PoolPak MPK series Installation and operating instructions

Installation, Operation and
Maintenance
MPK Series
FORM #: SVW07-MPKIOM-20170601
SUPERCEDES: SVW07-MPKIOM-20170331
UPDATED: JUNE, 2017
© 2017 PoolPak LLC. All rights reserved.

With more than 45 years of experience in indoor pool dehumidification equipment manufacturing, PoolPak®LLC is the most well-known brand in the
industry. Our people and products work daily to improve the quality and comfort of indoor pool environments. PoolPak®dehumidification solutions include
a variety of heating, ventilation, and air conditioning systems, in addition to an industry-leading PoolPak®support network. For more information, please
visit www.PoolPak.com.
3491 Industrial Drive
York, Pennsylvania 17402 USA
800-959-7725 Fax [phone]
© 2017 PoolPak LLC. All rights reserved. SVW04-MPK-IOM-20170601
TABLE OF CONTENTS
IMPORTANT ................................................................................................................................ 7
Warning ....................................................................................................................................................7
Intended Users............................................................................................................................................7
SECTION I: INDOOR POOL APPLICATION...................................................................................... 8
Introduction ................................................................................................................................................8
Creating an Ideal Environment for Indoor Pool Facilities...................................................................................8
Operating Cost...........................................................................................................................................8
Application ................................................................................................................................................8
Moisture Loads ...........................................................................................................................................8
Effects of Moisture.......................................................................................................................................8
Indoor Air Quality.......................................................................................................................................9
Occupant Comfort ......................................................................................................................................9
Pool Water Chemistry................................................................................................................................10
SECTION II: PRINCIPLES, FUNCTIONS AND FEATURES.................................................................. 11
The Mechanical Dehumidification System..................................................................................................... 11
Principles of Operation .............................................................................................................................. 11
Automatic Control of Air Temperature and Humidity...................................................................................... 11
Room Dew Point Control............................................................................................................................. 12
PoolPak Operation ....................................................................................................................................13
Air-Side Operation ....................................................................................................................................13
CPCS Control Functions .............................................................................................................................15
Overview .................................................................................................................................................15
Air Flow Monitoring and Control.................................................................................................................15
Humidity Control....................................................................................................................................... 16
Cold Surface Temperature Hunidity Reset.....................................................................................................17
Space Heating..........................................................................................................................................17
Smart Economizer (SEP) ............................................................................................................................. 17
Flywheel Air Conditioning (SEP).................................................................................................................. 17
Space Cooling (Optional) .......................................................................................................................... 17
Smart Pump Control (Optional) ................................................................................................................... 18
Networking Multiple Units.......................................................................................................................... 18
Occupied/Unoccupied Control Mode .........................................................................................................18
Air Conditioning with Air-Cooled Condenser ................................................................................................ 18
Air Conditioning with Water-Cooled Condenser ........................................................................................... 18
Air Conditioning with Chilled Water Coil .....................................................................................................18
Pool Water Heating................................................................................................................................... 18
Purge Mode (SEP) .....................................................................................................................................19
Event Mode (SEP)......................................................................................................................................19
Summer Ventilation Mode (SEP) .................................................................................................................. 19
CO2Based Demand Ventilation (Optional)...................................................................................................19
Features and Options ................................................................................................................................20
Standard Factory Mounted Features ............................................................................................................20
Standard Factory Supplied, Field Installed Features .......................................................................................20
Optional Factory Mounted Features ............................................................................................................20

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PoolPak®MPK Series IOM
Optional Field Installed Features ................................................................................................................. 21
Selection.................................................................................................................................................. 21
SECTION III: SIZING AND PERFORMANCE................................................................................... 22
PoolPak Unit Dimensions and Weights .........................................................................................................22
MPK Performance Summary .......................................................................................................................23
MPK Factory Charge .................................................................................................................................23
PoolPak Remote ACC Specifications ............................................................................................................24
Non-PoolPak Provided Air-Cooled Consenser Selection Procedure ..................................................................24
Remote Cooling Tower Condenser Sizing and Performance............................................................................25
Water Cooled Condenser Sizing and Performance .......................................................................................26
PoolPak Pool Water Condenser...................................................................................................................27
PoolPak Auxiliary Gas Furnace Option ........................................................................................................28
PoolPak Auxiliary Electric Heat Option ........................................................................................................28
SECTION IV: INSTALLATION........................................................................................................ 29
MPK Installation ........................................................................................................................................29
Introduction ..............................................................................................................................................29
Handling..................................................................................................................................................30
Rigging ....................................................................................................................................................30
Clearance ................................................................................................................................................30
Dust Installation.........................................................................................................................................30
Mounting .................................................................................................................................................30
Foundation ...............................................................................................................................................30
Inspection................................................................................................................................................. 31
Unit Hookup ............................................................................................................................................. 31
Gas Furnace Auxiliary Heat Option ............................................................................................................ 31
Power Supply............................................................................................................................................ 31
Control Wiring..........................................................................................................................................32
Condensate Piping ....................................................................................................................................32
Curb Mounting .........................................................................................................................................33
CPCS Controls Field Wiring .......................................................................................................................34
OVERVIEW ..............................................................................................................................................34
REMOTE INTERFACE UNIT (1) ....................................................................................................................34
Multi-Unit Network Connection (2) ..............................................................................................................35
Building Automation System Connection (3)..................................................................................................35
Cold Surface Temperature Sensor (4)...........................................................................................................36
Supply Air Temperature Sensor (5) ..............................................................................................................36
Remote Space Pressure Sensor (Optional) (6)................................................................................................36
ACC OR WCC Proof Interlock (7) ...............................................................................................................36
Freezestat (8) (Special Applications Only) ....................................................................................................36
Remote Exhaust Fan Status (9).....................................................................................................................37
Summer Ventilation Mode (SE/MSEP Only) (10)............................................................................................37
Event Mode Interlock (11) ...........................................................................................................................37
Purge Mode Input (SEP ONLY)(12)...............................................................................................................37
Occupied Mode Input (13) .........................................................................................................................37
Fire Trip Input (14) .....................................................................................................................................37
Smoke Purge Input (SE/MSEP Only) (15) ......................................................................................................37
Auxiliary Chilled Water Control Valve (16)...................................................................................................37
Auxiliary Hot Water Control Valve (17)........................................................................................................38
Remote Air Condenser Enable Signal (18) ....................................................................................................38
Smart Pump Control Output (19)..................................................................................................................38
Remote Exhaust Fan Interlock (S Only) (20) ..................................................................................................38
Auxiliary Pool Water Heating System (21) ....................................................................................................38
Alarm Output (22).....................................................................................................................................39
Auxiliary Air Cooling System (23) ...............................................................................................................39
Auxiliary Air Heating System (24) ...............................................................................................................39

