW and WC models not equipped with remote condensers require a simultaneous
call for air cooling before they will heat water. This feature prevents possible air
cooling when it is not desired.
Whenever a remote condenser is not utilized, the compressor will only run in
dehumidification mode if there is not simultaneous call for air cooling. This feature
prevents the conditioned room from becoming overheated and creating
uncomfortable room conditions.
2.3.1
Dehumidification / Air Reheat
When the room air requires dehumidification and heating, the dehumidifier runs in
the “reheat” mode. The hot refrigerant is discharged to the reheat condenser, which
warms the dehumidified air. The air which is discharged from the unit is drier and
about 20° warmer than when it entered.
2.3.2
Dehumidification / Air Cooling
When the room air requires cooling; or dehumidification and cooling, the dehumidifier
attempts to run in the air cooling mode. The hot refrigerant must be discharged to a
condenser other than the reheat coil. The refrigerant can be discharged to an
optional pool water condenser (PDW and WC models) or an optional remote outdoor
condenser (if so equipped). The air which is discharged from the unit is drier and
about 20° cooler than when it entered.
2.3.3
Dehumidification / Water Heating (PDW and WC Models Only)
When the pool water requires heating and the room air requires cooling, a
dehumidifier equipped with a pool water condenser attempts to run in the air cooling /
pool water heating mode. The hot refrigerant will be discharged to the pool water
condenser if the water flow proving switch shows that water is flowing through the
condenser. The air which is discharged from the unit is drier and about 20° cooler
than when it entered.
IH/WC/PD/PDW Installation & Operation Manual
23
NOTE: Units equipped with a CA2300W controller, a UNT controller, or a Johnson
Controls Aquastat (A28AA-29C) can also energize a field-supplied backup pool water
heater. You can find wiring details on the low-voltage wiring schematic affixed to the
electrical door of the dehumidifier.
2.3.4
Blower Operation
Units equipped with the standard CA2300 controller have been factory wired for
continuous blower operation. This helps prevent air stagnation and stratification.
Continuous blower operation is also required since the air temperature and humidity
sensors are mounted in the airstream inside of the dehumidifier. If the blower shuts
off, the sensors cannot read the actual room temperature and humidity. If your unit is
not equipped with the standard CA2300 controller, refer to the system wiring diagram
and the controller documentation for the possible blower operation options.
2.3.5
Air Heat (Optional)
If so equipped (see CONTROLS WIRING Section 1.4), a standard dehumidifier can
activate an auxiliary air heater when the room temperature drops below the set point.
supply air blower of the dehumidifier must run whenever there is a demand for air
heating. You must verify this when installing an auxiliary heater.
2.3.6
Outside Air (Outside Air Equipped Models Only)
During the “occupied” mode the dehumidifier will energize the outside air damper and
exhaust fan terminal contacts. Desert Aire IH and WC Series dehumidifiers will
operate in the occupied mode only if the occupancy timer is set accordingly. Desert
Aire PD and PDW models must operate in the occupied mode whenever the supply
blower runs. See Section 4.7 in the appendix for further outside air operation mode
details.
24
Desert Aire
3.
Service and Maintenance
You can prevent many future problems by adhering to the recommended
maintenance schedule shown. If you do discover a problem with the dehumidifier or
the installation, refer to the TROUBLESHOOTING GUIDE in Section 4.3. IF YOU HAVE
EXHAUSTED THE TROUBLESHOOTING GUIDE AND HAVE NOT DISCOVERED THE
PROBLEM, CALL THE DESERT AIRE SERVICE DEPARTMENT AT (414) 357-7400.
BE PREPARED WITH THE MODEL AND SERIAL NUMBER OF YOUR DEHUMIDIFIER.
3.1.
Routine Maintenance
Desert Aire dehumidifiers are designed for years of reliable service. However, like
any piece of machinery they require periodic maintenance.
3.1.1
Service Every Month
•
Check the air filters and replace them if necessary.
•
Check the coils in the dehumidifier and the optional remote condenser. Use
compressed air or a commercial coil cleanser if they are dirty or plugged.
•
3.1.2
Verify that the air flow around the remote condenser remains unobstructed.
Service Every Six Months
•
Tighten all field and factory electrical connections.
