PACKAGE UNITS  – PPH / PPS

Options and Accessories

PPH and PPS units are single packaged units that are factory assembled, tested and shipped fully refrigerant charged and complete with compressor, evaporator and condenser coils, fans and controls.

Designed for outdoor installation, they can be either cooling only or heat pump application. PPH and PPS units are available from 12 kW to 645 kW depending on the refrigerant used.

All AHU Systems

PPH / PPS Package Unit – Overview

To ensure the highest level of quality and reliability in our Chillers, all manufacturing and testing procedures are carried out according to ISO 9001:2015 Quality Management system and ISO 14001:2015 Environmental Management system.

  • Suction lines are insulated with closed cell foam insulation, then wrapped with a special protective material and then finally epoxy coated.  This gives further protection for the insulation against weather and other factors
  • Other exposed copper pipes and headers are epoxy coated, after being cleaned, to maintain pipe material and brazing protected against external conditions


Unit Construction – Condenser Side

  • Welded structural C-channel base painted with mono component catalysed primer sprayed paint
  • Base is equipped with welded brackets for heavy duty lifting lugs and with lifting legs for small models up to PPH 300 (82kW)
  • Easily accessible system components
  • Structural members are made fron gauge 15 [1.8mm] tubular cross members that are semi welded with stainless steel fasteners
  • All members and panels (side and roof) are painted with oven baked polyester electrostatic powder paint
  • Petra paint is certified up to 5000 hours salt spray test as per ASTM 117 A&B
  • Condenser coils are shielded by protective panels to ensure uniform air distribution across the coil face area and to provide additonal protection for the coil from external elements such as weather and foreign objects
  • A coil guard is placed on the lower part of the unit, all around the perimeter, to provide protection for the components
  • It is fabricated from gauge 18 [1.25mm] galvanised steel sheet metal and painted with Petra electrostatic powder paint
  • The coil guard is fitted in place by a spring load quick turn latch and is supported upon opening by stainless steel hinges

Compressors

 

  • Suction gas-cooled hermetic scroll compressor
  • Robust design: three Teflon impregnated bearings and integral cast-iron housing for better compressor alignment
  • IP 54 enclosure class terminal box
  • Scroll has inherent durability with few moving parts and low motor strain
  • Spiral surfaces wear in due to unique compliant design
  • Mounted on rubber-in-shear (RIS) vibration isolators
  • High volumetric efficiency with no dead space design
  • Minimised pressure losses with uniform gas compression in the scroll pockets at low velocities
  • Minimised heat ransfer losses because of a physical separation of suction and discharge gas
Scroll Compressor

Scroll Compressor

  • Suction gas-cooled semi-hermetic twin screw compressor
  • Variable slide valves allow the units to match actual load conditions, delivering exceptional part load performance
  • Rain-tight terminal box
  • Double walled pressure compensated rotor housing which is extremely stable and results in additional sound attenuation
  • Proven life-long bearings with pressure unloading
  • Optimised oil mangement with built-in directly flanged on oil separator
  • Long life fine filter mesh and magnets on oil circuit
  • Pressure relief bearing chamber ensures minimum refrigeration dilution in the oil
  • Large volume motor suitable for part winding or Star-Delta starting with integrated embedded sensors in each winding
  • Intelligent electronics including thermal motor temperature monitoring, phase sequence monitoring, manual reset lock-out and discharge temperature
  • Compressor starts unloading
  • Rubber-in-shear (RIS) vibration isolation
  • Oil level switch, high efficiency suction strainer and crank case heater
  • Compressor is equipped with built-in low pressure protection by a pressure transmitter connected to the unit controller

 

 

Screw Compressor

Screw Compressor

 

  • The digital scroll compressor uses digital technology to run at any capacity between 10% and 100%
  • Capacity modulation is achieved by by averaging the two states of loaded versus unloaded operations over time
  • Digital scroll is a good choice for modulation where multi-evaporator systems and precise temperature control is required
Digital Scroll Compressor

Digital Scroll Compressor

 

  • The VFD Scroll Compressor energy savings are realised due to the adaptation of the compressor speed to the actual cooling capacity and the compressor power input is directly related to this speed
  • In addition, other motors in the system will be adjusted actual needs
  • A reduction in the starting current occurs by creating a current slope at motor start-up
  • The adaptation of compressor speed to actual load enables a more precise process control and guarantees output values according to requirements
  • The number of ON/OFF cycles is limited which reduces mechanical stress on several system components and enhances overall system reliability

VFD Scoll Compressor

  • For reduced noise levels
  • The compressor jacket consists of a 9.5mm thick closed cell rubber sound insulation material inside a sound deflecting vinyl cover to provide superior sound reduction for scroll compressors
  • For reduced noise levels
  • The compressor compartment is constructed from gauge 16 [1.5mm] thick galvanised sheet metal insulated with a 9.5mm thick closed cell rubber insulation
  • All sheet metal is painted with Petra powder paint

NB  Compressor compartment installation may change the unit dimensions.  Please speak to us for more inofrmation

