1. Principles of correct VRV Installation A. Refrigerant pipe work
B. Drain pipe work
C. Service space
D. Information Flow
Hotel Applications Seminar, 9-11 November 2006
Speaker: Joachim Verhelst
I would like to give you some more detailed information about refrigerant pipe work, drain pipe work and service space requirements for a well performed VRV installation. (used in middle to large scale applications like Hotels.)
-- Daikin offers cooling solutions: cooling, heating air conditioning, = a confort level.
Not units only accomplish this, but also the information flow they recieve, also a descent installation of all important aspects, like Refrigerant and drain pipe, and respecting of good design, respecting service space.
--Wouldn’t it be easyer for you to convince a client to go for a Daikin product, if he knows that all this points of refrigerant pipe work attention points, drain pipe work importance and Service space requirements, are taken into consideration for the creation of his project?
-- Wouldnt it be good as a consultant to know the importance of VRV installation key attention points?
Now, These aspects are slightly different in a typical VRV installation, compared to a more simplistic split (skyair) or multisplit applications:

2. A. Refrigerant piping work
Explanation important points of refrigerant piping procedure
& new refrigerant
3 very important keywords, that will return in the whole of the presentation, are Dry, clean and Tight installation.
In every step of the installation of a VRV system, these 3 points have to be taken into account, even more then for the installation of a split or multisplit system, since the consequences if the installation is erronoous, is bigger here than they are in a smaller system.
However, as you know; there are many advantages to this system, like capacity reduction, load spreadding, costdown, and low service needs.
In the next slides, we will discuss every step of the installation shortly.
No moisture, no dirt, no leakage !

3. 1. Brazing with nitrogen replacement
Put and thought the N2 when brazing
N2 pressure is 0.8 kg
First of all, the installer brazes vertical piping:
Most prone to leaks, since most brazing needed. There shoud be an open ending; to displace the oxigen at the inner side of the tube during brazing; to avoid oxidation at the inside of the pipe, causing dirt/system malfunctions later.

4. Correct storage of pipes
Point of piping work
・Dry Clean Tight are same as R22
・For Dry : Put the cover for both end when store the pipe
　For Clean : Put the cover for both end when through the wall and leave the site
Please, do NOT use pipes for Sanitary purposes. Installers without VRV experience (first installation) sometimes say, the sizes of pipes/flairs don’t fit… Well: They do fit, but not with pipes of sanitary purposes. These have a totally different material purity and strenght, pressure test limits, totally incapable to capture the pressures working on the system (40 atmosphere!).

5. 2. Flushing Cleans the refrigerant pipes in order to prevent:
clogging of expansion valve (capillary tube)
Cause of contamination in piping:
oxidized film generated during brazing
entering of dust, particles, oil, etc. from outside
use of other refrigerant
Flushing: several times to be sure that water drops that stick to the pipes (adhesion forces) are loosened
Vacuum drying: at vacuum, water evaporates --> vapor is removed
insufficient cooling or heating
degradation of oil
oxidation of compressor

6. 3. Air tightening test Prevents Refrigerant Leakage in order to avoid:
Gas shortage
Insufficient cooling or heating
Temperature rising of discharge gas
Frost accumulation on heat exchanger

7. 3. Air tightening test Leak check is done with nitrogen:40
Leak check after 24 h.
at 38 Bar
Step 3 30 20
Leak check after 5 min.
at 21.5 Bar
Step 2 10
Step 1
Leak check after 3 min. at 10.3 Bar
3 min
5 min
24 hours

8. 3. Air tightening test The test is divided in 3 parts:
1: Vertical pipe
2: 1+Indoor piping
3: 2+Outdoor piping
3.8 Mpa during 24 hours
If air tight test is done only at the end when all pipes are brazed together, and a leakage is discovered (pressure drop during pressurized test, then it is very difficult to find out the leak point. Daikin recommend to divide the test for 3 times

9. 3. Air tightening test
Convenient tools for air tight test

10. 4. Vacuum drying
Prevents Moisture in Refrigerant Circuit in order to avoid:
clogging of expansion valve (capillary tube)
insufficient cooling or heating
degradation of oil
oxidation of compressor
Cause of moisture in piping:
water entering from outside (rain)
dew condensation occurring inside the pipes
Flushing: several times to be sure that water drops that stick to the pipes (adhesion forces) are loosened
Vacuum drying: at vacuum, water evaporates --> vapor is removed

12. 5. Additional charge of refrigerant
The calculation of the additional charge weight should take account of the length of pipe and the situation of branches
After calculation, the weight of additional charge shall be recorded on the name plate.
Input liquid into the liquid pipes from a charging cylinder following completion of the vacuum drying operation
When charging cannot completed, use the action of the compressor during the test run.

13. 5. Additional charge of refrigerant
Precise amount is calculated as a function of:
Length of pipe
Situation of branches
Added at the outdoor unit liquid valve
During last stage of vacuuming
At the start of the test run
Weight of additional refrigerant charge
Recorded on the outdoor unit nameplate.
Monitored with automatic system (VRV III leakage test)

14. 5. Additional charge of refrigerant
Depend on piping length additional charge is required
Circulate the additional charge amount by formula following the installation manual or
Eg Engeneering manual EEDE06-2 paragraph 2.6 Refrigerant Pipe selection, p 55
Or technical data- books under point Refrigerant Pipe Selection, eg p 180
Under installation, eg p 155 point 8.4 for RXYQ5-54P7W1B

15. New refrigerant R410A tools
Use the collect tools for new refrigerant
Some tools are used from present but most of all for R410A are need to prepare

16. B. Drain pipe work Adjust downward gradient
Should use the attached drain hose
If never use and connecting pipe to the unit directly drain-pan crack may occur
due to bending stress that cannot absorbed

17. Group Drain Piping
In the case of common drain piping take care about indoor units position
Otherwise water leak will may occur

18. Different orientations of outdoor units and walls
C. Service space
Different orientations of outdoor units and walls
Single units
Installation in rows
Centralised group layout
Short circuits are avoided
Maintenance is facilitated.
In the case of several outdoor units installation
Keep the enough space following the installation manual

19. D. Explanation to customer
Explain:
Hand over relevant printed materials.
1. How to use remote controller.
2. How to clean air filters in indoor units.
3. How to keep optimum operation.
4. How to check if trouble occurs or not.
5. Who to contact if an emergency occurs.
Enough explanation to use air conditioners makes very few service calls.
In the instruction manual Si39-303, Operation procedure P.207 to P.213 shows how to use remote controllers, optimum operation P.214 shows precautions to ensure the system operates properly, symptoms of air conditioners P.215 shows whether they are troubles or not.
And it is helpful for end users to know how they call for services and how the air filter is cleaned.
At the end, relevant printed materials, shown at Si Page 105, should be handed over to end users who can confirm what to do if anything happens.

20. Summary Installation Drainpiping Information flow to End-Customer
By a experienced (and trained) Daikin Installer
Keywords: “Clean, Dry, Tight!”
Drainpiping
With downward slope,
Widening tubes
Space foreseen in design
Information flow to End-Customer
About skillfull installation
About system features
About preventive and corrective service.
A decent explanation on “How to use air conditioner”
brings very few service calls.

21. The END