An unwelcome air conditioner odor might cause more than discomfort—it could prove dangerous.

You may have noticed an unusual smell emanating from your HVAC system. It may come from the unit or your vents. Up until now, you probably enjoyed clean, fresh, odorless air.

It makes sense if you’re concerned and have questions. A bad HVAC smell could indicate a serious problem. More importantly, it could serve as a sign that a health risk is present in your home.

A strange odor is normal when you switch from heating to air conditioning. However, some odors require urgent attention.

There are five common reasons why your HVAC might emit a strange smell. Keep reading to learn more!

1. Mold or Mildew

A musty odor is the most common culprit among smells that emanate from vents. If you experience this odor, it’s possible there’s mold in your ductwork.

Mold can form when there’s condensation in your HVAC unit. When this happens, moisture hasn’t drained properly.

As a result, it can migrate into your ducts. There, it will turn into mold growth.

When moisture gets trapped in your air conditioning unit, it can grow into harmful bacteria. The growth will distribute spores and mold as it expands.

There’s no mistaking the frequent smell of mold and mildew. You might notice it when you turn on your HVAC unit.

Firstly, you may want to turn your attention to the under-hood air intake vent. In all likelihood, it’s probably trapping dust, debris and dirt.

Your air intake vent can track all kinds of nasty things. These items include germs, mold and mildew. Over time, they can fester and grow in this trapped, wet environment.

2. Stale Air

Alternatively, you may notice that your air conditioning system releases a sour smell. It might remind you of your days in your high school gym. Alternatively, it might remind you of when you needed to wash your gym bag.

In that case, you may have a dirty filter. If you smell stale air, your filter is most likely saturated with bacteria and dust.

Fortunately, there’s usually a simple fix for this problem—change your filter.

If you smell stale air, it can come from any number of contaminants. These contaminants can include microbial volatile organic compounds (VOCs). They can also include fine particulates.

Your home will start to smell stale when there’s not enough air circulating through your home. Most often, you’ll notice stale air because of pent-up pollutants that contribute to the unpleasant scent. Alternatively, you may notice that the rooms in your home start to feel stuffy.

In the beginning, stale air is uncomfortable. At higher levels, however, stale air can become dangerous.

Unhealthy levels of stale air can cause skin irritation, headaches and fatigue. Furthermore, it can prove especially dangerous if you have underlying conditions such as allergies or respiratory problems.

3. Burning Odors

The smell of an electrical system burning is unmistakable. Electrical problems are one of the most common types of burning odors you might smell coming from your HVAC system. What’s more, they’re the most worrisome.

The smell of your electrical system burning could indicate a wiring problem. Alternatively, your HVAC system may have a circuit board malfunction. You may even face a problem as serious as your HVAC motor burning out.

A dirty air filter can contribute to this problem. It restricts airflow. What’s more, a blocked filter can cause electrical components to overheat.

Nearly all HVAC systems emit a burning smell during the first 24 hours of starting the system. This odor comes from an applied oil that ensures smooth operation.

However, you have cause for concern if the odor lasts longer than 24 hours. You should also worry if the burning smell returns later. In either case, these are signs of a serious HVAC problem.

You’ll want to turn off your HVAC system immediately if you smell something burning. You’ll also want to turn off your oil supply. Next, you should call an experienced service professional right away so that they can check your HVAC system.

4. Nail Polish Smell

You might notice the constant smell of nail polish remover when you turn on your HVAC system. If so, you’ve most likely also noticed that your air conditioner doesn’t keep your home cool, even with the fans going.

In this case, you probably have a refrigerant leak. When you have this kind of air conditioner leak, it can create a smell that’s reminiscent of acetone. You’ll smell it throughout your home.

You may have an old HVAC system. Alternatively, the HVAC system in your home may not have been properly maintained. In these cases, the AC coil can develop cracks or small holes.

If you smell something that reminds you of nail polish remover, you may smell the refrigerant coming from your HVAC system. The refrigerant in your conditioning system is called Freon.

It contains chemicals that can affect air quality in your home. What’s worse is that the chemical can enter your respiratory system.

Too much exposure to Freon odor can cause refrigerant poisoning. This condition can lead to problems such as difficulty breathing, headaches, nausea and vomiting.

Refrigerant poisoning can also cause skin and eye irritation as well as coughing. If you don’t have the problem fixed, it can lead to life-threatening conditions, such as irregular heartbeat or a buildup of lung fluid.

5. Rotting Smell

Finally, you may notice rotten smells coming from your HVAC system. A rotten smell is a sure sign of a dead rodent, lizard, bird or other critters. Sometimes, these unwanted visitors can get stuck in your HVAC system.

Over time, expired animals decay. As they do, they’ll emit an unpleasant odor. When you turn on your air conditioning, your HVAC system will discharge the odor into your home.

An experienced HVAC contractor in Austin TX can find the duct where the animal is located. They’ll then remove the critter from your ductwork. They’ll also check your remaining ductwork and seal any exposed entry points.