•
Check the blower belts in the dehumidifier and the optional remote condenser for
wear, glazing, and proper tension. Replace the belts if necessary. Adjust the
belts for approximately one inch deflection at their midpoints.
•
Conduct a SYSTEM PERFORMANCE AUDIT. A copy of this worksheet is located
in Section 4.4 of the appendix. Simply run copies whenever necessary. This
form is a valuable maintenance tool which can help you to uncover problems
before they get expensive. Compare the values to those documented on the
start-up report. If you require interpretation of the results, fax the completed form
to the Desert Aire Service Department for a analysis.
IH/WC/PD/PDW Installation & Operation Manual
25
3.1.3
Pool Water Chemistry
Pool chemistry must be maintained to ensure the proper pH, total alkalinity, calcium
hardness, and free chlorine. NSPI recommends the following levels for pool
chemistry:
pH ................................ 7.4 - 7.6
Total Alkalinity ..............100 - 150 ppm
Calcium Hardness ........ 200 - 250 ppm (Plaster Pool)
175 - 225 ppm (Vinyl or Painted Pool)
Free Chlorine ................1.0 - 3.0 ppm
Excessive chemical levels in the pool can be dangerous to users and can damage
pool hardware, including the dehumidification system. SERVICE PROBLEMS CAUSED
BY EXCESSIVE CHEMICAL LEVELS ARE NOT COVERED UNDER WARRANTY.
3.2.
Compressor Failure
Although some compressors fail because they are mechanically flawed, most failures
are due to system-related problems. Compressor failure can be caused by liquid
floodback, air or moisture in the refrigerant system, solid contaminants, excessive
heat or electrical service malfunctions. To avoid repeated callbacks, you must
determine the cause of the failure and then correct it.
If the compressor has failed because its motor has burned out, the refrigerant, oil,
and piping may have become severely contaminated. If a burnout has occurred, use
the following procedure to replace the compressor and clean the refrigerant system.
YOU MUST CLEAN THE SYSTEM THOROUGHLY TO PREVENT REPEATED
COMPRESSOR BURNOUTS! Use an oil test kit to determine the severity of the
burnout. Make sure you use rubber gloves and eye protection, as contaminated
refrigerant and oil can cause severe burns!
3.2.1
Mild Burnouts
•
If the burnout is mild, recover the refrigerant charge or transfer it to an unused
portion of the refrigeration circuit, such as the receiver or remote condenser.
You may need to energize the liquid line solenoid valve to evacuate the circuit
completely. On systems equipped with an optional pool water condenser, take
care to avoid freezing the condenser during evacuation.
•
If the compressor is equipped with rotalock valves, you may want to install and
evacuate the new compressor, and use it to pump down the charge.
26
Desert Aire
CAUTION! DO NOT ATTEMPT THIS WHEN A SEVERE BURNOUT HAS
OCCURRED!
•
Replace the suction filter with a suction line filter-drier. Sporlan manufactures
special “HH” filter-driers for cleaning system burnouts. These filters are
equipped with a tap for measuring the pressure drop across the filter. If you
install a filter without a tap, solder a tap in the suction line immediately upstream
of the filter.
•
Remove the old liquid line filter-drier and replace it with a new “HH” type filter one
size larger than the original.
•
Remove the old compressor if you have not already done so.
•
Install the new compressor. Be careful not to overheat its pipe stubs if it is not
equipped with rotalock connections.
•
Evacuate the system to purge the moisture and non-condensables from it. You
may need to energize the liquid line solenoid to evacuate all portions of the
refrigeration circuit.
•
3.2.2
Check the piping and joints for leaks, and recharge the system.
Severe Burnouts
•
If the burnout is severe, recover the refrigerant charge or transfer it to an unused
portion of the refrigeration circuit, such as the receiver or remote condenser.
You may need to energize the liquid line solenoid valve to evacuate the circuit
completely. On systems equipped with an optional pool water condenser, take
care to avoid freezing the condenser during evacuation.
•
Verify that the TXV and solenoid valves are not plugged with debris. Clean or
replace them if necessary.
•
Replace the suction filter with a suction line filter-drier. Sporlan manufactures
special “HH” filter-driers for cleaning system burnouts. These filters are
equipped with a tap for measuring the pressure drop across the filter. If you
install a filter without a tap, solder a tap in the suction line immediately upstream
of the filter.
