Unknown source of dust / fibers - how to identify & get rid of it?

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Old 10-31-15, 01:28 PM
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Exclamation Unknown source of dust / fibers - how to identify & get rid of it?

Hello, for the past year since my wife & I have been at our new home (believe it was built in the 1960s, a brick house), we've come down with respiratory issues.

I believe there's some source of dust or fibrous material that's causing it but no matter how much we clean, we can't get rid of it. If I turn off the heat or A/C (symptoms are year-round), and use a wet rag to wipe up settling dust, there'll be a gray/black layer of dirt but looking closely, it looks like they're tiny fibers.

We see this same stuff in thick layers when we clean out the exhaust fan in the bathroom, so it's in the air. We do have forced air heat, and the air filters are changed every other month.

I'm sure people will say make sure we vacuum regularly, but we do, almost every other day. We dust weekly.

My question is:
1) What can we do to identify where this stuff is coming from?
2) What can we do to get rid of it?

We don't have pets or kids, and both of us are gone during the day. The only time we don't have health issues is when the heat/AC is off and the windows are open. Once closed up, it's like this stuff is just recirculated or regenerated or something. Help!
 
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Old 10-31-15, 05:00 PM
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I'm sure people will say make sure we vacuum regularly, but we do, almost every other day. We dust weekly.
Unless you have a central vacuum system with an outside exhaust OR a portable vacuum with a HEPA filter you ARE recirculating the dust/dirt. Same is true from dusting unless you use a treated dust cloth that holds the dirt until it is washed.

Regular furnace filters do almost nothing to remove dust from the air as the particles are just too small. Using a much more restrictive filter will catch a bit more dust BUT it can also be harmful to the heating and cooling equipment. Electronic air filters CAN remove the dust but they need to be cleaned about once a week and even then they only work when the heating/cooling blower is running. Portable HEPA filters can help but they are noisy to run and the portable ionic air filters have the same problem of needing frequent cleaning as a furnace-mounted electronic air filter.

AS for identifying the dust/fibers in your air you would need the services of a testing laboratory that deals with air quality issues. A lab that tests for airborne asbestos could probably do it.
 
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Old 10-31-15, 05:23 PM
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With this happening with both ac and heat we can eliminate combustion issues with the furnace, but the hot water unit may still be an issue. What fuel do you use and how is your water heated?

I want to be sure the air circulating system, assumed to be used for both ac and heat, is not causing a backdraft issue with your water heater.

Bud
 
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Old 10-31-15, 05:53 PM
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We see this same stuff in thick layers when we clean out the exhaust fan in the bathroom, so it's in the air.
Is the same fiber seen where the forced air leaves the duct? Run your finger inside the cover plate.

Do you live near an above ground train station? I'm thinking that it could be steel dust. If not a train station, are there any factories, in the neighborhood?
 
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Old 11-01-15, 12:59 PM
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Yes, we use a vacuum that has a HEPA filter. In addition, when we dust, we assume some stuff won't stick to the duster & will eventually fall to the floor, which we then rely on the vacuum to grab up.

Our furnace filter is the minimum filtration. There was a period of time where I got one of those Filtrete filters that supposedly has super filtration, ran the blower {no heat or A/C} for a couple of hours a day hoping that it would serve as a whole-house air filter. Didn't notice any difference & switched back to the thin filters after hearing about putting too much strain on the blower.

HEPA air purifiers were one of the first things we ran to. To be honest, I can't be sure they make any difference, though when we look at the filters, they are picking up a good amount of dust.

We use natural gas as the fuel for our furnace and water heater, which are in the basement. The water heater is right next to the furnace & the flue for the water heater that leads to the chimney does pass by some {supply} ductwork. The outside of the ductwork right below the water heater is a little rusty, and only within a short ~2 foot span. The water heater flue is the only thing going into the chimney as the furnace has an intake & exhaust pipe for combustion. How can I check for backdrafting & how does that lead to dust?

Steel dust - the bathroom is right above the area of the basement where the furnace & water heater are. Yes, there is this same dust on the floor register for the bathroom. There's a register in the kitchen high on the wall which blows right at a counter. We also get it there too which is what makes me think it's coming out the HVAC system. There is an above-ground train station within a couple miles. Since you bring up, I'll mention that I did find a lot of metal-working-type tools by the previous owners. How can I positively identify if this is really steel dust without a lab test?

I guess I'll have to get it lab-tested so I'll look into that. I was hoping there's just something we need to clean really well & it'll eventually go away...
 
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Old 11-01-15, 01:18 PM
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If your water heater is now the only appliance being vented into that chimney, they should have installed a smaller vent pipe. If it still has the larger then it is probably suffering from a poor draft and subsequent condensation, thus the rusty duct below the WH exhaust. Am I reading this correctly?

