A majority of the energy used in education buildings is used for space heating; a majority of that is provided by boilers1. The trend in new school construction is toward hot water heating. However, steam has five to six times the potential energy of an equivalent mass of hot water and is easier to control. Considering the financial crunch that many school systems find themselves in between increasing energy costs and decreasing O&M budgets, the efficiency and simplicity of steam merit consideration.
Compared to hot water, there are several advantages to steam. Due to higher energy content per mass, the required heat transfer area is smaller, heat coefficients are higher, and distribution pipes and necessary plant sizes are smaller. Rather than costly circulating pumps and the relatively larger components needed for hot water systems, steam is distributed and controlled through pressure differentials. However, utilizing the heat of steam requires it to be condensed, which can be troublesome. In fact, condensate and its removal are the source of most of the problems associated with steam heating. To effectively take advantage of steam's higher energy content and flexibility, the byproduct, condensate, must be controlled and utilized so as not to hamper heat transfer, or, worse, lead to frozen or damaged coils.