•
Remove the old liquid line filter-drier and replace it with a new “HH” type filter one
size larger than the original.
•
Remove the old compressor if you have not already done so.
•
Install the new compressor. Be careful not to overheat its pipe stubs if it is not
equipped with rotalock connections.
•
Evacuate the system to purge the moisture and non-condensables from it.
IH/WC/PD/PDW Installation & Operation Manual
27
•
Check the compressor contactor for damage or pitted contacts. Some
compressors are equipped with start capacitors, run capacitors, and starting
relays. Check these components and replace them if necessary.
•
Check the piping and joints for leaks, and recharge the system.
•
Run the refrigeration system for an hour while you monitor the pressure drop
across the suction filter. If the pressure drop is 3 psig or less after one hour,
continue to run the system for 24 hours, then take an oil sample.
•
If the oil sample is dirty or acidic, or if the one-hour pressure drop is greater than
3 psi, then recover the system charge and replace both the suction and liquid
filter-dryers. Repeat the previous step until your oil sample tests negative.
28
Desert Aire
4.
Appendix
4.1.
System Rating Plate
The system rating plate is attached to the outside of the electrical box door. You will
require the rating plate information when you install and service the dehumidifier.
System model and
serial numbers
System electrical
specifications
Model No. PD0300RR2S
Serial No. 3094D5154
VoltagePhase/Hz
Compressor and
blower motor electrical
specifications
Refrigerant type
and factory charge
System working
pressure range
System wiring
diagrams
Control Voltage
208/230-1-60
24
31
Maximum Fuse 45
Compressor RLA 20.0
Blower
LRA 103
HP
FLA
0.5
4.9
Factory Charge lbs. 18
R22 ONLY
Wiring Diagram Numbers
HD-100 / LPD-0000
This Unit Is For Indoor Use
Indoor or outdoor
system rating
Figure 11. System rating plate.
IH/WC/PD/PDW Installation & Operation Manual
29
4.2.
Model Numbering Matrix
4.2.1
System Serial Number Code
Figure 12. System serial number code.
NOTE: If your dehumidifier is an engineered system, portions of this manual may not
apply.
30
Desert Aire
4.2.2
Dehumidifier Model Number
Figure 13. Dehumidifier model number matrix.
IH/WC/PD/PDW Installation & Operation Manual
31
4.2.3
Remote Condenser Model Number
Figure 14. Remote condenser model number matrix.
32
Desert Aire
4.3.
Troubleshooting
4.3.1
Supply Blower Will Not Run
POSSIBLE CAUSE
System terminal switch in open position
Loss of main power
Blower overload has tripped
Faulty control wiring
4.3.2
REMEDY
Close system terminal switch.
Check for tripped circuit breaker or
blown fuses
Correct cause and reset overload
Check for loose or incorrect wires on
system and controller
Compressor Will Not Run
NOTE: Under some circumstances the compressor will not run even though the
humidity in the room may be too high. See Section 2.3 for more information on the
control sequence for the dehumidifier.
POSSIBLE CAUSE
Control logic (see above)
Loss of main power
Blower overload has tripped
Faulty wiring
Compressor overload has tripped
Comp. failure may have occurred if:
A) Comp. draws locked rotor amps
B) Comp. starts but does not pump
C) Motor windings have shorted
Compressor delay-timer
IH/WC/PD/PDW Installation & Operation Manual
REMEDY
A) Adjust controller setpoints
B) On RR models with a remote
condenser installed: Verify that the
RC jumper has been installed in
dehumidifier (see Section 1.9).
Check for tripped circuit breaker or
blown fuses
Correct cause and reset overload
Check for loose or faulty wiring on
system and controller
Correct cause and reset overload
A) Replace compressor (or check fuses
on three-phase units)
B) Replace compressor
C) Replace compressor
Wait 3 minutes for timer
33
4.3.3
Evaporator Coil Ices Up (Suction Pressure Below 58 psig)
POSSIBLE CAUSE
Entering air is below 70oF (PD/PDW
Series only)
Faulty or improperly set hot-gas bypass
valve (IH/WC Series only)
Insufficient evaporator air flow rate
Lack of refrigerant
Restrictive filter drier
Defective expansion valve
Restriction in refrigeration piping
34
REMEDY
Raise entering air temperature
1) Set hot-gas valve to maintain 32o F
suction (58 psig)
2) Replace if defective
3) Open hot-gas isolation valve
1) Evaluate system air flow
(see Section 4.6)
2) Check for dirty filters or restricted
ductwork
3) Assure coils are clean
Reevaluate system charge
Evaluate filter pressure drop and
replace if necessary
Evaluate expansion valve performance
and replace if necessary.
