14
GENERAL SPECIFICATIONS
- Option B
(unit for system with 4 pipes)
The considerations made for selection A
are also valid when it comes to selecting for cold mode operation. In
this case, evaluate how to supply supplementary bank
BS-F2
envisaged as optional. Remember that the informa-
tion in the documentation refers to the top speed of the fan, thus the required efficiency parameter must be calcu-
lated again.
Use
Tab.6
attached to
Graph 3
Thermal power required at top speed
Pt max = 4000/0.85 = 4700 [Watt]
Graph 3
shows that with an ambient air temperature of
20 [°C]
, model
40
is unable to supply this power even when
supplied with water at
85 [°C]
and with a minimum
DD
t
of about
5 [°C]
. In these conditions, the maximum power deli-
vered by the unit at top speed is
4300 [Watt]
. Once this solution has been accepted,
Graph 3
shows that the requi-
red
4000 [Watt]
power can be obtained with an inlet water temperature of
85[°C]
and a
DD
t
of
16[°C]
or with an inlet
temperature of
80[°C]
and a
5[°C]
DD
t
. The second hypothesis requires the following water flow rate:
Qw=
Water flow rate [l/h]
DD
w3=
Water density at 80 °C [Kg/dm³]
Cpw3=
Specific heat of the water at 80°C [J/kg·K]
This water flow rate is not compatible with the application limits given in
Tab.3
. If the solution with inlet water at the
temperature of
85[°C]
and a
DD
t
of
16[°C ]
is used, the water flow rate should be
221 [l/h]
. In this case, the load loss
of the exchanger in model
BS-F2
can be found by means of
Graph 5
and is
10 [KPa]
. If valve kit
VB1-F
is used,
the additional load losses with the unit supplied would be shown by
Graph 15
and are
4 [KPa]
.
At this stage,
Tab.9
can be used to find the noise level produced by the selected unit (i.e. model
40
) operating at
medium speed in cold mode and at top speed in heating mode. This corresponds to an acoustic power rating of
47
dB[A]
and a corresponding sound pressure of
38 dB[A]
measured in cold mode operation in the indicated condi-
tions; with an acoustic power rating of
54 dB[A]
and with a corresponding acoustic pressure of
45 dB[A]
for ope-
ration in heating mode, again measured in the indicated conditions.
- Option C
(unit for systems with two pipes plus electric heating element)
Here again, selection for cold mode operation is the same as described for selection
A
. When it comes to operation
in heating mode and if the electric heating element is used as sole source of heat, the maximum power it delivers
can be found in the
Tab.
attached to
Fig.33
concerning model
RE-F2
, which can be used with model
40
and is
1500
[Watt]
, and which does not depend on the fan speed. In this case, the
4000 Watt
required can only be obtained by
integrating the power supplied by the electric heating element with the power supplied by the main bank fed with
hot water. Upgraded electronic thermostats
TE-F
and
TER-F
allow the electric power delivery to be controlled by
integrating the two sources or by selecting the electric heating element as single heat source. This option can be
selected in the installation phase by means of the dip switches on the thermostats. If the electric heating element is
used as integrating source, it will activate when the temperature of the water drops below
40 [°C]
.
- Option D
(unit for systems with two pipes for ducted installation)
Let us suppose that the unit must be installed in a false ceiling and that the air intake and delivery sections must be
ducted. The considerations made in example A for both cold and heating mode operation should be taken into
account when the most appropriate model is chosen. After this, the motor should be examined to ensure that the
fan is able to account for the load losses introduced by the air ducting system. Given the initial power delivery and
fan speed conditions, model
40
at an average speed processes
400 [m³/h]
of air, as shown in
Tab.2
. Supposing
that the overall ducting system, including any intake grilles mounted, the intake channel, delivery plenum, delivery
channel and delivery grille is around
45 [Pa]
with an air flow rate of
400 [m³/h]
and also considering that in the dehu-
midifying phase the additional load loss in the exchanger is about
4 [Pa]
as shown by the dotted curve in
Graph9
,
this same graph also shows that the most appropriate electrical connection to obtain that working head is connec-
tion
L-2
rather than connection
L-4
indicated by boldface and corresponding to the standard connection envisaged
for the medium speed. This means that the red and blue connection flexes for the maximum and medium speeds
must be respectively moved to positions 1 and 2.
]
h
/
l[
707
4196
97
.
0
5
3600
4000
cp
t
Pft
Qw
3
W
3
W
max
=
×
×
×
=
×
r
×
D
=
Содержание TOP FAN
Страница 49: ...NOTE...
Страница 50: ...NOTE...
