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•
Insulation materials for the pipes to be added on site must meet the following
specifications:
Branch piping for indoor unit or
VALVE KIT
•
This specification is based on copper for water piping. When using plastic pipe-
work, choose a thickness based on the plastic pipe performance.
•
Thermal insulation materials should have a thickness of 20 mm or larger.
•
Install a heater on site when pipes are installed outside where a temperature is
0°C or below and when the breaker may be turned off.
•
Installation of pipes in a high-temperature high-humidity environment, such as
the top floor of a building, may require the use of insulation materials thicker than
the ones specified in the chart above.
•
When certain specifications presented by the client must be met, ensure that
they also meet the specifications on the chart above.
3. Expansion vessel
Connect an expansion vessel to the expansion vessel connection port of the
hydro unit or to the return water pipe.
•
Install an expansion vessel to accommodate expanded water.
•
The maximum water temperature is 60°C.
•
The minimum water temperature is 5°C.
•
The circuit protection valve set pressure is 0.8-0.96 MPa.
•
The circulation pump head pressure is 0.2 MPa. (CMH-WM250/350/500V-A)
4. Leakproof the water pipework, valves and drain pipework. Leakproof all
the way to, and include pipe ends so that condensation cannot enter the insu-
lated pipework.
5. Apply caulking around the ends of the insulation to prevent condensation getting
between the pipework and insulation.
6. Add a drain valve so that the unit and pipework can be drained.
7. Ensure there are no gaps in the pipework insulation. Insulate the pipework right
up to the unit.
8. Ensure that the gradient of the drain pan pipework is such that discharge can
only blow out.
9. Hydro unit and VALVE KIT water pipe connection sizes and pipe sizes.
Connection size
Unit model
Water inlet
Water outlet
PFFY-WL20VEM-A
PFFY-WL25VEM-A
O.D.
PFFY-WL32VEM-A
22.0 mm
PFFY-WL40VEM-A
PFFY-WL50VEM-A
* If the length of branched water piping on WL50 equals or exceeds 40 m, use
pipes with an inner diameter of 30 mm or larger.
* PFFY-WL·VEM Series has no valve.
[Fig. 6.3.6] (P.7)
A To outdoor unit
B End connection
C Hydro unit
D To main piping
E Indoor unit without valve
E' Indoor unit with valve
F Auto air vent valve (Highest point on the water pipe) (supplied)
G Optional VALVE KIT
H Pipe length between indoor unit without valve and optional VALVE KIT is less than 5
m.
10. Please refer to the [Fig. 6.3.5] (P.7) when connecting the water supply.
11. Install a shut off valve and strainer in a place that is easy to operate and makes
maintenance work easy.
12. Apply insulation to the indoor unit pipework, strainer, shut off valve, and pres-
sure reducing valve.
13. Please do not use a corrosion inhibitor in the water system.
14. Use formula 0.1 [MPa] < 0.01 + 0.01 x A < 0.16 [MPa] for the supply pressure
range to be used.
(A: Head pressure (m) between the hydro unit and the highest indoor unit)
If the supply pressure is greater than 0.16 MPa, use a pressure reducing valve
to keep the pressure within the range.
If the head pressure is unknown, set it to 0.16 MPa.
16
20 mm or more
Pipe size
volume (ℓ)
Water out
Water return
O.D.
I.D.
I.D.
22.0 mm
≥ 20.0 mm
≥ 20.0 mm
6.5. Water treatment and quality control
To preserve water quality, use the closed type of water circuit. When the circulating
water quality is poor, the water heat exchanger can develop scales, leading
to a reduction in heat-exchange power and possible corrosion. Pay careful attention
to water processing and water quality control when installing the water
circulation system.
•
Removing of foreign objects or impurities within the pipes
During installation, make sure that foreign objects, such as welding fragments,
sealant particles, or rust, do not enter the pipes.
•
Water Quality Processing
Depending on the quality of the cold-temperature water used in the airconditioner,
1
the copper piping of the heat exchanger may corrode. Regular water quality pro-
cessing is recommended. If a water supply tank is installed, keep air contact to a
minimum, and keep the level of dissolved oxygen in the water no higher than 1
mg/ℓ.
Water quality standard
2
Items
pH (25°C) [77°F]
Electric conductivity
Chloride ion
Standard
items
Sulfate ion
Acid consumption
(pH4.8)
Total hardness
Calcium hardness
Ionic silica
Iron
Copper
Water
Sulfide ion
Refer-
ence
Ammonium ion
0.8
items
0.8
Residual chlorine
1.0
Free carbon dioxide
1.3
Ryzner stability inde
1.3
Reference: Guideline of Water Quality for Refrigeration and Air Conditioning Equip-
ment. (JRA GL02E-1994)
Consult with a specialist about water quality control methods and calculations
3
before using anti-corrosive solutions.
When replacing a previously installed air conditioning device (even when only the
4
heat exchanger is being replaced), first conduct a water quality analysis and
check for possible corrosion.
Corrosion can occur in cold-water systems even if there has been no prior signs of
corrosion.
If the water quality level has dropped, adjust water quality before replacing the
unit.
Low to mid-range
temperature water system
Recirculating
water
Make-up
[20<T<60°C]
water
[68<T<140°F]
7.0 – 8.0
7.0 – 8.0
(mS/m) (25°C)
30 or less
30 or less
[77°F]
(μ s/cm) (25°C)
[300 or less]
[300 or less]
[77°F]
(mg Cl-/ℓ)
50 or less
50 or less
2-
(mg SO4
/ℓ)
50 or less
50 or less
(mg CaCO
/ℓ)
3
50 or less
50 or less
(mg CaCO
/ℓ)
70 or less
70 or less
3
(mg CaCO
/ℓ)
50 or less
50 or less
3
(mg SiO
/ℓ)
30 or less
30 or less
2
(mg Fe/ℓ)
1.0 or less
0.3 or less
(mg Cu/ℓ)
1.0 or less
0.1 or less
not to be
not to be
2-
(mg S
/ℓ)
detected
detected
(mg NH
+
/ℓ)
0.3 or less
0.1 or less
4
(mg Cl/ℓ)
0.25 or less
0.3 or less
(mg CO
/ℓ)
0.4 or less
4.0 or less
2
6.0 – 7.0
–
Tendency
Corro-
Scale-
sive
forming
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