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Outside Air Temperature and Relative Humidity Sensor (25)...........................................................................39
Pool Water Piping and Installation...............................................................................................................40
PoolPak Pool Water Circulation Loop...........................................................................................................40
Auxiliary Water Heater (Field Supplied).......................................................................................................40
Main Pool Water Pump and PoolPak Pool Water Loop Pump Interlocks............................................................40
Pool Water Isolation Valves ........................................................................................................................40
Pool Water Pressure Transducer ..................................................................................................................40
Pool Water Piping Composition .................................................................................................................. 41
Freeze Protection....................................................................................................................................... 41
Condensate Drains....................................................................................................................................42
Condensate Drainage System Features ........................................................................................................42
Exceptions................................................................................................................................................42
Drain Trap Field Installation Instructions........................................................................................................42
Required Materials ....................................................................................................................................42
Remote Air Cooled Condenser....................................................................................................................44
Space and Location Requirements ...............................................................................................................44
Walls or Obstructions ................................................................................................................................44
Multiple Units............................................................................................................................................45
Units in Pits...............................................................................................................................................45
Decorative Fences .....................................................................................................................................45
Field Installed Piping..................................................................................................................................46
Piping Guidelines ......................................................................................................................................46
SECTION V: OPERATION ............................................................................................................ 50
CPCS Controller Operation ........................................................................................................................50
Remote Interface Unit (RIU) Features ............................................................................................................50
CPCS Controller Features ...........................................................................................................................51
Multi-Unit Network Operation ....................................................................................................................52
CM1 Network Configuration ......................................................................................................................52
RIU Network Configuration ........................................................................................................................52
Communications........................................................................................................................................53
Building Automation System (BAS) Connection..............................................................................................53
Virtual-Tech®Plus - REMOTE ACCESS PACKAGE(RAP) ...................................................................................53
Basic Controller Operation.........................................................................................................................53
Startup ....................................................................................................................................................53
Fault Condition .........................................................................................................................................54
Alarm Reset ..............................................................................................................................................54
Controller Navigation................................................................................................................................55
Main Menu ..............................................................................................................................................55
Status Screens...........................................................................................................................................55
Detailed Status..........................................................................................................................................56
Set Point...................................................................................................................................................58
Schedules.................................................................................................................................................59
Service ....................................................................................................................................................59
Input/Output Configuration ........................................................................................................................59
History.....................................................................................................................................................63
Unit Configuration .....................................................................................................................................65
Manual Mode...........................................................................................................................................71
Utilities.....................................................................................................................................................73
Airflow Balancing ..................................................................................................................................... 74
Overview ................................................................................................................................................. 74
Guidelines for Performing a Proper Airflow Balance...................................................................................... 74
Controller Adjustments ............................................................................................................................... 74
Troubleshooting......................................................................................................................................... 74
Overview ................................................................................................................................................. 74
System Status Information........................................................................................................................... 74

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PoolPak®MPK Series IOM
AlarmName:............................................................................................................................................. 74
CprFaultName: ......................................................................................................................................... 76
SensorName:............................................................................................................................................77
Fault History Log .......................................................................................................................................78
Manual Mode...........................................................................................................................................78
Digital and Analog Input Configuration........................................................................................................78
Digital Input..............................................................................................................................................78
Analog Input.............................................................................................................................................78
Digital and Analog Output Configuration.....................................................................................................79
Digital Output...........................................................................................................................................79
Analog Output..........................................................................................................................................79
Startup & Warranty...................................................................................................................................79
Pre-startup ................................................................................................................................................79
Startup.....................................................................................................................................................79
Owner Training.........................................................................................................................................80
Warranty .................................................................................................................................................80
Maintenance ............................................................................................................................................80
Overview .................................................................................................................................................80
Daily Maintenance .................................................................................................................................... 81
Monthly Maintenance................................................................................................................................82
Semi-Annual Maintenance..........................................................................................................................83
Annual Maintenance .................................................................................................................................83
SECTION VI: WIRING ................................................................................................................. 84
Remote Connections Schematic...................................................................................................................84
Multiple Unit Control Schematic ..................................................................................................................85
MPK Field Wiring - Communications............................................................................................................85
MPK Field Wiring......................................................................................................................................86
Table 1-1. Typical Pool Water & Air Temperature Set-Points ..............................................................................9
Table 1-2. Recommended Pool Water Chemistry ...........................................................................................10
Table 3-1. MPK Unit Performance (at 82°F and 60% RH)................................................................................23
Table 3-2. MPK Factory Refrigerant Charge (lbs of R-410A)............................................................................23
Table 3-3. PoolPak Provided Remote ACC Specifications................................................................................24
Table 3-4. Remote Cooling Tower and Chilled Water Cabinet Dimensions .......................................................25
Table 3-5. Cooling Tower and Chilled Water Line Sizes.................................................................................26
Table 3-6. WCC Performance.....................................................................................................................26
Table 3-7. Pool Water Capacity ..................................................................................................................27
Table 3-8. PoolPak Gas Furnace Option ......................................................................................................28
Table 3-9. PoolPak Electric Heat Option .......................................................................................................28
Table 4-1. Pipe Sizes for Remote Refrigerant Condensers ...............................................................................47
Table 4-2. Remote ACC Refrigerant (R-410A) Charge ....................................................................................48
Table 4-3. Refrigerant (R-410A) Charge for Different Line Sizes.......................................................................48
Table 5-1. Pool Water Chemistry .................................................................................................................82

