4 Capacities and selection data
Defrost Operation correction factor (fD)
TCGB0136 rev.1 - 05/2021
59
4
4.7 Defrost Operation correction factor (f
D
)
The heating capacity does not include operation during frost or defrosting.
When this type of operation is taken in account, the heating capacity must be corrected according to the following
equation:
Correction heating capacity = Correction factor x heating capacity
Outdoor inlet air temperature (ºC DB)
-7
-5
-3
0
3
5
7
Correction factor
0.95
0.93
0.88
0.85
0.87
0.90
1.00
?
N O T E
• Defrost correction factor corresponds to a relative humidity of 85%.
If the condition changes, the correction factor will be different.
• Defrost correction factor is not valid for special conditions such as
during snow or operation in a transitional period.
Heating
capacity
Reduced
capacity
due to frost
build-up
1 cycle
Time
Max. defrosting
4.8 Correction ratio due to humidity (CR)
The cooling capacity data for the outdoor units is taken from the cooling capacity tables. The tables are calculated on the
basis of a relative humidity of 50%.
In some situations, it’s possible that the temperature condition of the ambient to be conditioned, specifies other different
relative humidity, which affect at the Dry Bulb temperature. In this cases, it’s necessary to calculate the difference
between the indoor air inlet dry bulb temperature required by the system and the indoor air inlet dry bulb temperature
shown in the cooling capacity data.
This temperature difference requires an adjustment of the cooling capacity of the system.
Q
AC
=Q
C
+ (CR x (DB
R
- DB))
Model
CR
RAS-3HVRC2
0.34
RAS-4H(V)(R/N)(C/P)2E
0.43
RAS-5H(V)(R/N)(C/P)2E
0.51
RAS-6H(V)(R/N)(C/P)2E
0.59
4.9 Correction factor according to altitude (f
AL
)
The capacity is affected by the altitude of the installation location. When the altitude is above sea level, capacity must be
corrected with the altitude correction factor according to the following equation:
Correction capacity = Altitude Correction factor x Capacity
Altitude (m)
0
300
600
900
1200
1500
1800
2100
2400
2700
3000
Correction factor
1
0.97
0.94
0.90
0.88
0.84
0.81
0.78
0.75
0.72
0.69
