Kostrzewa Mini Bio 10 Notice Technique page 69

5. Design guidelines
5.D Water quality requirements
The water quality affects life and efficiency of the heating devices and
the entire system. Incorrect water parameters will result in the corro-
sion of heating device surfaces, transport ducts or lime scale deposits
thus leading to the 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.
The water for filling 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 require-
ments 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 flue system must conform to the relevant standards and
regulations.
The flue system removes a flue gas from a boiler room to the atmos-
phere. The flue system creates draught determined by:
temperature gradient between the flue gas temperature and the
ambient temperature (difference in density and pressure)
flue length
flue shape (bends, inclination, draught breaker etc.)
flue cross section
flue diameter (flue diameter must correspond to the boiler's flue
connector diameter)
flue internal surface roughness
flue cleanness flue gas tightness (seals, grouts etc.)
flue thermal insulation
changes in ambient conditions (temperature, pressure
fluctuations due to the air flow, roof shape, flue location in
relation to building envelope components etc.)
Experts in heating
The diameter of a duct connecting the boiler with the flue must cor-
respond to the diameter of the boiler's flue connector. Do not use any
reducing couplings of the boiler's flue connector or the flue. A tran-
sition between the flue and the duct may include a tee with a correct
combination of diameters. The flue design must guarantee that the
flue gas temperature at the entire flue length to the outlet is higher
than a dew point of the flue gas from a specific boiler (dry operation).
The flue and the smoke ducts must be fitted with drains or inspection
holes with sealed doors and in case of wet flue gas also with a con-
densate drain valve.
Guidelines:
in the lower range of Mini Bio / Mini Bio Luxury power, the flue
gas temperature may fall below 100°C, the boilers must be con-
nected to the moisture resistant flues (acid proof liners - steel
sheet, vitrified clay recommended); if the boiler is not connected
to the moisture resistant flue, perform required calculations or
use the existing flue data;
the connection between the boiler's flue connector and the flue
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 flue
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 flue duct length must not exceed the effective flue
height or 7 metres
Mini Bio and Mini Bio Luxury User Manual - ENGV 08.15
69