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Figure 2-1. Dewpoint Control Psychrometric .................................................................................................. 12
Figure 2-2. MPK System Schematic..............................................................................................................14
Figure 2-3. Active Airflow Control with Direct OA Measurement Schematic ......................................................16
Figure 3-1. MPK Dimensional Isometric View.................................................................................................22
Figure 3-2. Remote Cooling Tower Dimensions..............................................................................................25
Figure 4-1. Typical PoolPak Rooftop Installation.............................................................................................29
Figure 4-2. Single Point Power Supply..........................................................................................................32
Figure 4-3. Dual Point Power Supply............................................................................................................32
Figure 4-4. Remote Interface Mounting Plate ................................................................................................35
Figure 4-5. Pool Water Piping Schematic ..................................................................................................... 41
Figure 4-6. Negative Pressure Condensate Drain Piping Cross Section ............................................................43
Figure 4-7. Positive Pressure Condensate Drain Piping Cross Section................................................................43
Figure 4-8. Remote ACC Installation Clearances ...........................................................................................44
Figure 4-9. Remote ACC Installation Around Walls or Obstructions .................................................................44
Figure 4-10. Remote ACC Installation Clearances..........................................................................................45
Figure 4-11. Remote ACC Installation When Installing Units in Pits ...................................................................45
Figure 4-12. Remote ACC Installation When Installing Units Near Decorative Fences.........................................45
Figure 4-13. Remote ACC Above Unit ..........................................................................................................47
Figure 5-1. RIU Keypad ..............................................................................................................................50
Figure 5-2. CPCS Controller (CM1) Display .................................................................................................. 51
Figure 5-3. Startup Screen..........................................................................................................................53
Figure 5-4. Fault Condition Status Screen - Coil Freeze Warning.....................................................................54
Figure 5-5. Main Menu Screen ...................................................................................................................55
Figure 5-6. Status Screen 1: Return Air/Pool Status........................................................................................55
Figure 5-7. Detailed Status Screen 4: Airflow Status.......................................................................................56
Figure 5-8. Detailed Status Screen 5: Status Overview...................................................................................57
Figure 5-9. Detailed Status Screen 6: Operation Mode Stages........................................................................57
Figure 5-10. Detailed Status Screen 7: Fan Motor Status ................................................................................58
Figure 5-11. Detailed Status Screen 9: Compressor Module Status...................................................................58
Figure 5-12. Set Points Air Temperature Screen .............................................................................................58
Figure 5-13. Occupancy Schedule Screen ....................................................................................................59
Figure 5-14. Service - I/O Config screen......................................................................................................59
Figure 5-15. Digital Inputs - Smoke Purge screen............................................................................................59
Figure 5-16. Digital Outputs - Supply Fan screen ...........................................................................................60
Figure 5-17. Analog Inputs - Supply Air screen .............................................................................................. 61
Figure 5-18. Analog Outputs - Recirculation Damper Screen...........................................................................63
Figure 5-19. Fault Screen 1 – System Status Overview....................................................................................63
Figure 5-20. Fault Screen 2 – Airflow Status .................................................................................................64
Figure 5-21. Fault Screen 3 – Fan Currents ...................................................................................................64
Figure 5-22. Fault Screen 4 – Compressor Module 1 Fault Screen...................................................................64
Figure 5-23. Unit Configuration - Installed Features Menu...............................................................................65
Figure 5-24. Manual Mode Screen 1 - Overview ..........................................................................................71
Figure 5-25. Manual Mode Screen 4 - Airflow Control: Fan Speed (RPM) ........................................................72
Figure 5-26. Utilities Menu - Set Time and Date.............................................................................................73
Figure 6-1. PoolPak Control Panel................................................................................................................84
Figure 6-2. Multiple Unit Connection Schematic............................................................................................85
Figure 6-3. Field Wiring - Communications...................................................................................................85
Figure 6-4. MPK Field Wiring .....................................................................................................................86

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PoolPak®MPK Series IOM
IMPORTANT
This product has been thoroughly tested before leaving the PoolPak factory.
However, please check at the earliest opportunity that the product has arrived in good condition and that no
damage occurred during shipping. If any damage is suspected, contact the carrier to file a claim.
If the product is to sit in storage for a length of time before installation, contact PoolPak Service department for
proper storage guidelines.
Warning
Only suitably qualified personnel who thoroughly understand the operation of this product and any associated
machinery should install, start-up or attempt maintenance of this product. Non-compliance with this warning may
result in personal injury or equipment damage.
PoolPak Service department must be contacted at least 2 weeks prior to equipment startup. A PoolPak authorized
service technician will perform startup and provide training for owner and site personnel.
PoolPak recommends that all troubleshooting, service, and maintenance be completed by an authorized service
technician for the best service experience with the equipment. If a labor or parts warranty claim is expected,
PoolPak service must be contacted before any work is to be performed. Refer to the standard PoolPak®MPK
warranty for complete details.
Intended Users
This manual is to be made available to all persons who are required to install, operate or service the product or any
other associated operation. Please ensure that a copy of this manual is presented to the end customer. Additional
copies of this manual are available on request and on the PoolPak website, www.PoolPak.com.

