Capacity Correction Factor - Daikin VRV Series Technical Data Manual

5 Capacity tables

5 - 4 Capacity correction factor

RXYHQ12,14,24,36P(8)
Correction ratio for cooling capacity
Equivalent piping length (m)
NOTES
1 These figures illustrate the correction ratio for piping length in capacity for a standard indoor unit system at maximum load (with the thermostat set to maximum)
under standard conditions). Moreover, under partial load conditions, there is only a minor deviation for the capacity correction ratio, shown in the above figures.
2 With this outdoor unit, constant evaporating pressure control when cooling and constant condensing pressure control when heating is carried out.
3 Method of calculating the capacity of the outdoor units.
The macimum capacity of the system will be either the total capacity of the indoor units or the macimum capacity of the outdoor units as mentioned below,
whichever is smaller.
Condition: Indoor connection ratio does not exceed 100%
Maximum capacity of outdoor units = Capacity of outdoor units from capacity table at 100% connection ratio X Correction ratio of piping to farest indoor
Condition: Indoor connection ratio exceeds 100%
Maximum capacity of outdoor units = Capacity of outdoor units from capacity table at installed% connection ratio X Correction ratio of piping to farest indoor
4 When level difference is 50m or more and equivalent pipe length is 90m or more, the diameter of the main gas and liquid pipes (outdoor unit - branch sections)
must be increased. For new diameters, see below.
Model gas
RXYHQ12P8 28.6
RXYHQ24P
34.9
RXYHQ36P 41.3
5 When the pipe length after the first refrigerant branch kit is more than 40m, pipe size between first and final branch kit must be increased (refer also to
installation manual).
Model gas
RXYHQ12P8 28.6
RXYHQ24P
34.9
RXYHQ36P 41.3
6 Equivalent length used in the above figures is based upon the following equivalent length
equivalent piping length =
equivalent length of main pipe X correction factor +equivalent length of branch pipes x correction factor
Choose the correction factor from the following table.
When cooling capacity is calculated: gas pipe size
When heating capacity is calculated: liquid pipe size
Cooling (gas pipe)
Heating (liquid pipe)
Example
Main gas pipe size increase
Main liquid pipe size increase
In the above case:
(Cooling) Overall equivalent length= 80mx0.5 + 40mx1.0 = 120m
(Heating) Overall equivalent length= 80mx1.0 + 40mx1.0 = 80m
The rate of change in:
Cooling capacity when height difference = 0 is thus approximately 0.89
Heating capacity when height difference = 0 is thus approximately 1.0
• Outdoor Units • VRV HEAT PUMP • RXYHQ12-36P(8)
liquid
15.9
19.1
22.2
liquid
12.7
15.9
19.1
Correction factor
Standard size Size increase
1.0 0.5
1.0 0.5
Branch gas pipe size increase
Branch liquid pipe size increase
• VRV Systems • Outdoor Units
Correction ratio for heating capacity
Equivalent piping length (m)
3
1
5
3TW31472-1
60