
158
| CORRECTION FACTORS
MUL
TI V 5 Outdoor Unit Performance Data Manual
'XHWRRXUSROLF\RIFRQWLQXRXVSURGXFWLQQRYDWLRQVRPHVSHFL¿FDWLRQVPD\FKDQJHZLWKRXWQRWL¿FDWLRQ
©
/*(OHFWURQLFV86$,QF(QJOHZRRG&OLIIV1-$OOULJKWVUHVHUYHG³/*´LVDUHJLVWHUHGWUDGHPDUNRI/*&RUS
Equivalent Length Calculation for Correction Factors
TEL = (ELM x Correction Factor) + ELB, where
TEL = Total equivalent length
ELM = Equivalent length to first Y-branch
ELB = Equivalent length from first Y-branch to farthest indoor unit
HU = Indoor units above outdoor unit
HL = Indoor units below outdoor unit
([DPSOH(/0 ƍ
(/% ƍ
+8 ƍ
Outdoor Unit = ARUM072BTE5
7RWDOHTXLYDOHQWOHQJWK ƍ[ƍ ƍ&RROLQJFDSDFLW\
FRUUHFWLRQIDFWRUIURPWDEOHEH8 ƍZRXOGEHDSSUR[
Correction Factor
Overall Equivalent Pipe Length
Standard Application
Overall Equivalent
Length 295 feet
ARUM072-504BTE5 / DTE5
Cooling
1.0
0.5
Entering DB (ºF)
19.4 23.0 26.6 32.0 37.4 41.0 44.6
Derate factor
0.98 0.95 0.93 0.86 0.93 0.96 1.0
Table 1: Outdoor Unit Frost Accumulation Factor (Heating)
1
.
Defrost Correction Factor for Heating Operation
Figure 1: Equivalent Length.
Capacity tables do not take into consideration capacity reduction
when frost has accumulated on the condenser coil, nor during
defrost operation. Integrated heating capacity values can be
obtained as follows:
Formula: A = B x C
Where: A = Integrated heating capacity
B = Heating capacity value given in table of capacity
characteristics
C = Integrated correction factor for frost accumulation
There will be temporary reduction in capacity when snow piles up on the outside surface of the outdoor unit heat exchanger. The level of capacity
reduction depends on a number of factors, for example, outdoor temperature (°F DB), relative humidity (RH), and the amount of frost present.
1
At 85% outdoor air relative humidity.
Table 2: Pipe Length Correction Factor.
The correction factors shown below are calculated in the LATS software programs.
Outdoor Unit
Equivalent length
262 ft
Equivalent length
131ft
Branch
Indoor Unit
Indoor Unit
Gas pipe
Liquid pipe HU
HL
ELM
ELB
CORRECTION FACTORS