21
VTS reserves the right to implement changes without prior notice
Ventus Air Handling Units
Fig.11. Securing the screwed connections of the exchanger
Table4. Types of exchanger interceptors connections
Rated diameter of the connectors Dn [mm]
Water exchangers
Interceptor connection material
Way of connecting the interceptor
20
Brass
R 3/4” thread
25
Brass
R 1” thread
32
Brass
R 1 1/4” thread
50
Steel
R 2” thread
80
Steel
R 3” thread
Freon coolers regardless their rated diameter are equipped with copper connections adapted for hard soldering.
Supply and return exchanger connections should be connected so as the exchanger operates in a
counter- current way. Streamwise operation results in lower average temperature difference,
influencing the exchanger’s performance.
In the AHUs sizes VS 400-650 the water heat exchanger is divided for two coils. The supply
of these exchangers should be done in parallel
Note! Maximum operating pressure of the medium for water coils is 16 bar, tested
pressure – 21 bar.
Table 5 Requirements of the quality medium for the water coils:
Parameter
Value
Oil and grease
< 1 mg/l
pH at 25°C
8 to 9
Residual water hardness
[Ca
2+
,Mg
2+
]/[HCO
3
-
] >0.5
Oxygen
<0.1 mg/l
(as low as possible)
Examples of connecting supply and return pipelines for various AHU versions shown in the picture.