1) Check coil for kinks in tubing
2) Evaluate debris in distributor
Desert Aire
4.3.4
Head Pressure is Too High (Above 270 psig)
POSSIBLE CAUSE
Insufficient system air flow
Excessive refrigerant charge
Non-condensables in system
Defective refrigeration valves
Restriction in refrigeration piping
Refrigeration system is overloaded
Low water flow (PDW/WC Series only)
REMEDY
1) Evaluate system air flow
(see Section 4.5).
2) Check for dirty filters or restricted
ductwork
3) Verify that coils are clean
Re-evaluate system charge
Evacuate or purge system
Check 3-way, flooding, solenoid, and
check valves for sticking
1) Check coil and tubing for kinks
2) Replace dirty drier filter
1) Reduce entering air temperature or
relative humidity
2) Check register locations for shortcycling of air
Evaluate water flow rate for your
application
REMOTE CONDENSER PROBLEMS
WHICH CAUSE EXCESSIVE
PRESSURES:
Lack of air flow
Remote cond. blower does not run.
A) Overload tripped
B) Contactor faulty
C) Blower cycling on internal
protection
D) Remote Cond. jumper missing at
dehumidifier
Service valves closed or not fully open
Excessive pressure drop in line sets
Assure coil is clean and no air flow
restrictions exist around unit.
A) Reduce blower speed and reset
overload
B) Replace contactor
C) Reduce blower speed
D) Add necessary jumper in
dehumidifier (See Section 1.9)
Fully open service valves
Re-evaluate remote condenser
installation (See Section 1.9 for
guidelines)
NOTE: When the remote condenser is active and the outdoor temperature is
above 95°, normal head pressure can be as high as 300 psig.
IH/WC/PD/PDW Installation & Operation Manual
35
4.3.5
Unit Runs But Walls and Windows Drip
POSSIBLE CAUSE
Air and pool water temperature
imbalance
Poor air distribution
Unit air flow is too high
Unit is undersized
UNITS NOT EQUIPPED WITH THE
CA2300 SERIES CONTROLLER:
1) Controller installation
2) Air stratification
4.3.6
REMEDY
Adjust setpoints so that air temperature
is 2o F above water temperature. 80o F
water and 82o F air recommended for
most jobs
Evaluate duct design and dehumidifier
location (See Sections 1.2 and 1.6)
Evaluate system air flow
(See Section 4.5)
Re-evaluate unit sizing. Check for
initially neglected sources of heat or
humidity
1) Assure that sensors are NOT located
near supply registers, windows,
heaters, saunas, etc.
2) Consider continuous blower
operation.
Pool Water Heating Problems (WC and PDW Models Only)
NOTE:
1. PDW models require the installation of a field supplied water proving switch
before the water heating mode can be activated.
2. Lack of water heating may be a symptom of another refrigeration or controls
problem not related to the water circuit.
3. Under normal conditions the water temperature rise across the dehumidifier
should be between 4o and 15o F.
•
LOW WATER TEMPERATURE INCREASE is a symptom of excessive water flow
rate. Excessive water flow can erode the water condenser and cause premature
equipment failure.
•
HIGH WATER TEMPERATURE INCREASE is a symptom of insufficient water flow.
This can be caused by an undersized pump, insufficient water diversion or
restrictions in the water piping such as dirty filter(s). This would also lead to high
operating pressures in the water heating mode.
36
Desert Aire
4.4.
System Start Up Report
A copy of the system start up report can be found on the following page. This report
needs to be filled out thoroughly by a qualified service technician and returned to
Desert Aire for warranty validation. Please ensure that the model and serial number
of the unit is noted on this form. The model and serial number can be found on the
systems rating plate located on or near the electrical compartment service door.
Failure to complete and return this form will void the units warranty. These reports
are also helpful when trying to correct existing problems. Should you need system
diagnosis help, fax the completed worksheet to the Desert Aire Service Department
using the number provided. Be sure to include your name and a telephone number
where you can be reached.
