Dunham Bush DMAR-D Series Direct Fired Absorption Chiller

Cooling Capacity from 150 – 2000RT (528 – 7034kW)
Heating Capacity from 120 – 1600RT (422 – 5627 kW)

The DMAR-D features:

• Energy-efficient evaporative absorption design
• Advanced gravity drip technology
• Fully automatic air purging system
• Multilevel anti-crystallization system
• VFD (Variable Frequency Drive) control system
• Professionally engineered structural integrity
• Intelligent advanced monitoring system

The Dunham Bush DMAR-D Series Absorption Chiller represents a paradigm shift for large-scale industrial facility engineering in environments facing high electricity rates or unstable power grids. Traditional central air conditioning systems rely on electric centrifugal or screw chillers that draw enormous amounts of electricity to run mechanical compressors. During the hot summer months, these electric HVAC systems can account for up to 40% to 60% of a facility's entire electricity bill. The DMAR-D completely bypasses this issue by substituting mechanical compression with a highly advanced thermally driven chemical absorption cycle.

At the core of the DMAR-D is a double-effect refrigeration loop that utilizes water as the eco-friendly refrigerant and Lithium Bromide ($LiBr$) as the non-toxic absorbent. The process begins in the high-temperature generator, where a high-efficiency direct burner combusts natural gas, LPG, or diesel to boil the diluted $LiBr$ solution. This releases high-pressure water vapor, which moves into a series of heat exchangers to cool your building's chilled water loop down to a precise $44^\circ\text{F}$ ($6.7^\circ\text{C}$). Because the system only requires small fluid pumps instead of a giant compressor motor, the chiller's total electrical footprint is remarkably small, requiring only a fraction of the power used by traditional electric chillers.

To maintain optimal efficiency over a long service life, the DMAR-D features an integrated auto-purge mechanism. This automated system continuously extracts non-condensable gases from the vacuum shell, preventing interior corrosion and maintaining the deep internal vacuum required for top thermodynamic performance. The system is managed by an advanced microprocessor controller that automatically modulates the fuel burner flame to match real-time building cooling demands, ensuring maximum fuel economy.

Key Technical Highlight Matrix

Core Functions of the Dunham Bush DMAR-D Series

• Thermally Driven Chilled Water Production: Generates high-volume chilled water loops for central air conditioning by directly burning gas or liquid fuels, bypassing the need for an electric compressor.

• Double-Effect High Efficiency Cycle: Utilizes a dual-generator structure (high and low temperature) to recapture internal thermal energy from the first stage, maximizing cooling output per unit of fuel consumed.

• Simultaneous Cooling and Heating Output: Highly flexible configuration options allow the DMAR-D to supply chilled water for air conditioning and hot water for industrial processes or heating at the same time.

• Proactive Vacuum Maintenance: The high-efficiency automated purging loop continuously cleans the internal vacuum chamber during operation, protecting internal tubes from oxidizing and keeping heat transfer high.

Strategic Importance Across Bangladesh

1. Government Institutes, Public Infrastructure & High-Security Complexes

State-run properties—including major public hospitals, international airport terminals, defense communication headquarters, and government administrative secretariats—require deep, non-stop central cooling that cannot fail during local power grid outages.

• Reduces Strain on the National Grid: By using natural gas or diesel instead of massive electrical connections, public infrastructure projects can free up megawatts of power for surrounding residential communities.

• Uninterrupted Backup Cooling Security: Since the chiller runs on direct fuel combustion, critical operations like hospital operating rooms and data centers can maintain full central cooling using backup diesel lines, even during total electrical grid blackouts.

2. Private Garment Factories (RMG), Heavy Industry & IPP Power Plants

For Bangladesh's massive Ready-Made Garment (RMG) textile spinning floors, pharmaceutical processing zones, and large commercial shopping developments, managing monthly operational utility costs is vital for profitability.

• Substantial Monthly Financial Savings: Facilities with dedicated natural gas connections can generate central cooling at a fraction of the cost of peak-rate electricity, significantly lowering monthly manufacturing overhead.

• Ideal for Tri-Generation and Industrial Plant Balancing: For factories running local gas generator setups, the DMAR-D can be integrated into a tri-generation strategy, balancing energy usage and maximizing fuel efficiency across the entire facility footprint.

Why Buy From Bhai Bhai Engineering?

Installing and maintaining a double-effect direct-fired absorption chiller requires specialized engineering expertise. Bhai Bhai Engineering provides comprehensive, professional industrial HVAC support across Bangladesh:

• Verified Authentic OEM Equipment: We source directly from authorized global Dunham Bush manufacturing networks, delivering brand-new equipment complete with verified factory certificates and clear serial numbers.

• Turnkey Industrial Mechanical Execution: Our experienced local engineering team manages the entire project—from rigging and placing the heavy chiller shells to installing fuel lines, cooling tower integration, and advanced water treatment systems.

• Transparent Local BDT Project Quotations: Avoid unexpected currency shifts or hidden import fees. We offer detailed, transparent financial proposals in Bangladeshi Taka (BDT) tailored to clear corporate reviews or public tender requirements.

• Long-Term Specialist Maintenance Support: Absorption chillers require precise vacuum maintenance and chemical balancing. We provide specialized local technicians trained to manage $LiBr$ solution testing, vacuum purging, and burner tuning to maximize your system's life.

Contact Us for a Quotation

Optimize your industrial utility balance with elite, fuel-driven absorption cooling technology. Contact our specialized industrial sales engineering desk in Dhaka today to receive a detailed commercial proposal and technical product data sheets tailored to your facility's layout configurations.

• Corporate Headquarters: Podirdia, Khilbarirtek, Vatera, Dhaka-1212. (Nur-E-Madina Mosjid Complex)

• Sales & Project WhatsApp: +8801722039029

• Corporate Mailbox: bhaibhaiengineering51@gmail.com

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

Frequently Asked Questions (FAQs)

Q1: How can an absorption chiller create cold water using a fire burner heat source?

Ans: It uses a specialized chemical vacuum process. Inside a deep vacuum, water boils at a very low temperature (around $40^\circ\text{F}$ / $4.5^\circ\text{C}$), absorbing heat from your building's water loop. The concentrated Lithium Bromide solution then absorbs this water vapor, and the direct fuel burner is used to boil the water out of the solution so it can condense and repeat the cycle.

Q2: Does this chiller require a separate outdoor cooling tower?

Ans: Yes. A direct-fired absorption chiller rejects heat from both the refrigeration cycle and the fuel burner. Because of this, it requires a cooling tower water line connected to the condenser and absorber sections to dissipate that thermal load into the outside air.

Q3: Can the DMAR-D chiller run on multiple types of fuel?

Ans: Yes. The Dunham Bush DMAR-D series can be equipped with specialized multi-fuel burners. This allows the system to switch between natural gas, LPG, or light diesel fuel depending on seasonal availability or fuel costs in Bangladesh.

Q4: What special maintenance do absorption chillers require compared to electric chillers?

Ans: Electric chillers require compressor motor and oil checks. Absorption chillers have no large moving parts, meaning mechanical wear is very low. Instead, maintenance focus shifts to maintaining a strict internal vacuum via the auto-purge system and performing annual testing of the Lithium Bromide solution to prevent internal corrosion and check inhibitor levels.