More assumptions. A water heater develops the lowest draft pressure of any appliances, thus more susceptible to negative house pressures. Add to that (or subtract), if the larger chimney is still in place, the WH would be having difficulty warming up that much air and be even more susceptible and thus most likely backdrafting.

Again, more speculation. So where is the negative pressure coming from. A likely culprit might be pressure differences created by forced air duct system. Rarely are supply and return air volumes and pressures well balanced and they are most often not sealed. Are all of the seams and junctions on the ducts sealed? Are those ducts all located inside the conditioned living space?

Since you have identified your problem as being associated with both the ac and the heat and I assume both use the same ducts an imbalance, for any of many reasons, could be creating a negative enough pressure so that some or all of the WH exhaust is ending up in your basement.

Now, far too much speculation here so get me back on track where I may have fallen off.

Bud
 
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Old 11-01-15, 05:28 PM
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How can I positively identify if this is really steel dust without a lab test?
You should be able to feel it, if you rub it between your fingers. I also asked about factories. Are there any there?
 
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Old 11-02-15, 05:08 AM
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Have you considered your attic as a source.
If it were poorly sealed and has inadequate venting it is possible for there to be a positive pressure in the attic in relation to the house.
Look for Zonolite or some type of fibre-fill insulation and see if the fibres are similar.

Here are some pics to help identify Zonolite.

Here is some Gov't info on it.
 
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Old 11-02-15, 08:42 PM
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Bud, yes the water heater is the only thing in the chimney, but it does look like the water heater's flue goes all the way up the chimney. Hard to explain but it's like it's a metal sleeve in the chimney that's connected to the flue. So it's like the effective diameter of the chimney is still just the diameter of the water heater's flue pipe.

The ductwork is in the basement. I can't tell if they're sealed, it's just metal. I don't feel any obvious air coming out. The basement is partially finished - I can see the main floor while in the basement but we do have some drywall on the outsides.

I'm not seeing how the water heater can create dust though?


Pulpo, it doesn't feel metallic, more of a soft feeling than hard & gritty. There may be some factories nearby? But not any huge ones like a car factory or something.

GregH, the attic has some brown wooly stuff but didn't look like the pictures you had. More like somebody shaved an animal and threw its hair all around. They do look like fibers but they're more straight as opposed to the tiny curly ones in the dust we see.
 
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Old 11-02-15, 09:08 PM
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Pulpo, it doesn't feel metallic, more of a soft feeling than hard & gritty. There may be some factories nearby? But not any huge ones like a car factory or something.
You might want to talk to some neighbors. If it's an environmental problem, others may have been affected. I would contact the DEC &/or EPA too.
 
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Old 11-06-15, 12:00 PM
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Id collect some and send them to get tested fist.
 
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Old 11-24-15, 07:53 AM
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Bud9051, you mentioned the water heater could be backdrafting. I think I do have this issue.

I've been looking at my furnace recently & by accident, I felt warm moist air coming from the water heater flue pipe while I was down there. The furnace & blower were off.

Issue: the first couple inches of the flared part of the flue was warm but the rest was ice cold and the water heater had been burning for a while. Outside temp is 20 degrees F. Other times I've been down there and the whole pipe is very hot, so something was not right.

Discovery: The bathroom fan was on. As soon as I turned off the fan, the flue pipe started warming up like crazy and I no longer felt the moist air near the water heater/flue connection. I tested this theory out twice to verify it, and I'm talking 10 minutes of backdrafting before turning off the fan. I could turn the fan on after the pipe was warm & it didn't backdraft, so I guess the initial draft fails if the bathroom fan is on. My fan is 60 cfm.

Second discovery: I now know why the corner of the basement that has a window on each side is always a lot more wet than the other windows. All my basement windows have some condensation but these were always the worst. When I forced the water heater to backdraft, I had a temperature/moisture reader in the corner and it shot up from 50 to 70% humidity.

Some quick reading & I guess I just need some makeup air, so keeping a window cracked seemed to fix it.

So, I'm wondering if you were onto the right track, because if a bathroom fan could cause backdrafting, that would mean it's sucking up air from the chimney & into the bathroom? And then the furnace/AC just recirculates it (since this was a year-round problem)?
 
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Old 11-24-15, 09:58 AM
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In the energy auditing business we run a "worst case pressure" test. We establish which doors need to be left open or closed and then turn on all exhaust appliances, bath fans, kitchen fans, dryer, central vac, attic exhaust fans (they can pull air from the house, and any others we determine might make conditions worse. Then we fire up the water heater and see if it can establish a draft within 60 seconds. It is not that all of these conditions will exist very often, but it is good to have a solution that works under this extreme.

The window solution is a temporary fix as windows get closed.

Without having to go back and review the entire thread I'll ask, how is the water heater vented? Does it share a flue with the furnace?

