INTRODUCTION

PETRA’s ESC (Energy Saving and Conservation) system is uniquely designed to enhance energy savings and produce optimal reduction in power consumption.

The ESC system consists of PETRA’s Heat Pump Water Source (indoor unit) which operates in either heating or cooling mode to provide the required comfort conditions to the application space.

The ESC system is made up of a closed loop of water; therefore, any loss of water is highly unlikely. Compared to other HVAC systems, PETRA’s ESC system has a higher COP in both heating and cooling.

Also, the ESC system is suitable for multi-story and high rise buildings (apartments, hotels,schools, hospitals, and offices).

PETRA’s ESC system is designed to eliminate power sharing problems between different occupants, because each user has his own indoor unit and pump. Therefore, each individual electricity reflects leads to actual power consumption per user.

Another advantage of the ESC system is during mild seasons such as spring and fall, where occupants on the sunny side and interior of the building operate the ESC system in cooling mode and occupants in the shady side of the building operate the ESC system in heating mode. This case provides a form of heat recovery and produces great energy savings in addition to increasing the COP significantly.
 

FEATURES AND BENEFITS

Superior Efficiency

• ESC System exceeds the new ASHRAE 90.1 efficiency levels at both full load and part load efficiency.

• The system’s efficiency is not affected in the case of high rise buildings. There are only water connections between indoor and
  outdoor units, hence refrigerant pressure losses are minimal.

• The ESC system is a closed water loop, thus water losses are insignificant as opposed to water source heat pumps utilizing
   open loop cooling tower systems.


Low Noise Units

The ESC system offers low sound power level units measured in accordance with the BS ISO 3744 standard, by adopting low noise scroll/ reciprocating compressors, condenser fans and specially designed refrigerant piping.

The indoor units (PWSP) are provided with a specially designed compressor acoustic enclosure (compartment) in order to reduce the noise level of the indoor unit to unsurpassed values (Nc30).
 

Compact Physical Footprint

The ESC system offers a compact footprint to serve the areas and applications which have space constrains and it also allows close spacing installation.
 

Outstanding Finishing

•  All exposed piping, including coil headers, are epoxy coated for extra protection and long life.

•  All coil U-Bends are protected with a galvanized steel painted cover plate mounted at the U-Bend coil side. The plate covers the
   entire U-Bend coil side.

•  All suction lines are covered with rubber insulation wrapped in cheese cloth and epoxy painted for extra protection.


Quality Assurance

•  To ensure the best performance each unit is factory test run.

•  ESC system units are produced in an ISO 9001-2000 listed manufacturing facility.

•  PWSP series is rated in accordance with the ARI standard 320

•  ESC system unit’s construction complies with the ASHRAE 15 safety requirements.


Easy Installation and Maintenance

•  Complete factory wiring, easy listing provisions, factory installed options and start up, facilitate quick and easy installation.

•  Minimal time is required for installation using PETRA ESC system pumping cabinet (which is a part of the ESC system).

•  All components and refrigerant piping are located inside the indoor unit for superior accessibility and serviceability.

•  Minimal cost and time are required for site installation due to the simple piping system between indoor and outdoor units. This
   combination can be carried out either by pex- pipe, copper pipe or black steel pipes.
 

Design Flexibility

These PWSP package units meet the same high engineering and performance standards that are characteristics of all PETRA air-conditioning systems.

A wide range of unit capacities and options are available to meet specific design requirements.

The advanced microprocessor controller enables the consumer to select specific operating parameters according to particular needs.


Power Sharing

To avoid any power sharing problems and to allow each occupant to pay his own electricity bill, the PETRA ESC system provides the following logic of power distribution:

•  Each user separately owns a compressor and pump, which represents (99%) of the total power consumption for each user.

•  The only common electricity sharing between users is due to the dry cooler fans. This represents the rest of the power
    consumption (1% for each user)


Cooling & Heating Modes

Multiple users can perform different modes on the same ESC system without any sharing problems, i.e. some users can operate the ESC in cooling mode while others can operate the system simultaneously in heating mode and vice versa. For heating purposes, boilers can be eliminated in the ESC system, since electric heaters can be used for supplementary and / or main heating systems.

FEATURES AND BENEFITS

Energy Saving

•  Part load condition

At part load condition the coefficient of performance (COP) will reach high values and there will be no need for the dry cooler fans to operate. At these part load conditions, a controller at the inlet of the dry cooler controls the fans and deactivates them. This will minimize the running cost for the building owner.

•  Full load condition

At full load conditions, where all users run their indoor units simultaneously, the water velocity will be high resulting in a pressure drop in the system. In this condition, a booster pump (installed on the dry cooler) will operate to compensate the pressure drop.

Pumping System

Indoor units (PWSP) can be combined with an outdoor unit (PDC) by the central pumping system. This has a single pump design where all occupants are sharing the same pump, and will be built in the dry cooler.(Std)

Pumping Unit Components:

•  Stop valves

•  Fittings and reducers for pipe connections

•  Air vents to remove air bubbles from system

ESC Pumping Cabinet (Optional)

For multi-zone buildings and for easy installation, PETRA provides a specially designed pumping cabinet to serve several zones. Each space contains a corresponding pump inside the cabinet, thus a compact size cabinet is used to supply multi-spaces.


Installation Requirements

        1. PETRA Dry Cooler (PDC) outdoor unit
        2. PETRA Water Source (PWSP) indoor units
        3. Pumping cabinet
        4. Water pipes (supply and return between indoor and outdoor), could be pex-pipe (recommended) or black steel or other proper pipes