Hoval RoofVent CON-9, Design Handbook

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255
B
C
E
E
F
G
H
I
J
K
L
M
N
Total ventilation cold requirement Q
V
(in kW)
Q
V
= V · ρ· c · (t
fresh
– t
room
)
ρ = Specific air density 1.2 kg/m³
c = Specific heat capacity of the air 2.79 · 10
-4
kWh/kg K
t
fresh
= Design fresh air temperature in °C
t
room
= Desired room temperature in °C
Q
V
= 18'360 · 1.2 · 2.79 · 10
-4
· (30 – 24)
Q
V
= 37 kW
Required sensible cooling capacity total Q
C
(in kW)
Q
C
= Q
CL
+ Q
V
Q
CL
= Cooling load in kW
Q
C
= 260 + 37
Q
C
= 297 kW
Required sensible cooling capacity per unit Q (in kW)
Q = Q
C
/ n
Q = 297 / 12
Q = 25 kW
Selection of coil type
■ First, use Table J8 to define the air inlet temperature at
the cooling coil.
■ Using the required cooling capacity per unit and the air
inlet conditions at the cooling coil, select the required coil
type from Table J9 or Table J10.
Note
Note that the total cooling capacity Q
tot
must be used
for dimensioning of the chiller.
For the fresh air conditions 30 °C / 40% and the extract air
temperature 26 °C, the air inlet conditions at the cooling coil
are 28 °C / 40 %.
Select coil type C with 25 kW sensible cooling capacity at
LPCW 6/12 °C and air inlet conditions 28 °C / 40 %.
Checking the ancillary conditions
■ Maximum floor area reached
Calculate the floor area reached per unit using the
selected number of units. If it exceeds the maximum
value listed in Table J4, increase the number of units.
■ Compliance with minimum and maximum distances
Check the resulting distances based on the hall geometry
and arrangement of the units, using the information in
Table J11.
Floor area per unit = 108 · 40 / 12 = 360 m²
Max. floor area reached = 729 m²
→ OK
Minimum and maximum distances can be complied with
when units are arranged symmetrically.
→ OK
Definitive number of units
With a larger number of units, there is more flexibility of
operation. However, the costs are also higher. For an
optimal solution, compare both the costs and ventilation
quality of the system.
12 LK-9s with cooling coil type C are selected. They guar-
antee cost-effective and energy-saving operation.
RoofVent
®
LK
Design example