Daikin FXZQ-MVE Introduction Manual page 35

7 Selection procedure
7-2 Capacity correction ratio
1
7-2-6 RXYQ18,26,28,30,38,40,42,44MY1B
7
• Rate of change in cooling capacity
NOTES
1 These figures illustrate the rate of change in capacity of 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 from the rate of change in capacity shown in the above figures.
2 With this outdoor unit, evaporating pressure constant control when cooling, and condensing pressure constant control when heating is carried out.
3 Method of calculating cooling / heating capacity (max. capacity for combination with standard indoor unit)
cooling / heating capacity = cooling / heating capacity obtained from performance characteristics table x each capacity rate of change
When piping length differs depending on the indoor unit, maximum capacity of each unit during simultaneous operation is:
cooling / heating capacity = cooling / heating capacity of each unit x capacity rate of change for each piping length
4 When overall equivalent pipe length is 90m or more, the diameter of the main gas and liquid pipes (outdoor unit-branch sections) must be increased
except for the gas pipe of RXYQ38,40,42,44MY1B.
Diameter of above case
Model
RXYQ18MY1B
RXYQ26,28,30MY1B
RXYQ40,42,44MY1B Not Increased
5 When the main sections of the interunit pipe diameters are increased the overall equivalent length should be calculated as follows.
Overall equivalent length = Equivalent length to main pipe x 0.5 + Equivalent length after branching
When the gas pipe diameter is increased: correct cooling capacity.
When the liquid pipe diameter is increased: correct heating capacity.
Example
Equivalent lenght
80 m
Size increase
Outdoor unit
In the above case (Cooling)
Overall equivalent length = 80m x 0.5 + 40m = 80m
The correction factor in capacity when H
EXPLANATION OF SYMBOLS
H : Level difference (m) between indoor and outdoor units with indoor unit in inferior position
p
H : Level difference (m) between indoor and outdoor units with indoor unit in superior position
M
L : Equivalent pipe length (m)
α
: Capacity correction factor
Diameter of gas pipes
Model
RXYQ18MY1B
RXYQ26,28,30MY1B
RXYQ40,42,44MY1B
34
• Introduction
gas liquid
ø 31.8 ø 19.1
ø 38.1 ø 22.2
ø 22.2
Equivalent lenght
40 m
Indoor unit
Branch
= 0m is thus approximately 0.88
p
gas liquid
ø 28.6 ø 15.9
ø 34.9 ø 19.1
ø 41.3 ø 19.1
• Systems • Introduction
• Rate of change in heating capacity
3D040057