01/2009

Innovations for

Existing Plants

contacts

Jared Ciferno

Technology Manager

National Energy Technology

Laboratory

626 Cochrans Mill Road

P.O. Box 10940

Pittsburgh, PA 15236-0940

412-386-4822

jared.ciferno@netl.doe.gov

Barbara Carney

Project Manager

National Energy Technology

Laboratory

3610 Collins Ferry Road

P.O. Box 880

Morgantown, WV 26507

304-285-4671

barbara.carney@netl.doe.gov

Ken Mortensen, PE

Principal Investigator

Technical Director, Water 

Resources

SPX Cooling Technologies

7401 West 129th Street

Overland Park, KS 66213

913-664-7723

ken.mortensen@spx.com

Improvement to Air2Air® Technology

to Reduce Fresh-Water Evaporative

Cooling Loss at Coal-Based

Thermoelectric Power Plants

ProMIS/Project No. :DE-NT0005647

Background

The production of electricity requires a reliable, abundant, and predictable source 

of freshwater - a resource that is limited in many parts of the United States and 

throughout the world. The process of thermoelectric generation from fossil fuels 

such as coal, oil, and natural gas is water intensive. According to the 2000 U.S. 

Geological Survey, thermoelectric-power withdrawals accounted for 48 percent of 

total water use, 39 percent of total freshwater withdrawals (136 billion gallons per 

day) for all categories, and 52 percent of fresh surface water withdrawals.

As a growing economy drives the need for more electricity, demands on freshwater 

supplies for thermoelectric power generation will also grow. However, electric 

utilities will have to compete with demands from other off-stream use sectors, 

such as public supply, domestic, commercial, irrigation, industrial, and mining. 

In addition, the need to leave water in streams and rivers to achieve environmental, 

ecological, and recreational goals will further complicate the future allocation of 

the nation’s freshwater resources. As such, the availability of adequate supplies 

of freshwater to produce electricity as well as the potential impact of power plant 

operations on freshwater quality are receiving increased attention.

Description

The Air2Air® involves contacting warm, wet air from the cooling tower with 

relatively drier and cooler ambient air. This is done in an air-to-air heat exchanger 

made up of plastic sheets with two discreet air pathways. As the warm, moist air 
from the tower is cooled, water condenses out and is collected. This water is very 

high quality and can be used either as an offset to cooling water or in another 

application where high quality water is needed, thus offsetting water treatment costs. 

The Air2Air® also acts as plume abatement for the cooling tower.

SPX Cooling Technologies is presently investigating the Air2Air® for evaporative 

cooling towers (Figure 1) under the U.S. Department of Energy (DOE) Grant No. 

DE-FC26-06NT42725. The preliminary findings from the research are encouraging 

in that the basic principles behind the technology are sound and the water savings 

are substantial. However, in the course of executing this project, construction costs 

of the validation cell (Figure 2) exceeded expectations. To be economically viable, 

more research is required to develop an efficient heat transfer pack and redesign the 

overall geometry of the tower including pack orientation and superstructure. 

Primary Project Goal

The primary objective is to further enable Air2Air® to become a commercially 

viable water saving technology by solving issues of economy as they relate to 

cooling tower superstructure volume, pack cost, ducting details, heat transfer pack 

efficiency, and watertight wet path seals.

PARTNERS

SPX Cooling Technologies

Diagram of Air2AirTM Water Conservation Cooling Tower
Objectives

The specific technical objectives to support the goal of increasing the commercial 

viability of the Air2Air® technology include:

•	 Increase the efficiency of the heat transfer pack.

•	 Ensure that wet path seals are watertight to allow for non-vertical pack module

orientations.

•	 Design a shorter Air2Air® cooling tower, thus significantly reducing capital

expenditures.

•	 Design a simpler duct configuration to reduce material and labor costs.

Benefits

The implementation of Air2Air® technology on existing cooling towers (retrofit) 

and new cooling towers would reduce freshwater consumption by thermoelectric 

power plants. Water savings could be expected to range from 15 to 25 percent, 

which for a typical 300 MW power plant would be approximately 600,000 gallons 

per day. In the case of salt-water cooling towers, high quality freshwater could be 

generated for other uses.

Planned Activities

•	 Design a new cooling tower configuration including plenum, support, and ducting

design to improve material and labor costs.

•	 Determine a surface treatment for the heat transfer surfaces to enhance heat

transfer.

•	 Adjust sheet spacing to optimize the balance between heat transfer and pressure

drop.

•	 Investigate wet path seal technology to develop more effective seals.

PERIOD OF 

PERFORMANCE

10/01/08 to 12/31/10

Cost 

Total Project Value

$815,083

DOE/Non-DOE Share

$652,066 / $163,017
Project520.indd

•	 Identify one to three sealing methods.

•	 Design the tooling/machine required for the heat exchanger.

•	 Send tooling design to vendor.

•	 Test adequacy of tube seals.

•	 Determine thermal performance of test pack at SPX Research and Development

Center.

Address

National Energy 

Technology Laboratory

1450 Queen Avenue SW

Albany, OR 97321-2198

541-967-5892

2175 University Avenue South

Suite 201

Fairbanks, AK 99709

907-452-2559

3610 Collins Ferry Road

P.O. Box 880

Morgantown, WV 26507-0880

304-285-4764

626 Cochrans Mill Road

P.O. Box 10940

Pittsburgh, PA 15236-0940

412-386-4687

One West Third Street,

Suite 1400

Tulsa, OK 74103-3519

918-699-2000

Customer Service

1-800-553-7681

Website

www.netl.doe.gov

Air2Air Validation Cell in Operation Next to Wet Only Cooling Cells