0603RHC4-JLGBEN
17
/
21
Consequently, 2.06m³/s (7413 m³/h) flows through the
heat exchanger enclosure and the remaining 1.55m³/s
(=5587m³/h) (= 3.61m³/s – 2.06m³/s) flows through
the by-pass channel.
From section 4.1.2 the maximum allowable airflow
through the heating module enclosure is 23979 m³/h
(for this example).
We notice the 7413m³/h is still below this maximum
allowable figure. Consequently there is no probability
of condensation forming within the tubes.
Pressure drop :
The total pressure drop can be derived from figure 12.
Use the air flow through the heat exhanger enclosure
to determine the total pressure drop. (@7413 m³/h)
Result : 70Pa (approx)
Figure 13a
Figure 13b
12.0 Installation of RHC
units in series
12.1 General
12.1.1 Two RHC 4000(M) units can be installed in
series. Units can be bolted together using the
pre-punched holes in the duct flanges (see fig.
3 for dimensions B and C). Apply a sealant
between two units in order to avoid air leakage.
12.1.2 Each individual unit requires its own
combustion circuit as described in sections 8.0
& 9.0.
12.1.3 Instructions
concerning the burner and controls
section (see section 5.0) must be followed.
The controls sections of the 2 units in series
can be combined, resulting in one enclosure.
The recommendations as described in section
4.1.2 are applicable for RHC units when
installed in series. Checking the possibility of
condensation forming within the tubes must be
done (heating section by heating section),
taking into account the expected minimum inlet
temperature and the heat output conditions for
each individual heating section.
12.2
Limitations for use
12.2.1 Minimum airflow requirement through heat
exchanger enclosure :
For RHC units, installed in series, the minimum
airflow duty through the heat exchanger
enclosure (see fig. 4 – table 1) must be
observed as indicated in table 7.
12.2.2 Maximum airflow through heat exchanger
enclosure :
12.3
Pressure loss through multiple heating
modules
The charts below (figures 14) indicates the
pressure loss over the heating module versus
the total air volume through the heat exchanger
enclosure (see figure 4 and table 1). The
temperature rise (
△
T) as shown is for 100%
heat output.
Table 7 :Minimum airflow requirements for 2 RHC
units in series :
Model
V (m
³
/h)
Model
V (m
³
/h)
2x 4050-06
5950 2x 4110M,13
13600
2x 4060-07
7150 2x 4125M,15
15600
2x 4075-09
8800 2x 4150M,18
17500
2x 4100-12
11700 2x 4175M,21
20600
2x4200M,24
23300
V = min. airflow required through heat exchanger
enclosure
