Defrost Correction Factor For Heating Operation; Equivalent Length Calculation For Correction Factors; Pipe Length Correction Factor - LG Multi V 5 Data Manual

CORRECTION FACTORS
The correction factors shown below are calculated in the LATS software programs.

Defrost Correction Factor for Heating Operation

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.

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
Outdoor Unit = ARUM072BTE5
Table 2: Pipe Length Correction Factor.
Correction Factor
Standard Application
ARUM072-504BTE5 / DTE5
Cooling
158 | CORRECTION FACTORS
Overall Equivalent Pipe Length
Overall Equivalent
Length 295 feet
1.0 0.5
©
Table 1: Outdoor Unit Frost Accumulation Factor (Heating)
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
1 At 85% outdoor air relative humidity.
Figure 1: Equivalent Length.
Equivalent length
Gas pipe
Liquid pipe HU
Outdoor Unit
.
1
Equivalent length
262 ft 131ft
ELM
ELB
Indoor Unit
Indoor Unit
HL
Branch