• American Energy Exchange, Inc.
• ABB
• Aerospace Controls -
• AC Pump - 
• Barton -
• Carrier Corporation 
• Cemline Corporation
• Cleaver-Brooks 
• Danfoss 
• Dupont
• Goulds -
• Graham -
• Heatway -
• Hoffman Specialty -
• Johnson Controls
• Kewanee -
• Liebert
• McDonnell & Miller -
• McQuay International
• Preferred Utilities
• Refrigeration Technologies -
• Standard -
• SquareD
• Trane
• Weil-McLain - Boilers
• Wessels Company
• York International Corporation

• Engineering Toolbox
• HVACware
• hvac toolbox

• ABMA -
• ARI - .
• ASHRAE -
• ASME - 
• ASPE -
• DOE - Motor Challenge -
• DOE - Steam Challenge -
• EPRI
• GAMA -
• Hydraulic Institute
• Hydraulic Institute - www.pumps.org.
• IEEE Standards i
• IGSHPA -
• MCAA -
• NAOHSM -
• New England Fuel Institute -
• SMACNA -

Metal-Era  -

Metal Suppliers Online -

Smart Metal - Snips

• AEC InfoCenter
• ARCAT
• BuilderWeb -
• Construction Materials.COM
• Cool-Links -
• HVAC Mall 
• HVAC Online
• PlumbingWeb - 
• The Blue Book of Building and Construction - 
• Thomas Register 
  Thomas Register Index -  
• Yahoo - Construction - HVAC