Dunham Bush DMAR-H Series Hot Water Absorption Chiller

Cooling Capacity from 120 – 2646RT ( 422 – 9305kW)

The DMAR-H 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-H Series Absorption Chiller represents the pinnacle of modern waste-heat utilization (waste-to-cooling technology) for large commercial and industrial complexes. In standard industrial facilities across regions like Gazipur, Savar, and Chittagong, captive gas generators or production boilers throw off massive amounts of thermal energy in the form of high-temperature exhaust and hot water. Typically, this heat is simply dumped into the atmosphere. The DMAR-H captures this otherwise lost energy, passing the waste hot water through an advanced internal heat exchanger to generate cold water for central air conditioning or industrial processing—all while drawing near-zero electricity from the grid.

Because the chemical refrigeration process takes place within a deep vacuum envelope, water acts as the natural green refrigerant, boiling at remarkably low temperatures (around $4.5^\circ\text{C}$). The concentrated Lithium Bromide ($LiBr$) salt solution acts as a powerful non-toxic chemical sponge, drawing in the chilled water vapor. The incoming industrial waste hot water is then introduced into the system's generator chamber to separate the water from the salt solution, allowing the loop to run continuously. Since the entire machine requires electricity only for small fluid circulation pumps instead of a massive mechanical motor, its operational power footprint is practically negligible.

To ensure long equipment life and uniform thermodynamic performance, the DMAR-H features an automated multi-level anti-crystallization framework. If sudden power dips or temperature shocks hit the external hot water feed lines, the chiller’s automated dilution valves adjust internal fluid concentrations instantly, keeping the chemistry flowing safely. Combined with an automated high-capacity air purging system, the internal vacuum stays perfectly clean and completely free of corrosive oxygen pockets, maximizing operational uptime.

Key Technical Highlight Matrix

Core Functions of the Dunham Bush DMAR-H Series

• Waste-Heat-to-Cooling Conversion: Captures unneeded hot water streams from factory processes and converts them into heavy-duty chilled water for central air distribution.

• Advanced Gravity Drip Distribution: Drops the internal $LiBr$ solution across the tubes using a high-efficiency gravity dripping setup, creating a consistent liquid film that maximizes internal heat exchange.

• Automated Vacuum Shielding: Runs a continuous, automated vacuum purge to isolate and expel non-condensable gases, keeping heat-transfer surfaces clean and highly efficient.

• Variable Fluid Interlocking (VFD Control): Features integrated variable-frequency drives on the internal solution pumps to adjust fluid flow in real time based on changing building loads, cutting energy use during off-peak hours.

Strategic Importance Across Bangladesh

1. Government Infrastructure, Cogeneration Plants & Eco-Projects

Public sector developments—including national power distribution plants, large public medical teaching complexes, and eco-certified municipal buildings—must meet strict green energy and fuel-efficiency standards.

• Maximizes Captive Generation Efficiency: Government infrastructure running local gas-fired or biomass generators can use the DMAR-H to capture jacket water heat, significantly raising the facility's overall fuel utilization efficiency.

• Reduces National Grid Peak Loads: Shifting high-tonnage central hospital or office air conditioning demands away from electric motors protects the local power grid from high-ambient summer overloads.

2. Private Garment Factories (RMG), Green Textile Mills & Chemical Plants

For Bangladesh's export-driven Ready-Made Garment (RMG) factories and green LEED-certified textile mills, lowering the cost per yard of fabric is crucial for staying competitive globally.

• Near-Zero Operational Cost Cooling: By using existing waste hot water from local gas generators to power your facility's central cooling, your monthly HVAC energy bills drop close to zero.

• Earns Premium International Sustainability Points: Installing a waste-heat recovery absorption chiller helps factories achieve high scores on international green building frameworks, making your facility a preferred supplier for top global brands.

Why Buy From Bhai Bhai Engineering?

Procuring, designing, and commissioning a high-capacity hot water absorption chiller requires specialized industrial engineering expertise. Bhai Bhai Engineering delivers professional HVAC project management across Bangladesh:

• Direct OEM Import Guarantee: We deal directly with authorized Dunham Bush global manufacturing tracks, supplying 100% genuine, brand-new equipment complete with verified serial numbers and original factory warranties.

• Turnkey Industrial Integration: Our experienced local engineering team manages the complete installation—including hydraulic balancing, generator jacket water loop integration, cooling tower setup, and precision water treatment lines.

• Transparent Local BDT Pricing: Avoid unexpected financial surprises from shifting import duties or logistics. We provide clear, comprehensive upfront pricing proposals in Bangladeshi Taka (BDT) structured for corporate boards or government procurement reviews.

• Long-Term Chemical & Vacuum Maintenance Support: Absorption systems require precise fluid chemistry. We provide local, factory-trained technicians to handle annual $LiBr$ solution testing, corrosion inhibitor adjustments, and vacuum pump balancing to maximize your chiller's working life.

Contact Us for a Quotation

Turn your industrial waste heat into free central air conditioning. Contact our specialized industrial sales engineering desk in Dhaka today to get a detailed commercial proposal and technical product data sheets based on 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 does a hot water absorption chiller create cold water without electricity?

Ans: It replaces the electric motor compressor with a thermal chemical cycle. Inside a deep vacuum chamber, water boils at an extremely low temperature and absorbs heat from your building's cooling loop. A concentrated Lithium Bromide liquid salt solution absorbs this water vapor, and your factory's waste hot water is used to boil the water out of the salt solution so the cycle can repeat continuously.

Q2: What temperature does the waste hot water need to be to run the DMAR-H?

Ans: The Dunham Bush DMAR-H series is engineered to operate efficiently using industrial hot water streams typically ranging from $180^\circ\text{F}$ to $210^\circ\text{F}$ ($82^\circ\text{C}$ to $99^\circ\text{C}$), which aligns perfectly with standard gas generator jacket cooling outputs.

Q3: Does this chiller require an outdoor cooling tower loop?

Ans: Yes. Because an absorption chiller must dissipate heat from both its internal refrigeration cycle and the hot water energy source, it requires a steady outdoor cooling tower loop to manage the thermal load.

Q4: What happens if the factory generators go offline and the hot water stream stops?

Ans: The DMAR-H features an integrated microprocessor control panel that constantly monitors incoming hot water temperatures. If the hot water stream stops or drops below operating thresholds, the system safely modulates internal valves and goes into a automated dilution run to prevent crystallization, waiting safely for the heat source to return.