High Capacity

Fresh Air Cooling

Where outdoor ambient conditions and equipment operating ranges allow it, Fresh Air Cooling is the most energy efficient form of cooling available for Data Centres or high sensible cooling applications. Modern electronic systems are also more tolerant of swings in temperature and humidity making Fresh Air Cooling an option to be considered for heat dumping or recovery in high sensible load facilities. Higher operating room temperatures utilising hot or cold aisle containment provide temperature differentials that now make such systems feasible and economical. The EDPAC High Capacity Fresh Air range includes Direct and Indirect Fresh Air Cooling. Fresh Air cooling can be achieved using:

Enthalpy Managed Mixing (EMM) systems using direct fresh air mixed as required with return air; these systems can be independent or used to complement existing EDPAC close control systems. These systems are available in add-on plenum type or unit type configurations.

Indirect Air to Air (A2A) systems using separated air streams preserve room integrity by allowing full control of the humidity and /or temperature within tightened control bands. These systems can be independent or complemented by existing close control technologies including secondary cooling coils in either direct expansion or chilled water. Refer to the EDPAC Air to Air systems catalogue for further information on Air to Air systems.

System Optimisation:

Optimising cooling within any system requires that the opportunity for free cooling should be maximised. Maximising the indoor room operating temperature means that the available operating temperature differential is optimised. Typical return air temperatures in modern facilities are typically in excess of 30oC and being managed in hot aisle systems within a range of 28 to 47oC. Management of the Supply air path within a temperature range of 26 to 35oC means that a differential to the equipment can be in excess of 12oC or more. These differentials will optimise the system COP for any system regardless of the cooling strategy adopted.

High Capacity

Fresh Air Cooling

Enthalpy Managed Mixing:

Enthalpy Managed Mixing (EMM) systems incorporate a Return Air Management system traditionally referred to as an Economiser type system; these systems include the use of a Fresh Air Damper, Mixing Damper, Supply fan and Dump fan(s). The EMM systems are available as integral systems that can be located within the space along with existing close control systems or mounted on top of an existing downflow close control system in the form of a plenum, should the available height permit.

EMM systems manage the return, supply and fresh air from / to the room. The air is either dumped to atmosphere or other heat recovery process or mixed in with fresh air introduced via the fresh air damper; the dumped air is managed using an array of variable speed high efficiency EC fans. The supply air to the space is managed using variable speed high efficiency EC fans; this supply air is mixed air incorporating a variable percentage of the return air and fresh air to achieve the required system volume. System components include:

Supply air EC fan to manage the room pressure and / or temperature as required.

Dump air EC fan to manage the proportion of air dumped to atmosphere or to heat recovery.

Fresh Air damper controlling the level of fresh air introduced to the mixed air stream.

Mixing damper to control the proportion of the Return and Fresh air streams to achieve the required supply air temperature to the controlled space.

System controller that monitors the condition of Fresh air and Return Air to optimise the supply air conditions to the controlled space.

In plenum fresh air systems, the controller is integrated with the main unit controller to form an integrated cooling solution with backup or boost management as required.

General Features:

All EDPAC systems utilise the highest quality components; many of which are readily available worldwide. All of our products incorporate the following:

EC backward curved centrifugal fans offering super premium efficiency motors, low Specific Fan Powers and fan selections well below their nominal capacities.

High Capacity

Fresh Air Cooling

EC fans that can either be located within the unit OR suspended from the unit under the raised floor.

Cabinets that are not only robust, but constructed from powder coated pre-treated steel.

Control systems that allow local system management and optimisation, BMS communication and redundancy control.

High system COP’s as the controllers manage the airflows (fan speed) and seek to optimise the available cooling based on prevailing conditions.

Inherent system resilience, due to the fan speed selection at low (part) loads thus allowing fans to ramp to 150% of design air volumes. Set-point management both locally and remotely allows system capacity to be temporarily increased in the event of a critical failure.

Fan speed control to manage space pressurisation or temperature as required.

Backdraft dampers for non-operating systems can also be incorporated.

Fresh Air Systems – General Engineering Data

Model – DECPFxxBN00S 06 08 12 16 20 24 28 32

Full Fresh Air Unit

Width mm 650 850 1250 1650 2050 2450 2850 3250

Depth mm 650 850 850 850 850 850 850 850

Height mm 1980 1980 1980 1980 1980 1980 1980 1980

Plenum Systems

Width mm 650 850 1250 1650 2050 2450 2850 3250

Depth mm 650 850 850 850 850 850 850 850

Height (w/ Exhaust Fans) mm 1000 1000 1000 1000 1000 1000 1000 1000

Height (no Fans) mm 800 800 800 800 800 800 800 800

System Capacity

Airflow - m3/s 1.7 2.4 3.8 5.1 6.5 7.9 9.3 10.7

kW Sensible @ 10oC ΔT 21 29 46 62 79 95 112 129

kW Sensible @ 12oC ΔT 25 35 55 75 94 114 135 155

kW Sensible @ 14oC ΔT 29 41 64 87 110 133 157 181

Notes: a) Capacities shown are gross – deduct fan absorbed power to achieve net capacity. b) Systems are assumed as Downflow with EC fans. c) Systems include return air grills and selected filtration. d) Capacity data is based on Air density of 1.2kg/m3