High-density polyethylene (HDPE) plastic cooling towers, used in U.S. industrial sectors for a number of years, are most recently finding a niche internationally, notably with installations at two projects in the Middle East.
In recent months, HDPE cooling towers made by Rockaway, N.J.-based Delta Cooling Towers have been integrated into a solar-powered cooling project underway in Abu Dhabi, United Arab Emirates as well as a water-treatment project in Jenadriyah, the heritage and cultural city located in the Riyadh province of Saudi Arabia.
The Abu Dhabi project is a pilot program meant to bring rooftop air conditioning to the city’s Transmission & Despatch Co. (TRANSCO) via concentrated solar panels to provide energy to the building’s air-conditioning system during peak demand hours.
Heat and humidity
"Essentially, the project is using solar power to produce cold water for air conditioning," says Mohammad Alkarmi, CEO of Limitless International Corp. of Raleigh, N.C., the exporting organization that sold the towers and an authorized agent for Delta Cooling Towers in the Middle East.
"We believe that this cooling tower technology is ideal for cooling applications in the Middle Eastern countries, where very high temperatures and high humidity — especially in the gulf region — would prevent most metal cooling towers from lasting very long because they would rust and corrode easily," Alkarmi says.
The Abu Dhabi National Energy Co. and Chromasun Inc., a San Jose, Calif.-based solar panel manufacturer, installed 27 solar panels on TRANSCO’s rooftop in Abu Dhabi. TRANSCO is a subsidiary of Abu Dhabi Water & Electricity Authority (ADWEA).
The system is meant for rooftop application and operation in high temperatures and dusty conditions.
"Essentially, they are simply using the hot water that is coming from the solar panels to get cold water from the chiller," Alkarmi explains. According to TAQA, besides significant energy savings, the rooftop solar cooling technology has great potential for peak shaving, for reduced emissions and better grid efficiency.
Long-term reliability
"The HDPE plastic cooling tower will never rust or corrode, as opposed to either stainless steel or galvanized metal clad models, which will eventually rust and corrode," Alkarmi says. "The Delta HDPE design does not require any coating or galvanizing or other exterior protection. It simply will never rust or corrode, and will last well over 20 years."
In fact, the manufacturer recently increased the warranty period from 15 to 20 years. Some metal-clad cooling towers are guaranteed for only two or three years, after which they require sizable maintenance and or replacement investments.
"The low maintenance requirements and long-term operating lifespan make the HDPE models highly appropriate for the atmospheric conditions of the Middle East, especially in the UAE, Saudi Arabia and Qatar, where the weather is extremely hot and humid," Alkarmi adds.
Limitless International also recently supplied a new HDPE cooling tower to a reverse osmosis (RO) water treatment plant in Jenadriyah, Saudi Arabia.
Cooling towers can be an important element in water and wastewater treatment applications because microorganisms used in the treatment process can be compromised when water temperatures get too warm. Cooling towers are a viable alternative to cooling water in tanks and ponds, which may be unavailable in dry climates.
