They dump high humidity, wet outdoor air directly into the air handler closet
Some have electric blowers that bring in this moist outdoor air 24 hours a day
Some are "passive" and bring in moist air only when the air handler is running to either heat or cool the home
Most concealed radon mitigation systems will deliver outdoor air containing from 20 to 240 pounds of water vapor each day. That is from twenty pints to 240 pints of water per day. One pint = One Pound of water
Although an air conditioner will remove some of the moisture some of the time, in a hot, humid climate, many air conditioners are already struggling to keep up with moisture without any extra load from a radon system. And of course, air conditioners do not operate all the time even if a concealed radon system runs 24/7
A condo may soak up several thousand pounds of water before mold starts to grow, so it may take months and sometimes years for the home to reach the critical 70% moisture saturation level and cause mold to show up.
Just because there is a delay between the time a radon system is installed and the time the mold and moldy odor problems appear does not mean that the radon system is not the cause.
Concealed Radon Systems are often very easy to discover
if you know what to look for. On the outside of the home, look for an air
intake that looks like one of these. On some units the air intakes are in
the hallway.
The hot, humid outdoor air is usually dumped through a grille and into the air handler closet. Look for a grille that may look like this. You can clearly see moisture and mold damage from radon system operation:
This installation had a blower that was hidden behind finished drywall and an unmarked panel. Unless a person removed the unmarked panel and stuck his head up inside the dropped ceiling space, he would not even know there was anything up there that could have cause his severe mold problems.
One condo had an unmarked meter that looked like this.
It is a pressure gauge that indicated that something caused pressure to
build. In this case, the gauge was installed incorrectly to indicate that
any air was being delivered, but instead actually indicated that the outdoor
filter was completely clogged up. RESULT? The higher the reading, the less
air was being delivered into the condo and the higher the radon levels. Most
radon system indicators, even in radon systems that are not hidden are not
properly installed. Very often, the information they provide is erroneous
and misleading. No jury would approve of such installations and would
quickly decide they were negligently designed and installed. The reading on
this meter, like many others, does not show that the radon system is working
properly. Instead it indicates that the filter is completely clogged with
dirt and the radon system is not delivering any outdoor air. Either
the person who installed this meter did not know what he was doing, or he
wanted the meter to show when the system was not working...The condo owner
had no clue what this meter was for. He thought it was part of the water
system.
If your unit has both of these, it definitely has a radon system. If there are no labels anywhere that you can find, including in the electrical circuit breaker panel, you can be certain that your condo's radon system was intentionally concealed from you.
We discover these concealed radon systems when we are invited to inspect and bid on mold remediation or to solve a moldy odor problem. I suspect that most of the time, the homeowner calls an air conditioning firm to install a new air conditioner. They are glad to install one for $5,000.00 to $7,000.00, but they do not address the real cause of the mold which is the concealed radon system. New air conditioners are very unlikely to solve the mold problem because the concealed radon system continues to deliver water vapor every day. A new air conditioner is not the answer. Better radon mitigation technology is the answer.
RadonMan, Inc dried out the home, cleaned up the mold and installed an advanced radon mitigation system. The problem is permanently solved:
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Now, the radon system automatically turns itself on when the condo is occupied and turns itself off 60 hours after the last person leaves. The fully automatic radon system only operates when it is needed.
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Now, the relative humidity is constantly monitored every few seconds, and if the indoor relative humidity rises above about 53%, automatic systems make adjustments tor radon system operation to keep indoor relative humidity out of the mold growth danger zone and in the human comfort zone.
Sometimes, RadonMan is invited to inspect condos that testing has shown to have high radon levels, tens and elevens instead of the USEPA limit of four. Upon investigation, I find that the condo also has a moldy odor. When I look carefully, I find that the condo has a concealed radon system. Imagine, a condo with a concealed radon system that has mold issues and still does not reduce high radon levels. Not a very good bargain for the owner of the condo. He ought to get money back and more money for his trouble...and for the mold damage that must be cleaned up. The firm that installed this system brags about having lots of insurance and that he has installed tens of thousands of radon systems in Florida. Now that the facts are out, I suspect that the lawyers will soon be paying attention. Especially since some folks claim to get seriously ill from exposure to mold.