Condenser Coils

  • Petra’s flat-bed or V-segment air cooled condenser coils are designed to deliver their duties with optimum performance for all design conditions
  • Coils are manufactured from seamless copper tubes mechanically expanded into aluminium fins
  • Type L heavy-wall seamless copper tubes are provided for the coil headers
  • The condenser coils are hydrostatic pressure tested in accordance with the UL 1995 – 2000 standard
  • All coils are air pressure tested by dry air up to 3,100 kPa under water
  • All coils are dry cleaned after manufacturing for optimum system cleanliness
  • Coils are manufactured from seamless copper tubes mechanically expanded into copper fins
  • Type L heavy-wall seamless copper tubes are provided for the coil headers
  • The condenser coils are hydrostatic pressure tested in accordance with the UL 1995 – 2000 standard
  • All coils are air pressure tested by dry air up to 3,100 kPa under water
  • All coils are dry cleaned after manufacturing for optimum system cleanliness
  • A water based organic type pre-coated fin designed to give better retained performance compared to the typical organic type
  • The top coat is made of hydrophilic resin of polyvinyl alcohol mix with hydrophilic lubricants
  • This provides a better level of retained performance as well as improvement in the area of surface friction to help extend the lifespan of a punch dies
  • Paint is certified as per ASTM 117 A&B up to 3,000 hours salt spray test
  • Aliphatic Acrylic Polyurethane type, with high gloss finish and exceptional weathering performance characteristics
  • Used extensively in many industrial markets, 134 VOC provides a smooth, durable finish that has superior resistance to corrosion, abrasion and chemical exposure
  • Paint is certified as per ASTM 117 A&B up to 3,000 hours salt spray test

Condenser Fans and Motors

  •  Petra Package Unit condenser fans are of the external rotor type
  • The external rotor motor features a space saving compact design, optimum cooling, full speed controllability and low starting currents
  • Coils are manufactured from seamless copper tubes mechanically expanded into aluminium fins
  • Sealed for life ball bearings fitted throughout the range with an L10 life expectancy of approximately 40,000 hours depending on the conditions of operation
  • Thermal contacts are fitted with external rotor motors
  • Embedded deep in the windings of the motors, the contacts are bi-metal cutout design which are temperature dependant
  • Should the temperature of the motor rise to the limit, the bi-metal cutouts activate and cut off the power, thereby providing full protection to the motor
  • Lower speed (700/900 rpm) and thus lower sound levels as the standard fans
  • Same construction and specification as the standard fans
  • Used to enable the unit to operate in low ambient conditions, head pressure can be controlled by varying the speed of the condenser fan motors
  • Other low ambient options are available for temperatures below 0°C

Refrigeration Circuit

The components for each refrigeration circuit are:

  • Liquid line solenoid valve (for compressors>5hp)
  • Liquid line shut-off valve (for compressors>5hp)
  • Expansion valve (for compressors>5hp)
  • Filter drier
  • High/Low safety pressure switch
  • Service point with charging nipples
  • Liquid, discharge and suction pipes are all hard copper pipes
  • The pipes are formed using automated CNC pipe bending machines in order to minimize brazed joints which in turn increases system reliability
  • Epoxy paint is applied to all of the exposed copper piping in the refrigeration circuit
  • The hot gas bypass consists of a mechanical valve capacity regulator used to adapt compressor capacity to actual evaporator load.
  • It is installed in a bypass line between the high and low pressure sides of the refrigeration system and is designed for hot gas injection in the evaporator just after the expansion valve
  • The hot gas bypass valve is UL listed, file SA7200
  • The hot gas bypass valve allows additional capacity reduction for units operating below the minimum step of unloading for the compressor
  • If the hot gas bypass is installed on the lead compressor only, the lead/lag function (for the compressor) will be eliminated
  • The pressure relief valves comply with the requirements of the ASME (Boiler and Pressure Vessel Code Section VIII, Division 1)
  • The relief valve is designed or set to open at a predetermined set pressure to protect pressure vessels and other equipment from being subjected to pressures that exceed their design limits
  • Optional fixed pressure gauges for monitoring of refrigeration discharge and suction pressures
  • Additionally, the gauges are used to verify suitable refrigerant charge and proper system performance
  • The gauges are Bourdon type, stainelss steel housing, oil filled
  • Oil filled pressure gauges provide greater protection of the gauge internals from corrosive atmospheres
  • The gauges are provided with a dual scale of both PSI and BAR

 

 

 

  • Electronically operated step motor flow control valves, intended for the precise control of liquid refrigerant flow
  • Synchronised signals to the motor provide discrete angular movement , which translates into precise linear positioning of the valve piston
  • The electronic expansion valve is easily interfaced with microprocessor based controllers
Petra Electronic Expansion Valve

