YMGI
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Your Modern Green Idea
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1. IDU/ODU rated capacity collocation ratio C = Sum of rated cooling capacity of indoor unit / Sum of rated cooling capacity of
outdoor unit.
2. If all of the indoor units are fresh air indoor units, the quantity of refrigerant added to each module is 0kg
3. If outdoor air processor is connected with normal VRF indoor unit, adopt the perfusion method for normal indoor.
Example1:
The ODU is composed of 3 modules: 72kBtu/h, 120 kBtu/h and 120 kBtu/h. The IDUs are made up of 7sets of
48 kBtu/h.
IDU/ODU rated capacity collocation ratio C= 48×7/(72+120+120)=108%.The quantity of included IDUs is more
than 4 sets. Please refer to the above table.
o
Refrigerant charging amount B for 72kBtu/h module is 4.0kg (8.8pounds).
o
Refrigerant charging amount B for 120 kBtu/h module is 4.0kg (8.8pounds).
o
Refrigerant charging amount B for 120 kBtu/h module is 4.0kg (8.8pounds).
So, Σ Refrigerant charging amount B of every module=4.0+4.0+4.0=12kg (8.8+8.8+8.8 =26.4pounds).
Suppose the Pipeline charging amount A=Σ Liquid pipe length × refrigerant charging amount of every 1m (or
1in.) liquid pipe=25kg (55.1 pounds)
Total refrigerant charging amount R=25+12=37kg (55.1+26.4=81.5pounds).
Example 2:
Outdoor unit is a 72kBtu/h module and the indoor unit is a 72kBtu/h fresh air unit. The quantity (B) of refrigerant
added to this module is 0kg (0pounds).
So, ΣB (Quantity of refrigerant added to each module) = 0kg (0pounds).
Suppose that A (Quantity of refrigerant added to connection pipe) = Σ Length of liquid pipe x Quantity of
refrigerant added to liquid pipe per meter) = 5kg (11pounds).
R (Quantity of added refrigerant in total) = 5+0=5kg (11+0=11pounds).
Modular combination of outdoor unit is subject to combinations that is currently available.
After confirming that there is no leakage from the system, with the compressor not in operation, charge additional
R410A to the specified amount. To add the additional refrigerant charge to the unit, use the filling opening of the liquid
pipe valve of the outdoor unit.
If required additional refrigerant cannot be quickly filled to increase the pressure in the pipe, set the unit to cooling mode
at startup and then fill the refrigerant from gas valve of outdoor unit. If ambient temperature is low, the unit can be set to
heating mode instead of cooling mode.
