Dust In The Wind

Welcome one and all and the question of the day is one I get from my clients on a regular basis. “Why is my house so dusty, I dust and twenty four hours later it’s back?” While there are several things that cause a dusty home such as windows, how tight the structure is, and how many people and animals live in the home, the biggest culprit is your attic and the ductwork hidden within.

Let’s start with a basic building science lesson. Every building is under a very slight amount of negative air pressure. It’s just the nature of a building that the air pressure is ever so slightly lower inside than out. This is not pressure that you can feel and it can only be measured with very sensitive instruments. As usual, unseen things can cause very interesting effects.

In most single-family homes there are soffit vents around the outside of the roof line. These can vary in size and design, however what you are looking for are usually rectangular screens that are under the roof deck about every two to three feet. So back to our negative air pressure for a minute, air pulls into the soffit vents from outside, mingles around in the attic and streams down the walls. Yes walls are hollow in your typical construction scenario. That said, any openings in the walls allows attic air into your home, these can be outlets, light switches, ceiling fans, recessed can lights, etc.

Wait — weren’t we talking about ductwork? The answer is 100% yes, in a normal single family home air is traveling through the ductwork at around 400 feet per minute – translation, about 8 miles per hour. If there are any failing connections, or holes of any type in the duct system, the velocity of the air creates a little miniature tornado, which sucks in whatever is around it. This would be dust, dirt, mold, pollen allergens, etc.

One of the quickest ways to know if you have a duct problem behind the dust in your home is to take a look at the vents themselves. Remember, air is blowing out of those vents and if you see dust on the fins of the grilles or dark colored streaking across the ceiling there is a good chance that your duct system needs some love and attention. Our poor ductwork gets ignored in general because it is unseen and forgotten about in our attic. Think about this, if your home was built in the 1980’s you have almost forty-year old ducts that have been hanging out in an environment that on a typical summer day the temperatures reach well over 150 degrees. The connections in the attic don’t stand a chance after that length of time with no maintenance.

As always, I’m an email away at THW@artplumbingandac.com, or you can schedule your duct evaluation at www.artplumbingandac.com or give us a ring at 1-800-475-1504 and us and our thermal cameras will be out in a flash.

The real question of the day is what is the airspeed velocity of a swallow laden with a coconut? True fans will know the answer is another question. Make it a great day.

House Whisperer out!!!