pediatric housecalls Robert R. Jarrett M.D. M.B.A. FAAP

Wood Burning Fireplaces and Humidity

[Someone calling themselves on the internet “Jameyandcandy” wonders what they can do to humidify their home when using their wood burning fireplace.]

I have a wood burning fireplace. The air is so dry. I went to search for a humidifier but there are so many types that it just made me confused. Can someone help me figure this out.

There are more things to deal with during the winter when using your woodburning fireplace than the smoke particulates that it pumps into the neighborhood and environment.

Obviously, the air quality inside your home is our topic here and you asked about the effects on humidity. It’s hard to say whether it’s the cold air outdoors (the reason you’re using the fireplace in the first place) which is condensing water out of the air or the fire in the fireplace that is making the air in your home so dry; but it is, and our eyes, noses and mouths suffer.

Irritated mucus membranes and lungs can be due to either: the copious amounts of non-visible particulates pumped into the air inside your home or the lack of humidity; so it’s important to differentiate the two.

The cold temperature takes humidity out of the air in general, everywhere – inside and out. On the other hand, burning carbon (wood) into carbon dioxide (fire) actually produces molecules of water during combustion; so, if anything, indoor air should be more humid (than cold, outside air).

So, symptoms which seem to increase when inside the home more than they were outside are more likely due to the stove or fireplace’s micro-particulates (smoke etc.) inside the house than anything the fire does to humidity. The fire does not make inside air more dry. It was dry in the first place from the outside cold.

Back in the day when fires were actually mandatory for most people’s cool-weather survival it had evolved into being an actual stove and not a mere hole in the wall; and pioneers usually kept a kettle full of water warming. But even that was more of an attempt at using laboriously-gathered wood judiciously to heat the water than for “humidity control.”

I think from the small amount of information I’ve given in this limited space, you can see that there’s a lot more to giving a good answer to this question than “what brand of humidifier should I buy.”

If there are any allergies in the house (especially respiratory like asthma) a fireplace should NOT be used at all – IF you can at all help it (especially for merely convenience, picturesque or “traditionalism” reasons).

If you MUST use a fireplace then it shouldn’t be used in this day and age without the additional provision for micro-particulate removal (i.e. electrostatic precipitator filtering) for everyone’s health.

As a secondary concern, humidity can be provided by a host of mechanisms from units placed directly inside the house furnace-flow, to pans of water on/near the stove/fire or to an electronic humidity-maker device in all the rooms frequented by humans.

A furnace electrostatic precipitator/humidifier combination is, to my way of thinking, a good investment for your home – even if you don’t use a fireplace.