Comparative life-cycle cost analysis of underground heat distribution systems

Journal Article · Sun Nov 01 04:00:00 EST 1998 · Journal of Transportation Engineering

DOI:https://doi.org/10.1061/(ASCE)0733-947X(1998)124:6(594)· OSTI ID:316108

Carnahan, J V ^[1]; Marsh, C ^[2]

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1. Univ. of Illinois, Urbana, IL (United States)
2. Army Construction Engineering Research Lab., Champaign, IL (United States)

An analytical model was developed to compare the life-cycle costs of two types of underground heat distributions systems: directly buried conduits and concrete trench installations. The costs of initial construction, routine maintenance, operation, repair, and replacement are represented in the model. Comparisons are made to explore the influence of failure rates, heat loss assumptions, the discount rate, and the policy on partial section replacement. Failure rate estimates are obtained from the literature and also from survey results obtained by the US Army. Life-cycle cost computations indicate that, when initial construction costs are the same, concrete trench installations have a cost advantage of $18--$42 per foot over buried steel conduit when other cost components are taken into account over a 25-year lifetime. The cost advantage of concrete trench over fiberglass reinforcement plastic (FRP) buried systems is $32--$133 per foot. The variation in the cost advantage reflects the variation in the estimate of the failure rate for buried steel and FRP systems. Routine maintenance was crucial for the buried systems to avoid dramatic increases in operation and replacement costs that would make the cost advantage of concrete trench installation even greater than stated above. In contrast, the low incidence of failure associated with concrete trench systems made their life-cycle costs relatively insensitive to maintenance policy.

• Sponsoring Organization: USDOE
• OSTI ID: 316108
• Journal Information: Journal of Transportation Engineering, Journal Name: Journal of Transportation Engineering Journal Issue: 6 Vol. 124; ISSN JTPEDI; ISSN 0733-947X
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
COST BENEFIT ANALYSIS
FAILURES
HEAT DISTRIBUTION SYSTEMS
HEAT LOSSES
LIFE-CYCLE COST
RELIABILITY