16
Piping installation
English
Piping instal
lation
Unit resistance and PHE resistance by glycol
concentrate
The unit is composed of water pipes and PHE basically.
To ensure correct operation and predict the expected
performance, Flow and Resistance table can be used and Flow and
resistance characteristic is dependent on Glycol concentration.
0
10
20
35
40
50
60
70
10
20
35
40
50
60
70
20
40
60
80
100
120
140
0
10
20
30
40
50
60
AE050CXYD**/AE080CXYD**
Water Flow rate [LPM]
Water Flow rate [LPM]
W
at
er
Pr
es
su
re Dr
op [kP
a]
W
at
er
Pr
es
su
re Dr
op [kP
a]
AE120CXYD**/AE160CXYD**
WATER
PG 10%
PG 20%
PG 30%
PG 40%
PG 45%
WATER
PG 10%
PG 20%
PG 30%
PG 40%
PG 45%
Changing Glycol concentration can cause the pressure drop of the
system and it can lead to make flow rate slow.
Just in case of performance degradation, installer shall be careful
of flow rate changes.
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.
Freezing Points of Propylene Glycol - Water Mixtures
Percent Propylene
Glycol [wt.%]
Freezing Point [℉]
Freezing Point [℃]
0
32
0
10
26
-3
20
20
-7
30
10
-12
36
0
-18
40
-5
-20
43
-10
-23
48
-20
-29
Freezing protection: Anti-freeze valves
In order to prevent system water from freezing inside the pipework
during subzero ambient conditions after a sudden power outage, anti-
freeze valves are advised if glycol is not a suitable solution.
An anti-freeze valve opens when the medium (water) is below a
certain low temperature value.
When using the EHS for cooling in the summertime, an anti-freeze
valve with ambient sensor is required to avoid unwanted opening due
to low water temperatures.
To protect the field piping against freezing, install the following parts:
d
d
c
c
a
b
a
Outdoor Unit
nc
2way
nc
2way
Backup
heater
Primary pump
Strainer
Expansion vessel
※
nc : normally closed
a
Shut-off valve (in/out)
b
Aeration valve (optional - field supply)
c
Anti-freeze valve (optional - field supply)
d
Normally closed valves (recommend - field supply)
CAUTION
• If the system is utilized for both cooling operations (summer),
please install anti-freeze valves with an ambient air sensor in
order to avoid valve opening due to low water temperatures.
Alternatively set FSV #1012 (minimum cooling set point) to 7 °C or
higher in order to prevent triggering the anti-freeze valves during
cooling operation.
Part
Description
If necessary, you can close the valve to isolate the
water in the outdoor unit.
Aeration valve (to clear the water from the system).
Protection for the field piping. The anti-freeze valve
must be installed (field supply)
• Vertically to allow water to flow out properly and
free from obstructions.
• At the lowest point in all field piping.
• In the coldest part and away from heat sources.
Water isolation inside the house in case of a power outage.
Normally closed valves (located indoors near the
inlet/outlet pipes) can prevent all water in the indoor
plumbing from draining when the anti-freeze valve is
opened. (filed supply)
• Power outage: The normally closed valves close to
shut off the water in the house. When the anti-
freeze valve is open, only water outside the house
is drained.
• Other situations (eg pump failure): When the anti-
freeze valves open when the power is still applied
to the normally closed valves, the system will drain
completely.
Summary of Contents for AE CXYD Series
Page 29: ......
