• Introduction
1
7
•
Systems • Introduction
34
7
Selection procedure
7-2
Capacity correction ratio
7-2-6
RXYQ18,26,28,30,38,40,42,44MY1B
•
Rate of change in cooling capacity
•
Rate of change in heating capacity
3D040057
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.
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
In the above case (Cooling)
Overall equivalent length = 80m x 0.5 + 40m = 80m
The correction factor in capacity when H
p
= 0m is thus approximately 0.88
EXPLANATION
OF
SYMBOLS
H
p
: Level difference (m) between indoor and outdoor units with indoor unit in inferior position
H
M
: Level difference (m) between indoor and outdoor units with indoor unit in superior position
L
: Equivalent pipe length (m)
α
: Capacity correction factor
Diameter of above case
Model
gas
liquid
RXYQ18MY1B
ø 31.8
ø 19.1
RXYQ26,28,30MY1B
ø 38.1
ø 22.2
RXYQ40,42,44MY1B
Not Increased
ø 22.2
Diameter of gas pipes
Model
gas
liquid
RXYQ18MY1B
ø 28.6
ø 15.9
RXYQ26,28,30MY1B
ø 34.9
ø 19.1
RXYQ40,42,44MY1B
ø 41.3
ø 19.1
Equivalent lenght
Equivalent lenght
Indoor unit
Outdoor unit
Branch
Size increase
80 m
40 m