www.poolpak.com | 800-959-77258| MPK Series - Installation, Operation and Maintenance
SECTION I: INDOOR POOL APPLICATION
Introduction
Creating an Ideal Environment for Indoor Pool Facilities
Indoor pool facilities are unlike any other structure in design, construction and maintenance requirements. Humidity,
air and water temperatures are especially difficult to control, and improper management usually results in an
uncomfortable environment, excessive operating costs and possibly serious structural damage. Effectively controlling
these special conditions requires control hardware and control sequences specially engineered for large commercial
indoor pool applications. The PoolPak®System utilizes an environmental control package designed to meet all
special needs of the indoor pool environment, while reducing energy usage and building maintenance costs.
Operating Cost
Energy consumption is a direct function of the variables necessary to satisfy the occupant and protect the facility.
These variables include space heating and cooling, water heating, humidity removal and ventilation. Maintaining
ideal and precise environmental conditions has a fairly high cost of operation. A majority of the indoor pools,
regardless of geographic location, require water and space heating 70% to 90% of the year.
Application
Moisture Loads
An indoor swimming pool produces large quantities of water vapor through evaporation, which accounts for
roughly 95% of the pool water heat loss, making the water colder. This excessive humidity will form damaging
condensation unless removed from the building. In the past, the method of removing this water vapor was by
ventilating an otherwise energy efficient building, exhausting the humid air and the energy it contained. Additional
energy was used to bring in and heat the make-up air and to heat the pool water.
More cost effective technologies offer an alternative method adding heat exchangers and mechanical heat recovery
systems with many useful options. The ideal solution to removing the water vapor from the pool area is to convert
the latent (wet) heat contained in the moist air back into sensible (dry) heat, placing it back into the pool water
and air.
Effects of Moisture
Excess humidity in natatorium structures may be readily apparent as condensation on cool surfaces such as
windows and outside doors, the growth of mildew or mold, and, when coupled with poor pool chemistry, the
accelerated corrosion of metals. In its less obvious forms, moisture may penetrate walls and ceilings and cause rot
that becomes noticeable only when large scale structural failure occurs. Humidity levels are also a major factor in
the comfort of pool users.

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PoolPak®MPK Series IOM
Indoor Air Quality
Pools and water parks with water features have a higher evaporation rate than a standard pool because of the
increased water surface area. Chloramines (See Pool Water Chemistry on the next page), which are present in
the water, become more concentrated in the air as the “water to air” interactions increase, affecting the indoor
air quality. A strong “chlorine” odor is an indicator of poor pool water chemistry, and is generally offensive to the
occupants. Higher levels of chloramines can cause skin/eye irritation and respiratory problems commonly known
as “lifeguard lung”. Most poolrooms are designed with a minimum ventilation rate to dilute the airborne pollutants
generated from the chemical interactions in the pool water. Typically these rates are based on ASHRAE standard
62.1 and dictated by local codes at about 0.5 CFM per square foot of pool and deck area, but depending on the
pool water chemistry the ventilation rate may not always be adequate for good poolroom indoor air quality.
However, increasing ventilation rates can significantly add to the cost of operation. Energy conservation strategies,
such as heat recovery, airflow measurement, and CO2 based ventilation control help control costs while improving
indoor air quality. Depending on the geographic location and season of the year, treating the outside air has a
direct effect on energy consumption. Some facilities prefer higher than minimum ventilation rates, up to 100% of
OA, to maximize indoor air quality, but the cost of treating this air can be significant.
Occupant Comfort
Occupant comfort in a natatorium is easy to understand. If you ever swam in an outdoor pool on a cold, windy day
or exited a pool in a dry, desert location you will probably notice an immediate chill. The opposite is true where
high humidity is not adequately controlled either through ventilation or by mechanical means. The moisture level
can reach such a state where it is oppressive or stuffy. Common complaints are difficulty in breathing and the room
being perceived to be warmer than the actual dry bulb temperature would suggest.
Regardless of the source of discomfort, users will not enjoy the facility if water/air temperatures and humidity
levels are not within a narrow range. Ideal water temperature is around 82°F with the air temperature about 2°F
higher to prevent chilling when exiting the pool and to minimize evaporation from the pool surface. Here are some
recommended temperatures for poolrooms, which can be adjusted to meet specific needs of bathers. In general,
“active” poolrooms are maintained at lower temperature ranges so the users don’t overheat, warmer temperatures
are more common for seniors or children or less active pools.
The desirable humidity range is generally between 50 and 60% (see Table 1-1). Greater than 60% creates a sticky
feeling and/or difficult breathing. Low humidity results in evaporative cooling on the bather’s skin, resulting in a chill.
Poor air movement caused by improper duct placement within the poolroom will also lead to occupant discomfort.
Excessive supply air blowing on bathers can create drafts, while uneven air distribution may create stagnant zones
within the space.
POOL TYPE WATER TEMP (°F) AIR TEMP (°F) ROOM RH %
Recreational Pool 80 to 85 Water Temp + 2 55 to 60
Therapy Pool 86 to 92 86155 to 60
Whirlpools 99 to 104 86155 to 60
Table 1-1. Typical Pool Water & Air Temperature Set-Points
1Normally max 86°F to minimize overheating of occupants

