It happens every year. You finally get cold enough to give in and turn on your heater for the first time. It starts to warm your home, but then you find yourself sniffling and sneezing. You probably think that allergy season should be over, but your heater can help it make a comeback.
If you suffer from renewed allergy symptoms after turning on your heater, you are not alone. Read on to learn why your heater can trigger seasonal allergy symptoms and what you can do to breathe more easily this winter.
5 Reasons Your Heater May Trigger Allergy Symptoms
Depending on the climate where you live, you may go the better part of a year without turning your heater on. While it sits unused, dust, pollen and other allergens start to build up on the heating elements and in the heating vents.
When you start to use your heater after keeping it off for months, two things happen. First, the heating elements burn off all the dust that has built up on them over the warmer seasons. (This can cause a smoky smell, and it may even set off your fire alarms.) Second, your heater starts to blow out all the debris collected in the heating vents.
Because your heater can circulate allergens around your home just as efficiently as it circulates warm air, you may notice your allergy symptoms start to flare up around the time you start using it to fight the cold outdoor weather.
1. Pollen may have accumulated in the ducts.
If you are allergic to tree or grass pollen, you probably expect to experience your most severe allergy symptoms during the warmer seasons. Trees typically produce and spread pollen in the early spring, and grasses do so during late spring and summer. People who are sensitive to pollen may experience allergies during that time, especially when they spend time outdoors.
It makes sense to think that the colder weather should bring relief for your pollen allergies. However, that is not always the case. While your heater is turned off during the spring and summer, pollen has the opportunity to accumulate undisturbed in the heating vents.
Then, when you finally use your heater again, it blows all of that pollen right into your home, bringing back those pesky seasonal allergy symptoms you thought you were rid of.
2. Dust from your heater may carry extra mold spores.
Airborne mold is common, both indoors and outdoors, and its existence is not always cause for worry. Unless you are sensitive to mold, you probably will not notice the presence of mold spores in the air.
When mold spores land on a surface in your home and start to grow, it is time to be concerned. Mold needs two things to grow: moisture and nutrition. When dust — often made up of dead skin cells and other organic material — starts to build up in your air ducts, it can provide the food mold needs to start growing.
Then, when you turn your heater on, it can blow that dust (along with the mold spores it contains) into your rooms. Because heating systems recirculate indoor air for efficiency, the dust and mold may remain in the air until they are trapped by a filter or settle on the floor or other surface.
If you are sensitive to mold, exposure may cause nasal congestion, coughing, wheezing, eye and skin irritation, and increased allergy or asthma symptoms.
3. Dust carries more than just allergens.
Pollen, mold spores, and dust mites are not the only pollutants found in household dust. It may also harbor volatile organic compounds (VOCs) and other toxins that can cause or worsen allergy and asthma symptoms.
VOCs are carbon-containing chemicals often found in indoor air. They can be emitted by manufactured products, including electronics, furniture, and cleaning chemicals. Once VOCs are in the air, they have the potential to be partially absorbed by the dust in your home.
Short-term effects of inhaling VOCs can include:
- Eye, nose and throat irritation;
- Nausea and vomiting;
- Dizziness or loss of coordination;
- Skin rashes.
VOCs evaporate readily at room temperature, but colder winter temperatures may slow this process. Several studies have shown that dust is more likely to carry VOCs during the winter than in the warmer months of the year.
4. Dust is harder to filter in the winter.
Dust is a type of pollution known as particulate matter (PM). It consists of tiny particles that are light enough to float in the air. When enough dust particles stick together, they get too heavy to float and start to fall. This is how dust comes to coat the surfaces of your home.
Moisture in the air makes it easier for dust particles to stick together. However, cold winter air holds less moisture than warmer air. When humidity is low — as it often is during winter — dust particles are less likely to clump together. Smaller dust particles are more likely to remain in the air, and they may also slip through air filters more easily.
5. Dry air may make you more vulnerable to allergens.
If you find yourself experiencing more allergy symptoms after turning on the heater, an increase in airborne allergens may not be the only culprit. Dry air, or air with a low relative humidity, may also make you more susceptible to allergic reactions and infections.
The relative humidity (RH) of your home is the percentage of moisture in the air compared to the total amount of water vapor the air can hold before it starts condensing into a liquid. If the RH in your home is too high, the excess moisture can provide the perfect environment for mold growth to thrive.
However, a too-low RH comes with consequences too. Cold air already holds less moisture than warmer air, and using a heater can dry the air out even further. Breathing in this dry air all day can cause your sinuses to start to dry out.
Think of your mucus as a line of defense between your respiratory system and the air you breathe. Its job is to catch pollutants you inhale before they reach your lungs. When it dries up, it starts to lose its ability to catch allergens, viruses, and bacteria that you breathe in. This makes it more likely for your body to react strongly to airborne allergen exposure.
How can you enjoy your heater without triggering allergy symptoms?
When dry, cold air makes you more vulnerable to allergens and other pollutants — and your heater is only making things worse — you can help protect yourself by taking steps to improve your indoor air quality this winter.
- Ditch your evaporative cooler: Research has shown that homes that use evaporative coolers instead of central air conditioning have more problems with dust mites and other airborne allergens. If possible, switch to another option, such as a portable air conditioner, window unit, or ductless air conditioner.
- Check your furnace filter: For best air quality results, change your furnace filter at least as often as the manufacturer recommends. If dust or pet dander cause your filter to fill up more quickly, you will need to change it more often. If possible, consider upgrading to a HEPA filter. (Note: HEPA filters are dense, and they can restrict airflow in some HVAC systems. Check with an expert to see if your system can handle a more efficient filter.)
- Perform furnace maintenance: Regular maintenance can help you keep your furnace working efficiently and reduce the chances of it triggering your allergies when you turn it on.
- Look into a radiant heater: If you find yourself constantly dealing with dust, pet dander and other allergens in your home, a heater with a fan may not be your best option. Radiant space heaters use a concentrated infrared radiation system to warm people and objects in a room without blowing air and stirring up dust.
- Clean your ducts: When large amounts of dust, mold or other debris have collected in your air ducts, it may be best to hire a heating and air conditioning professional to clean them. Just be ready to give your home a good dusting afterward. If you have allergies, you should leave the house while the technician works.
- Use an air purifier: No matter what you do, you will probably still have some level of allergens and other pollutants in the air inside your home. An air purifier — especially one that destroys allergens, such as Molekule — can work with your HVAC system to filter pollution and improve your indoor air quality.
- Use a humidifier: A humidifier can help you combat the effects of dry air in your home. Ideally, you should keep your indoor relative humidity between 30 and 50%. Keeping it any higher than that can increase mold and dust mite growth.
- Dust and vacuum more frequently: Source control is one of the most efficient ways to battle indoor air pollution. Reduce allergens in your home by dusting with a wet cloth, using a vacuum with a HEPA filter if possible, and cleaning your curtains and bedding regularly.
You do not have to dread turning on your heater each year or fear of how it will affect your allergies. By maintaining your furnace, changing your filters regularly, and taking other steps to improve your indoor air quality, you can minimize your indoor allergen exposure this winter.