By Andrew Roberts & Mark Hines, Paddock Pool Equipment Co.
When it comes to some indoor pools, it’s time to clear the air. What the staff, swimmers (including children and their parents) and others visiting the facility are breathing is a big deal, but do you understand just how much of a big deal it is? Keep reading to find out.
Ever walk into the pool and smell the chorine before you see the water? What you think is the normal “pool smell” is really not. What you are really smelling is the byproduct of free available chlorine doing exactly what we need it to do — get rid of nasty stuff in the water. That byproduct comes in three different varieties:
â—Ź Monochloramine
â—Ź Dichloramine
â—Ź Trichloramine
The first two (mono and dichloramine) stay in the water and are what is referred to as combined chlorine — you know, the stuff you monitor and shock when it gets too high.
The third one, however, leaves the pool water and off-gasses into the air. These off-gassed trichloramines are what you are smelling.
Apart from just smelling bad, they are accompanied by the following effects:
â—Ź Breathing issues
â—Ź Skin and eye irritation
â—Ź Corrosion of metal fittings, futures and deck equipment
â—Ź Destruction of mechanical systems and ductwork
â—Ź Degradation of structural support systems and building materials
So, what does that mean?
It means that people exposed to heavy chloramines can develop breathing issues, including chronic obstructive pulmonary disease (COPD) and permanent lung damage. Mass hospitalization has and continues to occur when chloramines get out of control.
It means that maintenance cost is significantly increased to keep corrosion off of deck equipment, as well as in the form of repainting, repairing or replacing other metal fixtures throughout the building.
It means that dehumidification systems (one of the most expensive systems in your building), air ducts, registers, fans, belts, motors and more are actively being destroyed much quicker than they would under normal wear and tear.
It means buildings are more prone to high-end structural repair needs, taking large amounts of funds away from program development and facility growth.
Natatorium design has come a long way, but the same mistakes are made over and over again. 
Hang on, we have good news. There is a solution, and it can be accomplished on new and existing indoor pools alike thanks to one thing: We know where these pesky chloramines are.
Chloramines are about four to five times heavier than air. So, guess where they like to hang out? Right on the pool surface.
What’s the solution you ask?
When designing (or redesigning) the air handling system for a natatorium (room with a pool in it), we want to keep a few things in mind:
â—Ź Get fresh air into the breathing zone(s)
● Don’t de-stratify the air
â—Ź Use a low source capture system
â—Ź Keep chloramines away from return air vents
Let’s answer some questions that may have just popped into your head.
What is a breathing zone? An area where people’s mouths are likely to be situated within the building. This typically includes:
â—Ź Just above the pool water
â—Ź Midway up on the deck
â—Ź In any spectator areas
What do you mean, don’t de-stratify the air? Don’t mix it. Keep it layered. Keep the bad air low and the good air high.
What is a low source capture system? It is an exhaust-only system that drags air from a specific place (in this case, where chloramines are hanging out) and removes them from the building, where they’re never to be smelled again. Low source capture can be placed in the gutter, the deck drain, a prefabricated bench or wall systems. Remember when we said that these gasses like to hang out just above the pool water? This exhaust system removes the bottom layer of bad air, while keeping the good, heated and treated air inside and recirculated as intended.
Why keep chloramines away from the air returns? If those chloramines get into the returns, guess where else they end up? Coming out of the air supply and right into the breathing zones of swimmers, spectators and staff.
Think of it as a slice of pie. We want to remove the crust, while preserving the filling. And we want to keep any crumbs of the crust away from the spoon used to add more filling to the pie. The crust is the chloramine laden air; the filling is the good, reusable heated and treated air; and the spoon is the return. Think of a low source capture system as a knife that separates the two and does only that.
Let’s be honest. Saying that smelly pools are okay is not okay.
At Paddock Pool Equipment Company, we have spent the last 12 years working on improving the quality of air inside natatoriums and have provided clean air solutions for more than 500 facilities.
We do this with a product called the Evacuator®. It is our opinion, and the opinion of many others, that any pool built inside of a building needs Evacuator technology.
Good indoor air quality is fundamental to the health, safety and enjoyment of those working, training or playing in your aquatic facility, and is essential to maintaining the look and functionality of the building itself. If your pool smells, let’s clear the air.
To learn more, click here or call 800-849-2729.