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Pool Water Chemistry
Proper water chemistry (Table 1-2) in swimming pools is critical for the health of the bathers and the condition of
the enclosure and components. An enclosure with poor water chemistry has a noticeable “chlorine” smell, which is
an indication of high chloramine levels in the air. Not only does this have an effect on the water, but it affects the
bathers and the air they breathe.
Dehumidification/ventilation equipment is not designed to remedy the effects of poor pool chemistry, but is designed
to deliver prescribed ventilation to manage smaller amounts of pollutants generated from normal pool activity. Pool
water chemistry is a part of daily maintenance and it is recommended that the users follow the current National Spa
and Pool Institute standards. For more information, see the PoolPak®Educational Library article Indoor Pool Water
Chemistry.
POOL SPA
IDEAL MIN MAX IDEAL MIN MAX
Total Chlorine (ppm) 1.0 - 3.0 1 3 3.0 - 5.0 110
Free Chlorine (ppm) 1.0 - 3.0 1 3 3.0 - 5.0 110
Combined Chlorine (ppm) 0 0 0.3 0 0 0.3
Bromine (ppm) if applicable 2.0 - 4.0 2 4 3.0 - 5.0 210
pH 7.4 - 7.6 7.2 7.8 7.4 - 7.6 7.2 7.8
Total Alkalinity (ppm) 80 - 100 80 180 80 - 100 60 180
TDS (ppm) 1000 - 2000 300 3000 1000 - 2000 300 3000
Calcium Hardness (ppm) 200 - 400 150 1000 200 - 400 150 1000
Calcium Acid (ppm) 30 - 50 10 100 30 - 50 10 100
Table 1-2. Recommended Pool Water Chemistry

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PoolPak®MPK Series IOM
SECTION II: PRINCIPLES, FUNCTIONS AND FEATURES
The Mechanical Dehumidification System
Principles of Operation
The PoolPak System is a complete environmental control system designed expressly for indoor swimming pool
enclosures. It takes into account two important factors: the swimming pool occupant (personal comfort) and the
swimming pool environment (the physical structure and surrounding furnishings).
The swimming pool enclosure can be a hostile environment for equipment, decor and building structures. A PoolPak
System’s major function is to dehumidify the pool enclosure air through a vapor compression cycle. During this cycle
the PoolPak System recycles the sensible and latent heat and places it back into the pool water and air as needed.
This recycling process saves money and keeps your pool environment efficient and safe.
Solid state microprocessor technology, working in conjunction with sensors, continually monitors water and air
conditions to provide superior occupant comfort. Unlike typical outside air ventilation systems, a PoolPak System
recycles energy and blankets the walls and windows with warm, dry air.
PoolPak dehumidification systems reduce the energy input required to maintain pool water and air temperatures.
By dehumidifying the air and recycling the latent energy back into the pool air and water, the unit will reduce
operating costs when compared to conventional heating and ventilating systems.
A PoolPak unit, when matched correctly to the evaporation rate of the pool water and overall dehumidification
requirements, will efficiently maintain the pool air at relative humidity levels between 50% and 60%. It should be
noted that a lower evaporation rate occurs when the pool enclosure’s air temperature is maintained above the
pool water temperature. Evaporation losses, and the energy required to maintain desired room conditions, will
dramatically increase if the air temperature is allowed to fall below the pool water temperature. It is recommended
that the continuous dry bulb temperature entering the evaporator of the PoolPak unit not fall below 75°F.
PoolPak LLC recommends that backup heating equipment for both pool water and pool enclosure air is capable
of carrying the full system heating requirements. This makes for a well-designed system that will provide the least
amount of pool down time if unforeseen system problems occur. Building conductive loads and other losses must be
taken into consideration when sizing the dehumidification system or the auxiliary heating/cooling equipment.
Automatic Control of Air Temperature and Humidity
An integral part of any PoolPak system is a proven microprocessor control system which automatically senses
and maintains comfort conditions. Sensors detect changes in humidity and air temperature in the indoor pool
environment and quickly regulate supply air conditions to meet set point comfort levels, even during periods of
unusually heavy pool use.
To prevent condensation on walls and windows, the PoolPak system automatically adjusts humidity in response
to changes in wall or window surface temperatures. As the seasons and weather conditions change, the PoolPak
System changes its own mode of operation. Throughout the year, the PoolPak® thinks “efficiency” and automatically
selects the least expensive energy source for the poolroom conditions.
PoolPak units include a factory mounted and wired space temperature and humidity sensor at the return air opening
of the unit.