Petra Electronic Expansion Valve

Electrical

  • Free terminal for remote ON/OFF connection
  • Free terminal for general alarm output (optional for Petra Mk IV Controller)
  • Control voltage is 220-240V for all components
  • Single point power connection for each electrical panel
  • Starting contactors for compressors and condenser fan motors
  • ON/OFF switch for each compressor (for advanced controller)
  • Control circuit breaker for short circuit protection
  • Short cycling protection for compressors (time delay)
  • Microprocessor controller for full management of unit operation and safety circuits
  • Power supply monitor (phase failure relay) used to protect the power circuit against over or under voltage conditions and against phase loss or reversing conditions
  • Direct online start
  • NEMA 3X with IP54 minimum enclosure standard electrical panel
  • Electrical panel is equipped with a heavy gauge galvanised steel access door (applies to PPH 360 and larger models)
  • Panel is painted with oven baked polyester electrostatic powder paint
  • Each door is equipped with external handle with key and tooled latch
  • Door contains sealing heavy duty clip on bulb gasket between the door and the panel to provide effective sealing
  • All doors have multiple hinges
  • Each door has a door retainer to keep the door open during service
  • Each door has a built-in pocket to accomodate the laminated wiring diagrams and IOM documents
  • Separate electrical box for condenser fan motors located on condenser side (for PPH 360 and larger models)
  • This device works with the door interlock to de-energise the power supply to the unit during service or repair operations
  • It has an external handle that is installed on the electric panel door
  • The switch has to be de-energised to open the electric panel
  • The disconnect switch can be supplied with a built in fuse or a non-fuse type
  • The earth leakage relay is a safety device used in electrical installations with high earth impedence to prevent shock
  • It detects small stray voltages on the metal enclosures of electrical equipment, and interrupts the circuit if a dangerous voltage is detected
  • The earth leakage relay can be supplied for the whole unit power supply or for each compressor
  • Please speak to us directly for more details
  • The control transformer is to supply power input to auxiliary components at 120 or 220 volts.
  • For example, for power input to bulk head lights or a GFI outlet

Ampere Meter and Volt Meter

  • The amp meter and volt meter are used to measure the power current and voltage consumption
  • Ampere meter is used for each phase
  • Volt meter is used to measure the voltage of the power supply between each phase and another between each phase and neutral

Dual Power Connection

  • The Package unit can be supplied with dual power connection
  • One power entry for compressors, and the second power entry for the rest of the unit
  • Each power connection can be equipped with a separate main disconnect switch

Electrical Component Options

  • External overload for each compressor
  • External overload for each condenser fan motor
  • Circuit breaker for each compressor motor
  • Circuit breaker for each condenser fan motor
  • NEMA 4X electrical panels made from galvanised steel
  • NEMA 4X electrical panels made from stainless steel

Unit Construction – Evaporator Side

  • Double skin glavanised steel for PPH 700 and larger models, single skin PPH 40 – PPH 640
  • 50mm injected foam, 3 pcf  insulation density as minimum for PPH 700 and larger models, 25mm injected foam for PPH 40 – PPH 640 models
  • No Metal Through panels along full panel parameter
  • 16-22 gauge painted interior and exterior panels
  • Standard panels are galvanized steel
  • Stainless steel and aluminum panels are optional
  • Each panel shall have a machine applied foam gasket that seals all around its edges
  • Petra paint is certified according to ASTM 117 A&B 5,000 hours salt spray test
  • Painted perforated inner skin is available as optional feature

50mm injected foam, 0.048g/cm³ insulation density as minimum

  • No Metal Through panels along full panel parameter
  • Petra paint is certified according to ASTM 117 A&B 5,000 hours salt spray test
  • Painted steel floor available as option
  • Aluminium tread plate floor available as option

 

 

Double wall G-90 galvanized steel

  • 38mm injected foam, 0.048g/cm³ insulation density as minimum
  • No Metal Through doors along full door parameter
  • 16-22 gauge painted interior and exterior panels
  • Standard panels are galvanized steel
  • Stainless steel and aluminum panels are optional
  • Clip on PVC gasket
  • Minimum two PVC AB Ind handles openable from inside & outside
  • Petra paint is certified according to ASTM 117 A&B 5,000 hours salt spray test
  • Inspection window (rectangular/circular)
  • Access doors that can be opened from inside & outside of the unit
  • One tooled latched handle
  • Heavy duty neoprene type door gasket
  • Door open against pressure (in-swing door)
  • Relief latch for pressure opened doors
  • Stainless steel piano hinges
  • Outdoor installed units are air and water tight and provided with flat roof covers with standing top seams
  • The unit roof cover extended to make rain gutters along the unit perimeter to ensure positive rainwater drainage
  • Gauge 20 (0.9mm) galvanized steel outer skin painted with electrostatic polyester powder coat, oven baked
  • Petra paint is certified according to ASTM 117 A&B 5,000 hours salt spray test
  • Double sloped roof canopy with standing top seams as standard
  • Rain gutters are provided along the full canopy perimeter to ensure positive rainwater drainage
  • All roof canopy components are fully caulked & sealed to prevent any water leakage
  • Roof canopy is coated with weather-proof, polyester powder electrostatic paint, oven-baked
  • Additional rain gutters are provided for access doors/panels (if not covered by rain gutters)
  • Petra paint is certified according to ASTM 117 A&B 5,000 hours salt spray test

Air Mixing

All dampers are made with a rigid anodized aluminum frame and with multi airfoil aluminum blades so as to reduce pressure drop and the sound generated when air passes through the blades.

