Daikin EPRA08EAV3, Installer'S Reference Manual

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8 | Piping installation
Installer reference guide
92
EPRA08~W1 + ETVH/9W
Daikin Altherma 3 H MT F
4P634886-1 – 2021.03
WARNING
Due to the presence of glycol, corrosion of the system is possible. Uninhibited glycol
will turn acidic under the influence of oxygen. This process is accelerated by the
presence of copper and high temperatures. The acidic uninhibited glycol attacks
metal surfaces and forms galvanic corrosion cells that cause severe damage to the
system. Therefore it is important that:
▪
the water treatment is correctly executed by a qualified water specialist,
▪
a glycol with corrosion inhibitors is selected to counteract acids formed by the
oxidation of glycols,
▪
no automotive glycol is used because their corrosion inhibitors have a limited
lifetime and contain silicates which can foul or plug the system,
▪
galvanized pipes are NOT used in glycol systems since the presence may lead to
the precipitation of certain components in the glycol's corrosion inhibitor.
NOTICE
Glycol absorbs water from its environment. Therefore do NOT add glycol that has
been exposed to air. Leaving the cap off the glycol container causes the
concentration of water to increase. The glycol concentration is then lower than
assumed. As a result, the hydraulic components might freeze up after all. Take
preventive actions to ensure a minimal exposure of the glycol to air.
NOTICE
Use ONLY propylene glycol including the required inhibitors, classified as category III
as per EN1717.
Types of glycol
The types of glycol that can be used depend on whether the system contains a
domestic hot water tank:
If… Then…
The system contains a domestic hot
water tank Only use propylene glycol
(a)
The system does NOT contain a
domestic hot water tank You can use either propylene glycol
(a)
or
ethylene glycol
(a)
Propylene glycol, including the necessary inhibitors, classified as Category III according to
EN1717.
Required concentration of glycol
The required concentration of glycol depends on the lowest expected outdoor
temperature, and on whether you want to protect the system from bursting or
from freezing. To prevent the system from freezing, more glycol is required.
Add glycol according to the table below.
Lowest expected outdoor
temperature Prevent from bursting Prevent from freezing
–5°C 10% 15%
–10°C 15% 25%
–15°C 20% 35%
–20°C 25% —
–25°C 30% —
–30°C 35% —