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PoolPak units have active airflow monitoring and control using variable speed fans and air flow monitoring station to
provide optimal airflow at lower cost.
Room Dew Point Control
The PoolPak CPCS controller operates using an advanced type of control utilizing dew point and dry bulb
temperature. This method of control is more accurate than conventional relative humidity control. The main purpose
of a dehumidification system is to maintain the amount of moisture in the pool area below a level that would cause
damage to the building. Relative humidity is a measurement of the percentage of moisture in the air at a given
dry bulb temperature in proportion to the maximum amount of moisture that could be contained at this particular
dry bulb temperature. Warmer air can hold more moisture than colder air and, therefore, changes in dry bulb
temperature will change the relative humidity reading without any change in the actual amount of moisture in the
air. The amount of moisture in the air is expressed as “grains of moisture per pound of dry air” and is directly related
to the dew point temperature.
See Figure 2-1 for reference. The CPCS uses dew point control to operate the PoolPak unit and maintain the moisture
level below the setpoint. The space dry bulb temperature and relative humidity determine the dew point temperature.
By varying the space temperature and space relative humidity set points, the dew point set point is changed. When
the space dew point temperature rises more than 1/2 degree Fahrenheit above the space dew point temperature set
point, the CPCS controller energizes the compressor for dehumidification. As the dew point temperature drops more
than 1/2 degree Fahrenheit below the dew point temperature set point the controller de-energizes the compressor.
When the outside air is to be introduced into the space for ventilation, adequate exhaust capacity via an integral
(or a separate external fan) must be specified to ensure the poolroom remains slightly negative. An inadequately sized
exhaust system may result in damage to the structure and pool odors may be forced into other areas of the building.
!CAUTION
80%
60%
40%
20%
If RA here, space
too cold, too humid
If RA here, space
too cold, humidity OK
If RA here, space too
hot, humidity OK
If RA here, space
too hot, too humid
0.000
30˚F/-1˚C
Dry Bulb Temp.
40˚F/4˚C 50˚F/10˚C 60˚F/16˚C 70˚F/21˚C 80˚F/27˚C 90˚F/32˚C 100˚F/38˚C 110˚F/43˚C 120˚F/49˚C
0.030
0.028
0.024
0.020
0.016
0.012
0.008
0.004
Humidity Ratio
lbw
/ lba
Dew Point
82˚F / 28˚C
80˚F / 27˚C
75˚F / 24˚C
70˚F / 21˚C
65˚F / 18˚C
60˚F / 16˚C
55˚F / 13˚C
50˚F / 10˚C
45˚F / 7˚C
40˚F / 4˚C
35˚F / 2˚C
30˚F / -1˚C
Figure 2-1. Dewpoint Control Psychrometric

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PoolPak®MPK Series IOM
PoolPak Operation
See Figure 2-2 to illustrate the following paragraphs.
Refrigerant-Side Operation
The PoolPak® draws in warm, moist air from the pool enclosure. This air passes through the evaporator
(dehumidification) coil and gives up heat energy to the refrigerant which is in a cool, liquid state. This exchange of
energy causes the air temperature to fall below its dew point, resulting in moisture condensation on the evaporator
coil. The moisture formed is collected by the unit’s condensate drain system. After passing through the evaporator
coil, the refrigerant becomes a cool gas.
The refrigerant enters the unit’s compressor, where it is compressed into a hot gas. While in the compressor, the
refrigerant absorbs the energy used to operate the compressor. This hot gas refrigerant then travels either through an
air reheat coil, the pool water condenser or to an optional auxiliary air condensing heat exchanger, which may be
either air or water cooled. If air heating is required, the air reheat coil is used. The hot refrigerant exchanges energy
with the cooler, dehumidified air coming from the evaporator coil. This causes the temperature of the air to rise for
heating.
If pool water heating is required the hot gas flows into a pool water condenser, where it adds energy to the
incoming pool water. This heats the pool water while the refrigerant is condensed into a warm liquid. If space
cooling is required, the refrigerant flows to the auxiliary air conditioning condenser bypassing the air reheat coil
and pool water condenser and allowing cool air from the evaporator coil to provide space cooling.
Air-Side Operation
The PoolPak system provides outside air ventilation to satisfy minimum air ventilation requirements during occupied
periods per ASHRAE standard 62.1.
The MPK unit can include an outside air damper (S), a factory mounted exhaust fan (SE), or an exhaust and purge
fan (SEP).
SEP models have an economizer function that can modulate up to 100% exhaust air and outside air. This operation
allows the unit to use outdoor ambient conditions if they are favorable for free heating, cooling, or dehumidification.
For a more detailed description of economizer and smart economizer operation, see the CPCS control functions
section.
The PoolPak unit has been designed to best recycle the energy from the return air during mechanical
dehumidification. In cooling modes for units employed with an exhaust fan (SE & SEP models), warm natatorium air
is exhausted before the evaporator coil. On the other hand, in heating modes for units employed with purge fans
(SEP and SP models), warm natatorium air is exhausted after the evaporator coil. This allows the unit to capture the
exhaust air heat energy for heating before exhausting the air to ambient.
An available supply of outdoor air and continuous air movement is required for indoor air quality. Therefore,
PoolPak does not recommend turning off the unit.

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Figure 2-2. MPK System Schematic

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PoolPak®MPK Series IOM
CPCS Control Functions
Overview
The PoolPak is controlled by the CommandPak Control System (CPCS), a microprocessor-based system that
incorporates all of the functions necessary to maintain correct natatorium temperature and humidity and control
pool water temperature. The CPCS is designed to work with the PoolPak dehumidification system to provide an
environment that is both comfortable and cost effective. It controls unwanted humidity in the pool enclosure and
helps to prevent unsightly condensation from forming on surfaces.
The PoolPak controls automatically operate the heating, dehumidification, and heat recovery systems in response
to the greatest requirements while adjusting unit outputs to maintain building conditions. The PoolPak® controls are
capable of providing full heating capacity to either air or water and of providing proportional control of heating
and dehumidification by loading stages of compressor capacity as necessary. As building requirements are
satisfied, the compressor unloads.
All PoolPak operating and logic controls are factory mounted and wired. The control sequences are designed
specifically to control swimming pool environmental conditions. The following is a brief description of the control
functions available with the CPCS System. For more detail or for finding this information in the controller, see the
MPK Installation and Operation Manual (IOM).
Air Flow Monitoring and Control
The best way to control building pressure is by measuring and controlling airflow rates. The PoolPak system employs
factory mounted VFD or EC motors on the supply fan array, exhaust fan, and purge fans to modulate airflow. The
controller receives feedback from fan inlet measuring stations and the outdoor air measuring station to continuously
monitor the outside air, exhaust air, purge air, and supply air flows. These components and CPCS controller logic
provide active airflow monitoring and control.
By tracking the airflow rate of the exhaust fan and outdoor air intake, a consistent building pressure can be
maintained. See Figure 2-3 for reference. The CPCS controller takes the outside air flow measurement and controls
the speed of the exhaust fan. This control maintains a constant return air flow/supply air flow differential whether the
system is operating at the minimum outdoor airflow rate or maximum outdoor airflow rate (ie. economizer mode).
To determine the desired air flow rates, the controller must be programmed with setpoints for the desired supply air
flow, the desired return air flow, the minimum outdoor air flow, and minimum mixed air temperature allowed. During
minimum outdoor air ventilation, the controller controls the outside air and recirculation air dampers to maintain the
minimum ventilation air requirement. During economizer mode, the controller modulates the outside air flow and
exhaust air flow to maintain space conditions.

