Daikin VRV II Series, Design, Installation & Testing Instructions, Page: 154 / 242

Appendix Si39-303
148 General Information
7.12.5 Example 5: Excessive noise due to incorrect angling of REFNET
joints
Situation
The noise of the refrigerant flow during defrosting is excessive.
Source of
Problem and
Remedial Action
The angle of the fittings was incorrect and needed to be rectified as shown in the following figure.
1. REFNET joints
The REFNET joints should be installed such that branches meet the main pipe either horizontally or
vertically at an angle of exactly 90 degrees.
2. REFNET header
The REFNET header is a lateral flow pipe and should be fitted so as to allow horizontal branch fittings.
(Vertical or sloping fitting is not permissible.)
Main Points !
Reasons for using refrigerant branch kit
Fittings of REFNET joints or headers which are not carried out in strict accordance with the principles
outlined here may result in complaints relating, for example, to “poor performance” of the system or
“noisy refrigerant flow”. (To prevent unbalance flow or oil shortage)