R3400 Technical data - Rendamax

Rendamax
Fig. 21
Distance between air inlet and flue gas outlet
The formation of unwanted condensation must be avoided. In the event that during the heating up
period condensation oc curs, the condensate must be able to flow back to the unit. Inspection of
the air supply and flue pipe must be possible.
The connection, exit position and height in relation to possible obstacles must comply with the
applicable national and local standards and regulations (see Supplement).
5.3.5 The Flue system
5.3.5.1 General
The flue pipe connection is at the rear of the appliance and has been designed for direct connection
to a corrosion resisting flue pipe.
Condensation forms because of the high boiler efficiency and the considerable degree of cooling
of the flue gasses that takes place against the walls of the flue pipe. In order to reduce flue gas
condensation as much as possible, the use of a double-walled and insulated flue pipe is recommended.
Aluminium or stainless steel is strongly recommended. Because a slight overpressure
exists in the flue pipe during a cold start-up, flue pipes should preferably be constructed from
seamless materi als. When the boiler functions as a high capacity boiler, the high efficiency can
lead to the formation of condensation in the chimney.
y
The condensate drain must never become blocked!
Direct connection to brick built stacks is not permitted because the combustion efficiency of the
boiler is › 83 %. The combus tion products at low flue gas temperatures will damage the stack.
The following table lists all the flue gas data for all types of boiler.
32 Doc890/3456CV02B