Desert Aire SA Series Owner's manual

Installation and Operation Manual
• Select
Aire (SA) systems
are dual refrigeration
circuit dehumidifiers.
• Systems remove between
55 and 340 pounds of
moisture per hour
.
• Refrigeration circuits
consist of scroll
compressors for high
performance and long life
.
• Models feature 8-row
evaporator coils for high
moisture removal capacity
.
• SA
systems include an
exclusive exhaust air heat
recovery system and
patented air flow
balancing.
• SA
’s dual refrigeration
circuit design allows
staging to minimize
energy consumption and
optimize energy recovery
.

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Desert Aire - SA Manual
DANGER
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.
Desert Aire
Dehumidication Equipment
Standard Limited Warranty
Desert Aire warrants the dehumidifying unit to be free from defects in materials and workmanship subject to the terms,
conditions and limitations stated herein.
TERMS
Desert Aire warrants all components (except as noted) for a period of two (2) years from the date of shipment. This
warranty shall be limited to the supply of new or rebuilt parts for the part which has failed because of
defects in workmanship or material, and does not include the cost for labor, transportation or other costs not herein
provided for. Replaced parts are warranted only for the remaining portion of the original warranty period.
CONDITIONS
The warranty is subject to the following conditions:
1. The unit must be properly installed and maintained in accordance with the Desert Aire
“Installation and Operation Manual” provided with each unit and/or other documentation
provided.
2. The Start-Up Report must be completed and returned to Desert Aire Service for evaluation. If no
  decienciesareidentiedaWarrantyValidationLetterwillbeissuedthatprovidesallwarranty
  datesandcoverage.Ifinstallationorstart-updecienciesarepresent,thesemustbecorrected
and communicated to Desert Aire in order to activate warranty.
3. This warranty shall not apply to any part that has been tampered with, or has been subject to
misuse, negligence or accident. A warranty can be obtained for altered equipment but only with
written consent from Desert Aire.
4. The following parts and components are excluded from the warranty: belts, lters, driers, fuses and
refrigerant.
5. Refrigerant coils or other components that corrode due to improperly balanced pool chemistry or
corrosive air quality will not be warranted.
6. All replacements or repairs will be FOB Germantown, WI.
7. This warranty shall be null and void if defects or damages result from unauthorized opening of the
refrigerant circuit, tampering with factory set controls, or operating outside the original design
conditions.

4Desert Aire - SA Manual
8. Desert Aire shall not be liable for labor costs incurred in diagnosing the problem, or the removal
or replacement of the part or parts being repaired.
9. Desert Aire must preauthorize all warranty coverage described herein.
ExtendedWarranty:
Your Desert Aire unit may have extended warrantees beyond this Standard Limited Warranty document.
Extended warrantees are only available at the time of the purchase of the original equipment. These extended war-
rantees are covered under a separate document and their terms and conditions are separate from this document.
It is mentioned in this document for informational purposes only. Any Extended Warranties will be identied on the
Warranty Validation Letter.
Any and all incidental or consequential damages are expressly excluded from this warranty. Some states do not allow
the exclusion of incidental or consequential damages for personal injury, so the above limitations may not apply to you
for certain damages. This warranty gives you specic legal rights, and you may also have other rights, which vary
from state to state. No person or representative is authorized to make any warranty or assume any liability not strictly
in accordance with the aforementioned.
Inquiries regarding warranty matters should be addressed to:
Desert Aire Corp c/o Service Manager
N120 W18485 Freistadt Road • Germantown, WI 53022
PH: [phone] • FAX: [phone] • E-MAIL: [email protected]
Additional copies of this manual can be purchased for a nominal fee from Desert Aire. Desert Aire also posts the most
current revision of our I/O Manuals on our website. For a digital copy of the I/O Manual for your unit revision, please
submit request to the contact information listed above.
GasHeatExchangerTen(10)-YearProratedWarrantyTerms(ForSA™unitswithgasheatonly)
Desert Aire offers an extended prorated eight (8)-year warranty for gas heat exchanger. All other heater components
are covered under the initial 2 year warranty.
2 Years Parts Only from date of shipment. Prorated from years 3-9 as follows:
Year 3: Desert Aire warrants 70% of replacement price
Year 4: Desert Aire warrants 60% of replacement price
Year 5: Desert Aire warrants 50% of replacement price
Year 6: Desert Aire warrants 40% of replacement price
Year 7: Desert Aire warrants 30% of replacement price
Year 8: Desert Aire warrants 20% of replacement price
Year 9: Desert Aire warrants 10% of replacement price

