The document outlines 12 key operational rules for cooling towers during the winter to prevent icing issues. These rules include conducting inspections, protecting air inlets, maintaining water circulation, and managing airflow effectively. It emphasizes the importance of regular monitoring and precautions against ice removal to avoid damage to the cooling tower structure.

1. A publication of

2. Avoid icing on your counterflow cooling tower
this winter. Follow these 12 rules for operating
your cooling tower in winter.

3. Rule #1

4. Complete a Fall Inspection
Rule #1

5. 1. distribution headers
Inspect…

6. 1. distribution headers
2. laterals
Inspect…

7. 1. distribution headers
2. laterals
3. nozzles
**Ensure nozzles are
clean and intact to
provide even water
distribution over tower
fill. This will help to
prevent icing.
Inspect…

8. Rule #2

9. Protect air-inlet opening
Rule #2

10. falls below 55
degrees, start
implementing cold
weather operations.
This begins with
protecting the air
inlet opening / louver
area (if installed).
When water
temperature…

11. falls below 55
degrees, start
implementing cold
weather operations.
This begins with
protecting the air
inlet opening / louver
area (if installed).
When water
temperature…
The most effective way to protect the air inlet
opening, is to install tarpaulins on the
windward side of the tower.

12. Rule #3

13. High heat load & water
circulation rate
Rule #3

14. needs to be maintained at
the highest possible level.
Once the air inlet opening
is protected, all other
components are
protected if there is a
substantial amount of
plant heat load.
Plant heat
load…

15. Circulating water flow should also
be maintained at the highest
possible rate by operating all
usable pumps. This is to ensure a
full warm water wash of the
internal components.

16. Rule #4

17. What if there is no heat load?
Rule #4

18. the circulating water
should be bypassed
directly to the cold
water basin.
If your tower is not
equipped with a bypass
capability, then shut
down your tower
completely.
If there is no
heat load…

19. the circulating water
should be bypassed
directly to the cold
water basin.
If your tower is not
equipped with a bypass
capability, then shut
down your tower
completely.
If there is no
heat load…
See our Winter Shutdown Checklist procedure to
ensure a proper shutdown during winter.

20. Rule #5

21. Complete visual inspections
Rule #5

22. under winter operations,
complete a visual
inspection of the tower
every 2 - 4 hours
depending on if the
ambient temperature is
within the rage of 20 -
40 degrees or below 20
degrees.
While running
your tower…

23. While running
your tower…
20 - 40
inspect every 4 hours
under winter operations,
complete a visual
inspection of the tower
every 2 - 4 hours
depending on if the
ambient temperature is
within the rage of 20 -
40 degrees or below 20
degrees.

24. While running
your tower…
< 20
inspect every
2 hours
under winter operations,
complete a visual
inspection of the tower
every 2 - 4 hours
depending on if the
ambient temperature is
within the rage of 20 -
40 degrees or below 20
degrees.

25. Rule #6

26. Maintain cold water temperature
by regulating airflow
Rule #6

27. fans can be cycled from
full speed to half speed or
be completely turned off.
This is the most effective
way to maintain cold
water temperature and
control ice formation.
To regulate
airflow…

28. The cold return
water should NOT
drop below 55
degrees
Fahrenheit.55
fans can be cycled from
full speed to half speed or
be completely turned off.
This is the most effective
way to maintain cold
water temperature and
control ice formation.
To regulate
airflow…

29. Rule #7

30. When reverse fan
operations are necessary
Rule #7

31. is still occurring, switch to
reverse fan operations.
Reverse mode should be
monitored continuously
and should only be used
for severe ice buildup
with systems that are
capable of this option.
If significant
ice build up…

32. Rule #8

33. When shutting fans down
Rule #8

34. from rotating in the
normal direction, allow
at least 2 minutes
before starting in
reverse direction.
When fans
are shut off…
{2 min.

35. Rule #9

36. Check the fan blades
Rule #9

37. for any ice buildup. If
your fan blades are free
from ice buildup, you
can now begin reverse
direction.
Check fan
blades…

38. for any ice buildup. If
your fan blades are free
from ice buildup, you
can now begin reverse
direction.
Check fan
blades…
**Even if the fans are still wind milling in the
forward direction, they can be reversed. Minimal
torque will be applied to the mechanical system.

39. Rule #10

40. Reverse operation
timeline
Rule #10

41. ONLY for a maximum of
20 - 30 min.
Operate in
reverse
direction…
20 – 30 minutes
{

42. Rule #11

43. Competing reverse fan
operations
Rule #11

44. When reverse
operation is
complete…
let the fan come to a complete
stop before re-starting.

45. let the fan come to a complete
stop before re-starting.
When reverse
operation is
complete…
Now with the fans shut off, flow
water for 15 min to prevent ice
buildup in the plenum area.
Again, visually check the fan
blades for ice buildup.

46. Rule #12

47. Never physically remove
ice from structure!
Rule #12

48. Or try to physically strip
the framework of the ice.
NEVER
remove ice…

49. any ice buildup on the
perimeter columns or the
bottom of the fill.
**It is important to
inspect this every 2-4
hours to prevent ice
build up this heavy.
(see photo to right)
Monitor
frequently…
Remember:
Melting will leave components in
good condition where as physical
removal of ice will generally cause
more damage.

50. Learn more about cooling tower winter operations: