Email   Password


ASHRAE Membership

ASHRAE membership is open to any person associated with heating, ventilation, air conditioning or refrigeration. ASHRAE is unique because its membership is drawn from a wide range of disciplines relating to the HVAC&R field. Approximately 51,000 individuals from more than 100 nations belong to the Society.

Discounts on Publications

ASHRAE members earn 15% off publications. Hundreds of titles are available including the complete collection of ASHRAE Standards including 90.1, 62.1 and 189.1.
Click here for information on joining or to join ASHRAE

Develop Leadership Skills

When you join ASHRAE, you are making an investment in yourself. When you become active in the Society by giving your time and sharing your knowledge, you get even more out of that investment.

Network with Industry Professionals

Each month, all over the world, ASHRAE chapters convene for an informational program featuring a speaker or topic that is key to professionals in the industry. Meet with your peers and share ideas.
Need technical info? Search ASHRAE's Bookstore >
Resources & Publications

102013--Historical Minute

Historical Minute -- October 2013

Steam Circulation

“In 1882, Napoleon Williames of Philadelphia patented in this country the art of circulating exhaust steam by the mechanical reduction of pressure upon the heating system. This being the foundation patent, broad claims were allowed, and every system of vacuum heating using mechanically induced circulation is founded more or less on this patent.
“In 1891, a patent was issued to Willis E. Hall, which, broadly stated, in its subsequent use consisted of the application of a thermostatic valve (trap) to the Williames system, and it seems as if the clearest way to describe it, is to call it the Williames thermostatic system.
“Based solely on these two patents, with the addition from time to time of a few upon specific forms of thermostatic valves and special devices for better control of various features, a system of steam circulation was developed and sold in considerable quantity.”
—“A new system of vacuum return line exhaust steam circulation” by James A. Donnelly, The Heating and Ventilating Magazine, October 1904.