BTW, good catch. Whether this is the source of the fibers or not, it is certainly a condition you don't want to exist and that exhaust, as you observed, contains a ton of moisture.

Bud
 
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Old 11-24-15, 09:43 PM
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The water heater is vented directly through the chimney with a metal chimney sleeve that goes all the way up to the cap. The furnace is isolated from the chimney (it has PVC pipes).

The interesting thing is that opening specific windows relieved the backdrafting. The window in the furnace room didn't do it, even with it all the way open. The windows that condensed instantly when the water heater backdrafts were the only ones that relieved the backdrafting once open.

The bad thing is that the backdrafting likely happens every morning. Because when we wake up to get ready for work, we cut the fan on, hop in the shower & usually have the fan running nonstop until we leave for work. This would mean we're dumping combustion and moisture every morning...

Like mentioned, the bathroom is where we see the dust/fiber the most, but also on flat areas near supply registers. Water heater is right by the furnace/duct work.
 
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Old 11-25-15, 05:00 AM
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If you suspect the exhaust is entering the duct system, if there is not a return down there then it could be typical leaks in seams and joints which all should be sealed, foil tape is the easiest.

When you open a window you do more than provide a path for air to enter, you shift the internal pressures throughout the house. Typically windows at the same elevation would have the same effect unless they are separated by a door.

Now, where it is the bath fan that has been identified as the trigger for this, recognize that the bath fan is your smallest exhaust appliance. Kitchen fans and dryers are usually larger, and just one fan is far from worst case. Point here is, your house is tight enough to be on the threshold of a disaster. I hate to wave the caution flag, but the exhaust from a combustion appliance that for some reason (flake of rust) starts burning poorly can contain large quantities of odorless carbon monoxide. Besides being potentially fatal, lower exposure can result in, Dull headache, Weakness, Dizziness, Nausea or vomiting, Shortness of breath, Confusion, Blurred vision, Loss of consciousness. That list was Googles collection on the search page but there are many articles on the subject.

And, your backdraft potential gets worse as the weather gets colder.

Since we don't know specifically how tight your home is, and in reality few are too tight, there is the posibility that the bath fan is communicating directly with the area of the water heater with that area isolated from all of the leaks in the rest of the house. Bathrooms often have holes for plumbing that may be involved here. Where is the bathroom/fan in relation to the water heater in the basement and is the space for the water heater isolated from much of the house.

The exhaust for the water heater sounds correct as long as there are no restrictions or obstructions, i.e. birds nest or dead animal. When the water heater is drafting properly there should be a robust plume of exhaust above the chimney and, if exhausting properly, that plume which is condensed moisture should not form until it is a few inches above the top of the chimney. If it is already condensing as it exits it may be depositing moisture inside the vent pipe.

Long winded this morning, sorry.
Bud
 
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Old 11-25-15, 08:47 AM
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Bud, I think you're really onto something because I just found probably the "holy grail" of this dust/fibers....

...on the top side of a return duct...right above the water heater. No other return ducts had this type of dust, which is like a furry feeling. The other ducts had the "usual" dust (if that makes sense). I was only feeling around & could not feel any bare metal on the top side, just the furry dust.

The water heater is 2 horizontal feet away from the return air trunk that goes from basement floor to basement ceiling. The return air duct that was furry at the top runs horizontal through the floor boards maybe 1 foot away from the water heater.

The bathroom is one room over, maybe a total horizontal displacement of 10 feet from the water heater. The windows I was opening & closing were in the basement - and only 2 out of 4 of those windows in the area changed the backdrafting. I'm just keeping it open all the time. The furnace room is not isolated from the rest of the house. It's "enclosed" & has doorways but no doors . I don't have a kitchen fan.

There were specs of rust near the flue, I cleaned them up to see if they'll come back. I'll have to really get this furry stuff tested. I inquired before but it was expensive, but since now we're talking about combustion, I guess I need to see if this is stuff that's generated due to backdrafting & then the furnace ducts are sucking them up. I already reduced the fan speed on my furnace to relieve some pressure.
 
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Old 01-30-16, 10:36 AM
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Just to update this thread...

...it was cellulose insulation. The analysis I got done said it was a high probability that the sample collected above my registers matched the same particles collected from the sample of dust in the attic.

Lot of the symptoms are spot on.

So the duct in the basement that had a really thick layer is a return duct, and is the closest return duct to the furnace, so it probably sucks the most.

However, this duct doesn't hit the attic (all of 'em are in the floor) & since the presence of the thick layer was outside the duct (in the basement), I presume that duct is somehow able to pull in attic air into the basement.

My initial fix is to seal up that duct where it's pulling it in, but how the attic dust is getting to the basement is a mystery.
 
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Old 02-03-16, 05:34 AM
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Might be time to get some make up air into the home. This will put the home back into a positive pressure.
 
 

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