IH/WC/PD/PDW Installation & Operation Manual
37
IH/WC/PD/PDW System Startup Report
WARNING — Only trained, qualified personal should service Desert Aire equipment. Serious injury and/or
death can result from improper service of this equipment. High voltage electrical components and refrigerant
under pressure are present.
Note! This Startup Report must be filled out completely and returned to Desert Aire for warranty activation.
All readings should be taken when equipment is operating at design conditions.
Model Number
Serial Number
Air Flow Information (see Section 4.5 of the Installation & Operation Manual)
Reheat coil static pressure drop:
inches WC
Evaporator coil static pressure drop:
inches WC
Electrical & Refrigeration System Readings (as measured by a qualified service technician)
Actual Supply Voltage:
Control Voltage:
°F
Return Air Temperature:
RH:
%
Compressor 1 amp draw
Line 1
Line 2
Line 3
Compressor 2 amp draw
Line 1
Line 2
Line 3
Blower amp draw
Line 1
Line 2
Line 3
Air Dehumidification Mode
* Air Cooling Mode
* Water Heating Mode
Compressor discharge pressure: (psig)
Compressor suction pressure: (psig)
o
Dehumidifier leaving air temperature: ( F)
Condensate trap installed:
Yes
Oil Level Sight Glass (if applicable):
°F
RC elevation is
ft.
* Water Cooled Installations:
* Outside Air (OA ) Installations:
½
¾
Amp Draw:
Full
R-22 added:
lbs
Line set length between RC and dehumidifier:
above
Water temperature:
Water flow rate (measured):
(See I&O Manual for details)
Less than ½
* Remote Condenser (RC) Installations:
Outdoor Ambient:
No
below
In:
dehumidifier
°F
Out:
°F
GPM
Outside Air Flow Rate:
OA duct is equipped with (check all that apply): Filters
Outside Air Damper Is Controlled by Dehumidifier:
Yes
CFM
Damper
Heater
No
inches WC
Activate outside air mode and measure evaporator coil static pressure drop:
Evaporator is:
Wet
ft.
Dry
CONSULT THE OPERATION MANUAL FOR INSTALLATION INSTRUCTIONS AND SYSTEM OPERATION GUIDELINES
* if so equipped
Submitted by:
Phone No.
Please Mail or fax to : Desert Aire Service Department
8300 W. Sleske Ct, Milwaukee, WI 53223-3844
PH: 414/357-7400 FAX: 414/357-8501
38
Date:
Desert Aire
4.5.
System Guidelines - Unit Air Flow
Each Desert Aire Dehumidifier is designed to operate at a specified air flow rate.
System air flow must be checked prior to troubleshooting the refrigeration circuit to
assure that such problems are not actually caused by improper unit air flow.
•
•
4.5.1
Problems with excessive air flow:
•
Reduction in moisture removal capacity.
•
High amperage draw by the blower motor.
•
Water carry over from evaporator coil
•
Excessive unit noise levels.
Problems with inadequate air flow:
•
Can cause excessive discharge (high side) refrigeration pressure.
•
Increase in system energy consumption.
•
Can lead to premature compressor failure.
Determining System Air Flow
Using a manometer or magnehelic pressure differential gauge, determine the static
pressure drop in inches water column across the unit's condenser coil. NOTE:
Newer units are equipped with pressure tap holes on the side panels just for this
purpose. If your unit is not equipped with such taps, simply drill two small holes in
the unit’s side panels (one in the blower compartment just downstream from the
condenser and one in the section between the evaporator and the condenser). Drill
the holes so that they are large enough for your static pressure taps. See Table 5 for
the proper pressure drop range for your unit. A low static pressure drop indicates
low air flow -- you must speed up the blower. A high pressure drop indicates high air
flow -- you must slow down the blower.
NOTE: Low system airflow can also be caused by airflow restrictions such as dirty
coils, filters, and duct work. Assure that this not the case before you speed up the
blower.
4.5.2
Blower Adjustment Procedure
WARNING! DISCONNECT POWER TO THE UNIT BEFORE YOU ADJUST THE
BLOWER.
