HMX DAMA Heat Exchanger and Indirect Evaporative Cooling: Understanding the Technology

DAMA is the core technology behind HMX's entire range of Indirect Evaporative Cooling systems, including the IDEC, Treated Fresh Air unit and Hybrid AHU. Understanding how DAMA works helps explain why HMX systems deliver energy efficient, dependable cooling across industrial and commercial buildings in more than 10 countries. This article explains what DAMA is, how it functions, and answers the long tail questions engineers and facility managers commonly ask about this patented heat exchanger.

What Is DAMA?

DAMA stands for Dry Air and Moist Air. It is a patented, cross flow, plate type polymeric heat exchanger optimised for Indirect Evaporative Cooling, where water is used as the refrigerant instead of conventional gases. DAMA is modular and scalable, used in systems ranging from 500 CFM for a small room to 2,00,000 CFM for a large industrial facility, and is fouling resistant, corrosion free, light in weight and built for a long service life.

What does DAMA stand for and why does the name matter?

DAMA stands for Dry Air and Moist Air, which describes the two separate air streams flowing through the exchanger: a dry primary air stream that becomes the cooled supply air, and a moist secondary air stream that carries the heat away. Keeping the two streams physically separate is what allows DAMA to cool air without adding moisture to it.

How Does the DAMA Heat Exchanger Actually Cool Air?

The primary air stream flows through the horizontal dry passages of DAMA. A secondary air stream, wetted with a thin film of water, flows through the adjacent wet passages. As the warm primary air moves through the dry channel, it loses heat through the thin separating wall to the water evaporating in the wet channel, and the primary air is cooled sensibly, meaning its temperature drops without any change in its moisture content. This is a straightforward heat transfer process, driven by the evaporation of water, that requires only fans and pumps rather than a refrigerant compressor.

How efficient is the DAMA heat exchanger?

DAMA's efficiency ranges from about 50 percent to 80 percent, depending on the wet bulb depression, meaning the difference between the dry bulb and wet bulb temperature of the incoming air, which typically ranges from 5 to 14 degrees Celsius and above in Indian conditions. The larger the wet bulb depression, the greater the cooling DAMA can deliver.

What Makes DAMA Different From a Conventional Air to Air Heat Exchanger?

Unlike conventional evaporative coolers, whose output weakens as ambient temperature climbs, DAMA's performance actually improves as the dry bulb temperature rises, since a hotter, drier day typically brings a larger wet bulb depression. This means a DAMA based system uses the same amount of power and continues to deliver fresh, cool air inside no matter how hot conditions get outside, a reliability that conventional evaporative pads cannot match.

Can DAMA perform well in warm and humid regions, not just hot, dry ones?

Yes. DAMA can perform efficiently in warm and humid regions using Indirect Evaporative Cooling on its own, and it can also be paired with a smaller chilled water or DX coil to handle the remaining load, giving building owners meaningful energy savings even outside classic hot, dry climates.

Where Is DAMA Used Across HMX's Product Range?

DAMA sits at the core of HMX's Indirect Direct Evaporative Cooling (IDEC) systems for large industrial and commercial spaces, HMX's Treated Fresh Air units that precool outdoor air ahead of existing air handling units, and HMX's Hybrid AHU systems that combine Indirect Evaporative Cooling with conventional air conditioning. Across these product lines, DAMA based systems now cool more than 20 million square feet of space, deploying over 100 million CFM in 10 plus countries.

Is DAMA corrosion resistant and how long does it last?

DAMA is a polymeric, plate type heat exchanger that is corrosion free and light in weight, engineered to resist fouling and to provide a long operating life with minimal maintenance compared with metal based heat exchangers used in some older evaporative cooling designs.

How Is DAMA Sized for a Specific Building or Process?

Sizing a DAMA based system starts with the building's required fresh air volume in CFM, the local design dry bulb and wet bulb temperatures, and the target supply air condition for the space or process. Because DAMA is modular, multiple units can be arranged in parallel or staged with a downstream coil to meet almost any combination of these requirements, from a single small room needing 500 CFM to a large industrial facility needing 2,00,000 CFM or more.

Does DAMA need a continuous water supply, and how much water does it use?

DAMA operates with a recirculating water system fed from a sump, topped up as water evaporates during the cooling process, rather than a continuous fresh water feed. Water consumption is generally modest relative to the cooling delivered and is a standard design input HMX's engineers calculate for each installation based on climate and system capacity.

Want a technical walkthrough of how DAMA can be sized for your building? Reach out to HMX's engineering team for a capacity and layout recommendation.

About HMX

HMX, part of the A.T.E. Group, designs and manufactures energy efficient, environment friendly industrial and commercial cooling systems. Built around DAMA, a patented plate type heat exchanger optimised for Indirect Evaporative Cooling, HMX systems today cool more than 20 million square feet of space across 10 plus countries and serve more than 500 customers, including leading brands such as ABB, Bosch, Coca Cola, Siemens, Tata Motors and Volkswagen. Eight HMX products carry the GreenPro Type 1 Ecolabel certification from the Global Ecolabelling Network, reflecting the company's commitment to low carbon, Net Zero aligned cooling for people and processes.