Steam humidification:
Reducing energy use, airstream heat gain, and condensate production
Updated!
Includes analysis of stainlesssteel-shielded dispersion tubes.
by Lynne Wasner and Jim Lundgreen,
Senior Mechanical Design Engineer
DRI-STEEM Corporation
Enlightened building owners demand accountability for every resource consumed in the construction and operation of new or renovated buildings. Meeting conservation benchmark standards requires measurable building performance, for it is commonly understood that if you can't measure it you can't improve it.
FIGURE 1-1:
TYPICAL DISPERSION ASSEMBLY
Commercial and industrial steam humidification is considered essential for most process, preservation, and health applications such as semiconductor manufacturing, printing plants, museums, schools, and health care facilities. Given the significant number of large buildings requiring steam humidification, it is time to make strides toward measuring and improving the energy efficiency and water consumption of these building systems. Recent advances in materials and manufacturing techniques are bringing attention to this issue,
specifically the energy and water wasted when dispersing steam into cool airstreams. This article describes these materials and includes data about their performance.
Steam dispersion basics
Humidifying with steam requires two essential functions: steam generation and steam dispersion.
Direct steam injection humidification systems disperse steam into duct or AHU airstreams from on-site boilers or unfired gas or electric steam generators. Unique to direct steam injection applications is the dispersion of pressurized steam.
Humidification steam can also be generated in a nonpressurized gas or electric steam generator connected to a dispersion assembly. This type of steam is often called
evaporative steam because the steam chamber operates at or near atmospheric pressure.
Shown here is a typical steam dispersion tube panel with uninsulated stainless steel tubes installed to span the full height
