Initial Selection Of Outdoor Unit; Capacity Revision Of Outdoor Unit - Gree GMV-S120WL/A-S Service Manual

Load (kW)
Specification 25 type
Capacity code 25

8.3.4.2 Initial selection of outdoor unit

(1) Basic principle for model selection of outdoor unit:
1) Know well about using habit of user, before using the unit, total capacity of indoor units
operated simultaneously should not be larger than capacity of outdoor unit, otherwise
it may cause deficiency in cooling (heating) of indoor units.
2) Sum of capacity codes of indoor unit should be within 80%~100% of capacity of
selected outdoor unit.
3) According to different factors in actual installation, it is suggested that capacity code of
outdoor unit should not be less than sum of capacity code of indoor units.
(2) Initial selection of capacity of outdoor unit
1) Calculate demand of total cooling capacity of indoor unit
Sum of the above capacity code of indoor units is 25×2+36×5+45 = 275, that is, the actual
cooling capacity is 27.5kW.
2) Define simultaneous utilization rate
According to actual using demand of user, all of the above indoor unit are turned on and used
at the same time (simultaneous utilization rate is 1), so the rated capacity of selected outdoor unit
should not be less than 27.5×1=27.5kW, otherwise it will cause poor cooling/heating effect in
actual ultilization.
Notes:
simultaneous utilization rate=sum of rated capacity of simultaneously operated indoor
units/sum of rated capacity of all the indoor units.
(3) Selection of capacity of outdoor unit
Inquire rated capacity sheet of outdoor unit, capacity code of outdoor unit which is larger than
27.5kW and has smallerst upper deviation is 280, that is to select outdoor unit with rated cooling
capacity of 28kW.
(4) Calculate rated capacity ratio of indoor and outdoor unit
Rated capacity ratio of indoor and outdoor unit is 27.5/28×100%=98%, the value is within
80%~100%, then the initial seleted outdoor unit with capacity of 28kW is in conformity with
requirements of model selection.
(5) Define model of whole unit
The model of outdoor unit that satisfies 28kW is GMV-S280W/A-X, therefore the selected
model of whole unit is GMV-S280W/A-X.

8.3.4.3 Capacity revision of outdoor unit

Actual output capacity of outdoor unit will be affected by many factors such as installation
(pipe length, height difference) and actual ambient temperature, thus rated capacity should be
revised according to actual situation.
(1) Collocation rate of unit
Collocation rate of unit=sum of rated capacity of indoor units/rated capacity of outdoor unit
Calculate collocation rate of unit is: （25×2+36×5+45）/280=98%
(2) Capacity revision coefficient of ambient temperature
Inquire cooling capacity revision sheet related to temperature, under the condition of outdoor
temperature of 35℃DB, indoor temperature of 29℃DB, collocation rate of unit is 98%, cooling
capacity is 28.6kW. 【For specific capacity revision data please see ralted instruction manual】
GMV5 Home DC Inverter Multi VRF Units
2 2
25 type
25
3 3
36 type 36 type
36 36
38
3 3 3
36 type 36 type 36 type
36 36 36
4
45 type
45