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Desert Aire - SA Manual
SafetyLabelsareusedthroughoutthismanual.TheycomplywiththeANSIZ535.4Standard.
Pleasebefamiliarwiththefollowinglabelsandtheirdenitions.
This is the safety alert symbol. It is used to alert you to potential
personal injury hazards. Obey all safety messages that follow this
symbol to avoid possible death or injury.
Indicates an imminently hazardous situation which, if not
avoided, will result in death or serious injury.
Indicates a potentially hazardous situation which, if not
avoided, could result in death or serious injury.
Indicates a potentially hazardous situation which, if not
avoided, could result in minor or moderate injury.
Caution used without the safety alert symbol indicates a
potentially hazardous situation which, if not avoided, could
result in property damage.
ProductWarningfortheStateofCalifornia:

6Desert Aire - SA Manual

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     TABLEOFCONTENTS
1 Introduction ...................................................................................................................... 9
1.1 Inspection ............................................................................................................... 9
1.2 Freight Damage Claims .......................................................................................... 9
1.3 Rigging ................................................................................................................... 9
1.3.1 Rigging the Dehumidier ............................................................................. 9
2 Installation ....................................................................................................................... 11
2.1 Position and Service Clearance ............................................................................. 11
2.2 Outdoor Air and Exhaust Air (When Equipped) ...................................................... 15
2.2.1 Units with Outdoor Air Only ........................................................................ 16
2.2.2 Units with Exhaust Air Energy Recovery ................................................... 18
2.3 Condensate Drain Piping ....................................................................................... 20
2.4 Pool Water Piping ................................................................................................... 21
2.5 Auxiliary Heat Coil Piping ....................................................................................... 23
2.6 Remote Condenser (Optional) .............................................................................. 24
2.7 High Voltage Wiring ............................................................................................... 24
2.8 Controls and Sensors ............................................................................................ 25
2.8.1 Air Temperature/Humidity Sensors .......................................................... 25
2.8.2 Water Temperature Sensor ....................................................................... 26
2.8.3 Installation of Sensors for the SelectAire™ with Integral Exhaust Fan ..... 26
2.8.3.1 Indoor Static Sensor Installation .................................................. 26
2.8.3.2 Outdoor Static Sensor ................................................................... 27
2.8.4 Installation of Optional VOC Monitoring Sensor ......................................... 28
2.9 Auxiliary Heating Control Wiring ............................................................................ 29
2.9.1 Auxiliary Heating - Dry Contact Closure .................................................... 29
2.9.2 Auxiliary Heating - Proportional Signal ...................................................... 30
2.10 Gas Heater (Optional) .............................................................................................. 30
2.10.1 Gas Heater Installation ............................................................................. 31
2.10.1.1 Gas Heater Installation with Roofcurb ...................................... 31
2.10.1.2 Gas Heater Installation with Housekeeping Pad or Dunnage .... 31
2.10.1.3 Mating Flanges ......................................................................... 31
2.10.1.4 Heater Alignment ...................................................................... 32
2.10.1.5 Outdoor Units: B-Vent Support Set-up Instructions .................. 33
2.10.1.6 Indoor Unit Set-up Instructions .................................................. 36
2.10.1.7 Finalize Installation ..................................................................... 36
2.10.2 Gas Heater Start-up .................................................................................. 36
2.11 Auxiliary Pool Water Heating .................................................................................. 37
2.12 Smoke Alarm Interlock ............................................................................................ 37
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8Desert Aire - SA Manual
3 Start-Up Procedures ..................................................................................................... 39
3.1 Preliminary Inspection ............................................................................................ 39
3.2 Airow Balancing .................................................................................................... 40
3.2.1 Airow Setup of SelectAire™ without Integral Exhaust Fan ...................... 41
3.2.2 Airow Setup of SelectAire™ with Integral Exhaust Fan ........................... 43
3.2.3 Final Air Balancing ..................................................................................... 47
3.3 Refrigeration Testing .............................................................................................. 51
3.4 General Testing ..................................................................................................... 53
3.5 Routine Maintenance Schedule ............................................................................. 53
3.5.1 Service Every Month ................................................................................. 53
3.5.2 Service Every Six Months ......................................................................... 54
4 Troubleshooting ............................................................................................................. 55
4.1 The Blower Does Not Run ...................................................................................... 55
4.2 The Compressor(s) Do Not Run ............................................................................. 55
4.3 High Pressure Alarms / Readings Above 575 PSIG ............................................... 56
4.4 Low Pressure Alarms / Evaporator Coil Icing ......................................................... 57
4.5 The Pool Water Is Too Cold ................................................................................... 57
5 Appendix .......................................................................................................................... 59
5.1 Compressor Failure ................................................................................................ 59
5.1.1 Compressor Replacement ......................................................................... 59
5.2 Recommended Duct Design ................................................................................... 62
5.3 Pool Water Chemistry ............................................................................................. 63
5.4 Recommended Controller Settings ......................................................................... 63
5.4.1 Controller Set Points ................................................................................. 63
5.5 System Operating Modes ....................................................................................... 63
5.6 Component Replacement, Charge, Evacuation, & Leak Instructions ..................... 64
5.7 System Rating Plate ............................................................................................... 68
5.8 Start-Up Supervision Supplemental Information .................................................... 68
5.9 System Start-Up Report ......................................................................................... 71
Start-Up Report ...................................................................................................... 72
Compressor Replacement Form ............................................................................ 78

