AVX-A – Achelous Air Cooled Screw Chiller

Cooling Capacity from 96 to 548 RT (338 to 1929kW)

The AVX-A Series features:-

●      High Efficiency Vertical Screw Compressors
●      Flooded Shell and Tube Evaporator
●      Advanced Microprocessor Controller
●      Suitable for Standard or High Ambient Application
●      Environmental Friendly
●      AHRI Certified
●      Green Refrigerants

The vertical configuration of the screw profiles guarantees exceptionally low vibration and minimal noise signatures while maintaining optimized internal oil management via an integrated multi-layered mesh element separator. Because the design is hermetic, it completely eliminates casing leakages and eliminates the need for periodic external oil pumps or frequent compressor overhauls.

To maximize thermal performance, the AVX series utilizes a premium flooded shell-and-tube evaporator. Unlike common DX (Direct Expansion) evaporators where refrigerant flows unevenly through small tubes, the flooded system submerges highly conductive, inner-finned copper tubes directly into a pool of liquid refrigerant. This design achieves excellent approach temperatures and maximizes heat transfer coefficients. The structural footprint features a space-saving V-coil condenser profile that maximizes air passage across the multi-slit aluminum fins, allowing the chiller plant to maintain a very compact footprint.

Key Technical Highlight Matrix

Core Functions of the Dunham Bush AVX Series

• Integrated Economizer Loop Operation: Liquid refrigerant passes through an internal sub-cooling economizer circuit before entering the evaporator. The resulting flash gas is injected directly into an intermediate port on the vertical screw compressor, significantly increasing overall cooling capacity and lowering kilowatt draw per ton.

• Infinite Slide Valve Capacity Modulation: Utilizes a rugged, hydraulically actuated slide valve mechanism that continuously adjusts the compressor loading from $100\%$ down to low part-load capacities. This system matches your facility's real-time cooling demands without causing frequent motor restarts.

• VFD Compressor/Fan Control Options (AVX-B): Optional variable speed inverter integration on both the main screw motors and the EC condenser fans allows the system to adjust dynamically to changing conditions. This technology elevates part-load energy efficiencies (IPLV) during rainy spells or cooler evening shifts.

• Advanced Safety and Fault Mitigation: The Vision microprocessor continuously monitors critical parameters, including oil pressure levels, phase balancing, freeze conditions, and discharge temperatures. It triggers preventative safety steps before mechanical damage can occur.

Industrial Importance in Bangladesh

1. Government Institutes & Strategic Public Assets

Large-scale public installations—such as automated database centers, regional secretariats, public medical college facilities, and air transport buildings—require steady cooling but often operate in areas with constrained water infrastructure.

• Eliminates Water Resource Strain: Operating entirely on an air-cooled heat rejection loop, the AVX series requires no water evaporation or cooling tower replenishment. This protects local municipal groundwater grids from heavy operational drawdowns.

• True Mechanical Redundancy: Multi-compressor models are built with entirely independent refrigerant systems per compressor. If one circuit undergoes planned maintenance, the secondary circuit runs continuously, keeping critical public operations online.

2. Private Sector Enterprises, RMG Mills & Commercial Complexes

For manufacturing and business operations—such as high-density textile plants, automated pharmaceutical production lines, and commercial high-rises in Dhaka or Chittagong—cooling downtime directly impacts profitability.

• High-Ambient Operational Stability: Designed and tested to operate smoothly in ambient temperatures reaching up to $52^\circ\text{C}$ ($125^\circ\text{F}$), the AVX series prevents thermal trip faults during peak Bangladeshi summer heat waves.

• Cleanable Evaporator Layout: The flooded evaporator features cleanable copper tubes and fully removable water heads. Maintenance personnel can easily brush away mineral scale left behind by local groundwater without needing to dismantle the main refrigerant lines.

Why Buy From Bhai Bhai Engineering?

Procuring a high-tonnage central chiller plant requires experienced technical support. Bhai Bhai Engineering provides comprehensive HVAC sourcing and engineering services in Bangladesh:

• Verified Authentic OEM Systems: We deal directly with authorized manufacturing channels, delivering 100% genuine, factory-tested Dunham Bush equipment with verifiable serial tracking.

• Experienced On-Site Commissioning: Our engineering team assists throughout structural verification, structural frame anchoring, pipeline alignment, flow balancing, and initial start-up phases.

• Transparent Local Commercial Proposals: We provide clear, upfront pricing in Bangladeshi Taka (BDT) with no hidden logistics charges, designed to integrate smoothly into formal corporate budgets and public tenders.

• Long-Term Preventive Maintenance Support: We keep critical consumables, electronic expansion modules, and original microprocessor parts locally in stock to prevent costly factory production delays.

Contact Us for a Quotation

Upgrade your facility's central cooling infrastructure with an efficient, reliable air-cooled screw chiller system. Contact our technical sales desk in Dhaka today to receive a detailed commercial quotation and technical drawings tailored to your project.

• Head Office Address: Podirdia, Khilbarirtek, Vatera, Dhaka-1212. (Nur-E-Madina Mosjid Complex)

• Sales Hotlines / WhatsApp: +8801722039029

• Corporate Email: bhaibhaiengineering51@gmail.com

• Engineering Platform: https://www.bhaibhaiengineering.com/

Frequently Asked Questions (FAQs)

Q1: Why is a flooded evaporator better than a standard direct expansion (DX) evaporator for large installations?

Ans: In the AVX flooded evaporator, the conductive copper tubes are completely submerged in liquid refrigerant. This design achieves significantly better approach temperatures and higher heat exchange rates, reducing the energy required by the compressor to hit target chilled water temperatures.

Q2: Can the Dunham Bush AVX series handle the severe summer heat waves in Bangladesh?

Ans: Yes. The AVX-A and AVX-B lines are specifically rated for high-ambient applications, maintaining continuous operation in outdoor environments up to $52^\circ\text{C}$ ($125^\circ\text{F}$) without triggering thermal high-pressure safety cutouts.

Q3: Does the AVX series require periodic compressor teardowns and overhauls?

Ans: No. The Dunham Bush vertical screw compressor features a hermetic, direct-drive design that eliminates external drive gears and mechanical shaft seals. This design prevents refrigerant leakage and eliminates the need for routine internal overhauls, with many units running past 100,000 hours reliably.

Q4: How does the system handle sudden power quality drops or voltage fluctuations?

Ans: The advanced integrated Vision controller actively monitors incoming phase symmetry, under-voltage conditions, and current overloads. If grid power fluctuates beyond safe margins, the system executes a protective safety shutdown and restarts automatically once power stabilizes.