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Figure 2-3. Active Airflow Control with Direct OA Measurement Schematic
Humidity Control
The primary function of the CPCS control system is humidity control. The CPCS control system accomplishes humidity
control by using either the economizer mode or mechanical dehumidification.
When equipped, the economizer mode is activated only if the following conditions are present: dehumidification
is required; air and water temperatures are satisfied; the absolute humidity of the outside air is lower than the
absolute humidity of the pool room air; and the outside air temperature will not adversely affect the pool room air
temperature. Whenever available, the economizer mode brings in favorable outside air to satisfy the pool room
requirements.
When economizer is not available, the PoolPak unit performs mechanical dehumidification. The PoolPak provides full
proportional control of relative humidity by staging unit capacity. The humidity controller energizes the compressor.
The moist air from the pool room is drawn over the evaporator coil, where the air is cooled below its dew point. In
this cooling process, the moisture in the return air is condensed onto the evaporator coil. The heat recovered in the
refrigerant from the dehumidification process is directed to the air reheat condenser if the space needs heating or to
the pool water condenser if pool water temperature is below the set point.

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PoolPak®MPK Series IOM
Cold Surface Temperature Humidity Reset
The CPCS control system includes a sensor that measures the temperature of the coldest surface in the pool
enclosure, usually an exterior window or door frame. When the temperature of this surface approaches the
dewpoint temperature of the space, the controller lowers the humidity setpoint to activate dehumidification. This
function helps to prevent condensation on the cold surface. Typical locations for this condensate prevention surface
temperature sensor are north facing exterior walls, windows, window/door frames, and skylights.
Space Heating
The CPCS controller will first look at the outside air to see if the space heating requirement can be met with the
economizer mode. If conditions are unfavorable, the unit will either enable the compressors to perform space
heating by heat recovery or by enabling the auxiliary heat system.
Space heating via heat recovery provides full proportional control of the space dry bulb temperature by staging
compressor loading of unit capacity with humidity override. Heat is recovered automatically from the pool room
return air in the evaporator coil and then re-directed into the reheat condenser coil. For SEP models, the warm
natatorium air is passed through the evaporator before being exhausted. Therefore, the PoolPak unit is able to
capture the heat energy from the warm pool air.
If additional heating is needed, the CPCS Controller then turns on the auxiliary heat system. The PoolPak
automatically controls the output of the optional factory-installed auxiliary air-heating system which can be hot
water, steam, electric or gas.
On a call for space heating only (humidity is satisfied), the controller can be configured to perform the first stage(s)
of heat as auxiliary heat instead. If there is also a dehumidification need, mechanical dehumidification with the
compressors will always be the first stage. Regardless, this setting change allows a facility to use auxiliary heat more
often.
Smart Economizer (SEP)
The Smart Economizer utilizes the simultaneous operation of the heat recovery and economizer control sequence.
When the PoolPak compressor is operating in the heating and/or dehumidifying heat recovery mode return air
passes through the evaporator. The sensible and latent heat in the return air is transferred to the refrigerant. Air
leaving the evaporator is cold and saturated. The exact temperature and dew point of the air leaving the evaporator
is monitored and compared to outside air temperature and dew point. If the outside air is warmer and/or dryer than
the air leaving the evaporator, all the air leaving the evaporator is exhausted and 100% outside air is drawn into
the PoolPak. All the heat recovered in the PoolPak unit refrigerant is transferred to the supply air in the air reheat
condenser. The Smart Economizer can save energy in addition to a standard mixing box and economizer.
Flywheel Air Conditioning (SEP)
If the unit is not equipped with auxiliary air cooling, this control sequence can be activated. Flywheel air
conditioning uses the large thermal storage capacity of the swimming pool. During occupied times, the PoolPak
cools the natatorium air by removing the sensible and latent heat from the air using the evaporator and directing
it into the pool water condenser. The pool water temperature is allowed to rise a maximum of 2°F above the pool
water temperature set point. Automatic staging of cooling capacity occurs in response to air conditioning load.
Space Cooling (Optional)
The PoolPak MPK (SE and SEP) units are equipped with economizer sections. The CPCS will automatically select the
most economical method for space cooling. An economizer utilizes outside air rather than the refrigeration system
to achieve space cooling. A sensor connected to the CPCS monitors the outside air temperature. When appropriate,
the controller will disable the compressor and bring in cool outside air for economical operation.
If space cooling is required and the unit is equipped with an auxiliary refrigerant condenser (air-cooled or water-
cooled), the CPCS will activate the space cooling mode of operation. The air cooling mode of operation is

