Specification Guide

Due to our policy of continuous product innovation, some specications may change without notication.

46 | DUCTED

Ceiling-Concealed Ducted System Engineering Manual

Altitude Correction Factor

The impact of air density must be considered on systems installed at a significant altitude above sea level, therefore, locally accepted

altitude correction factors must be applied.

Cooling / Heating Correction Factors

For Ceiling-Concealed Ducted systems, calculate the equivalent length of the liquid line from the outdoor unit to the indoor unit. Also, deter-

mine the elevation difference of the indoor unit above or below the outdoor unit. Find corresponding cooling or heating capacity correction

factors as shown below. Multiply the correction factors by the cooling or heating capacity obtained from the capacity table using design

conditions. The result is the NET cooling or heating capacity.

Refrigerant Line Length Derates

For air-cooled systems, a capacity correction factor may have to be applied to account for the length of the system’s refrigerant pipe. Rate of

change in capacity due to increased piping lengths is shown below.

Table 27: Low Static Ducted System Cooling and Heating Capacity Coefcient Factors.

Equivalent Piping Length for Piping Components

Piping Length (ft.) 24.6 32.8 49.2 65.6 98.4 131.2 164.0 196.9 229.7 246.0

Cooling Capacity Coefficient Factor

Rate of Capacity

Change (%)

LD097HV4 (9,000) 100 99.7 99.2 98.7 - - - - - -

LD127HV4 (12,000) 100 99.7 99.2 98.7 - - - - - -

Heating Capacity Coefficient Factor

Rate of Capacity

Change (%)

LD097HV4 (9,000) 100 99.7 99.2 98.7 - - - - - -

LD127HV4 (12,000) 100 99.7 99.2 98.7 - - - - - -

Table 28: High Static Ducted System Cooling and Heating Capacity Coefcient Factors.

Component Size (Inches)

Elbow (ft.)

1/4 3/8 1/2 5/8 3/4 7/8 1 1-1/8 1-1/4 1-3/8 1-1/2 1-5/8 1-3/4 2-1/8

0.5 0.6 0.7 0.8 1.2 1.3 1.5 1.6 1.8 2.0 2.1 2.3 2.5 2.8

EQUIPMENT SELECTION PROCEDURE

Table 29: Equivalent Piping Length for Elbows.

Piping Length (ft.) 16.4 32.8 49.2 65.6 98.4 131.2 164.0 196.9 229.7 246.0

Cooling Capacity Coefficient Factor

Rate of Capacity

Change (%)

LH247HV (24,000 Btu/h) 100 99.3 97.9 96.6 93.8 91.1 88.4 - - -

LH367HV (36,000 Btu/h) 100 99.3 97.9 96.6 93.8 91.1 88.4 85.6 82.9 81.5

Heating Capacity Coefficient Factor

Rate of Capacity

Change (%)

LH247HV (24,000 Btu/h) 100 99.7 99.2 98.7 97.7 96.6 95.6 - - -

LH367HV (36,000 Btu/h) 100 99.7 99.2 98.7 97.7 96.6 95.6 94.6 93.5 93.0