Air Heat Exchanger; Water Heat Exchanger Maintenance; Characteristics Of R-410A - Carrier AQUASNAP 30RQ Installation, Operation And Maintenance Instructions

12.6 - air heat exchanger

We recommend, that finned coils are inspected regularly to
check the degree of fouling. This depends on the environment
where the unit is installed, and will be worse in urban and
industrial installations and near trees that shed their leaves.
For coil cleaning, two maintenance levels are used, based on
the AFNOR X60-010 standard:
level 1
• If the air heat exchangers are fouled, clean them gently in
a vertical direction, using a brush.
• Only work on air heat exchangers with the fans switched off.
For this type of operation switch off the HVAC unit if
service considerations allow this.
Clean air heat exchangers guarantee optimal operation of
your HVAC unit. This cleaning is necessary when the air
heat exchangers begin to become fouled. The frequency of
cleaning depends on the season and location of the HVAC
unit (ventilated, wooded, dusty area, etc.).
level 2
• Clean the coil, using appropriate products.
We recommend TOTALINE products for coil cleaning:
Part No. P902 DT 05EE: traditional cleaning method
Part No. P902 CL 05EE: cleaning and degreasing.
These products have a neutral pH value, do not contain phos-
phates, are not harmful to the human body, and can be disposed
of through the public drainage system.
Depending on the degree of fouling both products can be used
diluted or undiluted.
For normal maintenance routines we recommend using 1 kg of
the concentrated product, diluted to 10%, to treat a coil surface
of 2 m . This process can either be carried out using a high-
2
pressure spray gun in the low-pressure position. With pressurised
cleaning methods care should be taken not to damage the coil
fins. The spraying of the coil must be done:
- in the direction of the fins
- in the opposite direction of the air flow direction
- with a large diffuser (25-30°)
- at a minimum distance of 300 mm from the coil.
The two cleaning products can be used for any of the following
coil finishes: Cu/Al, Cu/Al with Italcoat protection.
It is not necessary to rinse the coil, as the products used are pH
neutral. To ensure that the coil is perfectly clean, we recommend
rinsing with a low water flow rate. The pH value of the water
used should be between 7 and 8.
WARNING: Never use pressurized water without a large
diffuser. Do not use high-pressure cleaners!
Concentrated and/or rotating water jets are strictly forbidden.
Never use a fluid with a temperature above 45°C to clean the
air heat exchangers.
Correct and frequent cleaning (approximately every three
months) will prevent 2/3 of the corrosion problems.
Protect the control box during cleaning operations.

12.7 - Water heat exchanger maintenance

Check that:
• the insulating foam is intact and securely in place.
• the cooler heaters are operating, secure and correctly
positioned.
• the water-side connections are clean and show no sign of
leakage.

12.8 - Characteristics of R-410a

See the table below.
saturated temperatures (°C) based on the relative
pressure (kPa).
saturated Relative
temperature pressure
-20 297
-19 312
-18 328
-17 345
-16 361
-15 379
-14 397
-13 415
-12 434
-11 453
-10 473
-9 493
-8 514
-7 535
-6 557
-5 579
-4 602
-3 626
-2 650
-1 674
0 700
1 726
2 752
3 779
4 807
5 835
6 864
7 894
8 924
9 956
10 987
11 1020
12 1053
13 1087
14 1121
15 1156
16 1192
17 1229
18 1267
19 1305
20 1344
21 1384
22 1425
23 1467
24 1509
Aquasnap Puron units use high-pressure R-410A refrigerant
(the unit service pressure is above 40 bar, the pressure at 35°C
air temperature is 50% higher than for R-22). Special
equipment must be used when working on the refrigerant
circuit (pressure gauge, charge transfer, etc.).
saturated Relative
temperature pressure
25 1552
26 1596
27 1641
28 1687
29 1734
30 1781
31 1830
32 1880
33 1930
34 1981
35 2034
36 2087
37 2142
38 2197
39 2253
40 2311
41 2369
42 2429
43 2490
44 2551
45 2614
46 2678
47 2744
48 2810
49 2878
50 2947
51 3017
52 3088
53 3161
54 3234
55 3310
56 3386
57 3464
58 3543
59 3624
60 3706
61 3789
62 3874
63 3961
64 4049
65 4138
66 4229
67 4322
68 4416
69 4512
70 4610
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