District Energy

3rd Quarter 1994 | Volume 80 Number 1

Cover story: Trenchless Technology: Alternative to Traditional Construction (p12)

Rajesh Tanwani, Project Manager, LAG Steering Systems, Inc.

As existing district energy systems expand and new district heating and cooling systems are planned, the impact on an area due to the construction of underground piping systems varies and is temporary. Yet the concerns of people who use the streets, sidewalks and buildings adjacent to a district energy construction site are real. The cover story presents some of the standard methods of trenchless construction technologies and for which situations they are best suited.

A Decade of Service Leads to New Business Opportunities (p5)

Matthew J. Schuerger, PE, Vice President, District Energy St. Paul, Inc.

After more than a decade of success in St. Paul with hot water district heating. District Energy St. Paul's new district cooling system is growing rapidly, and expanded cogeneration is on the horizon. District Cooling St. Paul, the company's affiliate that operates the cooling system, presently has long-term contracts with 26 buildings, representing over 8500 peak tons. In June 1994, the company began operation of a 2.5 million gallon chilled-water storage tank.

Insulation Selection Can Optimize System Performance (p9)

Michael Musto, M.E., President, DriTherm, Inc.

Direct-buried steam and condensate lines are a constant topic of discussion due to the rising cost of utility construction. A major issue is how to insulate and protect against corrosion. Many loose- fill and pre-insulated products have been introduced over the years. Only one loose-fill system, Dri-ThermŽ, has been furnishing the same formula product to provide the required corrosion protection and insulation for more than 25 years.

Putting Micro-Tunneling and Hand Tunneling to Work in Baltimore (p20)

Fred Thornhill, Nova Group, Inc.

In March 1994, Trigen-Baltimore Energy Corporation awarded a contract to Nova-CPF for the design and construction of a 3,300-foot 12- and 16-inch steam pipeline expansion. The new line was to serve several new customers and eliminate operation of the Latrobe Boiler Plant. The project could not have been built using conventional construction methods and is a good example of the innovative thinking required to expand existing systems.

District Heating Linked Into Boston's Wastewater Megaproject (p24)

Scoff Hutchins, Design Engineer, Metcalf & Eddy, Inc.; Dennis Loria, PE, Executive Engineer, R. W. Beck; and Culab Hira, PE, Design Manager, Massachusetts Water Resources Authority

The Boston Harbor Project is the single largest public works project ever undertaken in New England. It is the second largest wastewater treatment facility being constructed in the nation. By completion in 1999, it will have cost about $4 billion.

The project includes a high-temperature hot-water-based district heating system designed to provide a maximum of 277 MMBtu per hour of thermal energy to meet the peak domestic heating and process thermal energy requirements of the entire complex.

New Energy Partnership: Reusing Wastewater for Cooling at Boeing (p28)

Andrew Clapham, Project Engineer for Site Development, The Boeing Company; Joel Jackman, Commercial/Industrial Services Consultant, Puget Sound Power & Light Co.; and Mary M. Lundt, MetroTherm Projects Coordinator, King County Department of Metropolitan Services

With its new Longacres Park Office Campus in Renton, Wash,, the Boeing Company is the first commercial customer using an effluent-based cooling system in the Pacific Northwest. The system officially began service in August 1994 and serves secondary-treated wastewater to Boeing as part of Metro's MetroTherm Program. MetroTherm is Metro's new program for making effluent available for heating and cooling uses by private companies, industries and governments.