To Protect The Water Circuit Against Freezing - Daikin Altherma 3 H MT ECH2O Series Installation Manual

5 Piping installation
e.1 Valve motor
e.2 Valve motor latch
f Water tap
g Automatic air purge valve
h Pressure gauge (field supply)
i Pressure vessel (field supply)
j Bypass valve
k Tank valve
2 Prepare for air purging according to the instructions (see
purge" [ 4 37]).
"8.2.2 To perform an air
3 Open the water tap.
4 Open fill and drain valve and monitor the manometer.
5 Fill the system with water until the external manometer shows
that the system target pressure is reached (system height +2 m;
1 m water column = 0.1 bar). Make sure that the pressure relief
valve does not open.
6 Close the manual air vent valves as soon as water emerges
free of bubbles.
7 Close the water tap. Keep the fill and drain valve open in case it
is necessary to repeat the filling procedure after the air purging
of the system. See "8.2.2 To perform an air
8 Close the fill and drain valve and remove the hose with non-
return valve only after air purging is performed and the system
is completely filled.
5.2.4 To protect the water circuit against
freezing
About freeze protection
Frost can damage the system. To prevent the hydraulic components
from freezing, the software is equipped with special frost protection
functions such as water pipe freeze prevention and drain prevention
(see the installer reference guide) that include the activation of pump
in case of low temperatures.
However, in case of a power failure, these functions cannot
guarantee protection.
Do one of the following to protect the water circuit against freezing:
▪ Add glycol to the water. Glycol lowers the freezing point of the
water.
▪ Install freeze protection valves. Freeze protection valves drain the
water from the system before it can freeze. Insulate the freeze
protection valves in a similar way as the water piping, but do NOT
insulate the inlet and outlet (release) of these valves.
NOTICE
If you add glycol to the water, do NOT install freeze
protection valves. Possible consequence: Glycol leaking
out of the freeze protection valves.
Freeze protection by glycol
About freeze protection by glycol
Adding glycol to the water lowers the freezing point of water.
Installation manual
12
purge" [ 4 37].
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
–5°C
–10°C
–15°C
–20°C
–25°C
–30°C
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.
Prevent from
bursting
10%
15%
20%
25%
30%
35%
INFORMATION
▪ Protection against bursting: the glycol will prevent the
piping from bursting, but NOT the liquid inside the
piping from freezing.
▪ Protection against freezing: the glycol will prevent the
liquid inside the piping from freezing.
Prevent from
freezing
15%
25%
35%
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ETSH/X(B)12P30+50EF
Daikin Altherma 3 H MT ECH₂O
4P663479-1 – 2021.07