There’s a lot of misinformation about mold in HVAC ( air conditioning ) systems and air ducts. Should you be concerned? Will sanitizing the ductwork solve the problem? In this episode, I break down the facts and debunk myths surrounding mold in your air conditioning and ventilation system.
You'll learn how mold grows in HVAC systems, how to detect and test for mold in air ducts and—most importantly—how to remove mold effectively without wasting money on ineffective solutions such as sanitizers and UV light shinning in the wrong places. Your health depends on the air you breathe—make sure it’s clean. Tune in to get the knowledge you need to protect your home and health.
The Mold Money Podcast
TRANSCRIPT:
Mold and HVAC systems, that's your heating, ventilation, and air conditioning system, and your ductwork - This is a really complex topic. It's also one that if you Google or use AI, search the Internet for what to do if you have mold.
Out of everything I've seen on ideas people have for how to get rid of mold and test for it, testing and inspecting air conditioning and heating systems for mold is ten times full of misinformation compared to everything else. It's probably because it's a very complex topic and one you probably want to get a consultation for.
If you need help understanding this better and knowing exactly what you should do in your house to get rid of mold and make sure you're doing the right thing that works without wasting your money, more importantly, doing what works to protect your health, head on over to healthylivingspaces.com and book a one-on-one consultation.
When you book a consultation you can send me pictures. We can talk on the phone if you need a quick answer. if you want to go really deep and understand why I recommend what the best thing to do is for your house and for your HVAC system that could cost a lot of money for your circumstances, book a longer consultation for a few hours.
Yes, mold in HVAC systems is a big problem, not because, as people say, spores are going to spread spores throughout my house. No, rather it's because it's in the air you breathe.
Much of the time what people think is mold in air ducts is not - It's just dirt. The only way to tell is to test it, and having a home inspector do a swab on it is the worst thing you can do. That's not going to work.
First, why does it grow? True or false? Moisture plus dust plus darkness equals mold growth. That's false.
Mold needs moisture. It doesn't need dust. It can't grow on dirt. Rather, it can grow on skin cells and organic stuff in the dust.
So we can say dust, but not darkness. Mold can grow in the light. It's a coincidence dark places are those that stay wet.
Mold needs a source of food. It can be if you're in certain places in the country, Florida, for example, and I worked there for a while, where the ducks are made literally out of fiberboard, duckboard, so the ducks themselves are insulated.
So you don't need to wrap the ducks with insulation like you have to do with metal ducks with fiberglass.
They make duckboard, it's literally all in one. That's a porous material that traps dust and can grow mold. Basically, you have to tear the ducks out if there's mold in those ducks. But before you panic, most of the time what people see is not mold, it's dirt, but you got to actually test it, not with a swab, with the tape lift properly.
There's courses on healthy living spaces also on how to test for mold properly, and examples of why a swab doesn't work. And if you use a tape lift, how to interpret the results. Because another thing people do is they send the tape or the swab to lab, and they ask the lab to count spores, which isn't really helpful. Do you know how many spores there are in mold growth? We just need to know if it's mold, yes or no.
Another true or false thing, high levels of humidity would cause mold. No, that's false. Mold needs liquid water, not humidity to grow. If humidity just by itself grew mold, we'd never be able to fix this problem.
Fortunately, it's engineering. And I'm an aerospace engineer, and this is just mold. What you want to do is avoid condensation, which happens when, ironically, you're making the ducts cold. So it's like a glass of cold iced tea in the summer. You're going to see sweat on the outside of the glass unless you insulate it. It's the same thing with your ductwork.
You're either running the air conditioning at super low temperatures, which is not because you want to be comfortable, but because when you built your house, you bought one that's too big, oversized, or you have standing water in the drain pan because the contractor put it in with the pan sloped wrong so that the pan doesn't drain, and then water gets sucked back onto the filter when it should be going down the drain.
And if you say, why is water going down the drain, ask why is there even water in the first place? If you make the air cold, it's going to have condensation inside your system. That's normal, but that's supposed to drip off into a drain pan and drain and not go through the air in your house and not get on the filters or anything else.
Open the system, it's got danger warning signs on it, and I agree it's probably not the best thing for you to do if you don't feel comfortable with it.
Number one, shut the power off.
Always shut the power off.
Number two, call an HVAC guy. You're going to pay a bit for that, and he's going to be like, what's the problem? He or she, you have to know what to look for. He/she's going to take the panel off. And you're going to look and go, what are we looking at?