An opposed blades arrangement is used with virtually no air leakage.

The damper blade’s rotation is achieved by the PVC gear’s rotation

  • Jam seals: flexible metal compression type along control damper sides
  • Blade seals: seal along control damper blade edge
  • Upon request the dampers are supplied with a manually adjustable lever that can be located on either side of the damper
  • Dampers could be linked for motorized operation

This type of damper is designed to pass an air streamaround a coil in order to control the air stream conditions.

Up to 100% air by-pass can be achieved if required

  • The mixing box module combines the incoming outdoor air with the circulated return air from the conditioned space
  • The mixing box is supplied with fresh and return air dampers
  • Exhaust box function is to exhaust some of the circulated air and return the rest to the supply air stream
  • Both mixing or exhaust box dampers are low leakage opposed
  • Aluminum blades type are used, and assembled in aluminum frame
  • Dampers can be operated manually or motorized by an actuator
  • A combination of mixing boxes with panel filters can be provided in one module
  • Economizer section with exhaust box is available

In Economiser operation, the outside air and return air dampers operate to maintain the supply control set point. If the Economiser operation cannot provide enough cooling to satisfy the supply air control set point, mechanical cooling will be energized.

Once mechanical cooling is operating, the outside air damper position is either set at 100% open or at the minimum position set point.

According to the application, the Economiser could contain an exhaust damper function
to exhaust some of the circulated air.  All Economiser dampers are low leakage opposed, aluminum blades type, and they are assembled in an aluminum frame.

These dampers can be operated manually or by an actuator (optional).  A combination of mixing boxes (OA & RA dampers) with panel filters can be provided in one module.

The Economiser also includes hoods for OA and EA damper opening or louvres for EA openings.

Filters

1- Pleated

  • Environment-friendly materials
  • High tensile strength media
  • Rigid construction
  • Maximum temperature up to 90ºC

2- Synthetic

  • A progressively structured filter media made from thermally bonded synthetic fibres
  • Operational temperature up to 130ºC

3- Aluminum

  • Flexibility in shape
  • Low resistance
  • Washable

50mm and 100mm thickness are available

Magnehelic filter gauge, dirty filter switch & pressure taps are available as optional features for all filters

Available for pleated, synthetic & aluminum flat filter types.

V-type filters are highly recommended whenever face velocity is to be reduced,

50mm and 100mm thickness are available

Magnehelic filter gauge, dirty filter switch & pressure taps are available as optional features for all filters

  • Used when higher level of filtration than flat or V-types is required
  • Made of synthetic media
  • Mechanically strong with high absorption resistance
  • Excellent performance in high moisture conditions
  • Low initial pressure drop
  • High dust holding capacity
  • Long service life
  • Maximum operating temperature 60ºC

50mm and 100mm thickness are available

Magnehelic filter gauge, dirty filter switch & pressure taps are
available as optional features for all filters

  • Used in clean room applications to achieve very high efficiency of filtration
  • Less costly installation space is necessary
  • Energy Saving
  • Long service life
  • Maximum operating temperature up to 90ºC

DX Coils

Petra’s direct expansion (DX) coils are designed to meet a wide range of temperatures, from air handler to sub-zero freezing applications

  • Circuiting is matched to compressor requirements, and the coil face can be split to suit specific needs
  • Coils are AHRI 410 certified and stamped
  • Coils are designed to deliver their respective dutioes at optimum performance under all conditions
  • Coils are tested at 3,100 kPa air pressure under water
  • Coils undergo dry chemical cleaning after manufacturing to ensure cleanliness
  • Airtight gaskets are used where coil pipes exit the unit casing
  • The sealing around the coil prevents air by-pass

Copper tubes

  • Coils are manufactured from seamless copper tubes mechanically expanded into aluminum fins, with type-L, heavy wall, seamless copper tubes for the coil headers.
  • The evaporator coils are hydrostatic pressure tested in accordance with the UL 1995 -2000 standard.
  • Copper return bends stub connections are brazed into expanded tube ends using brazing alloy
  • Available up to 12 rows

Aluminium fins

  • Aluminium alloy fins configured sinusoidal type fins
  • 8 – 16 fins per inch available

Distributor

  • Seamless copper tube
  • Distributor individually sized to coils to minimise pressure drop

Coil Casing (coil end plate)

  • Mill galavanised sheet metal with full slotted flanges for convenient mounting
  • Stainelss steel coil casing (optional)

 

 

Polyurethane pre-coating (for aluminum fins)
A water based organic type pre-coated fin designed to give better retained performances
compared to typical organic type. The topcoat is made of hydrophilic resin of polyvinyl alcohol mix with hydrophilic lubricants. It provides a better level of retained as well as improvement in the area of surface friction to help lengthen the life span of a punch dies. Paint is certified as per ASTM 117 A&B up to 3000 hours salt spray test

Polyurethane Post-coating (for aluminum & copper fins)
Aliphatic acrylic polyurethane type, with high gloss finish with exceptional weathering performance characteristics. Used extensively in virtually all industrial markets, 134 VOC provides a smooth, durable finish that has superior resistance to corrosion, abrasion and chemical exposure. Paint is certified as per ASTM 117 A&B up to 3000-4000 hours salt spray test

Coil connections can be provided on either right or left hand side facing air return.

 

 

The drain pan is supplied as standard under the DX cooling coil. Drain pan is made of 1.5mm thick painted galvanized steel with a connection from side. The drain pan is mounted on a channel base insulated with 6.4mm closed cell foam insulation class “O” to prevent condensation.  The drain pan is single sloped drain pan. Drain trap design.

Options:

  • Stainless steel drain pan
  • Drain pan connection from both sides
  • Double sloped drain pan
  • Double skin drain pan with gauge 16 outer with 1.5mm thickness
  • Threaded male/female design

Fans

Petra fans are high performance centrifugal fans.  The Package Unit can be equipped with different types of fans depending on cost and efficiency targets, as well as system static pressure.

The impeller size selection criterion is a balance between efficiency, capital cost, acoustic level considerations and the physical space available for the unit.

Standard Features

  • All Petra fans are AMCA certified
  • All fans are selected for optimum outlet velocities and low sound levels
  • We offer belt driven fans for models PPH 95 and larger, and direct drive fans for smaller models
  • Fans are supplied with flexible connection between the fan discharge outlet and the unit casing
  • This minimises the vibration and the noise levels by isolating the fan motor assembly from the rest of the unit structure
  • The fan shaft is made of steel, machined, grounded and epoxy coated to provide maximum rust protection
  • The shaft diameter is selected for maximum operational speed, whilst still being generously below the critical speed
  • The fan and fan motor assembly is mounted on rubber in shear (RIS) vibration isolation mounting
  • Non standard fan sizes
  • Pillow block bearing fans where the bearing is mounted on cast iron supports with grease points
  • Stainless steel fan shaft
  • Fan inlet measuring element mounted on the fan bell mouth
  • Double grooved fan sheaves
  • Inlet guide vanes for backward curved fans and airfoil fans to control the air flow rate
  • Twelve blade impeller for airfoil plenum fans for very quiet operation
  • Aluminium fan impeller
  • 25mm open type, 50mm seismic or 100mm seismic vibration isolation mounting for fan and fan motor assembly
  • Wire mesh on the fan inlet
  • Fan and fan motor drive assembly belt guard
  • Extended lubrication lines
  • Externally mounted motor with extended shaft
  • Twin fan arrangement for low height units
  • The fan motors are mounted on a glavanised steel base which is isolated from the unit casing with rubber mounts as standard
  • All motors of less than 7.5hp are provided with a variable pitch pulley for the motor and a fixed pulley for the fan*
  • Motors are Totally Enclosed Fan Cooled (TEFC), squirrel cage type with 4 pole class F insulation and IP55 protection

*where applicable

  • Fan motors suitable for explosion hazardous locations (ATEX)
  • Two speed motors
  • Standby motors with manual or automatic change over
  • Motor frequency inverter drive
  • Circuit breaker
  • Motor contactor
  • Spring vibration isolators
  • Premium efficiency motors
  • Class H insulation
  • 2 & 6 pole motors
  • Belt guard on fan motor construction

Forward Curved Fan (Standard)

  • First choice for low/medium and high static pressure systems
  • Competitively priced to suit most budgets

Backward Curved Fan (Optional)

  • Made of high efficiency backward inclined blades
  • Higher performance and lower sound level than forward curved fan types
  • Special design impellers built from mild steel
  • Impellers are welded, treated and painted with alchidic melamminic paint
  • Statically and dynamically balanced according to ISO 1940

Airfoil Backward Curved Fan (Optional)

  • Airfoil and flat shaped blades design
  • Lower operational costs due to higher static efficiency
  • Lower noise levels

Single Width Single Inlet (SWSI) Plenum Type

  • Plenum fans are used to pressurise the entire surrounding air plenum
  • This allows discharge ductwork to be directly connected to the air handler from any direction
  • The plenum fan design also saves space by eliminating the fan housing, transitions and diffusers within the air handling uunit
  • Plenum fans can be belt driven or direct drive

Single Width Single Inlet (SWSI) EC Type

  • EC fans are used to increase energy efficiency and provide supply fan technology control
  • EC fans are powered by energy saving EC motors
  • The electronically controlled EC fan motor reacts steplessly through the technologically advanced unit controller to changing output requirements
  • EC fan motors can run at partial load conditions in energy saving mode, and are unaffected by voltage fluctuations
  • EC fan motors consume up to 30% less energy than conventional fan and fan motor assemblies and provide variable speed through a signal from the controller
  • EC fan motor characteristics:
    • Upto 92% motor efficiency resulting in lower operating costs
    • Quiet operation, long life and maintenance free
    • Stepless load tracking to the prevailing conditions and demands

