FläktGroup Multi-DENCO - Page 82

Medium Connections Multi-DENCO
82 FläktGroup DC-2013-0101-GB • Subject to modifications • R5-08/2020
When using glycol:
• Water-glycol mixture does not have a burst effect starting from frost resistance of
-20 °C, as slush ice forms when the mixture is cooled below the freezing point.
• Use only one type of glycol, do not mix different types.
• Only charge the system with a prepared water-glycol mixture.
• Do not use Teflon seals if using water-glycol mixtures.
• Add glycol concentration to match the ambient temperatures to ensure energy
consumption of the pump is not excessively increased.
• Once a system is filled, always double check the water-glycol concentrations.
Minimum concentrations to prevent corrosion:
– Ethylene glycol = 20% by volume
– Propylene glycol = 25% by volume.
6.6.5 Connecting chilled water pipework
Access to water pipe connections can sometimes be difficult if there is no side access.
The procedure to remove indoor fans to allow easier access to the connections is in
chapter 6.2.12.
• Connect the piping system, to the chilled water inlet/outlet in accordance with best
practice and conforming to and local and national regulations.
6.6.6 Hot water heating (optional)
The L.P.H.W. (low pressure hot water) coil is fitted with a modulating three port valve,
which is wired and fitted within the unit casing.
It is important to consider the fitting of commissioning sets in the supply/return pipe-
work to allow accurate water measurements and flow adjustments. These should be
supplied and fitted in accordance with the manufacturer's recommendations.
The installation of the hot water pipework is similar to that of the chilled water pipework
(chapter 6.6.5).
NOTICE
Excessive volumes of glycol within a chilled water system can result in poor heat
transfer, increased viscosity and possible damage to pumps and valves.
• Glycol content must be less than 50% of total system content.
NOTICE
Incorrect fitting of water inlet and outlet connections can result in leaks and cooling
capacity reduction.
• Counter hold connection fittings to prevent damage.
– We recommend using a pipe wrench.
NOTE!
There are three different available connections depending on the size of the equip-
ment (see unit type code)
– 'BSP pipework connections'
– 'Flange pipework connections'
– 'Solder connections'