Sometimes it's really difficult to say. Often I'm frustrated because these things should be designed to take apart and inspect, but it's never in the manual when you buy a house to do. You only call the HVAC guy when there's a problem, when the air conditioning is not working.They're sealed up on purpose to keep them airtight because you don't want the humid air in there and you don't want cold air leaking. Moreover, most of the time, the drain pipe is installed afterwards by the plumber and the drain pipe blocks the access panel from being able to be opened real easily. You got to get in there.
Signs of mold in the ductwork or in your system. True or false, a musty, mildly like odor coming from the vents means you have mold. It doesn't. Most of the time, actually, it probably means that odor is coming from bacteria.
The solution for that is not to get rid of your ductwork and to call the mold remediation company. It's to put a ultraviolet light system on your HVAC, and you probably already have this if you live in a humid climate like Florida.
Maybe it's just burnt out, dirty, not working. It's not to kill mold. Mold's not the problem. Bacteria come when things get wet. Bacteria loves water, especially if your system cycles and shuts off, doesn't stay real cold like the refrigerator, it warms up. Bacteria love that. That's the odor problem.
Visible mold could still be present. Many times I've been fooled by what I think has to be mold because the system is dirty. Even swamp coolers. So much water. It looks like there's dirt on the filters. It's mold. The only way to tell is with the tape lift test. And if you're having a consultation with me, the longer consultation, I throw in, I tell you how to take samples and send them to me. Or if you take in the course, in the course, it tells you what lab to send it to and what to ask for, so you know exactly how to interpret the results, tell you is it mold or not.
The following are some more myths about mold and HVAC systems that I got from the internet, from Google, and from using AI, out of all things, artificial intelligence. Some of these facts that AI says, here's the myth, here's the fact, the facts that AI has given me are still myths.
Myth number one, mold can't grow in my air ducts because they're metal. Well, mold grows on dust. So the fact is mold grows on dust, not the metal itself. It is true. Rarely do I find mold growing on metal ducts.
It's suited to what am I going to do about it?
Be careful about spending money on sanitizing.
It's not going to work.
Be careful about spending money on getting the ducts cleaned.
Not even mold necessarily, what you're looking at.
We got to figure out why the odor's coming and fix the system for us before we jump to mold and test for mold.
Myth, I don't see mold, it's not there.
The fact that AI tells me is, quote, most mold growth is hidden inside the system.
Behind coils or deep in the ducts.
This is misleading.
Mold's microscopic.
You can't see mold because it's technically, you can't see it with your naked eye.
It's smaller than your eye can see until there are billions of spores.
And yes, behind the coils, kind of true.
Coils in your HVAC system are like the radiator on your car.
It's impossible to see through it.
It's also impossible to really clean effectively.
In really old commercial buildings where I've worked, and there's just air quality problems, forget about mold.
It's just, it smells or people are sick.
I've actually had the contractors cut the system out, take it out into the parking lot to power wash it.
And still it was in the end had to get a new system.
But before you do that, though, call me.
Myth from artificial intelligence is saying this is a myth.
Cleaning my vents gets rid of mold.
Well, technically, AI was telling you that metal ducts, the mold's in the dirt.
And technically you can clean metal pretty easily.
But again, we need to figure out what's causing the odor and what's causing the mold.
A myth, standard duct cleaning company can't fix mold.
I kind of agree with that.
But here's what AI says, fact, mold remediation requires specialized treatment, not just cleaning.
What does specialized treatment mean?
No, you don't need treatment.
You need to remove the mold.
But you gotta figure out, is it in my blower compartment?
Is it just on my filters?
Is it just in the compartment?
Because water wicked up because my drain pan wasn't working?
Or is it deeper in the ducts because my ducts are made out of fiberboard and there was condensation?
You gotta figure this out before you waste your money on sanitizing, which almost never works.
Okay, how to remove mold?
What not to do?
The Internet gave me this information.
Avoid using bleach because it evaporates quickly and doesn't penetrate deep.
We don't use bleach because it doesn't remove mold and it doesn't kill mold.
Don't just spray a disinfectant that's not going to fix things.
In the short term, most disinfectants have a fragrance, and you're going to think so, but a couple of weeks, months later, it's going to come back.
It's not going to work.
Replace your air filters, yes, sometimes even every three to six months.
Open the compartment.
Again, in the course, we have pictures on how to do this, so you can show your HVAC guy, clean the pans, make sure the coils are draining water properly.
You've got to have your HVAC guy come over, open that, know what to tell him.
You've got to know what to look for then.
The HVAC guy is going to say, or woman's going to say, what do you want me to do?
What are we looking at?
And then take pictures because after they seal it up for you, and it should be sealed with foil tape to make it airtight, you don't want to have to go, oh, I wonder, I wonder.
The Internet says to use an EPA-approved mold-killing solution.
