Freeze Protection Of Closed Circuit Cooler Coils - EVAPCO ESW Series Operation And Maintenance Instruction

Freeze Protection of Closed Circuit Cooler Coils

The simplest and most effective way of protecting the heat exchanger coil from freezing is to use an inhibited ethylene or propylene
glycol anti-freeze. If this is not possible, an auxiliary heat load and minimum flow rate must be maintained on the coil at all times so that
the water temperature does not drop below 50°F when the cooler is shut down. See Table 6 for recommended minimum flow rates.
If an anti-freeze solution is not used, the coil must be drained immediately whenever the pumps are shut down or flow stops. This is
accomplished by having automatic drain valves and air vents in the piping to and from the cooler. Care must be taken to ensure that the
piping is adequately insulated and sized to allow the water to flow quickly from the coil. This method of protection should be used only in
emergency situations and is neither a practical nor recommended method of freeze protection. Coils should not be drained for an
extended period of time, as internal corrosion may occur.
When the unit is in operation during freezing weather, some type of capacity control is normally required in order to keep water
temperatures from dropping below 50°F. Operating dry with a remote sump is an excellent way of reducing unit capacity at low
temperatures. Other methods of capacity control include two-speed motors, VFDs and fan cycling. These can be used individually or in
combination with dry/remote sump operation.
ATWB Products, eco-ATW & eco-ATWE
24'x24', 24'x28', 24'x36, 24'x40'
8.5'x9', 8.5'x12', 12'x12'-LP, 12'x12'-SP
8.5'x18', 12'x12'-LF, 12'x12'-SF, 12'x18'-LF, 12'x18'X-SF
** Not available as eco-ATWE
Closed Circuit Cooler
Footprint
3'x3'**
4' wide units**
7' wide units
8.5'x7.5'
8.5'x9' to 8.5'x21'
17'x12', 17'x14
10'x12', 10'x18'
10'x24, 10'x36', 20'x12', 20'x18'
20'x24', 20'x36'
12'x12', 12'x14', 12'x18', 12'x20'
12'x24', 12'x28', 12'x36', 12'x40'
24'x12', 24'x14', 24'x18', 24'x20'
LRWB Products
3' wide units
5' wide units
8' wide units
LSWE Products
4'x6', 4'x9', 4'x12', 4'x18'
5.5'x12', 5.5'x18'
8'x12', 8'x18'
8'x24', 8'x36'
10'x12', 10'x18'
10'x24, 10'x36'
ESWA Products
8.5'x9', 8.5'x12', 8.5'x18'
12'x12', 12'x18'
ESW4 Products
8.5'x6'-LP
12'x18'X-LP, 12'x18'X-SP
12'x18'X-LF, 12'x18'X-SF
14'x22'
Table 6 - Closed Circuit Cooler Minimum Recommended Flow Rate
Minimum Flows
Standard Flow
GPM
—
74
140
148
160
320
188
376
752
232
464
464
928
60
94
148
66
94
148
296
188
376
237
330
100
160
240
320
480
440
26
Series Flow
GPM
26
37
70
74
80
160
94
188
376
116
232
232
464
30
47
74
30
47
74
148
94
188
119
165
50
80
120
160
240
220