You could have any number of four-, six- or eight-legged “guests” invading your HVAC system. No, not your beloved fur baby.

There are many kinds of pests that can cause problems with your air conditioning unit. For instance, ants can chew through your electrical components.

Spiders can cover sensors with their webs. Even these small critters can cause big problems.

Some unwanted guests may look cute and cuddly. However, they can wreak havoc on your HVAC unit. Cute and cuddly-looking squirrels and raccoons often get trapped where they don’t belong.

There’s no foolproof way to keep unwanted critters out of your HVAC system. However, regular maintenance and annual inspections will help you to avoid problems with critters in your air conditioning unit.

The Importance of Good Indoor Air Quality

Since the emergence of COVID-19, indoor air quality is more important than ever. The pandemic has changed the way that the public thinks about ventilation and indoor air quality.

For years, HVAC experts have known about the importance of proper filtration and airflow. These characteristics create what’s needed for good quality indoor air.

As it gets cold outside, indoor air quality becomes more problematic. HVAC systems require the return of indoor air to heat the interior of your home. What’s more, winter humidity and dryness are also enemies of indoor air quality.

As temperatures get colder, it gets harder for HVAC equipment to do its job. The air that enters your home to your HVAC system poses more of a risk for this reason.

Today, researchers have found growing evidence that COVID-19 can remain airborne longer than originally anticipated. A properly functioning HVAC system can reduce the transmission of the virus through the air.

Ventilation and good indoor air quality are crucial components of staying healthy and the new normal.

Preventing Air Conditioner Odor

Again, many HVAC air quality problems start with a dirty or clogged filter. Alternatively, a filter can get exposed to too much moisture. In this instance, mold and mildew can start to grow.

Furthermore, many small organic particles continue to get trapped in the filter. As this process takes place, moisture will accelerate mold growth.

Your best defense against HVAC odors is to remove and clean around the filter. You also want to replace the filter as needed.

Some households may need to replace their filter every month. What’s more, it’s important to replace all of your filters, rather than just one or two of them.

When it comes to air conditioning odors, your filter is the top culprit. Fortunately, you can prevent your filters from becoming a stinky problem.

All you need to do is maintain a regular schedule for changing your filters. By doing so, you’ll keep smelly particles from permeating throughout your home.

You may also want to consider upgrading from a regular disposable filter. Instead, you might want to invest in a higher-quality filter.

You can make a big difference in removing particles that cause odors in your home with a high-efficiency air filter. A filter with a higher MERV rating can remove smaller particles that allow mold and bacteria to grow.

Removing Odors from Your HVAC System

You want to make a habit of checking your HVAC system for mold, mildew and unwanted pests. However, you can also prevent unwanted odors by claiming your evaporator coils regularly.

Again, you want to replace your filters regularly. However, you’ll also want to schedule routine HVAC maintenance.

An HVAC expert can make sure that bad odors don’t infiltrate your home. More importantly, they can check for dangerous hazards such as faulty wiring. An expert HVAC service person can also provide needed maintenance such as belt-tightening or replacing worn-out parts as needed.

You should have an HVAC technician clean your AC coils at least once a year. The cleaning will remove any built-up dirt, mold or mildew from your coils.

It will also reduce the chances that your system will develop any foul smells. More importantly, an annual cleaning and maintenance call will also ensure that your system runs more efficiently.

You should also consider allowing an HVAC technician to check your ductwork annually. If needed, they can remove any contaminants from your ductwork system. Ductwork cleaning will prevent bad air from circulating through your home.

Other Signs of HVAC Trouble

A bad smell isn’t the only way to tell whether there’s something wrong with your HVAC system. Poor airflow is another sign that you may have a problem with your unit.

Most often, you’ll notice poor airflow when there’s a lack of air. In this case, you may have a problem with your compressor or blower fan.

Alternatively, you may have a blockage in your duct system. For example, debris may have entered your duct system, stopping optimal airflow. Without service, these problems can greatly reduce the air quality in your home.

Strange sounds are another indicator of problems with your HVAC system. For instance, you might notice a rattling, grinding or squealing sound coming from your air conditioning unit.

If so, your HVAC system may have a significant mechanical issue. Accordingly, you’ll want to schedule an inspection as soon as possible.

Finally, you might notice that different rooms in your home are different temperatures. Unless you have zone control, air conditioning is supposed to keep your entire home at nearly the same temperature. However, a problem with your thermostat could prevent your HVAC system from functioning properly.

Odor Problems Aren’t Always a Quick Fix

In a perfect world, getting rid of odors in your HVAC system would always be as easy as changing your filter. However, that’s not always the case. Sometimes, your HVAC system needs some TLC.

When you have HVAC problems, you hopefully won’t have to purchase a new unit. An HVAC system is a considerable investment.

Trustworthy and skilled HVAC contractors in Austin TX will do their best to make repairs. They’ll also help to prolong the life of your HVAC system as long as possible.

It’s important to make a note of whether you smell strange odors coming from your HVAC system. Keeping an eye, or a nose, on your HVAC system can help you to keep track of whether there’s a problem. When your HVAC system is working right, you shouldn’t smell anything.

For example, an electrical smell could mean that your system is overheating. If you allow the problem to go unfixed, it could result in the need for a more expensive air conditioner repair.

Alternatively, you may notice another kind of burning smell when your heat or air comes on. In that case, your AC motor is possibly nearing the end of its lifecycle. Once the motor on your HVAC system goes, you’ll most likely need to replace your entire system.

Again, if you ever smell a burning odor, you’ll want to turn off your system immediately and call an HVAC technician. Furthermore, you’ll want to keep it off until they have a chance to do a thorough inspection.

Little Signs of Big HVAC Trouble

You may notice water coming from your HVAC system. Most people don’t think that moisture coming from their HVAC system is a big problem. In most instances, a homeowner will assume their air conditioning system is fine because it’s continuing to cool their home.

Unfortunately, moisture coming from your air conditioning system is a sign that there’s something wrong with your unit. You shouldn’t ignore the problem because your air conditioning is still working. By remedying the issue fast, you can save yourself a lot of money.

If you see moisture coming from your HVAC system, it usually means that your condensation pump or evaporator coil is malfunctioning. If these parts are damaged, they can cause other problems in your HVAC system. In fact, they can result in a complete system failure.

If you continue to use your HVAC system, you’ll eventually need to replace it if it’s leaking excessive moisture.

All parts of your air conditioning system are important. Your HVAC system is a finely tuned piece of equipment.

If one part is malfunctioning, it increases the chances of things going wrong with other parts of your system. Again, it’s critical to have your HVAC system inspected once a year to help avoid these kinds of issues.

Other Signs of Serious Problems with Your HVAC System

When you come home, you want to feel the air coming from your vents. After a long, hot day, nothing feels better than the cool air coming from your HVAC system.

However, there’s no guarantee that your HVAC system will always perform a desired. If there’s a problem with your air conditioning, it can affect the airflow through your vents.

In most cases, however, you can remedy the issue easily. Again, dirty filters are a top culprit of airflow problems.

Conversely, you may notice that your HVAC system isn’t getting as cold as you like. If this happens, there are a few issues that can cause your air conditioner not to function as desired.

For instance, HVAC systems use up the refrigerant. If your air conditioner has exhausted its refrigerant, an HVAC technician can recharge it and have your home cool again in no time.

In another scenario, your air conditioner may have a refrigerant leak. In that case, it won’t cool off your home as fast as you’d like.

Accordingly, you’ll need to have an HVAC technician take a look at your air conditioning system. If your AC coil is damaged, you’ll need a professional to resolve the issue.

Repair or Replace: What Are My Options?

At some point, you’ll start to notice that you’re calling an HVAC technician more than desired.

When this happens, you’ll need to do some math.

At some point, all equipment fails. No equipment lasts forever, including your HVAC system.

You can make your air conditioning system last longer with proper care. Changing your filters and scheduling yearly inspections is a good start.

However, you also want to have problems repaired as soon as they emerge. Still, you’ll reach the point of no return at some point.

When this happens, you’ll notice that your HVAC system needs repairs more frequently. The cost of fixing your system will add up quickly and start becoming more serious with each maintenance call. When repairs become more frequent and more costly, it’s time to get a new HVAC unit.

As a rule of thumb, you’ll want to get a new unit if you need to pay more than 20% of the total value of your HVAC system for repairs. If not, the next year, you may end up paying 40% over the original value of your air conditioning system. As each year passes, you’ll pay more and more to keep your old HVAC system running.

The Benefits of Upgrading Your HVAC System

There’s a great benefit in investing in a new HVAC system. A newer unit will save you money on your electricity bill and repair costs.

You won’t make your investment back immediately. However, you’ll save a considerable amount of money in the long run.

What’s more, a new HVAC system will give you peace of mind. You won’t have to pay for inspections, repairs and parts three times a year.

Today’s quality HVAC systems are Energy Star-rated. They last longer than older models. Accordingly, they’ll almost always save you money in the long run.

Your Trusted Austin TX HVAC Service Provider

Now you know more about five worrying air conditioner smells to watch. Hopefully, you have a better idea of what to do when you smell a worrying air conditioner odor.

We’ve provided exceptional HVAC service for Greater Austin TX for more than a decade. It’s an honor when homeowners trust us to work on their HVAC system.

We’ll always treat your property with the respect that it deserves. In fact, we’ll treat your home as if it were our own.

We’re a local company that focuses on delivering quality service. What’s more, all our HVAC experts live and work in the community. We’re committed to giving our customers reasonable quotes and honest advice.

Don’t wait until it’s too late. If you smell a strange odor coming from your air conditioning or notice another problem, contact Schneider Mechanical at (512) 695-4323 or connect with us online to have the problem repaired as fast as possible.