Legionnaires’ Disease and Commercial HVAC Systems

Legionnaires’ Disease and Commercial HVAC: What to Check on the Roof

Saw the New York Coverage and Want an Inspection? Call (626) 357-3535 Now

You may have seen NBC News coverage of the Manhattan Legionnaires’ outbreak and wondered whether a rooftop AC has anything to do with it. It can, and the connection is water rather than the air handler itself. Legionella grows in warm building water that is not treated and not kept moving. Cooling towers, decorative fountains, and unused pipe in a large loop are the usual places issues start to occur, and unfortunately, a new filter or a UV lamp at a coil does not treat that water, nor resolve the problem.

We look at the HVAC side of that question from our home base in Monrovia and on commercial buildings we already serve in the San Gabriel Valley and nearby Los Angeles County. We are not diagnosing anyone, and we are not saying California has the same outbreak.

Why a Cooling Tower Is Part of This

A cooling tower cools a building by moving air across circulating water. That loop is safe when the water is treated and kept moving. It becomes a problem when treatment slips, or when a section of pipe sits unused and the water in it stays warm. Legionella grows more easily in that kind of standing water.

The tower needs a written treatment schedule, circulating water, and no dead legs sitting at the temperature that bacteria like. Drift eliminators matter, too. They keep droplets from leaving the tower and drifting toward outdoor air intakes or the sidewalk.

If nobody on the property team can name who is responsible for that maintenance and treatment plan, start in the mechanical room and go from there.

Also, read the CDC overview and OSHA’s workplace notes. Those agencies cover public health. We help cover the equipment next to the water, including helping you determine who treats the tower, when the drift eliminators were last inspected, whether unused pipe is still in the loop, and how outdoor air and filtration are set up if people in the building already complain about the air.

Get the Water Vendor and the Mechanical Contractor in the Same Meeting – Call (626) 357-3535 and We Will Represent You on the Mechanical Side

Questions to Ask This Week

Who treats the tower, and how often is treatment documented? When were drift eliminators last inspected? Are there unused branches in the loop that stay warm? What is the plan when occupants already complain about air quality? Those are the questions you should ask in a meeting with both your mechanical contractor and water-treatment vendor together. We can sit in on the mechanical side of that meeting to help ensure the right steps are taken, though we do not write a full water-management plan in place of a treatment vendor.

A new filter is not a water-management plan, and neither is a UV lamp at a coil. Both can help indoor air, but both still leave tower water untouched. If people in the building already complain about the air, learn more about commercial IAQ, filtration, and UVGI strategies. If the conversation has stayed on indoor devices only, learn more about workplace germ-control HVAC approaches.

What the News Does Not Change

Coverage from Manhattan is not a California outbreak notice, and we are not offering medical advice. Do not shut a tower off because of a headline across the country. Follow the water-management plan you already have and the public-health notices that apply to your county. Then, sit down with a mechanical contractor and your water vendor together.

General indoor-air work is separate from tower water, but these two conversations often show up at the same time. Filters and ventilation can help how the air feels and improve quality. For the indoor-air side of the equation, start with our new complete sick building syndrome guide.

Other Commercial Work From Monrovia

Equipment selection, installation, and repair are already part of the commercial work we offer. Learn more about commercial HVAC systems if you need a clearer picture of our systems and services. You can also learn more about commercial air conditioning installation if your next step is replacement rather than a water-system meeting. Or, read more about commercial HVAC repair if your tower or condenser is already down. Not seeing what you need? Read our full Air-Tro commercial services for the rest of our commercial offering.

What a Site Walk Usually Includes

On a site walk, we look at how the tower or other water-adjacent equipment is arranged, whether access and lighting make inspection realistic, and whether the mechanical room has a living record of treatment and service rather than a binder no one has opened this year. We are not the health department. We are the contractor who can tell you whether the equipment side of the story matches what the water vendor says on paper.

If we already maintain the building, we have the service history. If we have never been there, we need to walk the site before we put anything in writing.

Which Buildings This Actually Involves

This only applies to a building with a cooling tower or another water-based heat-rejection system. Hotels, larger offices, campuses, and some medical or senior properties are the usual cases.

A small retail suite with a packaged rooftop unit and no tower is a different story. That unit still needs service, but legionella risks are typically not found with these systems.

Decorative fountains and unused domestic-water lines can still matter even when there is no tower. Tell us what is on the roof and whether the property has any decorative water before we come to your property.

Los Angeles County public-health notices and your building’s own water-management plan still govern what you do after you read any national news. We help you match the mechanical equipment to that plan – we do not replace the health department.

What to Have Ready Before We Walk the Roof

Have the last water-treatment report, the name of the treatment vendor, a roof access plan, and any occupant complaints from the last few months. If a binder exists, bring it even if nobody has opened it this year. Serial numbers and a simple roof sketch help. If you do not have those things, say so. That gap is useful information. It tells us the mechanical record and the water record may not be talking to each other.

What You Leave With

You should leave a site walk knowing whether the tower and related equipment match what the water vendor describes on paper, whether access and lighting make ongoing inspection realistic, and which questions still belong with the treatment vendor instead of with us. You should not leave with a medical claim or a promise that a filter change closed the subject.

Ask Better Questions About Building Water and Air – Call (626) 357-3535

Frequently Asked Questions

Is There a California Outbreak Behind These Questions? No. National news is why these questions are coming in. Follow local public-health notices for current cases rather than treating coverage from another city as a local alert.

Does a New Filter Stop Legionella? No. Filters can help indoor air, but they do not treat tower water. A filter change is not a water-management plan.

Should the Tower Be Shut Off After National News? Not because of an article. Follow the water-management plan and the treatment vendor, then bring the mechanical contractor into that same conversation.

Can You Write the Water-Management Plan? We review the mechanical side. A full plan usually also involves the water-treatment vendor and building staff. We will not pretend one site walk replaces that document.

Do You Work These Buildings From Monrovia? Yes. Commercial dispatch leaves from 1630 S. Myrtle Ave. in Monrovia and covers the commercial properties we already serve in the San Gabriel Valley and nearby Los Angeles County markets.

Ask Better Questions About Building Water and Air

Legionnaires’ disease and commercial HVAC meet in the water system. The tower, the loop, the unused branches, and the outdoor air intakes are all part of the same picture. If the property team cannot name who treats the water, when the drift eliminators were last checked, or whether idle pipe is still tied into the loop, the mechanical room is the place to start.

Air-Tro can walk that room with you. We look at the equipment next to the water, how the tower is being maintained, and how outdoor air and filtration are set up if people in the building already complain about the air.

Call Air-Tro at (626) 357-3535 when your building needs review.