Turbinates and dry air

Posted Wednesday, November 28, 2012 in Sustainable Maine

Turbinates and dry air

by Paul Kando

Once upon a time, before texting, blackberries, iPads, and MP3 players, there were parlor games. In one I recall closed-eyed players took turns pointing a pencil at a random page of a foreign language dictionary. Then, opening their eyes, they had to tell a story about the word upon which the pencil happened to land. To win a round, your story had to come closest to the real meaning of the word. I thought of that game reading about “turbinates” the other day. Who are they? Installers of wind turbines?  Somber, turban-wearing men discussing Sharia law?  Bodyguards of a sultan?

Actually turbinates are part of the nose, the key functions of which are to filter and humidify the air we breathe and to provide us with the sense of smell. Divided by the nasal septum there are two separate nasal cavities. The ridge-like structures that line each of these are called turbinates. Their job is to produce mucus for the nose. The more familiar sinuses are not part of the nose itself, but a connected network of cavities in the skull, located in the cheekbones, the forehead, on either side of the bridge of the nose, and in bones behind the nasal cavity. The sinuses drain into the nose through a narrow duct and, except for a thin layer of mucus, they are normally empty.

The turbinates and sinuses are covered with a complex lining of millions of cilia. The lining secretes mucus to keep the nose moist and capture allergens, viruses and bacteria. The cilia then spread this mucus in a wavy, dance-like pattern, to capture the irritants. When the cilia are damaged – by tobacco, allergens, bacteria, viruses, chemicals or some illness like cystic fibrosis – we develop sinusitis. The common symptoms are increased mucus production, nasal congestion, and discomfort in the cheeks, forehead or around the eyes. Allergens – pollen, dust mites, mold, or pet dander – can cause our nasal defenses to overreact, causing allergic rhinitis. A stuffy nose, sneezing, and itching are the result.

 

 

Cilia (magnified 3,500 x)                    Moisture damage inside a wall

Dry winter air can also prompt the nose to produce excess mucus and stuffiness, causing us to breathe through the mouth. The result is dryness of the mouth and throat. We may even greet the morning with what feels like a sore throat. The immediate remedy is to drink some water. Some people run a humidifier in the bedroom.

But what causes indoor humidity to become so low in the winter, even though our indoor life and habits remain the same as during other seasons? And what can we do to mitigate this problem? The culprit is usually a leaky house. When our heating system is running, the indoor air absorbs moisture as it warms. The warm, moist air expands and becomes lighter. It rises and, if it can, it will escape the warm house through holes and cracks in upstairs walls and ceilings, into the cold attic or wall cavities, taking the moisture with it. Meanwhile the escaping warm air is continually replaced by outdoor air filtering in through leaks in the basement and other lower parts of the building. This winter air is cold and therefore holds little moisture. So, without us realizing, our heating system turns our leaky home into a dehumidifier. Not only do those air leaks rob us of precious, increasingly expensive heat, but also of moisture in the air.

Is adding more moisture the answer? – Consider this: if the moisture we add just leaks out of the house, we don’t gain very much. However if the moisture enters the wall cavity and other structural parts and condenses there, it can cause real damage. Over time it can even destroy affected parts of the structure. Therefore the best line of defense against low indoor humidity is to seal the leaks. A hole as small as a millimeter across can convey over two cups of water vapor in 24 hours. A single electrical outlet provides up to 15 square millimeters of hole into the interior of a wall. Count up your potential leaks and do the math: that’s a lot of water to lose from the air – and to damage your house. An energy audit should tell you how much air and moisture your house leaks and also pinpoint where the leaks are, so you can fix them.

Now you literally don’t even have to look beyond the tip of your nose for encouragement to fix those leaks. Perhaps you have been procrastinating about home energy efficiency. So, who knows, in your dreams, restless due to that chronic stuffiness, you may even find yourself dragged in front of a court full of those somber turbaned men, to be judged for all your shortcomings.

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