Robur GAHP Line AR Series, Инструкция по установке, эксплуатации и обслуживанию

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GAHP-AR – Installation, start-up, use and maintenance manual
40
Edition: 2014-08
Table 13 gives the approximate freezing temperature of the water, the consequent
increased pressure drop of the appliance and of the circuit, according to the percentage of
monoethylene glycol. This table should be taken in regard for the sizing of the pipes and
the circulation pump (for calculation of internal pressure drops of the appliance, refer to
the TECHNICAL DATA paragraph, on page 9).
Nevertheless, it is advisable to consult the technical specifications of the monoethylene
glycol used. If automatic loading systems are used, a seasonal check of the quantity of
glycol present in the plant is also necessary.
% of MONOETHYLENE
GLYCOL
10 15 20 25 30 35 40
WATER FREEZING POINT
TEMPERATURE
26.6 °F 23.0 °F 17.6 °F 10.4 °F 5.0 °F -4.0 °F -13.0 °F
PERCENTAGE OF
INCREASE IN PRESSURE
DROPS
— 6% 8% 10% 12% 14% 16%
LOSS OF EFFICIENCY OF
UNIT
— 0.5% 1% 2% 2,5% 3% 4%
Table 13 - Approximate water freezing point temperatures
As other hydronic appliances, Robur heating and cooling systems operate with grid-water
of good quality. In order to prevent any possible problem of operation or reliability caused
by filling or top-up water, please refer to codes and norms about water treatment for
thermo-hydraulic installations in civil or industrial applications. Parameters indicated in
Table 14 must be complied with.
CHEMICAL AND PHYSICAL PARAMETERS OF WATER IN HAETING/COOLING SYSTEMS
PARAMETER UNIT OF MEASUREMENT ALLOWABLE RANGE
pH \ > 7
(1)
CHLORIDES ppm < 125
TOTAL HARDNESS (CaCO
3
) °f < 15
IRON ppm < 0.5
(1)
COPPER ppm < 0.1
(1)
ALUMINIUM ppm < 1
LANGELIER’S INDEX \ 0 – 0.4
HARMFUL SUBSTANCES
FREE CHLORINE ppm < 0.2
(1)
FLUORIDES ppm < 1
SULPHIDES ABSENT
(1) In accordance and respecting current and local regulation
Table 14 – Chemical and physical parameters of water.
Water quality can be measured through parameters like acidity, hardness, conductivity,
chlorides content, chlorine content, iron content and the like.
The presence of active chlorine in the water, in particular, can jeopardize parts of
the installation and Robur units. Therefore, please make sure that active chlorine
content and total hardness are compliant with the allowable ranges reported in
Table 14.