1
2
3
4
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■
■
■
■
■
NOTE
Depending on the expected lowest outdoor temperature, make sure
the water system is filled with a weight concentration of glycol as
Charging water
mentioned in the table below.
Connect the water supply to a drain and fill valve (see "Main
Minimum outdoor temperature
Glycol
(a)
components" on page 12).
23°F (
–5°C)
10%
Make sure the automatic air purge valve is open (at least 2
14°F (
–10°C)
15%
turns).
5°F (
–15°C)
20%
Fill with water until the manometer indicates a pressure of
–10°F (–20°C)
25%
approximately 29 psi (2.0 bar). Remove air in the circuit as much
as possible using the air purge valves. Air present in the water
WARNING
circuit might cause malfunctioning of the backup heater.
(a)
ETHYLENE GLYCOL IS TOXIC
Check that the backup heater vessel is filled with water by
The concentrations mentioned in the table above will not
prevent the medium from freezing, but prevent the
opening the pressure relief valve. Water must flow out of the
valve.
hydraulics from bursting.
NOTE
During filling, it might not be possible to remove all
Caution: "Us e of glycol"
Caution: Use of glycol
air in the system. Remaining air will be removed
through the automatic air purge valves during first
Use of glycol for installations with a domestic hot
operating hours of the system. Additional filling
water tank:
with water afterwards might be required.
- Only propylene glycol having a toxicity rating or
The water pressure indicated on the manometer
class of 1, as listed in "Clinical Toxicology of
will vary depending on the water temperature
Commercial Products, 5th edition" may be used.
(higher pressure at higher water temperature).
- An approved pressure relief valve of 30 psi
(2.0 bar) must be installed at the inlet of the
domestic hot water tank heat exchanger.
However, at all times water pressure should
remain above 43.5 psi (0.3 bar) to avoid air
entering the circuit.
The maximum allowed water volume is then reduced
according to the figure "Maximum allowed water
volume" on page 15.
Refer to the installation manual of the domestic hot
water tank for more information.
The unit might dispose some excessive water
through the pressure relief valve.
Water quality must be according to "Safe Drinking
water Act (42 U.S.C. 300f)".
In case of over-pressure when using glycol, be sure to
connect the safety valve to a drain pan in order to
Piping insulation
recover the glycol.
The complete water circuit, inclusive all piping, must be insulated to
Corrosion of the system due to presence of glycol
prevent condensation during cooling operation and reduction of the
heating and cooling capacity as well as prevention of freezing of the
Uninhibited glycol will turn acidic under the influence of
outside water piping during winter time. The thickness of the sealing
oxygen. This process is accelerated by presence of copper
and at higher temperatures. The acidic uninhibited glycol
materials must be at least 1/2 inch (13 mm) with
= 0.275 Btu-inch/hr sq ft
2
.°F (0.039 W/mK) in order to prevent
attacks metal surfaces and forms galvanic corrosion cells
freezing on the outside water piping.
that cause severe damage to the system.
If the temperature is higher than 86°F (30°C) and the humidity is
It is therefore of extreme importance:
higher than RH 80%, then the thickness of the sealing materials
■
that the water treatment is correctly executed by a
should be at least 3/4 inch (20 mm) in order to avoid condensation on
qualified water specialist;
the surface of the sealing.
■
that a glycol with corrosion inhibitors is selected to
counteract acids formed by the oxidation of glycols;
■
that in case of an installation with a domestic hot
water tank, only the use of propylene glycol is
allowed. In other installations the use of ethylene
glycol is permitted as well;
■
that no automotive glycol is used because their
corrosion inhibitors have a limited lifetime and contain
silicates which can foul or plug the system;
■
that galvanized piping is not used in glycol systems
since its presence may lead to the precipitation of
certain components in the glycol’s corrosion inhibitor;
■
that it has to be made sure the glycol is compatible
with the used materials in the system.
Be aware of the hygroscopic property of glycol: it
absorbs moisture from its environment.
Leaving the cap off the glycol container causes the
concentration of water to increase. The glycol
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 glycol to air.
Also refer to "Checks before initial start-up" on page 24.
Installation manual
EDLQ036~054B EBLQ036~054BA6VJU1
16
Unit for air to water heat pump system
4PW56182-1
