Kostrzewa Twin Bio Manual De Uso página 65

5. Design guidelines
5.D. Water quality requirements
The water quality affects the life and effi ciency of heating
devices and the entire system. Incorrect water parameters will
result in the corrosion of heating device surfaces, transport
ducts or lime scale deposits. It may lead to failure or damage
of the entire heating system. The warranty does not cover any
damage caused by corrosion and lime scale deposits.
Strict adherence to the water quality requirements is
a precondition for the warranty.
Boiler water requirements:
The water for fi lling boilers and heating systems must meet
the requirements of relevant standards and regulations.
Required boiler water parameters:
• pH >8.5
• total hardness <20°f
• free oxygen content <0.05 mg/l
• chloride content <60 mg/l
The treatment method for water used in the heating systems
must meet the above requirements. Use of antifreeze additives
must be consulted with the manufacturer (KOSTRZEWA). Failure
to comply with the boiler water quality requirements may result
in damage to the heating system components (e.g. boiler) and
is not covered by the warranty. It may invalidate the warranty
and result in additional charges in case an authorised service
centre is involved.
5.E. Flue system guidelines
The fl ue system must conform to the relevant standards
and regulations.
The fl ue system removes fl ue gas from the boiler room to the
atmosphere. The fl ue system creates draught determined by:
• temperature gradient between the fl ue gas temperature
and the ambient temperature (difference in density and
pressure);
• fl ue length;
• fl ue shape (bends, inclination, draught breaker etc.);
• fl ue cross section;
• fl ue diameter (fl ue diameter must correspond to the boiler's
fl ue connector diameter);
• fl ue internal surface roughness;
• fl ue cleanness;
• fl ue gas tightness (seals, grouts etc.);
• fl ue thermal insulation;
• changes in ambient conditions (temperature, pressure
fl uctuations due to the air fl ow, roof shape, fl ue location in
relation to building envelope components etc.).
Experts in heating
The diameter of the duct connecting the boiler with the fl ue
must correspond to the diameter of the boiler's fl ue connector.
Do not use any reducing couplings of the boiler's fl ue connector
or the fl ue. The transition between the fl ue and the duct may
include a tee with a correct combination of diameters.
The fl ue design must guarantee that fl ue gas temperature at
the entire fl ue length to the outlet is higher than the dew point of
the fl ue gas from a specifi c boiler (dry operation). The fl ue and
smoke ducts must be fi tted with drains or inspection holes with
sealed doors and in case of wet fl ue gas also with a condensate
drain valve.
Guidelines:
• in the lower range of Twin Bio boiler, fl ue gas temperature
below 100°C may be observed and therefore the boiler must
be connected to moisture resistant fl ues (acid proof liners
– steel sheet, vitrifi ed clay recommended);
• if the boiler is not connected a the moisture resistant fl ue,
perform required calculations or use the existing fl ue data;
• the connection between the boiler's fl ue connector and the
fl ue must be insulated and as short as possible, slightly
upwards without sharp bends and a minimum number of
bends;
• the smallest diameter or cross section of a natural draught
fl ue and a smoke duct must be min. 0.14 m, whereas
the smallest diameter must be min. 0.12 m if the steel liners
are used;
• horizontal fl ue duct length must not exceed the effective fl ue
height or 7 metres.
User Manual Twin Bio - PLV 09.13
65