Change the blower speed by adjusting the motor pulley. To adjust the variable pitch
pulley, first loosen the set screw. To slow down the blower, turn the outer pulley face
IH/WC/PD/PDW Installation & Operation Manual
39
counterclockwise (to decrease its pitch diameter). To speed up the blower, turn the
outer pulley face clockwise (to increase its pitch diameter).
AFTER EVERY ADJUSTMENT BE SURE TO:
•
Tighten the set screw against the flat spot on the pulley hub so you don’t damage
any threads.
•
Adjust the belt tension if needed.
•
Check to assure that the blower motor current draw does not exceed the rating
printed on the rating plate.
NOTE: System airflow will tend to decrease over time due to belt wear and dirty
filters and ducts. Always adjust the blower speed to the high side of the pressure
drop range.
If the blower motor current draw exceeds its rating but your airflow is still too low, the
static pressure losses in the ductwork and grilles may be higher than the unit was
designed for. If this happens, consult the Desert Aire Service Department. Please be
prepared with system serial and model number.
Model
0100/0125
0200
0300
0400
0500
0750 / 0800
0950 / 1000
1200
1500
Total
System CFM
540
950
1400
1900
2300
3500
4100
5500
6900
Condenser Coil Pressure
Drop Range (inches WC)
0.19” - 0.21”
0.23” - 0.25”
0.20” - 0.22”
0.14” - 0.16”
0.20” - 0.22”
0.28” - 0.30”
0.25” - 0.27”
0.40” - 0.42”
0.32” - 0.34”
Table 5. Standard Reheat Coil Pressure Drops
4.6.
System Guidelines - Unit Operation
4.6.1
Controller Set Points
It is important to determine your comfortable set points and to avoid further
controller adjustments. It takes time for the unit to establish equilibrium at a
given setpoint. Therefore, continued setpoint adjustments will lead to high
energy consumption and user discomfort. Continuous blower operation is
recommended. This will reduce air stratification and assure that the
refrigeration circuit is activated only when it is necessary.
40
Desert Aire
RECOMMENDED SET POINTS:
•
Humidity: 50% to 60% RH
•
Air temperature: 2o to 4o F above the pool water temperature
WARNING: Never disable a dehumidifier in a pool room application unless the pool
has been drained. Even when not in use, pool water continues to evaporate adding
moisture to the air. During these periods of high humidity moisture will seep into
walls, ceilings, furniture, etc.. Although the dehumidifier may be capable of regaining
control of pool room conditions after re-start, in the long run, moisture damage to the
pool room will become apparent.
4.6.2
Refrigeration System Pressures
Many factors affect refrigeration pressures on a given day. Such factors include
ambient temperature, water temperature, air flow volume, and relative humidity.
However, for the sake of troubleshooting:
•
Normal suction pressure range: 55 to 70 psig
•
Normal discharge pressure range: 180 to 270 psig
NOTE: Always check the system air flow before you troubleshoot the refrigeration circuit
(see Section 4.5).
4.6.3
Temperature Rise or Drop Across Unit
•
Typical air temperature rise across unit (Reheat mode): 10o to 20o F
•
Typical air temperature drop across unit (Air conditioning or water heating mode):
10o to 20o F
NOTE:
•
If your unit does not meet these temperature ranges, check the system air
flow (See Section 4.5).
•
These guidelines do not apply to dehumidifiers with outdoor air intakes
when they are in the “occupied” mode.
IH/WC/PD/PDW Installation & Operation Manual
41
4.7.
Outside Air Supplemental Information
4.7.1
PDW and PD Operation Mode
Figure 15. PD / PDW models, Occupied Mode Operation.
4.7.2
IH and WC Operation Modes
Figure 16. IH / WC Models, Unoccupied Mode Operation.
Figure 17. IH / WC Models, Occupied Mode Operation.
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Desert Aire
4.8.
SMACNA Duct Designs
You must use proper duct design to ensure that the dehumidifier operates efficiently
and without problems. Undersized or restrictive ducts reduce the system airflow,
which can cause premature compressor failure. Use the following diagrams as a
guide when you design the duct system.
No!
Yes!
Figure 18. Recommended Duct Designs for Desert Aire Dehumidifiers.
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43
4.9.
Determining if Outside Air Pre-Heating is Required
Desert Aire systems require that outside air be pre-heated if mixed air temperatures
inside the unit may fall below 45 °F. To determine if an application requires outside
air pre-heating, the following study needs to be conducted:
1. Determine the following:
•
Design return air temperature. For pool rooms typically 82 °F.
•
Outside air winter design temperature. Use values as specified by design
engineer or ASHRAE tables.
•
2.
Total system CFM and required outside air CFM
Determine worst case Mixed Air Temperature using the following equation:
MAT = (winter temp °F) x (OA CFM) + (return air temp °F) x (system CFM - OA CFM)
(system CFM)
(system CFM)
3. If MAT is less than 45 °F, then the pre-heating of outside air is required.
NOTE:
•
Proper system airflow and outside air CFM must be confirmed at the time of
installation.
•
Outside air duct must be equipped with filters and a motorized damper provided
by installing contractor or as optional equipment on Desert Aire dehumidifiers.
•
Outside air duct must be insulated to prevent condensation which may form on
the exterior of the duct during winter months.
EXAMPLE:
PD0500 (2300 system CFM), pool room application, 500 CFM of
outside air. Location: Minneapolis, Minnesota.
MAT = (-16 °F) x 500 + 82 °F x (2300 - 500) = 60.7 °F
2300
2300
CONCLUSION: No need for outside air pre-heat.
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Desert Aire
4.10.
Approximating Outside Air Volume
When servicing or installing a Desert Aire unit, it may be necessary to determine
and/or set the amount of outside air CFM entering the unit. Proper outside air CFM
settings can be approximated using two simple equations as follows:
Figure 19. Approximating Outside Air CFM.
OACFM = LACFM x (LATEMP - RATEMP) / (OATEMP - RATEMP)
LATEMP = (OACFM x (OATEMP - RATEMP) / LACFM) + RATEMP
NOTE:
•
This method is just an approximation! In applications where strict code
compliance is required proper airflow must be determined by a professional
testing and balancing contractor.
•
Refrigeration circuit must remain inactive during this procedure (blower on only).
•
When measuring air temperatures, several readings must be taken across a duct
and averaged.
•
Proper LACFM (total system airflow) must be confirmed prior to this procedure.
This is done by achieving specified air flow pressure drop across the reheat coil.
See Section 4.5. for details.
EXAMPLE 1:
Determine how much OA CFM is entering a PD0500.
Measured:
LACFM = 2300, LATEMP = 73 °F, RATEMP = 82 °F, OATEMP = 40 °F
Solution:
OACFM = 2300 x (73 °F - 82 °F) / (40 °F - 82 °F) = 490 CFM
EXAMPLE 2: Determine proper outside air damper setting to achieve 900 CFM of
OA on an IH0750.
Given:
Desired OACFM = 900
Measured:
LACFM=3500, OATEMP=40 °F, RATEMP=82 °F
Solution:
LATEMP = (900 x (40 °F - 82 °F) / 3500) + 82 °F = 71 °F
i.e. adjust outside air damper until a system leaving air temperature of 71 °F is
achieved
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45
4.11.
Start-up Supervision Supplemental Information (Optional)
A Desert Aire factory start up is an option which can be purchased with the
equipment. A factory start up includes several key services:
•
The expertise of an accomplished, factory-trained mechanic who will supervise
the commissioning of the equipment.
•
This Desert Aire representative will assist the installing contractor with filling out
the Start Up Report.
•
He will also inspect the installation to make sure that the dehumidifier has been
properly integrated with the rest of the equipment on the jobsite.
•
Finally, he can train the maintenance personnel to operate and service the
equipment if necessary.
A factory start up does not include installation assistance. The installing contractor is
responsible for ensuring that the system is ready for start-up when the Desert Aire
representative arrives.
When the installing contractor is confident the system will be ready, he should
contact the Desert Aire Sales representative to schedule the start-up. Please call at
least two weeks before the desired start up date to help prevent scheduling conflicts.
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Desert Aire
SERVICE BULLETIN 010
IH / WC / PD / PDW / ND / SA FACTORY START-UP SUPERVISION
A Factory Start-Up requires a Desert Aire Service Department Technician to visit the job-site and provide supervisory
experience to installing contractors as they perform the required procedures as outlined in our warranty activation start-up
report. The company technician will also present an educational review of the dehumidifier’s operating and maintenance
requirements. A CST Start-Up is performed by a local Certified Service Technician who has been trained by Desert Aire.
