5 Piping installation
Installation manual
9
ETBH/9W
Daikin Altherma 3 H MT W
4P634879-1 – 2021.03
b
a
a
Water IN (screw connection, 1")
b
Space heating water OUT (screw connection, 1")
NOTICE
Overpressure bypass valve
(delivered as accessory). We
recommend to install the overpressure bypass valve in the
space heating water circuit.
▪ Mind the minimum water volume when choosing the
installation location of the overpressure bypass valve
(at the indoor unit, or at the collector). See
check the water volume and flow rate"
8].
▪ Mind the minimum flow rate when adjusting the
overpressure bypass valve setting. See
check the water volume and flow rate"
8] and
"8.2.1 To check the minimum flow rate"
32].
NOTICE
Install air purge valves at all local high points.
NOTICE
In case an optional domestic hot water tank is installed: A
pressure relief valve (field supply) with an opening
pressure of maximum 10 bar (= 1 MPa) must be installed
on the domestic cold water inlet connection in accordance
with the applicable legislation.
5.2.2
To fill the water circuit
To fill the water circuit, use a field supply filling kit. Make sure you
comply with the applicable legislation.
NOTICE
Make sure both air purge valves (one on the magnetic filter
and one on the backup heater) are open.
All automatic air purge valves MUST remain open after
commissioning.
5.2.3
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.
WARNING
Ethylene glycol is toxic.
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.
Types of glycol
The types of glycol that can be used depend on whether the system
contains a domestic hot water tank:
