Daikin RELQ72TAYDA - Page 63

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RELQ-TATJA / TAYDA / TAYCA EDUS371705C-D
-Conrmcapacitycorrectionfactorbypipinglengthandleveldifference(K1)
(K1) = 0.924
0.924
-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
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
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
-Calculate the corrected capacity of RELQ192TAYCA (C) by using (K1) and (K2).
Corrected capacity of RELQ192TAYCA (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) < 173.0 MBH (A), so need to select a larger outdoor unit.
The capacity of RELQ240TAYCA at the same condition is 186.3 MBH, which is more than the heat load (A): 173.0 MBH.
So the selection is complete.