Never again try to fix the problem with sanitizers.
That's not the problem.
Internet also says to seal the duct leaks.
That's easier said than done.
If there's an obvious leak, yes.
What we should be doing is when the house is built, we should be using infrared camera, like they do to make sure the house is airtight, not leaking heat or cold air to the outside.
We should go into the attic of the crawl space and be using the infrared camera to look for heat or coldness leaking from the ducts before we blow the insulation in, so we can fix the leaks then.
Once all the insulation is in, this is hard to do in practice.
The easiest thing to do is if you live in a humid climate, make sure your UV light works and is shining on the coils directly.
My mentor, Will Spates, in Florida, he's deceased now, bless his heart, taught me everything about Florida and humid climates.
Key thing is if some UV systems are on the market, they're sold to just install, the idea being as air flows through the ducts, the UV light is going to hit it and kill the mold.
Doesn't work, even for the bacteria.
It has to be shining on the cooling coils, and that could be something that's hard to implement if you have an existing system that doesn't have a space for it.
In terms of prevention, in the pan slope properly, and draining the water properly, and sized properly, and you have a UV light, you shouldn't really be having any problems unless something is not working properly.
Only way to tell is to open the access panel, have a look.
Now, in terms of testing, don't call a mold inspector to test the air to see if there's mold in your furnace or air conditioning system.
Here's why.
Starters have done it more than once because as an engineer, when I got into this business 20, 25 years ago, I don't go out and do it for money for a client first, I go do it for myself, and then when I go to a client the first and second and third, fourth time, I don't even charge them everything.
I'm taking extra samples on my own, running experiments to see, did this really work?
And guess what?
It doesn't really work.
It sounds simple like, just go put the air tester up to the spore trap cassette, the air sampler, whatever we're going to use to test the air and the duct work.
Put it up to the duct with air coming out.
But what's the baseline?
And did you know actually, ducts actually act like a filter, meaning some of the air that's going through there, some of the dirt is actually getting stuck to the ducts.
And ironically, yes, you will see this if you do enough testing.
The air coming out of the ducts is cleaner.
I mean, there's a filter too.
So what you'll get out of the ducts, if you compare it to the mold in the air in the house, in the living space and outside, will not only have lower mold count, it'll have a lower mold count depending on how good your filter is.
Because aspergillus penicillin is a really small spore.
You might need a HEPA filter or an allergy reduction to cut that down versus a stocky botchus or an alternari or a cladosporium.
Big spores to where your cheaper air filters can clean them out easier.
Plus all the air is mixing.
You really need to run the thing for at least 15 minutes to get enough air pumped out of it.
One strategy is, and this is the more realistic one, but it's a lot of samples.
You need your outside air sample.
You need your inside when your system has been shut off and left off for 24 hours, and you take more than one because there's variability, and then you turn the system on after you've taken some baseline samples with it off, and you let it run for at least 15 minutes, and you take two more samples.
So we got like at least five samples now.
The trouble still is for your ducks to be that dirty to moldy to contaminate the air, that is a long shot, not the best way.
Maybe you do it anyhow because you do what you gotta do.
Just don't count on that to be an absolute black and white magic thing.
Most of the time, you're still going to be like, you know, it doesn't look that much different.
You got to inspect the ducks.
It doesn't work to just hold the air sampler up to the air coming out of the vents at all.
That is not going to work.
As you can see, testing is kind of hard.
What is easy is taking the tape lifts.
Is it mold?
Yes or no?
If it isn't mold, why does it smell?
If you can figure out what's causing it, then you can jump to, you know what?
I'm just going to get a new system.
And I know this will get rid of the problem because this is what the problem was with the system or I'm just going to replace all my ducks.
Huge project, taking out the installation, running ducks, expensive, but I know it's going to work.
Why?
Because I know that it was made out of fiberboard.
I know that the fiberboard got molded because my air conditioning system wasn't working, indeed, he made it failing enough or something like this.
Most important thing is first identify the problem, then if you want to throw $10,000 or $20,000 in your system, might be the best idea.
Definitely work better than sanitizing, definitely work better than the ultraviolet light if you're just going to install an ultraviolet light system that doesn't shine on the coils after the fact.
If you have questions, go to healthylivingspaces.com, take a course, hire me to do a consultation.
If you have a quick one-up question, I also take questions on Healthy Living Spaces on the home page.
You can submit a question.
You can also put it in the comments for this episode, and I will answer it in a future episode.
Thanks for listening.
I'm here to help you create the healthiest living space possible so you can be healthy, go out and do the thing you're meant to do in life.
Certified by ACAC • 20+ Years Experience • Author of Mold Money