Why Does My House Get So Dusty?

Why Does My House Get So Dusty? Let’s take a look at how, and what you can do to prevent, or at least reduce, dust in your home.

The buck stops with me when it comes to making sure a steady flow of business is coming in for everyone who works for Magic Touch Mechanical – Mesa, AZ. One of the ways I make sure that happens is by looking for the trends in what our clients are contacting us about. So, when we got three separate inquiries last week from people asking – why is my house so dusty, I took notice and it prompted me to write this article.

Actually, this isn’t so much a recent trend, it’s actually an ongoing reason people contact us. When people call us to schedule a Home Energy Audit, we always ask them what their main concerns are and why they’re looking to get an energy audit in the first place. The second most common answer (after high utility bills) is –  “My house is always dusty” and most people are quick to point out that they clean and dust their home regularly and usually say something along the lines of: “Two days after I clean my house is dusty again”. If you read last week’s post, Is Duct Cleaning Worth It? you already know it’s not you, it’s your house, but with one exception. So, let’s examine how dust is getting into your home and how to prevent it.

Note: As I began writing this article, I realized I would probably have to make it a short series of articles to cover all the information or this post would turn into a novel, so I’ve covered a few of the biggies in this first article. Check back soon for part two.

How does dust get into your house? 

  • Dust from poorly sealed doors & windows – If you think I’m going to be the millionth person you hear say “check the weather-stripping and seal around doors and windows”, you’re right – but I’m going to add a twist: THE PROBLEM ISN’T YOUR DOORS AND WINDOWS! (I don’t mean to shout with ALL CAPS, I just want to make sure you don’t skip ahead too fast because this is important).

Of course it’s important to have well sealed windows and doors, but even homes with the worst of windows and weather-stripping can be relatively dust free – and have less dust than homes with good windows & doors and tightly sealed weatherstripping.

The Problem: Home’s leak – some more than others.

In home efficiency contracting we refer to this leakage in terms of air infiltration / exfiltration. Many homes are under a “negative pressure”, meaning the outdoor air pressure is higher than the indoor air pressure – especially when the AC, furnace or ventilation fans are running. When a home is under negative pressure it “sucks” air through those leaky areas which is called air infiltration. Obviously if your home is sucking in outside air like a vacuum cleaner it’s also going to suck the dust in that air inside with it.

The Solution: Make changes that put your home in a slightly positive pressure.

You’re going to need a building science expert like the BPI Certified Building Analysts, Energy Auditors, and Certified Building Envelope Specialists we employ at Magic Touch to test and address this. While it’s important to hire an expert, who understands how a home “breathes” to fix this problem…it’s not necessarily always an expensive venture to accomplish it.


  • Dust from leaky central air ducts – Leaky ductwork is often a main culprit making your home dusty. The importance of having your central air conditioning and heating ducts tested and sealed to reduce high energy bills is pretty self-explanatory considering heating and cooling your home can account for 60% of your annual energy costs, but how leaky ducts introduce dust into your home may not be so easy to understand for the layperson.

The Problem: Air ducts leak – some more than others.

Most of the homes we provide air conditioning service to in and around Phoenix, AZ have the ductwork installed in the attic and behind wall chases. For all intents and purposes, these spaces are considered to be “outside”, meaning they are outside the “thermal envelope” (the insulated and conditioned areas of your home).

When you consider how dusty it is in central Arizona it’s easy to understand how a lot of dust can settle in the attic and behind walls over the years. If you use your attic for storage you know how much dust is in the air when you disturb anything up there.

Dust is light so it can get sucked into an air stream very easily. When your air ducts are leaky, that dust gets sucked right into them whenever your furnace or air conditioner is running and blown right into your house.

The Solution: Have your air ducts tested for leaks and have them professionally sealed if needed.

Here again, you need a certified professional with sophisticated testing equipment to determine how leaky your HVAC ducts are and exactly where the leaks are. You also need someone with the experience to seal ducts properly so they are permanently sealed for the life of the ductwork. Check with your local utility company to see if they offer any assistance or rebates for duct testing and sealing. Here in the Phoenix, AZ area, both SRP and APS offer duct sealing rebates when the work is tested, completed, and post-tested by a certified contractor like Magic Touch Mechanical.


  • Dust from vacuuming your home – I saved the best for last. This one is something you probably didn’t consider and is the one that won’t cost you anything to fix!

The Problem: You’re cleaning wrong.

Some of the dust that enters your home from the other two sources I talked about in this article does eventually end up settling on floors and furnishings. Unless it’s disturbed, gravity does its job and keeps it there…that is until you come along with your vacuum cleaner and suck it up and blow it right back into the air again!

It’s easy to see this phenomenon when the blinds are open and the sun is shining through just right, you’ll actually see more dust floating in the air after you clean than before you started. The fine dust particles get sucked into the vacuum but are too small to get captured in the vacuums filter and are blown right out the exhaust back into the air again…over and over and over.

The Solution: Don’t use your vacuum until after you’ve dusted using the proper tools for the job. I recommend the following steps to prevent putting already settled dust back into the air:

  1. Start up high and move downward. Start at the highest level and work your way down by wiping furnishings with a Swiffer or similar brand feather duster. Not just any old feather duster – you specifically want something the dust will cling to. Old-school feather dusters just push the dust around without trapping it on the duster and are pretty much guaranteed to put the dust right back into the air. Think of old feather dusters as dust movers, as opposed to dust removers. Move slowly with your duster to wipe up the dust not wipe off the dust.
  1. Use lint rollers to clean off fabric blinds, curtains, and furniture instead of vacuuming them.
  1. If you have wood or tile flooring use the Swiffer Sweeper or similar style of floor sweeper instead of vacuuming.
  1. If you have carpet or areas you can’t reach with anything other than a vacuum, there are a couple of steps you can take:
  • If you’re not using one already, get a vacuum that has replaceable HEPA filters and change your filters regularly.
  • Empty the cartridge or bag and wipe off the inside of the vacuum compartment and attachments with a slightly moistened cloth or paper towel before vacuuming. This will prevent any loose dust left from the last time you vacuumed from getting blown back into the house.
  • Before putting the vacuum away, empty it even if it’s not full. Empty it into the outside trash whenever possible to avoid excess dust from getting back into the air.

If you live in the Phoenix, AZ area give Magic Touch Mechanical a call and tell us your home is too dusty and you need our help! We provide indoor air quality services and products to customers in Mesa, Chandler, Tempe, Scottsdale, Gilbert, Glendale, Peoria and surrounding cities. See if we service your area here.