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1 Introduction
Desert Aire dehumidiers are designed to provide years of reliable service when installed properly.
Read these instructions carefully before you install the dehumidier.
1.1 Inspection
Desert Aire inspects and tests each dehumidier before it leaves the factory so that you receive a quality
piece of equipment. Unfortunately, equipment may become damaged in transit. Inspect the
dehumidier carefully before signing the receiving papers. Check for both visible and concealed damage.
Use a halogen leak detector to check the piping for refrigerant leaks.
1.2 FreightDamageClaims
If the dehumidier has been damaged, document the extent of the damage. Take pictures if possible.
Next, obtain a claim form from the carrier. Promptly ll out and return the form. Carriers may deny claims
that you have not lled out within a week of delivery. Notify Desert Aire of any damage.
1.3 Rigging
1. Failure to observe rigging instructions may lead to equipment damage,
personal injury or death.
2. Lifting method and procedure must comply with all local and national codes
and regulations.
3. The use of safety slings in addition to lifting lugs is required.
4. Do not lift the dehumidifier in high winds or above people.
Desert Aire dehumidiers are solidly built and can be very heavy. Avoid personal injury and damaged
equipment by planning the installation carefully. Use moving equipment whenever possible.
 1.3.1 RiggingtheDehumidier
Desert Aire dehumidiers are equipped with four or more lifting lugs. Use spreader bars and
safety straps when you use these lugs for rigging.
• Utilize all of the lifting lugs provided when hoisting unit.
• Test-lift the dehumidier to verify that it is properly balanced.
• Do not lift the dehumidier in high winds or above people.
• The top panels are not designed to support the weight of persons. The top panels are
weather proofed and excessive weight may cause water to penetrate through cracked
seams. Damage incurred through caved or distorted top panels will not be covered
under warranty. If you must walk on the top panels, carefully walk on the edges where
structural integrity is greatest.
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10 Desert Aire - SA Manual
Figure 1 - Typical Rigging for the SA Dehumidier
1. Do not tip the dehumidifier on it’s side.
2. Avoid dropping the unit down stairways or subjecting it to severe
mechanical shock.

