Requirements for Individual Facilities. The actual loads and
conditions are determined from the design of each building and facility.
Refer to P-272, Definitive Designs for Naval Shore Facilities, as guidance for
preliminary estimates of requirements. The facility layout, design, and
geographic factors will further define requirements.
System Load Demand Factors.
For demand factors, refer to Table 1.
Aboveground and Underground Systems. When selecting a system,
corrosiveness of soil for underground systems, cost and degree of hazard.
Refer to para. 18.104.22.168.
Distribution Routes. Select the most direct routes, avoiding all
Aboveground Piping Routes. Aboveground systems are generally lower
in life-cycle costs but are less convenient in areas of heavy traffic.
Consider blockage of access to areas for future development along with
vulnerability to damage and acts of vandalism or sabotage.
Consider aboveground heat distribution systems for use in lieu of
underground systems because of generally longer life and lower maintenance and
use wherever operations and local conditions permit.
Buried Piping Routes. Select routing to allow for proper drainage
of the system. Manholes and provision for piping expansion must be considered
in space allocation. Consider minimum separation of parallel piping runs
where temperatures in the runs vary widely. Consider cover and drainage
provisions for manholes.
Economic Studies. Refer to NAVFAC P-442, Economic Analysis
Handbook, for procedures in life-cycle cost analyses. Economic studies for
all piping system types must include life-cycle (owning, operating, and
maintenance) costs. For prefabricated/pre-engineered underground steam or hot
water systems, perform the economic analysis, developing costs from heat loss
data provided in Part 1 of Appendix A or from heat losses calculated from
procedures provided in NFGS-02694. For concrete shallow trench systems of
greater than 500-foot (152.5 m) length, use the additional procedures outlined
in para. 2.3.6 and modify NFGS-02696 accordingly. Consider first an
aboveground system, which, in most cases, will be economically advantageous to
the Government. Also consider whether or not the facility is permanent or
temporary. Provide a separate economic analysis for the selection of an
insulation system among those allowed in NFGS-02696.
Annual Owning, Operating, and Maintenance Costs.