Daikin R22, Refrigerant Piping Design Manual, Page: 4 / 78

AG 31-011 • REFRIGERANT PIPING DESIGN 4 www.DaikinApplied.com
Refrigerant Piping
Several HVAC systems require field refrigeration piping to be
designed and installed on-site.
Examples include:
• Condensing units
• Direct expansion (DX) coil in air handlers
• Remote evaporators with air-cooled chillers (
Figure 1 )
• Chiller with a remote air-cooled condensers
The information contained in this Application Guide is based
on Chapter 2 of ASHRAE’s Refrigeration Handbook and Daikin
Applied’s experience with this type of equipment. A properly
designed and installed refrigerant piping system should:
• Provide adequate refrigerant flow to the evaporators, using
practical refrigerant line sizes that limit pressure drop
• Avoid trapping excessive oil so that the compressor has
enough oil to operate properly at all times
• Avoid liquid refrigerant slugging
• Be clean and dry
Figure 1: Typical Field Piping Application