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2 Installation
 Manualappliestostandardunitcongurationsonly.
2.1 Position and Service Clearance
Desert Aire dehumidiers require routine maintenance to operate efciently.
• Allow a minimum of 36 inches of clearance around the service side of the dehumidier for piping,
electrical connections, and service access. Install the unit on a sturdy, level mounting base or
platform that will prevent vibration and sound transmission. Never install the dehumidier on a
wooden platform without consulting the design engineer for spring isolation requirements and
sound control materials. Do not install the unit near occupied rooms such as ofces or guest
rooms.
• Level the dehumidier to ensure proper condensate drainage.
• Install blocks under the unit if necessary to provide clearance for the condensate trap. Install
blocks underneath each corner and each lifting lug.
Figure 2 - Dehumidier with Blocks Installed for Trap Clearance
• Install outdoor dehumidiers equipped with an outdoor air intake away from plumbing vents,
furnace ues, or equipment which could contaminate the air supply.
• If the dehumidier is to be mounted on a roof curb, make sure that the curb has been properly
mounted and supported. Place gasketing around the perimeter of the curb before setting the
dehumidier in place. This will help prevent air or water leaks.
• You must not install an indoor rated dehumidier in an unconditioned space or where ambient
temperatures can fall below 45°F. If you must install the dehumidier outside or in an
unconditioned space, you must use an outdoor rated dehumidier. Desert Aire equips
outdoor-rated units with weatherproong and thicker insulation. You can determine if your unit is
outdoor-rated by inspecting the unit rating plate. (See Section 5.7 in the Appendix for details.)
• Duct design and installation should conform to ASHRAE and SMACNA low velocity duct
standards. See Section 5.2 in the Appendix for additional duct recommendations.
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12
FLEXIBLE NEOPRENE
DUCT CONNECTOR
LOCATE ANODIZED ALUMINUM
RETURN AIR GRILLE AS HIGH
AS POSSIBLE IN ROOM.
INSTALL TURNING VANES
IN ALL ELBOWS.
INSULATED OUTSIDE AIR INTAKE DUCT,
(SIZE FOR CODE REQUIREMENTS)
MOTOR OPERATED DAMPER
WEATHER-PROOF INTAKE HOOD
REMOTE
CONDENSER
TEMPERATURE AND HUMIDITY CONTROLS
MECHANICAL EXHAUST WITH BACK-DRAFT DAMPER
(WALL OR ROOF MOUNTED)
NOTE: CAPACITY SHOULD NOT EXCEED INTAKE VOLUME.
Figure 3 - Basic Pool Room Layout
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13
Use turning vanes whenever the duct makes an abrupt turn, especially in the return
air duct. Poor return air distribution will reduce the moisture removal.
VAPOR BARRIER
AUX. HEATING
WINDOW
ANODIZED ALUMINUM
FLOOR DIFFUSERS
(SIZE FOR PROPER
AIR FLOW)
SUPPLY PIPING
LOOP SYSTEM
POOL
P. C.D. COATED SPIRAL
GALVANIZED PIPE
ANODIZED ALUMINUM
RETURN AIR GRILLE
LOCATE AS HIGH AS
POSSIBLE
RETURN AIR DUCT
DESERT AIRE DEHUMIDIFIER
FILTER RACK
FLEXIBLE DUCT
CONNECTIONS
POOL DECK
CONDENSATE PIPING
Figure 4 - Typical In-Ground Duct Layout
• You may use galvanized sheet metal ducts for all but underground installations and
severely corrosive environments.
• Do not use berglass duct boards or acoustic duct liner for air distribution in highly
humid applications, such as pool room dehumidication.
• If a duct must be installed in an unconditioned area, or if you are installing an
outdoor air intake duct, insulate it with two inches of berglass duct wrap with an
intact vapor barrier.
• Direct the supply air toward skylights, exterior walls and windows, and spectator
areas. Since air movement will increase the evaporation rate of the pool, direct
the supply air grilles away from its surface.
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14
Figure 5 - Soft Duct Layout with Skylight Grille
• Install return air grilles or louvers as high as possible in the enclosure. Normally,
one centrally-located grille will be adequate. Avoid under sizing this grille or
“short-circuiting” of air with nearby supply registers.
• Select grilles and diffusers for low static pressure loss and proper throw and CFM
rating.
• Keep the noise criteria levels of the grilles between 35 and 45 dB.
• Use anodized aluminum grilles to prevent premature corrosion.
Desert Aire - SA Manual
VAPOR BARRIER
MAIN SUPPLY
AIR DUCT
WINDOW
POOL
BRANCH SUPPLY AIR DUCT
ANODIZED ALUMINUM
RETURN AIR GRILLE
LOCATE AS HIGH AS POSSIBLE
RETURN AIR DUCT
DESERT AIRE DEHUMIDIFIER
SKYLIGHT
FLEXIBLE DUCT
CONNECTIONS
POOL DECK
ANODIZED ALUMINUM
CEILING DIFFUSER
ANODIZED ALUMINUM
SIDEWALL REGISTER
VAPOR BARRIER