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independent of the need for dehumidification. In this compressor mode, the heat removed from the space air by
the evaporator will be directed to the auxiliary condenser. For MSE and MSEP units, the air is exhausted before the
evaporator. By exhausting the warm air before the evaporator, the highest enthalpy air is removed from the system
which reduces the load on the air cooled condenser.
AIR CONDITIONING WITH AIR-COOLED CONDENSER
The PoolPak can be equipped with a properly sized integral or remote air-cooled condenser. The remote condenser
can also be installed on a separate pad.
AIR CONDITIONING WITH WATER-COOLED CONDENSER
The PoolPak can be equipped with a remote-mounted water-cooled condenser. This condenser can be either
cleanable or non-cleanable. Sensible and latent heat recovered in the air conditioning mode is rejected to the water
condenser if pool water temperature requirements are satisfied.
AIR CONDITIONING WITH CHILLED WATER COIL
When chilled water is available, a chilled water coil can be factory-installed upstream of the supply fan. The coil
has a factory-installed and wired three-way flow control valve and is controlled by the PoolPak control system.
Pool Water Heating
If the space temperature is at or above the set point and the pool water temperature is below the set point, hot gas
is directed to the pool water condenser when the compressor is running. During times when the pool water requires
more heat than is available from the pool water condenser, the PoolPak® activates the auxiliary pool water heater.
An auxiliary pool water heater must be supplied as part of the pool water pump and filter system.
Smart Pump Control (Optional)
Smart Pump Control allows the CPCS to control operation of a field-installed booster pump to the PoolPak pool
water condenser. When the CPCS determines that pool heating and space cooling are required, a contact
closure signal activates the remote pump. The pump will be deactivated when the pool heating and space cooling
requirement is satisfied. This control sequence requires separate field mounting of a factory supplied pool water
temperature sensor where continuous pool water flow is expected.
Networking Multiple Units
CPCS networking allows multiple units to be connected together. The units will work with each other to control water
temperature, air temperature and relative humidity. Networked units have all the features of standard units plus the
ability to control water temperature in multiple pools. All units on the network are accessible from a single remote
interface unit for convenience.
Occupied/Unoccupied Control Mode
The PoolPak unit time clock allows 7-day, 24-hour scheduling of operational control for both occupied and
unoccupied times during the year. During unoccupied times, the outside air damper and exhaust fans are kept in the
closed/off position. This strategy minimizes the air-heating and/or air-cooling load during unoccupied periods. Also
during unoccupied mode, the supply fan speed is reduced by 20% (Night Fan Setback) further reducing fan energy
costs. During occupied times, the PoolPak operates to maintain outside air at programmed natatorium parameters.
Contact factory for pool water temperature set points greater than 87°F.
NOTE

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PoolPak®MPK Series IOM
Purge Mode (SEP)
The PoolPak has a purge cycle to fully ventilate the natatorium at the airflow (CFM) specified for the unit’s supply
fan. The purge cycle is programmable by the owner as necessary to ventilate the natatorium after shocking the
pool. Unit controls provide completely automatic operation by controlling the supply fan and return (or purge) fan
and by opening the outside air and exhaust air dampers for the programmed time intervals.
Event Mode (SEP)
The Event Mode changes the ventilation air quantity to meet the demands of an event or situation where additional
outside air is needed. The unit controller can store up to 28 schedule events, which are user adjustable at the
Remote User Interface (RUI). During Event Mode, the minimum damper position is raised to a value higher than the
minimum damper setpoint. For each event, the screen shows the day of the week, the hour in 24-hour format, the
minute, and the event type.
Summer Ventilation Mode (SEP)
Summer Ventilation Mode permits the pool operator to open the doors and windows during the summer. The CPCS
control system uses the space doors and windows as its outside air intake by closing the unit’s outside air damper
while driving to full 100% exhaust mode through the exhaust and purge dampers at the PoolPak unit.
CO2Based Demand Ventilation (Optional)
The amount of outside air ventilation is controlled by the PoolPak unit based on the CO2level sensors in the return
air stream.

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Features and Options
Standard Factory Mounted Features
• Direct drive plenum fans
• Variable frequency drives or EC motors
• Two inch, double wall, foam insulated panels
• Airflow monitoring (transducers located on fans and outside air)
• Evaporator coil (heat recovery coil)
• Air reheat condenser coil
• Pool water condenser coil
• Compressor performance monitoring: suction and discharge pressure transducers
• Supply air configuration: all sides available.
• Dampers: outside air, recirculation air, evaporator bypass air
• Gravity relief dampers on exhaust and purge (SE/SEP)
• Temperature (T) and relative humidity (H) sensors:
• Return air, T and H
• Air of the evaporator, T and H
• Supply air, T
• Pool water, T
• Compressor suction temperature, T
• Filters and filter rack (return and outside air)
• Remote monitoring via internet
• Dirty filter indicator
• Network multiple units – connect up to 5 units
• Weatherproofing for outdoor installation
Standard Factory Supplied, Field Installed Features
• Temperature (T) and relative humidity (H) Sensors:
• Cold surface temperature sensor, T
• Outside air, T and H
• Pool water, T (only if Smart Pump Control option is selected)
• Remote Interface Unit (RIU)
Optional Factory Mounted Features
• Integral hot water coil and valve
• Integral auxiliary heat module (gas furnace or electric heat)
• Integral air cooled condenser and associated refrigerant piping
• Integral chilled water coil and valve
• Remote exhaust fan control
• Building automation system connection (LonWorks, Modbus, or BACnet)
• Freeze protection
• Smart Pump Control