Why am I sneezing all of a sudden?

It’s hard sometimes to pinpoint the exact cause of health changes, but many times it’s possible if we take time to consider when the symptoms start and what changed in our daily routine.  

Here’s are some things to consider: 

• Change in diet 

• Change in personal products (soaps, lotions, deodorants, toothpaste/mouthwash)

• Change in medication

• Change in people/pets living in the home

• Change in cleaning products

• Change in routine – spending more time in one building/room/car than before

• Change in weather –which means a change in heating/cooling the home, change in allergens/pollens, change in outdoor air quality 

In much of North America, there are distinct cooling and heating seasons.  As we move into the fall season, we turn on heaters and furnaces for the first time in 6+ months, and suddenly, respiratory symptoms change/emerge. If these symptoms persist after the initial “burning dust” smells go away (as dust burns off heating coils), or start up every time the thermostat clicks the heater on, then you may consider that your system needs cleaning.  This is especially true if you smelled any musty smells during the cooling system; mold formed during use of the AC could now be drying out, flaking off and sending small particles of mold throughout the home.  

There are several ways to approach this.  First, make sure that you’ve changed the HVAC filter recently.  If you’re out of filters and want to try increasing the filtration on your system for cleaner air inside, contact us with the size of the return grille(s) and the model of your air handler, and we’ll be glad to give you a custom recommendation for new filters in the highest MERV for your system.

If you have a mini-split and haven’t cleaned the filter in a while, it’s time to do that.  If you haven’t cleaned the mini-split unit in more than a year, here’s an article to help you do that. 

Next, if the symptoms persist, you might want to investigate your central HVAC system.  This article gives 5 places where you may find mold in the system:

• Air Ducts – Dust + humidity = prime mold real estate

• Evaporator Coils – Condensation from cooling builds up

• Drip Pans – If clogged or tilted, standing water can foster mold

• Air Filters – Dirty filters trap spores and allow them to colonize

• Supply and Return Vents – Especially near bathrooms, basements, or kitchens

Here are some photos from a 5 year old system in a humid climate:

In addition, we would add that another likely place for mold in a central HVAC is the plenum.   The plenum is the area after the air handler where the ductwork branches out in all directions to serve the different rooms in your home. Here’s a common sight: mold on the internally insulated ductwork.

Source: Mold/Mildew on the supply plenum box liner

This happens because of the internal insulation, which traps dust.  You can see in the photo that the two metal ducts on either side do not have mold on them; neither would clean flex duct.  The problem detecting this situation is that the plenum it may not be an easy place to get to; since the ducts are screwed into the “box” here, you may have to disconnect a duct fitting from the duct and insert a camera to see what’s going on inside the plenum.

If you find mold on internal insulation in your HVAC, don’t fall for duct cleaning or encapsulation, which are typical sells for “duct cleaners”.  First of all, internally insulated ducts cannot be cleaned.  The cleaning equipment used (rotating brushes) would tear up the insulation and make the problem worse–you would have bits of insulation AND mold spores going throughout your home.  Secondly, encapsulation is not feasible if the surface can’t be cleaned first.  Encapsulation also involves a chemical/adhesive that will also need to cure and may pollute the air in your home.  Check out our article if you are considering hiring a duct cleaner anyway... 

If the moldy insulation is foil-faced, you can clean it using a non-toxic cleaner like Concrobium Mold Control, which cleans and acts as a mold deterrent for some months.  If the insulation is fibrous like fiberglass duct board, you can also use this product, however be aware as the mold dries out that it can break apart and send mold fragments into the air.  In this case, it’s best to have the insulation replaced with a foil-faced insulation by an HVAC tech OR externally insulate the unit to avoid insulation problems again (the mold may come back with any dust that enters but at least it’s easier to clean).  There are encapsulant products on the market like Superstratum Endurance Coating, however this contains a 1,2-Benzisothiazolin-3(2H)-One (BIT) antimicrobial which can be irritating to the skin.  It’s best to do your research on any product that can be distributed throughout your home via the HVAC system.  

Yes, your health symptoms can be tied to the HVAC system, so it’s a good idea to check on it every once in a while (yearly at least!).

Photo by Taylor Vick on Unsplash