Combined Direct and Indirect Evaporative Air Coolers

MasterFormat Division 23 76 19: Combined Direct and Indirect Evaporative Air Coolers

As energy costs rise and environmental concerns grow, the demand for sustainable cooling solutions is increasing. Combined direct and indirect evaporative air coolers, classified under MasterFormat Division 23 76 19, offer an energy-efficient alternative to traditional air conditioning systems, especially in dry and semi-arid climates.

What is a Combined Direct and Indirect Evaporative Air Cooler?

A combined direct and indirect evaporative air cooler, also known as a two-stage evaporative cooler, is a cooling system that utilizes both direct and indirect evaporative cooling principles to lower air temperatures. It combines the high efficiency of direct evaporative cooling with the ability of indirect evaporative cooling to cool air without adding humidity.

How Does a Combined Direct and Indirect Evaporative Air Cooler Work?

These coolers operate in two stages:

1. Indirect Evaporative Cooling: In the first stage, warm outdoor air passes through a heat exchanger. Water is evaporated on one side of the exchanger, cooling the air on the other side without adding moisture. This pre-cooled air then enters the second stage.
2. Direct Evaporative Cooling: In the second stage, the pre-cooled air passes through a wetted media pad. Water evaporates directly into the airstream, further cooling the air and adding some humidity.

This two-stage process results in cooler air temperatures compared to direct evaporative coolers alone, while still maintaining a more comfortable humidity level than traditional air conditioning.

Where are Combined Direct and Indirect Evaporative Air Coolers Commonly Used?

Combined direct and indirect evaporative air coolers are particularly effective in climates with low to moderate humidity levels. Common applications include:

• Commercial buildings
• Industrial facilities
• Schools and universities
• Hospitals
• Data centers
• Greenhouses

What are Installation Best Practices for Combined Direct and Indirect Evaporative Air Coolers?

Proper installation is crucial for optimal performance and longevity of these systems. Key best practices include:

• Sizing: Accurately determine the cooling load of the space to select the correct size and capacity unit
• Location: Choose a location with adequate fresh air intake and exhaust capabilities
• Ductwork: Design and install efficient ductwork to ensure proper airflow distribution
• Water Quality: Implement a water treatment system to prevent mineral buildup and maintain efficiency
• Maintenance: Establish a regular maintenance schedule, including media pad replacement, cleaning, and system checks

What are the Top Manufacturers for Combined Direct and Indirect Evaporative Air Coolers?

Several reputable manufacturers specialize in combined direct and indirect evaporative air coolers, offering a range of sizes and features. Some prominent names include:

• Baltimore Aircoil Company (BAC)
• Climate Technologies (Brands include: Evapco, DRI)
• SPX Cooling Technologies (Brands include: Marley, Recold)
• Johnson Controls
• Carrier

Conclusion

As energy efficiency and sustainability become increasingly important, combined direct and indirect evaporative air coolers offer a compelling solution for various applications. By understanding their functionality, suitable applications, and installation best practices, building owners and facility managers can make informed decisions to optimize their cooling systems and reduce their environmental footprint.