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II : Calculate Dx-coil inlet air (Lossnay outlet air) condition
See the calculations and table in STEP1-III.
III : Calculate the capacity of Dx-coil unit
(1) Air volume factor
(A) Designing air volume
(B) Related air volume of Lossnay unit at fan speed 4
(C) Air volume ratio = (A) / (B)
(D) Air volume factor C
(Find C
from the graph on page 62. )
1
(2) Air condition difference factor
Specification condition
(A) Air condition difference factor C
Designing condition
(B) Outdoor air wet-bulb temperature
(C) Lossnay outlet air dry-bulb temperature
(D) Air condition difference factor C
(Find C
from the graph on page 62. )
2-2
(E) Total air condition difference factor C
= C
/C
= (D) / (A) = 0.75/1.02
2-2
2-1
For the quick reference of air condition difference factor C
(3) Corrected refrigerant pipe length factor
Read out the refrigerant pipe length factor C
(A) Refrigerant pipe length
(B) Refrigerant pipe length factor C
(4) Adjusted Dx-coil unit capacity
(A) Dx-coil unit cooling capacity on the specification
(B) Adjusted Dx-coil unit cooling capacity
= (A) x C
x C
x C
1
2
IV : Calculate the supply air conditions from Dx-coil unit
Enthalpy of supply air from Dx-coil : h
h
: Enthalpy of Dx-coil inlet air
i
(equal to Lossnay outlet air) [kJ/kg(DA)]
C
: Capacity of Dx-coil unit [kW]
a
Enthalpy of supply air from Dx-coil :
h
= C
/ (ρ x Q
/ 3600)+h
o
a
f
= 6.0 / (1.2 x 1000 / 3600)+31.7
Absolute humidity, the ratio of water weight
against the unit weight of dry air, is unchanged
during heating.
Supply air condition from Dx-coil can be read out
by the psychrometric chart.
STEP4. Comparison of Lossnay + Dx-coil unit capacity with required capacity
By calculations from STEP 1 to 3, the capacity of Lossnay + Dx-coil unit is summate as shown below.
Capacity calculation result
(A) Required heating capacity
(B) Lossnay energy recovery
(C) Dx-coil heating capacity
(D) Lossnay + DX-coil unit system heating capacity
= (B) + (C)
As a result, (D) is bigger than (A).
Therefore, under this example condition, Lossnay + Dx-coil unit system has enough capacity as all-in-one air-conditioning system.
9
Model selection and capacity calculation
CHAPTER
1
2-1
2-2
2
using the capacity correction ratio curve on the page 63.
3
3
= 8.1 x 1.0 x 0.74 x 1.0
3
= C
/ (ρ x Q
o
a
f
[kJ/kg(DA)]
i
Dry-bulb temperature
Wet-bulb temperature
Absolute humidity
Relative humidity
Enthalpy
, see the page 63.
2
/ 3600)+h
[kJ/kg(DA)]
i
Supply Air from Dx-coil unit
1000 m
/h
3
1000 m
/h
3
1.0
1.0
1.02
1 ˚CWB
–
16.8 ˚CDB
0.75
0.74
7.5 m
1.0
8.1 kW
6.0 kW
31.7 kJ/kg(DA)
6.0 kW
49.7 kJ/kg(DA)
[°C]
34.5
[°C]
17.8
[kg/kg(DA)]
0.0058
[%]
17
[kJ/kg(DA)]
49.7
13.8 kW
8.0 kW
6.0 kW
14.0 kW
52
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