In order to evaluate a roadway heating system which utilized the energy stored in the earth for snow melting, a 3200 square foot experimental heated pavement was constructed in Trenton, New Jersey. Heat was extracted from the earth by means of a grid of pipes buried 3 to 13 ft. below ground and transferred via an ethylene glycol-water solution to pipes embedded in a test pavement. For purposes of comparison, a section of pavement heated by electrical resistance wires was also included as part of the installation. Results of operation have indicated that the best snow melting has taken place on sections of portland cement concrete containing 3/4" and 1-1/4" wrought iron pipe spaced on 6" centers and embedded at a depth of 2 inches. These sections produced an average heat dissipation rate of approximately 100 BTU's per square foot of surface area per hour when 2 linear feet of pipe buried in the earth were coupled to 1 linear foot of pipe embedded in the test pavement. Snow melting rates were usually between 1/4 inch and 1/2 inch per hour. During the Summers of 1970 and 1971 the system was operated for the purpose of transferring heat from the warm pavement to the earth where it could be stored for use during the winters. Heat was successfully transferred; however, due to the loss of heat to the surrounding earth and the atmosphere during the fall, no significant storage of heat was achieved by the start of the snow season. The thermal insulation used with the pipes buried 3 to 13 feet in the earth was not effective in reducing heat loss during the fall. Though this installation was shown to be more economical to operate than an electrically heated pavement, the total cost was higher when construction cost was considered. /Author/

  • Corporate Authors:

    New Jersey Department of Transportation

    Division of Research and Demonstration, 1035 Parkway Avenue
    Trenton, NJ  United States  08625
  • Authors:
    • Winters, F
    • Sasor, S R
  • Publication Date: 1977-2

Media Info

  • Features: Figures; Photos; Tables;
  • Pagination: 28 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00173932
  • Record Type: Publication
  • Source Agency: National Technical Information Service
  • Report/Paper Numbers: FHWA-NJ-77-003A Final Rpt.
  • Created Date: May 18 1978 12:00AM