Cooling Tower Cleaning: Is Your System Dirty and Tired?

In case you haven’t noticed — and we know that you have — summer time is almost upon us. And as the pleasantly cool nights and mild days give way to increasing heat and humidity, it’s time to switch over from heating to air conditioning and bid a fond farewell to that brief spring interval when we can open the windows and soak up the outdoor sweetness of the season. This means the onset of the heaviest annual load on the cooling towers in our HVAC systems — which in turn means it’s time to focus our attention once again on best practices — including various types of Goodway’s products — for achieving maximum cooling performance for maximum energy efficiency.

One of the main risks in all of this is that our cooling towers may become “fatigued.” That’s how Tom Ryder, an engineer and cooling tower expert with Delta Cooling Towers, puts it in “Maintenance for Cooling Towers” (Industrial Heating, March 2, 2011). (Also see Ryder sharing the same valuable information in a widely reprinted article — see, for example, here, here, and here — from 2010.) “If cooling towers are not kept in good shape and receiving preventive maintenance, they can become ‘fatigued,’ which can in turn put a strain on system equipment and downstream processes,” he writes.

What we’d like to call out for your attention right now is that in his article Ryder emphasizes not only the importance of preventive maintenance but of routine maintenance. It’s the combination of these two approaches that heads off operational headaches, unnecessary energy drains, and expensive repairs.

Ryder compares cooling towers to cars, and underscores the fact that if you continuously run either of them “in the red,” you’re going to encounter serious trouble sooner or later, including “overheated equipment, increase in scrap material, refrigeration losses, heat-exchanger inefficiencies and other severe operational consequences….The cost of overlooking the maintenance of a cooling tower can be heavy, almost regardless of application.” He lays out the further implications in one of the additional article linked above: “[U]nless the cooling tower is well maintained, the water it provides devices such as heat exchangers, production machinery and HVAC systems will be less able to draw off heat. For example, the ‘cold side’ of a heat exchanger will receive water that is not as cool as optimum. Therefore, the heat exchanger will be less able to draw off heat from process fluids.” In other words, the cooling tower simply won’t be able to do, or won’t be able to do well, the job for which it’s specifically designed.

Thus:

Just as with automobiles, routine and preventive maintenance of cooling towers is necessary to avoid costly repairs. Fill material or wet decking should be serviced or replaced in cooling towers….If you are running water through fouled cooling-tower wet decking, you will not get the necessary dissipation of heat, and the water getting down to the tower sump will not be cold enough for the processing equipment. Ventilation louvers should be washed down, as well as the wet decking, which facilitates the cooling evaporation process. Drift eliminators should be checked to prevent unnecessary water loss. Plus, any repairs such as patching, welding or cleaning of cooling-tower sheeting should be done as required.

He also mentions the necessity of cleaning off any scale left by evaporation, making sure to use the method appropriate to your specific type of cooling tower (plastic or metal; the latter kind can be harmed by descalers).

So as you switch over to air conditioning with the advent of warm spring and summer weather, we urge you to avoid cooling tower fatigue by staying on top of both your routine and preventive maintenance issues. We could fill you full of proverbs and platitudes here: The best defense is a good offense. Nip it in the bud. The early bird gets the worm. And so on. Or we could just end with a worthwhile quote from Goodway’s own Steve Spielmann, to complement Ryder’s words above:

We all know that with today’s energy costs and the vulnerabilities of the power grid, it is in every maintenance professionals’ interest to operate as efficiently as possible. Maintaining a clean cooling tower results in colder chilled water being delivered to the chiller increasing the efficiency of the chiller and making chiller tube cleaning easier. America will never run out of electricity, but it is vitally important for us all to do our best to conserve energy. Economically it just makes sense. So, everybody, let’s keep those cooling towers clean. (“New TechnologyEnhances Cooling Tower Maintenance ”)

Matt Cardin
Goodway Blogging Team