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2.2 OutdoorAirandExhaustAir(WhenEquipped)
Desert Aire SelectAire™ dehumidiers may be equipped with an opening which will draw outdoor
air into the conditioned space. This will help you to comply with ASHRAE Standard 62, which requires
the introduction of outdoor air into commercial buildings.
Additionally, the SelectAire™ unit may be equipped with a fan and dampers for exhausting air from the
building. This ensures that the building is at a negative static pressure relative to adjacent spaces and
outdoors. Should the unit be equipped with an outdoor air option only and no exhaust fan is integral to
the unit, it is the installer’s responsibility to ensure that a separate exhaust fan is installed and properly
interlocked with the outdoor air operation. Dry contacts for signaling the fan are provided.
Several modes may be available that provide for different outside air and exhaust ow rates.
These include:
• Unoccupied mode
In the Unoccupied mode, typically outdoor air dampers will be closed and a very small
amount of exhaust air is extracted from the building in order to ensure the space is
negatively pressurized. When a Low Exhaust option is selected, the Unoccupied mode
can be congured to bring in low ow rate of outdoor air in order to offset any amount of
exhaust that may be extracted from this separate system. Unoccupied mode is engaged
when no other mode is presently engaged.
• Occupied mode
This mode is used when a typical amount of occupancy in the space is to be
encountered. Occupancy can be commanded with any of the following: Internal
Occupancy Schedule via an integral seven-day programmable time clock, a contact
closure, or through the Building Management System (BMS) network.
• Event mode
This mode is typically used to signal the unit to bring in greater amounts of outdoor air
when spectators are expected to be present. The mode can be activated through a dry
contact closure or Building Management System (BMS) network. Note that the
Occupied mode must be engaged when Event mode is commanded or no change will
occur.
• Max OA mode
Max OA mode is typically used to signal the unit to bring in a very high level of outdoor
air under specic circumstances. If equipped with the economizer option, outdoor
sensors monitor the OA condition. When the outdoor conditions are appropriate to
reduce the temperature and/or humidity, the unit will index to MAX OA mode
automatically. Additionally, if equipped with a VOC monitor option, and the VOC reading
from the sensor exceeds the set point, the unit will index to Max OA mode. The mode
Desert Aire - SA Manual