Heat Recovery

  • Petra uses Energy Recovery Wheels, both sensible and enthalpy, in the Package Units as an energy recovery solution
  • Whilst meeting all applicable ventilation and energy-use standards, the Heat Recovery Energy Wheels improve indoor air quality and reduce the total HVAC equipment capacity
  • Harnessing the energy present in the exhaust air stream is a cost effective and sustainable method to improve indoor air quality
  • Standard Energy Wheels are aluminium, but polymer types are available as an option

Energy Wheel (Aluminium)

Rotor

  • Enthalpy heat and humidity recovery wheels are manufactured from aluminium, treated for corrosion resistance and include a low co-adsorption Ion Exchange Resin (IER) media to adsorb and transfer humidity in the vapour phase

Benefits of using rotors with Ion Exchange Resin media

  • Ion Exchange Resin (IER), unlike silica gel or molecular sieve, does not have ‘pores’ and yet has storage capacity
  • IER has the lowest co-adsorption coefficient in the industry, lower even than the 3A molecular sieve
  • Wheel surfaces are ground and polished smooth for long seal life and to prevent annular cross contamination between the air streams
  • Designed to keep negative pressure in both the supply and exhaust streams to maintain the wheel in place and prevent tilting or air flowing from the exhaust side to the supply side

 Cassette

  • The cassette of the rotary heat exchanger has a built-in purge section that provides minimum cross contamination of the exhaust air
  • The cassette is constructed from a minimum of 10 gauge steel to ensure rigidity and stability
  • Casing side panels are removable to provide easy access to the internal parts
  • The cassette has a built-in purge section to prevent carry-over of the exhaust air to the supply air stream
  • The supply and exhaust air streams are isolated from each other by means of adjustable seals secured to the cassette panels and duct dividers
  • The seals consist of a double layer of neoprene wiper seals
  • The seals are installed in contact with the wheel flange in order to minimise leakage between the supply and exhaust air streams
Optional features for Energy Recovery Wheels

  • By-pass dampers with controlled actuator
  • Recirculation dampers with controlled actuator
  • VFD for freeze protection
  • Rotation failure detector
  • Stainless steel drain pan beneath the Energy Wheel section

 

Energy Recovery Wheel

  • Heat pipe heat recovery is an operational principle based on natural (free energy) evaporation and condensation of a fluid that takes place inside of a closed loop coil assembly, and does not require a pump
  • The fluid flows between the two coil sides in the closed loop by changing phase between a gas and a fluid, and utilising the characteristics of the medium (as a gas or fluid) to move around the system
  • At Petra we build and tests our own Heat Pipe coils in our factory
  • Heat Pipe coils are manufactured from 3/8″ seamless copper tubes mechanically expanded into aluminium fins

Benefits of Heat Pipes

  • High Energy Efficiency Ration (EER)
  • Reduction of electrical consumption and MCA / MOP at installation site
  • Reduced weight of Package Unit when compared to other Heat Recovery options such as a Plate Heat Exchanger or Energy Wheel
  • Easy maintenane
  • Smaller footprint for the overall unit

A. Heat Recovery Type

  • A Heat Recovery Heat Pipe can be used in one season only (i.e. summer or winter), and can be installed in either a double-deck or side-by-side unit design
  • Petra’s Heat Recovery Heat Pipe utilises two coils filled with a refrigerant in a closed circuit design
  • The energy exchange between the supply and exhaust streams will create enough force to change the phase of the refrigerant between vapour and liquid and thus create a difference in pressure allowing the gas to flow between the two coils without the need for a pump
B. Humidification Type

  • A Dehumidification Heat Pipe is placed as a wraparound coil assembly surrounding a cooling source (the DX coil)
  • Petra’s Dehumidifaction Heat Pipe is used where humidity treatment is required for a 100% make-up air package unit providing a non cross contamination solution to reduce humidity without any additional cost
  • It utilises two coils filled with a refrigerant in a closed circuit design and wrapped around a DX coil
  • The system consists of a pre-cool coil (upstream) and a reheat coil (downstream)
  • The energy exchange between the humid outside air hitting the pre-cool and cold dehumidified air exiting the DX coil and hitting the reheat coil will create enough force to change the phase of the refrigerant between its vapour and liquid state, thus creating a difference in pressure that allows the gas to flow between the two coils without the need for a pump
  • Petra’s Dehumidification Heat Pipe reduces the mechanical cooling energy consumption by between 15% and 20%

 

Heat Pipe Heat Recovery

  • Runaround coils consist of two finned tube coils (air to water heat exchangers) piped together
  • One of the two coils is in the outdoor air stream and the other is in the exhaust air stream
  • This type of heat recovery system is limited to sensible energy heat transfer
  • This type of heat recovery relies on thermal conduction for energy recovery
  • It consists of alternate layers of plates, separated and sealed
  • This type of heat recovery is limited to sensible energy recovery
  • Cross flow heat exchangers are used in double-deck units

Other Sections and Features

Various types of humidifiers are available and selection depends on the application.  Humidifiers can be supplied with or without controllers, sensors and all other hardware.

