Formula To Calculate The Expansion Vessel Pre-Pressure; To Check The Water Volume And Flow Rate Of The Space Heating Circuit And Brine Circuit - Daikin EGSQH10S18AA9W Installer's Reference Manual

6 Preparation
WARNING
Due to 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.
INFORMATION
Be aware of the hygroscopic property of anti-freeze fluids:
it absorbs moisture from its environment. Leaving the cap
off the anti-freeze fluid container causes the concentration
of water to increase. The anti-freeze fluid concentration is
then lower than assumed. And in consequence, freezing
can happen after all.
Preventive actions MUST be taken to ensure minimal
exposure of the anti-freeze fluid to air.
▪ Non-brass metallic piping. When using non-brass metallic
piping, insulate the brass and non-brass properly so that they do
NOT make contact with each other. This to prevent galvanic
corrosion.
▪ Valve – Change‑over time. When using a 2-way valve in the
space heating circuit, the maximum change-over time of the valve
MUST be 60 seconds.
▪ Domestic hot water tank – Capacity. To avoid stagnation of
water, it is important that the storage capacity of the domestic hot
water tank meets the daily consumption of domestic hot water.
▪ Domestic hot water tank – After installation. Immediately after
installation, the domestic hot water tank must be flushed with fresh
water. This procedure must be repeated at least once a day the
first 5 consecutive days after installation.
▪ Domestic hot water tank – Standstills. In cases where during
longer periods of time there is no consumption of hot water, the
equipment MUST be flushed with fresh water before usage.
▪ Domestic hot water tank – Disinfection. For the disinfection
function of the domestic hot water tank, see
water control: advanced" on page 46.
▪ Thermostatic mixing valves. In accordance with the applicable
legislation, it may be necessary to install thermostatic mixing
valves.
▪ Hygienic measures. The installation must be in compliance with
the applicable legislation and may require additional hygienic
installation measures.
▪ Recirculation pump. In
legislation, it may be required to connect a recirculation pump in
between the hot water end point and the recirculation connection
of the domestic hot water tank.
c
a b
d
Installer reference guide
20
"8.3.2 Domestic hot
accordance with the applicable
a Recirculation connection
b Hot water connection
c Shower
d Recirculation pump
6.3.2 Formula to calculate the expansion vessel
pre-pressure
The pre-pressure (Pg) of the vessel depends on the installation
height difference (H):
Pg=0.3+(H/10) (bar)
6.3.3 To check the water volume and flow rate
of the space heating circuit and brine
circuit
The indoor unit has 2 expansion vessels of 10 litre, one for the
space heating circuit and one for the brine circuit.
To make sure that the unit operates properly:
▪ You must check the minimum and maximum water volume.
▪ You might need to adjust the pre-pressure of the expansion
vessel.
▪ You must check the total space heating water volume unit.
▪ You must check the total brine water volume in the unit.
Minimum water volume
Check that the total water volume per circuit in the installation is
minimum 20 litre, the internal water volume of the indoor unit NOT
included.
INFORMATION
If a minimum heating load of 1 kW can be guaranteed and
setting [9‑04] is changed by the installer from 1 to 4°C, the
minimum water volume can be lowered to 10 litre.
INFORMATION
In critical processes, or in rooms with a high heat load,
extra water might be required.
NOTICE
When circulation in each space heating loop is controlled
by remotely controlled valves, it is important that the
minimum water volume is guaranteed, even if all of the
valves are closed.
e
e
e
a
c
d d
b b
a Indoor unit
b Heat exchanger
c Backup heater
d Pump
e Shut-off valve (field supply)
f Collector (field supply)
g By-pass valve (field supply)
T1 T2 T3
f
M1 M2 M3
g
f
FHL1
FHL2
FHL3
EGSQH10S18AA9W
Daikin Altherma ground source heat pump
4P351748-1D – 2016.02