8
4.
CONNECTION TO SYSTEMS AND START-UP
4.1.
CONNECTION TO DUCTS
At the points of connection to the air ducts, the Air
Treatment Units have a smooth or a flanged surface.
In order to optimise the connection with the ducts, you
must:
- clean the connection edges between duct and unit
- fit a seal to the flanges in order to prevent air
infiltration
- tighten the connecting screws firmly
- treat the joint with silicone to enhance the seal.
If the connection is made with rubberised canvas
joints, make sure they are not taut on completion of
assembly so as to prevent damage or the transmission
of vibrations.
In order to ensure the tightness of the connections and
the integrity of the unit structure, the weight of the
ducts must under no circumstances bear down on the
unit. The ducts must be supported by BRACKETS.
4.2.
CONNECTION OF HEAT EXCHANGERS
In order to prevent damage to the exchanger at the
joint between the steel manifold and the copper
circuits, you must:
- Use a pipe wrench to apply force in the opposite
direction when making the connection to the mains
pipe (fig. 1.1)
- Fit brackets to support the connecting pipes.
The weight of the pipes must under no circumstances
bear down on the manifold.
4.2.1. Water exchange
In order to ensure an optimum heat exchange, you must:
- WASH the heat exchanger before connecting it to the
water mains
- once installed in a workmanlike fashion, any air present
in the hydraulic circuit must be expelled using the
relevant valve.
To allow easy extraction of the exchanger during
maintenance:
- the connections to the mains must be made in such a way
as to allow removal of the exchanger
- ON-OFF VALVES must be installed to exclude the heat
exchanger from the hydraulic circuit
- A VALVE must be installed on the lower manifold to allow
complete drainage, and a VALVE must be titled to the
upper manifold to vent the air from the exchanger (fig. 12)
The normal heat exchange in a heating or cooling water
exchanger occurs in REVERSE CURRENT (fig. 13).
In order to prevent the formation of ice in the heating
units in the presence of particularly low outside
temperatures, an EQUICURRENT heat exchange system
may be provided (fig. 14).
This configuration must be determined at the design stage
and not during installation, since an obvious reduction in
efficiency will result if a heat exchanger sized for reverse
current heat exchange is used for equicurrent operation.
