I published an article in the March, 2005 issue of Engineered Systems Magazine entitled “Heating with Steam”. Following is an excerpt with a link to the article in its entirety.
“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, 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 its condensing, 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.”
Download the article in pdf here.