HVAC Maintenance Implications of Nearby Fires

The West Coast is again facing epic wildfires filling the air with soot and ash settling onto roads, cars, and buildings, sometimes hundreds of miles away from the fires. For managers of commercial buildings, the flying ash increases the possibility of HVAC maintenance problems particularly in facilities with open cooling towers. Some building managers close to the fires have reported increased microbial growth in their open cooling towers as a result of the additional airborne particulates. The algae growth is clogging up the tower fill and wet ash is being drawn into the piping systems restricting the flow of tower water. If not immediately corrected, pipe fouling in open towers is an expensive and disruptive situation to correct.

But whether a commercial building is in the vicinity of raging wildfires or just next door to a building fire, commercial service teams need to understand the maintenance implications when unplanned debris mixes with tower water or coats HVAC equipment.

Cooling tower water treatment and proper cleaning is paramount to the long life of the tower. A tower’s water treatment plan has to be set up for the water quality present in your facility. When water parameters change, like the introduction of ash or airborne solids, the treatment plan needs to change too. If the plan does not adjust to the new water quality, the cooling tower is at risk of developing microbial growth including algae blooms and biofilms. In the case of cooling towers near the wildfires, if a significant amount of ash or debris mixes with the condenser water or settles in the tower basin, even before microbial growth begins, building managers risk having their towers break down.

Maintenance staff need to be proactive with water treatment and should understand that treatment is not always a “set it and forget it” process. If in-house maintenance staff do not have the skills to develop and implement a plan, find a licensed professional contractor to help with water treatment. Whether performed in-house or by a service contractor, if your cooling tower has never been properly treated, you will need to start with a clean slate. This means draining the tower and cleaning the piping system, tower fill, and the interior and exterior of the tower itself. Cooling towers that have been untreated for years will likely be coated in a biofilm that needs to be physically removed. A variety of tools are available for removing biofilm such as Goodway’s full line of tower cleaning products. 

Tower vacuums remove slime, mud, algae, bacteria and other contaminants from the sides and floor of the cooling tower basin. An accessory kit extends cleaning performance with additional hoses and various brushes. The tower fill should be descaled to remove minerals that have attached to the fill over time. With thick scale removed from the tower, a regular cleaning schedule is a critical next step, even if fire ash is not a threat. An EPA registered biocide, like BIOSPRAY® Tower should also be used to clean hard, non-porous surfaces. It kills 99% of Legionella when used as directed, and can be used as an emergency treatment option, or as part of ongoing maintenance. Goodway’s “How to Clean Cooling Towers” checklist details the step-by-step tower cleaning process.

Once the biofilm and debris are removed, the condenser pipes should be flushed, the strainers cleaned, and the pumps serviced. If debris or organic materials are left behind anywhere in the system, the contaminants can grow back quickly and the tower can be clogged again sooner than it would have been with a proper cleaning.

After a complete cleaning the condenser water can be refilled and the proper water treatment mixed into the system. Again, maintenance staff need to be familiar with water treatment procedures otherwise the equipment shutdown will have been a wasted effort.

Fine particles of ash can also be drawn into the outside air vents of HVAC equipment overwhelming filters and getting stuck on cooling coils and in the ductwork. It also coats and clogs exposed condenser and evaporator coils, which will need those coils cleaned immediately. When ash from outside gets past filters and mixes with building return air, a biofilm can form very similar to what grows on dirty cooling towers. The biofilm prevents proper airflow across the coil and, because of the ash, can create a very thick slime inside the equipment that has to be cleaned off by hand. If ignored for too long the wet ash may be impossible to clean and the coil might have to be replaced. In addition to regular filter changes especially when faced with increased pollution from fires, Goodway’s Coil Cleaning Systems and Chemicals offer maintenance staff a way to clean and disinfect cooling coils to prevent more serious health problems for occupants. If ash or mold develops in duct systems, there is a full line of equipment to bring duct systems to like new condition.

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