16
can be activated programmatically as described above or through the Building
Management System (BMS) network.
• Purge mode
Purge mode is used to clear airborne byproducts of the pool disinfection process as
required by the operator. This is typically done when the space is not occupied. When
the need is determined, a signal is given via a contact closure or through the Building
Management System (BMS) network. The unit will bring in the specied amount of
outdoor air (typically at a very high ow rate).
During purge mode the refrigeration system is disabled. The heating system is controlled
from the supply air temperature sensor only and is set to a point that only avoids major
condensation from occurring at the ducts and diffusers. In this way, the energy required
to clear the air of these byproducts is minimized while avoiding issues with introducing
very cold air.
In all modes the unit monitors the static pressure of the zone and modulates the exhaust airow
rate to maintain the set point. Typically this is set to -0.050 WC. This means that the exhaust air
ow rate will be greater than the outdoor air ow rate to maintain this negative static. Building
envelopes that are leaky may require much more exhaust air than outdoor air. The amount of
outdoor air in each mode may be limited through the controls if desired, but the space must be
kept at a negative static pressure in order to avoid mold and property damage.
Note that condensation may occur when cold outdoor air is mixed with warm, humid return air
inside the dehumidier. During the winter months, this moisture can freeze and cause serious
damage to the equipment. Desert Aire dehumidiers are equipped with an internal temperature
sensor which will close the outdoor air damper if it senses freezing temperatures inside the unit.
If outdoor temperatures in your area drop below 32°F, and outdoor air code compliance is
required at all times, you may need to install a preheating coil. System failures caused by
improper outdoor air duct installations are not covered by the Desert Aire warranty.
The ducting method you use depends on the SA type of dehumidier you have.
2.2.1 Units with Outdoor Air Only
There are three possible congurations for the outdoor air openings when equipped with
outdoor air only:
1. A SelectAire™ unit congured for Outdoor Air with Damper has a duct connection with an
outdoor air damper and actuator between the evaporator and the reheat condenser coils.
The unit controlled will energize a set of dry contacts during occupied times. Use these
dry contacts to control an additional outdoor air damper if required and/or the exhaust
blower. The exhaust blower and the outdoor air louvers, lters, additional dampers, and
actuators must be eld-supplied. Figure 6 shows typical ducting for a SelectAire™ unit
congured for Outdoor Air with Damper.
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Figure 6 - Indoor Dehumidier with Outdoor Air Duct Connection with Damper
2. A SelectAire™ unit congured for indoor installation with Outdoor Air with Damper
and Filter option has a module which contains lters and a factory-installed damper
and actuator. This module has a anged opening for a eld-installed outdoor air
duct. The unit controller will energize a set of dry contacts during occupied times.
Use these dry contacts to control the exhaust blower. Outdoor air louvers and the
exhaust blower must be eld-supplied. Figure 7 shows typical ducting for an indoor
SelectAire™ unit congured for Outdoor Air with Damper and Filter.
Figure 7 - Indoor Dehumidier with Filter and Damper Module
3. A SelectAire™ unit congured for indoor installation with Outdoor Air with Damper and
Filter option has a module which contains lters and a factory-installed damper and
actuator. This module has an outdoor air intake protected by a weather hood. The unit
controller will energize a set of dry contacts during occupied times. Use these dry
Desert Aire - SA Manual

18
contacts to control the eld-supplied exhaust blower. Figure 8 shows typical ducting for
an outdoor SelectAire™ unit congured for Outdoor Air with Damper and Filter.
Figure 8 - Outdoor Dehumidier with Filter and Damper Module
The outdoor air duct used for options 1 and 2 must be insulated to prevent condensation
from forming on it during the winter. Since cold outdoor air can cause moisture to
condensate and freeze on surfaces when it mixes with the warm, humid return airstream,
you must preheat the outdoor air whenever possible.
2.2.2 Units with Exhaust Air Energy Recovery
There are two possible congurations for units containing Exhaust Air Energy Recovery:
1. An indoor SA unit with Exhaust Air Energy Recovery contains a module which handles
outdoor makeup air and exhaust air. This factory-installed module includes lters,
dampers, actuators, and an exhaust blower. This module has anged openings for the
outdoor and exhaust air ducts. The ductwork and louvers must be eld-supplied. The
humid exhaust air may form an icy fog when it blasts outside during the winter. Install the
outlet grille in a location where this fog will not damage the building or create a safety
hazard. Figure 9 shows typical ducting for an indoor SelectAire™ unit congured for
Exhaust Air Energy Recovery.
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Figure 9 - Indoor Dehumidier Showing Outdoor Air and Exhaust Duct
2. An outdoor SA unit with Exhaust Air Energy Recovery contains a module which
handles outdoor makeup air and exhaust air. This factory-installed module includes
lters, dampers, actuators, and an exhaust blower. The module ordered for an
outdoor unit discharges the exhaust air to the atmosphere and draws in outdoor air.
Both air streams are protected by a weather hood.
Figure 10 - Outdoor Dehumidier Showing Outdoor Air and Exhaust
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20
2.3 Condensate Drain Piping
The condensate drain connection on the standard Desert Aire SA series dehumidiers is a 1-1/2”
PVC stub which penetrates the base rail of the unit.
Figure 11 - SA Standard Condenser Drain Location
An SA series dehumidier ordered for roof curb mounting has its drain connection on the underside of
the unit to help prevent freezing. This drain has a 1-1/2” MPT tting.
Figure 12 - SA Roof Curb Unit Showing Condensate Drain Location
Whichever type of drain your dehumidier has, it must be trapped to prevent condensate from backing
up in the drain pan. The cabinet of the dehumidier is under negative pressure whenever the supply
blower is running. If you do not trap the drain, condensate will be sucked into the cabinet, where it may
cause premature corrosion and property damage.
Desert Aire - SA Manual