The Importance of a Cooling Tower Filter

Before we get started here are a few definitions that may come in handy:

1. Waste Heat:  Heat rejected or escaping from furnaces of various types (as coke ovens, cement kilns, or steel furnaces) after it has served its primary purpose.
2. Wet Bulb Temperature:  Temperature at which no more evaporation will occur, and thus no further decrease in the temperature. The air will continue to cool until the air can evaporate no more moisture.
3. Dry Bulb Temperature:  Temperature of air measured by a thermometer freely exposed to the air but shielded from radiation and moisture. DBT is the temperature that is usually thought of as air temperature, and it is the true thermodynamic temperature.
4. Carnot cycle:  An ideal heat-engine cycle in which the working substance goes through the four successive operations of isothermal expansion to a desired point, adiabatic expansion to a desired point, isothermal compression, and adiabatic compression back to its initial state.

​A cooling tower is a heat rejection device. Its basic purpose is to pull in hot water used by various machines and cool it down so it can either be re-used or evaporated. The re-use of cooling tower water is called working fluid.

An air conditioner is an example of a system that would need a cooling tower. Many schools, hospitals and large office buildings will use a HVAC cooling tower to dispose of unwanted heat in the chiller. In other words the cooling tower helps reject the hot water.

One of the biggest pros to a water cooling tower is that you are being more energy efficient. This is due to air cooled towers need to reject heat at a higher Dry Bulb temperature, they  then,  have a lower average reverse carnot cycle. In turn making water cooled chillers more efficient due to the heat rejection at or near wet bulb temperatures.

Cooling towers are needed and great assets to larger buildings. But along with the positives comes negatives. Fortunately there is a fix for the downfalls of a cooling tower. It boils down to the filtration of the cooling tower water.

So why would you need to filter cooling tower water? Its a logical question to ask. There are various reasons and many companies are now implementing these filtrations systems because the small cost far outweighs the bigger, continuous cost of fixing the issues of a non filtered cooling tower.

First, the basin of a cooling tower can accumulate a thick layer of solid contaminants. The settled solids provide protection for water borne bacteria from administered biocide chemicals.  This also  makes the amount of chemical you use more costly because you will have to use more to allow the needed chemicals to reach the basin.  By filtering the cooling tower water, you are taking a preventive measure to stop the build up all together, lower maintenance costs and decrease your chemical treatment usage.

​Over time the basin will need to be cleaned out due to all the buildup or "sludge" to maintain cooling tower efficiency. This is not only costly it is also time consuming. Sludge also requires special disposal requirements that can add to the on-going maintenance costs.  Basin Sweeping Systems can be paired with cooling tower filtration to maximize the benefits of filtration.  Basin Sweeping Systems stir the water in the cooling tower so the contaminants do not settle and can be filtered out.  Cooling Tower Filtration combined with a basin sweeping system cut down on maintenance, costs and maintain a clean cooling tower sump.

On to a much bigger issue. Have you ever heard of Legionella? Its basically a severe form of Phenomena. Its a deadly disease occurring most often in those with low immune systems and older generations. Anyone can contract it and its caused by bacteria. This bacteria grows inside cooling towers. The bacteria is difficult to kill inside the cooling tower using typical chemicals. It lives in the backwaters of the systems typically covering the submerged areas of the system. Filtering the water significantly reduce if not completely rid a cooling tower of this problem.  Who is legally responsible if someone were to contract this? You are!  There was an incident where an entire building team was sued due to pollution to people within the building. This included, engineers, contractors, subcontractors and so on.

Spray nozzles that distribute water over the cooling tower fill allow the cooling tower to work effectively and efficiently.  With dirt and other contaminants getting into the cooling water, over time spray nozzles become clogged which causes poor distribution through the fill.  Without proper water distribution, the cooling tower does not cooling the water down enough which effects the rest of the system it serves.

​Adding on a cooling tower filtration system might seem like an unnecessary luxury on the surface. If you look into it and really learn about the need for a cooling tower filter and the cost without one the choice is an easy one to make.  Innovative Water Treatment has unique solutions for all of your filtration needs.  Contact us today to discuss your application!