Chapter 15: Steam Heating System Design
This chapter is divided into three parts. The first pertains mainly to the design of large commercial, industrial, and institutional steam heating systems. The second is chiefly concerned with design of one pipe systems in residential pipe installations. The third applies to design of two pipe steam heating systems of various types for residential and larger installations.
LARGE SYSTEMS
Vacuum pumps are essential in large steam heating systems to assure quick and uniform distribution of steam to all parts of the system and to obtain prompt return of condensate to the boiler. Basic system components are shown in Figs. 15-1 to 15-4.
Figure 15-1: Single boiler with Hartford connection
Figure 15-2: Basic components of steam heating system
Figure 15-3: Vacuum heating pump maintains a vacuum in the return piping under all operating conditions
Figure 15-4: Mechanical lift should be installed to handle returns below the level of pump inlets
Steam supply to the heating units may be upfeed or downfeed, as desired. When downfeed supply of steam is desired, the mains are located above the heating units and supplied by main risers. Steam is distributed by downfeed risers from the mains. When upfeed supply of steam is employed, the mains are located below the heating surfaces and steam is supplied through upfeed risers. A combination of downfeed and upfeed supply may be employed depending on building construction.
Steam mains must pitch down in the direction of steam flow so as to provide concurrent flow of steam and of condensate occurring...