Daikin VRV IV REYQ-TAYCA, Design Manual

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54
REYQ-TAYCA EDUS371706C-D
-Confirm capacity correction factor by piping length and level difference (K1)
-Calculate capacity correction factor by piping heat loss (K2)
(K2) = 1 + (heat loss factor per feet of piping × (equivalent piping length – 25 ft.)) / 100
In cooling mode, heat loss factor per feet at 93°F is calculated as below.
(R) Heat loss factor per feet = 0.072
*2
+ (0.098
*1
– 0.072
*2
) × (93
*3
– 86
*4
) / (95
*5
– 86
*4
) = 0.0922
Using “Equivalent piping length = 200 ft.” and “Heat loss factor per feet = 0.0922”,
(K2) = 1 + (0.0922 × (200 – 25)) / 100 = 1.161
-Calculate the corrected capacity of REYQ192TAYCA(C) by using (K1) and (K2).
Corrected capacity of REYQ192TAYCA (C) = (B) × (K1) / (K2) (add defrost correction factor for heating capacity)
Therefore (C) = 201.8 × 0.924 / 1.161 = 160.6 MBH
If the corrected capacity (C) is the same or greater than the required total heat load (A), selection is complete.
If (C) < (A), return to Procedure [3]–2 and provisionally select a larger outdoor unit.
In this example, 160.6 MBH (C) < 173.2 MBH (A), so need to select a larger outdoor unit.
The capacity of REYQ216TAYCA at the same condition is 177.6 MBH, which is more than the heat load (A): 173.2 MBH.
So the selection is complete.
Cooling Ambient temperature
Heat loss factor per feet
of piping (%)
Heating Ambient temperature
Heat loss factor per feet
of piping (%)
5°F 14°F 23°F 32°F 41°F 50°F 59°F 68°F
0.328 0.305 0.282 0.256 0.233 0.210 0.187 0.161
(K1) = 0.924
41°F
0.000
50°F
0.000
59°F
0.013
68°F
0.030
77°F
0.046
86°F
*4
0.072
*2
93°F
*3
(R)
95°F
*5
0.098
*1
104°F
0.125
0.924