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rachel101 · Jan 14, 2008, 10:44 AM

I've been changing out all my electrical outlets and switches because they were beige and I like white... anyway I find that some of the electrical outlet boxes are full of dust. I pulled out the shop vac and took care of it and I noticed it was outlets that are powering something constantly (ie: electric toothbrush, etc.) and I suppose it's the constant static that draws the dust but is it a fire hazard?

I take house fires very serously and wonder if cleaning these is a bi-annual chore I need to take up?

tkrussell · Jan 14, 2008, 11:03 AM

If you clean out your outlet boxes twice a year, I think you may be the first.

No, this dust does not pose any immediate threat.

If there was a short, the sparks could ignite the dust. However, this is why it is so important that every outlet box have a proper cover plate, and any knockouts are filled in with blanks.

Enclosing electrical boxes is mandatory to contain any sparks from reaching any combustibles in the general area. Any dust inside the box would be extinguished if ignited by a properly covered box.

Now, if you doing a project such as your doing now, sure, now is the time to clean the boxes out. But consider, how long has it been since the boxes were opened, probably a very long time, for the amount of dust to accumulate.

So, it is a good thing to clean these out, but I would not get worked up about it. Checking a sample every couple of years I would think is plenty.

rachel101 · Jan 14, 2008, 11:08 AM

Thanks much. I will take that off my list of things to be concerned about and I truly don't want to be the only person alive who actually cleans these things periodically. Whew... I can unpack my bags and stop tripping.:)

ballengerb1 · Jan 14, 2008, 11:08 AM

If this dust was a fire hazard 3/4 of the homes in the USA would be ashes. If you have the cover off anyway it won't hurt to lightly suck out the dust but if you start cleaning your outlet boxes every two years you are wasting your time and energy. Some electrical appliances like a TV can build a static charge but the dust in your outlet is more likely from a slight draft allowing room air to vent through the wall cavity toward your attic or outside.

Stratmando · Jan 14, 2008, 03:20 PM

One thing though, if you are getting excessive accumulation of dust around wall plates, switches and recepticles. Had this proble in my house and have seen others.
In ALL Cases it was the return air was not properly ducted, and was sucking air out of the walls, creating a negative pressure. Dust was the result.
Does it outline your wall plate, or switches?

ballengerb1 · Jan 14, 2008, 03:32 PM

Strat makes a good point since most forced air systems use the wall cavity as a return duct.

rachel101 · Jan 14, 2008, 04:05 PM

The only places where it was excessive was of course the electrical outlet next to my A/C return so that made sense. A couple of other outlets, one in the bathroom where the electric toothbruch is plugged in, and another where the telephone answer machine is plugged in. I figure these items are "on" 100% of the time so the static probably draws the dust in. Most of the boxes were fine. Since I've had fires in two houses that started in the walls I just try to be real aware because the best way to fight a fire is before it ever starts.

Stratmando · Jan 14, 2008, 05:02 PM

Smoke Detectors save Lives. Forget who say that. It is good Advice. The can help save your family, A couple of Fire Extinguisher in opposite sides of the house, or more if necessary. I have 1 in Master Bed, One in Kitchen.
Personally I would make Code so as not to Pull air from the walls, but have all air to enter the Reurn air come from within the house, not within the walls, plus you are cooling inside the walls also.
At our house. I blocked within the walls with 2X4 where They cut through for the return air to prevent this.
No Dust sucking outlets now.

ballengerb1 · Jan 14, 2008, 06:16 PM

Strat, using the wall cavity of an interior wall is allowable by code for a return air run. Almost every house in the USA with force air has them until they reach the basement and enter the plenum.

Stratmando · Jan 15, 2008, 06:01 AM

I have to disagree with the "Almost every house". If it is alowable by code, it shouldn't be.
All the really nice Houses and systems I have seen don't,
Maybe we are talking 2 different things. My house for example Has Air Handler in the Garage, They cut about a 2X2 1/2 foot hole between Garage and house. When we had dust around wall plates, and switches, I removed the filter cover, and filter, Look up inside wall and it WAS open. I blocked off with 2X4's so NOW everything goes through filter, the air being sucked from the walls was not filtered, Your coils will clog. Any AC guy that doesn't do that, MAY be looking for return Business. I will always think it is wrong.
Only on rare occasions do I see the lint on plates, in ALL cases, it was pulling from the walls.

ballengerb1 · Jan 15, 2008, 08:25 AM

I think we are talking about slightly different things. The home I picture have return air ducts, usually one from every room in the house. These return ducts are high on the wall at about 6.5', air is pulled into the grill, down the interior wall cavity to the basement or crawl where it is connected to main return air plenum. Air is filtered, goes through the heat exchanger and then out the supply plenum. All heated supply air is in a galvanized duct to the heat registers in the floor or wall. From what you desrcibe with a 2x2 hole in the wall you have no return air ducts at all, air is pulled directly into the handler. By code no switches, receptacles or other openings can be placed into one of the return air cavities.

Stratmando · Jan 15, 2008, 02:14 PM

Before I placed 2 X 4's in stud wall to block, I could look up and see the switch box to the Kitchen. Now all the air that is pulled through unit is filtered, No Wall plate dust.
Ballenger, I'm glad it was an missunderstanding. Answers prior to this have been good. Figured we had to be talking different animals. Keep up the good work.
Air is pulled directly in, no return duct work.

ballengerb1 · Jan 15, 2008, 02:20 PM

Yep, what you describe would not be allowed for a return air cavity because of that box. We can use a cavitythat has any receptacles or openings. I think you have desribed the equivalent of a fire stop and it worked out fine for your purposes. Have a good one Strat.
Bob