The types of humidifier available are as follows:

A.  Self-contained steam cylinder type

  • With immersed electrodes, the steam cylinder’s stainless steel steam distribution pipe is complete with electronic controls for water level regulation and automatic flushing

B.  Electric Pan Humidifier

  • With the Electric Pan Humidifier, air is humidified by evaporating water in a painted galvanised sheet metal tank using electric element heaters
  • The humidifier tank is provided with a float valve, drainage output, quick-fill opening and awater level switch

 

  • Petra offer a tubular type gas heater, completely assembled and wired, integrated with the air conditioning unit and suitable for outdoor applications*
  • The heat exchanger has been designed to provide maximum and uniform heat transfer with low pressure drop for the gas, and the curved, non-welded, serpentine design experiences less thermally induced stress making it highly durable for longer service life
  • Manufactured from heavy duty 20 gauge aluminised steel as standard, and available with 409 stainless steel material as an option
  • Drum and tube design is also available as an option
  • Our standard gas heater is supplied with 1-stage gas valve, 2-stage gas valve
  • Electronic modulation gas valve is available as an option
  • The modulating valve is mounted between a standard gas control valve and burner manifold and is fully open with no power applied to it
  • The minimum ratio that can be reached is 50% of the full input rate, with full modulation from 50% to 100% for units with one gas heater
  • The turn down ratio can be lowered to 25% when using two gas heaters in one unit, and even less when using three gas heaters in one unit

*indoor application subject to availability of fresh air in the space

  • This plate is provided when high face velocities exist, especially when final filters are provided in the air handling unit, or in multi-zone and dual ducts to provide even air distribution between hot and cold zones
  • The diffuser is made of heavy gauge galvanised steel perforated plate

The air washer section comes complete with:

  • Stand pipes with spray nozzles that upply fine water mist
  • PVC plates specially shaped to form droplet eliminators
  • Water pump equipped with the following openings:
    • Drain connection
    • Supply connection
    • Suction connection
    • Overflow
    • Quick-fill
  • Inspection window and access door
  • The sound attenuator can be supplied wherever a significant reduction of fan noise is required
  • Sound absorption is achieved by installing mineral wool splitters, fixed in galvanised steel frames and mounted parallel to the airflow
  • Various splitter lengths are available to provide a range of attenuation performances
  • The sides exposed to the air stream are covered with a glass fibre scrim to avoid erosion of the mineral wool by the air stream
  • The standard thickness of the splitters is 200mm
  • Sound attenuators can be provided in the supply and return air-side
  • The attenuators can be supplied with different sizes depending on the required sound level
  • The sand trap louvre is constructed of heavy gauge galvanised steeel with U-shaped plates mounted and encased in a galvanised steel frame
  • These plates prevent large particles from entering the air handling ubnit with the fresh air
  • Including a sand trap louvre helps to prolong filter life and ensure the cleanliness of the air stream
  • To avoid water carry-over at high velocities, Petra recommends using a PVC droplet eliminator in the unit
  • Eliminator blades are manufactured from reinforced polypropylene, encased within a galvanised steel frame
  • The droplet eliminators are designed to completely eliminate water carry-over from cooling coils with minimal air pressure drop
  • In most cases droplet eliminators are fitted within the cooling coil module, but could be fitted anywhere inside the air handling unit if required
  • Aluminium eliminators are available as an option

Optional Accessories

  • A vapour proof bulkhead light can be provided as an optional feature or serviceable internal part
  • The terminals for these lights can be either with or without switches
  • This optional accessory is useful for carrying out any service or maintenance tasks when there is insufficient natural light

 

  • Electric heaters are available in a wide range of capacities (kW and stages)
  • The electric heaters are mounted on the coil module to reduce the unit footprint, but can be supplied as a stand alone section if preferred
  • Heaters are made of copper plated steel fins brazed to a steel tubular sheath which includes an 80/20 Nickel/Chrome resistance wire connected to terminal pins
  • The tubular sheath is filled with high quality compressed magnesium oxide to ensure even heat distribution along the element
  • The terminal pins are insulated with ceramic bushes to isolate the element electrically and thermally from the casing
  • Auto and manual cutout is supplied as standard with the electric heaters

The following components will be supplied with the unit:

  • Automatic safety cutout
  • Manual safety cutout

Optional features for electric heaters:

  • Contactor for each stage
  • Power circuit breaker for each stage
  • Air flow switch
  • SCR modulating control