The CST performs all duties of commissioning and also trains responsible parties on the proper maintenance and
operation of the unit.
“Factory Start-Up is not an installation bid & therefore the system must be ready to run before scheduling.”
The Desert Aire Service Dept. will advise contractors of their responsibilities and coordinate all site visits. This start-up
procedure may be performed by Desert Aire OR an authorized “Certified Service Technician.” This document requires a
signature and must be returned to Desert Aire before the Factory- or CST-supervised start-up can be scheduled. Desert
Aire will confirm the start-up dates upon receipt of the pre-start-up checklist. If a return trip must be scheduled due to
insufficient job-site preparation, a second P.O.# must be issued to Desert Aire for re-scheduling.
The following list of items will apply to all start-ups and is the responsibility of the installing contractor. If you are
unable to supply any of the following equipment, you must contact Desert Aire before signing this document.
You can reach Desert Aire at (800) 443-5276.
Items needed for Start-Up:
‰ Equipped service vehicle and service technician – Technician will be trained.
‰ Refrigerant manifold gauges – 2 sets
‰ Air balancing equipment (magnehelic or manometer differential pressure gauge)
‰ Volt/Amp/OHM meters in working order.
‰ Digital Thermometer w/clamp on sensors OR laser type temperature probe.
‰ 50# of R-22 & weigh in scale
‰ Hand Pump for adding oil to compressor (Copeland Scroll) 9 ton compressor & larger
Items to be completed before Start-Up:
‰ Dehumidifier leak checked (with halogen leak detector) and inspected for internal concealed damage – remove
access panels and inspect the interior of the unit for transit damage. Contact Desert Aire immediately if damage
is noted (800) 443-5276
‰ Dehumidifier leveled and properly supported per the installation manuals recommendations.
‰ Outside air duct filters and damper installed (if applicable) – See installation manual.
‰ Condensate P Trap installed with heat trace for winter operation.
‰ Remote condenser plumbed and inspected for freight damage (If applicable)
‰ Remote condenser circuit leak checked, evacuated and charged (if applicable – see installation manual for R-22
weights and condenser locations)
‰ All electrical connections terminated and verified for proper voltage at the unit.
‰ All field controls and sensors installed and circuits verified that they are wired correctly. If there are any
questions, contact Desert Aire (800) 443-5276
‰ Pool filled, water and air temp minimum 80 degrees (if applicable)
‰ Pool water heating circuit connected to dehumidifier with flow meter and balancing valves installed in circuit (if
applicable)
‰ Verify the installation of the booster pool water heating pump and purge air from the water lines (if applicable)
‰ Verify that voltage matches nameplate design for the condenser and the dehumidifier.
A MINIMUM TWO WEEK LEAD TIME IS NEEDED TO SCHEDULE START UP
Desert Aire Corporation • 8300 West Sleske Court • Milwaukee, WI 53223 • (800) 443-5276 • Fax (414) 357-8501
IH/WC/PD/PDW Installation & Operation Manual
47
SERVICE BULLETIN 010
IH / WC / PD / PDW / ND / SA FACTORY START-UP SUPERVISION
Desert Aire Corporation • 8300 West Sleske Court • Milwaukee, WI 53223 • (800) 443-5276 • Fax (414) 357-8501
Please complete this two page document, sign and return to Desert Aire for start-up scheduling. Dates will be scheduled
after this form is received. Please print clearly.
Unit Information
Model #
___________________________________________________________
Serial #
___________________________________________________________
Contractor Information
Installing Contractor
Address
______________________________________________________________________
_______________________________________________________________________________
_______________________________________________________________________________
Phone #
_____________________________________
Jobsite Information
Jobsite Address __________________________________________________________________________
__________________________________________________________________________
Jobsite Contact
______________________________________ Cell # ______________________________
Jobsite Phone # __________________________________________________________________________
Signature, Jobsite Supervisor ________________________________________ Date __________________
Test & Balance
Contractor Name
________________________________________________________________________
Technicians Name __________________________________ Phone # ______________________________
Test & Balance Completion Date
____________________________________________________________
Desert Aire Sales Representative
Company Name ___________________________________________________________________________
48
Desert Aire
8300 West Sleske Court
Milwaukee, WI 53223
(414) 357-7400
Fax:(414) 357-8501
31 - 07/05