MARLEY MIDDLE EAST AIR COOLED AND WATER COOLED chiller STUDY (1998)

This study was carried out for the Marley Cooling Tower Company, Kansas City USA, to highlight the critical issues determining the use of air-cooled or water-cooled liquid chilling units in the Middle East. The Marley Middle East Study is best summarized from an extract from our Client’s monthly newsletter-the MESA Momentum, Feb 2000 issue.

Quote “It’s 125 degrees F and you want to do what with our water?”

I In the U.S., perhaps as much as 95% of commercial air-conditioning systems are water-cooled. In the Middle East, the percentage is about that high for air-cooled systems.

Most of us know that water is a more efficient cooler than is air. At Marley, we were interested to know more about the comparison, to know what drove the Middle East market. We were unable to find objective literature on the subject. In late 1998, we decided to commission a comparative study.

We decided to compare systems in two sizes, 500 and 1000 tons, in the context of Dubai.

At Mario’s suggestion, we added to the scope a survey of air conditioning consulting engineers in the Arab Gulf in order to learn their perceptions of the two systems.

We emphasized to Mario that we wereinterested in objective findings and sent him on his way.

Mario started by doing research for related studies. He then sketched the two hypothetical locations: the 500-ton as a rooftop of a 14-storey office building and the 1000-ton as a ground level, remote a/c plant for a business park. He contacted major chiller makers for their equipment selection and proposals. He made layout drawings for four installations: 500 tons both air and water-cooled and the same for 1000 tons. He made four sets of schematics for estimating piping and electrical materials. He compiled take-off quantities and then retained Gulf contractors to do material estimating and maintenance proposals.
He calculated the water consumption and solicited local water treatment companies for proposals. He subcontracted a sound consultant to select and price attenuation to equalize the roof top alternatives. He retained a marketing firm to carry out the survey of consulting engineers. Finally, Mario did life cycle cost analyses, comparing the 15-year cost for air and water systems at the two different capacities.

Mario’s study revealed that air cooled systems in both sizes enjoyed advantages in purchase price, plan area and maintenance costs. And, of course, the water consumption was zero for the air-cooled systems versus ‘substantial’ for the water-cooled. However, in both sizes those differences were more than compensated by energy savings available from the water-cooled systems. In general, the 500-ton water-cooled system paid back for its other costs after five years of operation and the 1000-ton after three years or less.

Marley shared the findings with their representatives in the Arab Gulf and suggested the idea of a local seminar. Each one accepted enthusiastically. Marley commissioned Mario to adapt the study for water and electricity costs the other five territories.

Starting in October, Marley presented a series of seminars hosted by:
Faisal Jassim Trading Co., Dubai, U.A.E.

• Adearest/Sleiman Group, Abu Dhabi, U.A.E.
• Nouri Industrial Establishment, Kuwait,
• Mohammed Jalal & Sons, Bahrain,
• Masdar, Comm’l. Supply Div. of CIDC,
  Saudi Arabia,
• Bahwan Engineering Co., Oman.

Every representative did highly professional work:

Promoting the subject of the seminar, Assuring the attendance of influential consultants, users and contractors, Hosting the seminar in a five-star facility and following it with a buffet lunch or dinner.

Marley,.for.its.part:
Arranged for the seminar material in PowerPoint format, added seminar segments on cooling tower fundamentals, Marley Ozone, Marley Controls and Clearflow, Provided handout copies of the presentation on compact disk for each territory, Traveled to each office for preparation, seminar presentation and follow-up.

Much of what was covered in the ‘fundamentals’ section came as news to most attendees. Some mythical objections were dispelled. Much was learned in Q&A, by presenter and attendees alike. In the end, there was substantial positive reaction to the subject matter.

We could not have been more pleased with the work done by our Consultant, Mario Seneviratne of Green Technologies or by our six representatives. Now, short weeks after the presentations, we continue to follow up on contacts from the seminar. We are enjoying some warmer receptions as well as some inquiries from first-time sources.