Electric Heater
kW
6
7.5
9
12
15
21
24
30
36
42
45
51
57
60
66
72
75
Single Stage
1 Only
kW
6
7.5
9
12
15
21
24
30
36
42
45
51
57
60
66
72
75
2 Stages
1st
kW
3
3
4.5
6
7.5
10.5
12
15
18
21
22.5
27
28.5
30
33
36
37.5
2 Stages
2nd
kW
3
4.5
4.5
6
7.5
10.5
12
15
18
21
22.5
24
28.5
30
33
36
37.5
3 Stages
1st
kW
-
-
-
4.5
6
7.5
8
10.5
12
15
15
18
21
21
24
24
27
3 Stages
2nd
kW
-
-
-
4.5
6
7.5
8
10.5
12
15
15
18
21
21
21
24
27
3 Stages
3rd
kW
-
-
-
3
3
6
8
9
12
12
15
15
15
18
21
24
21
  • This optional feature is fitted within the Package Unit to to disable render  microbes, bacterial and fungal contaminates, inactive
  • The lamps are extensively used in health care facilities – hospitals, biological laboraties and pharmaceutical environments
  • The ultra-violet lamps are installed inside HVAC systems, creating inhospitable conditions in which the organsims cannot survive
  • The VFD is to provide factory pre-wiring to the motors terminals to a solid state variable frequency drive to control the motor speed through modulating electrical signal
  • The VFD is encased in a metal box

PPH / PPS Range of Air Cooled Package Units

The PPH and PPS range of Air Cooled Package Units is available with either refrigerant R452b, R410a or R134a.

The model references,  capacities, dimensions, sound data and operating weight is given in the tabs above, but for more detailed information please call us on 0118 988 0101 or sign in here to download the specifications

Please contact us on 0118 988 0101 or email uksales@petra-ww.com for the full specification details of the PPH/PPS range

Air Flow
Rate
(l/s)
Model 40
661
50
873
60
1,062
85
1,180
95-1
1,534
95-2
1,534
105-1
1,746
105-2
1,746
115-1
1,888
115-2
1,888
135-1
2,124
135-2
2,124
160-1
2,124
160-2
2,124
175-1
3,067
175-2
3,067
195
3,775
230
4,247
300
4,719
360
5,191
450
5,899
530
6,607
640
7,550
700
10,382
800
11,326
900
12,033
1000
13,213
1100
14,517
1200
15,101
1400
16,988
1600
18,876
1800
20,764
2000
22,651
2200
28,314
Cooling Capacity
@35degC
50Hz
Model 40
10
50
14
60
18
85
23
95-1
26
95-2
25
105-1
28
105-2
30
115-1
33
115-2
33
135-1
41
135-2
41
160-1
45
160-2
47
175-1
53
175-2
55
195
60
230
71
300
85
360
96
450
128
530
150
640
190
700
204
800
231
900
291
1000
317
1100
347
1200
375
1400
392
1600
448
1800
505
2000
562
2200
694
Dimensions (mm)
L
Model 40
1,140
50
1,140
60
1,140
85
1,140
95-1
1,600
95-2
1,600
105-1
1,600
105-2
1,600
115-1
1,600
115-2
1,600
135-1
1,600
135-2
1,600
160-1
1,600
160-2
1,600
175-1
1,650
175-2
1,650
195
1,650
230
1,650
300
1,880
360
1,880
450
2,440
530
2,440
640
2,440
700
2,700
800
5,360
900
5,360
1000
5,870
1100
5,870
1200
5,870
1400
8,660
1600
8,660
1800
8,660
2000
8,660
2200
11,530
Dimensions (mm)
W
Model 40
1,140
50
1,140
60
1,140
85
1,140
95-1
1,550
95-2
1,550
105-1
1,550
105-2
1,550
115-1
1,550
115-2
1,550
135-1
1,550
135-2
2,230
160-1
2,230
160-2
2,230
175-1
2,230
175-2
2,230
195
2,230
230
2,230
300
2,230
360
2,230
450
2,230
530
2,230
640
2,230
700
2,230
800
2,230
900
2,230
1000
2,230
1100
2,230
1200
2,230
1400
2,230
1600
2,230
1800
2,230
2000
2,230
2200
2,230
Dimensions (mm)
H
Model 40
940
50
940
60
940
85
940
95-1
1,370
95-2
1,370
105-1
1,370
105-2
1,370
115-1
1,370
115-2
1,370
135-1
1,370
135-2
1,370
160-1
1,370
160-2
1,370
175-1
1,620
175-2
1,620
195
1,620
230
1,960
300
2,260
360
2,460
450
2,460
530
2,460
640
2,460
700
2,460
800
2,460
900
2,460
1000
2,460
1100
2,460
1200
2,460
1400
2,460
1600
2,460
1800
2,460
2000
2,460
2200
2,460
Operating Weight
(kg)
Model 40
296
50
300
60
328
85
383
95-1
422
95-2
422
105-1
422
105-2
422
115-1
427
115-2
427
135-1
438
135-2
438
160-1
498
160-2
498
175-1
672
175-2
672
195
697
230
737
300
952
360
1,042
450
1,356
530
1,740
640
1,810
700
2,676
800
4,047
900
4,124
1000
5,385
1100
5,439
1200
5,437
1400
7,242
1600
7,512
1800
7,653
2000
7,732
2200
10,130

*All stated kW capacities are based on 35°C ambient temperature, 12/7°C water entering / leaving temperature and 50Hz power supply 

Please contact us on 0118 988 0101 or email uksales@petra-ww.com for the full specification details of the PPH/PPS range