Legionnaires’ Disease

Portacool Portable Evaporative Coolers with Kuul ComfortA Discussion on Legionnaires’ Disease

What is Legionnaires’ Disease?

Legionnaires’ Disease is a type of pneumonia caused by inhaling bacteria from a misting source that has been contaminated by Legionella. Legionella bacteria is found in warm, stagnant water environments like hot tubs and larger plumbing systems. This is further explained by the Centers for Disease Control and Prevention (CDC) at

Background on Legionnaires’ Disease:

According to the CDC, outbreaks are most commonly associated with “buildings or structures that have complex water systems, like hotels, hospitals, long-term care facilities, and cruise ships.” ( While Legionnaires’ Disease can be deadly in extreme cases, it is important to note that most healthy people do not become infected after exposure. Those affected typically have compromised immune systems or are battling underlying health issues. The disease can be treated with antibiotics and most cases are successfully treated. The most expansive outbreak happened in 1976 at an American Legion conference, and it is where the disease got its name.

Prevention of Legionnaires’ Disease:

The CDC points out: “The key to preventing Legionnaires’ Disease is maintenance of the water systems in which Legionella grow, including drinking water systems, hot tubs, decorative fountains, and cooling towers.”

Do Portacool portable evaporative coolers pose a concern for spreading Legionella bacteria?

Portacool portable evaporative coolers that are maintained correctly on a regular basis are less susceptible to legionella bacteria. Here’s why:

If you see or feel a spray of water that collects on people, objects, equipment or floors, that is not a portable evaporative cooler. Misters, atomizer fans, foggers and vaporizers operate in a converse method that causes wet conditions. These systems require sterile water to operate safely as they deliver aerosols that are big enough to carry bacteria.

Additionally, portable evaporative coolers are not classified, nor considered to be the same, as a cooling tower or evaporative condensers. Those are part of bigger building operations and not portable.

Any confirmed cases caused by this kind of cooler?

Portacool portable evaporative coolers have not been indicated or linked to any case of Legionnaires’ Disease. Neither has the Kuul Comfort™ evaporative media (a type of rigid evaporative media), which is utilized to absorb the water and facilitate water molecule evaporation into the air to generate cool air from the portable cooler.

Is there a guarantee against the development of Legionella bacteria with this portable evaporative cooler or Kuul Comfort™ evaporative media?

To eliminate any concern for harboring any kind of bacteria in the cooler’s water reservoir, proper operation and proactive maintenance of the Portacool portable evaporative cooler is of utmost importance.

In use operation:

Given the nature of operation necessary for achieving optimal cooling with Portacool portable evaporative coolers and its evaporative media (Kuul Comfort – a type of rigid evaporative media), there is reduced proclivity and overall reduced likelihood of creating a conducive environment for Legionella bacteria growth. Why? Portable evaporative coolers do not use mist or aerosols of water in the cooling process. In addition, the water flows constantly by means of a pump when in use in Portacool portable evaporative coolers.


Daily usage maintenance:

Allow evaporative media to dry completely once every 24 hours. Turn off the pump approximately 15 minutes before shutting the fan down each day to allow the media to dry all the way through and prevent the growth of any bacteria or algae on the Kuul Comfort media.

Weekly usage maintenance:

The portable evaporative cooler should be drained each week when in usage on a regular basis. All Portacool evaporative coolers have a drainage plug. (Portacool models manufactured since 2017 come with a 2” drain on the bottom.) Locate the drain, unscrew the cap and allow water to drain. Ensure the Kuul Comfort evaporative media is completely dry, then remove and wipe down the inside of the evaporative cooler. It is best to use a shop vac to remove any remaining water, and at the same time, get any dust/dirt that may have settled inside the reservoir.

As needed maintenance:

To prevent any algae or bacteria from being present on the Kuul Comfort evaporative media, you can shock dose the reservoir with an appropriate amount of household bleach (Sodium Hypochlorite – NaClO) into the system sump/reservoir taking care to utilize the correct amount – ranging from ½ tablespoon of NaClO for 8 gallons of water in the Portacool Cyclone 110, all the way up to 2.25 oz for reservoirs up to 75 gallons in the Portacool Hurricane 370 – following this chart.

What is the key takeaway for ensuring Legionella bacteria is not a concern when using a Portacool portable evaporative cooler and its Kuul Comfort™ evaporative media?

Proper and proactive maintenance is key not only to achieve optimal cooling, but also to eliminate any concern for harboring potentially harmful bacteria in a Portacool portable evaporative cooler or its Kuul Comfort evaporative media. Installation of the proper methods of flushing and dosing noted above will help combat the growth of any unwanted bacteria in an evaporative cooling setting.