Duct cleaning?

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Sep 2, 2016
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Location
Seattle
Does anyone have any experience with duct cleaning? I understand that it's typically not required (per the EPA) but I think we could benefit from it. The original furnace was never properly filtered for nearly 40 years; the original owners used fiberglass hammock filters and then retrofitted panel filters that didn't seal properly, so I assume a lot of dust has bypassed the filter and settled in the supply ducts. I've since replaced the furnace and have proper filtration at the air handler, but there is still a lot of dust in the house. Some family members also suffer from allergies and I was hoping this could help.

I'm not sure how much value there is in cleaning the returns - our return "ducts" are just the floor joist cavities and the return air would get filtered at the air handler anyway. I would also upgrade to MERV11 from MERV8 filters after the cleaning. Camfil's MERV11 filters actually have less restriction than their MERV8 filters (0.24 iwc vs. 0.27), and would capture a lot more particles between 0.3-3 microns compared to MERV8 (filter efficiencies).

I also understand that there are a lot of scammers and fly-by-night operations, so I would likely contract a NADCA member for a hopefully better workmanship. We don't have any flex ducts to be careful of.

Any feedback is appreciated!
 
We have had it done twice in 25 years at this house. First time brought up a lot of lost construction materials from the build of the house. We should have done it sooner, like when we initially purchased the house. Second time more than ten years later revealed a lot of dust, etc. We found a good, reliable vendor and were pleased with the results. We were somewhat careful about our research and apparently hit the jackpot.
 
We have had it done twice in 25 years at this house. First time brought up a lot of lost construction materials from the build of the house. We should have done it sooner, like when we initially purchased the house. Second time more than ten years later revealed a lot of dust, etc. We found a good, reliable vendor and were pleased with the results. We were somewhat careful about our research and apparently hit the jackpot.

Thanks for your input! Do you know if the dust was mainly from the returns or supply ducts? Did you notice less dust in the house after the cleaning?
 
Don;t know the origin of most of the ducts. The vendor did them all, and I was not there when it was done. We did notice less dust in the house afterwards and believe the cost was worth it. We are both sensitive to dust and mold so a periodic cleaning makes sense to us.
 
I worked with a guy who owned a duct cleaning business for a while. I saw first hand what was in the ductwork of peoples homes and in business's. One home that was probably 30 years old and never had a cleaning, was NASTY. Dog hair, cat hair, dust , dander, people hair, dead mice. Some people don't realise you have to use good filters , and change them on a regular basis. We would drill a 2 inch hole in the accessible areas of ductwork, and take pictures that showed what was in the duct. Then do the cleaning and take the after shots. We put what was basically a big shop vac at the furnace end, then did the cleaning with were rubber tubes that would knock the dirt loose in the duct. It would get collected in the bag of the vacuum. You also remove the vent covers on the supply side and the return side, and vacuum out what was there. We also did duct cleaning in a hair saloon. It was a 10 inch diameter round duct, that was 100 % full of lint from the driers that they washed the sheets they cover people with when getting their hair done. They had had a fire in the duct, but being it was soo clogged, there wasn't enough air to get the fire really going good. Then there's dryer vents. They need to be cleaned at least once a year, especially if it's in heavy use. Most people never give cleaning of vents a thought, but I've seen what happens when you don't.,,
 
I had both cold air returns and heated registers cleaned. If this is your first cleaning job, don't be surprised to see pieces of drywall as many lazy carpenters will sweep floor debris into the register openings. You will not get a good job done for $250. Expect the whole job to cost much more and will take atleast 4-5 hours to complete. Holes will be cut into your ducts at stategic spots and will be patched up with premade sheet metal panels. Anything less is a hack job.
 
I recommend it. Son bought a house a few years ago and had the ducts done. Before and after photos were amazing. Amazing how clogged they were and amazing how good they looked after.
 
Does anyone have any experience with duct cleaning? I understand that it's typically not required (per the EPA) but I think we could benefit from it. The original furnace was never properly filtered for nearly 40 years; the original owners used fiberglass hammock filters and then retrofitted panel filters that didn't seal properly, so I assume a lot of dust has bypassed the filter and settled in the supply ducts. I've since replaced the furnace and have proper filtration at the air handler, but there is still a lot of dust in the house. Some family members also suffer from allergies and I was hoping this could help.

I'm not sure how much value there is in cleaning the returns - our return "ducts" are just the floor joist cavities and the return air would get filtered at the air handler anyway. I would also upgrade to MERV11 from MERV8 filters after the cleaning. Camfil's MERV11 filters actually have less restriction than their MERV8 filters (0.24 iwc vs. 0.27), and would capture a lot more particles between 0.3-3 microns compared to MERV8 (filter efficiencies).

I also understand that there are a lot of scammers and fly-by-night operations, so I would likely contract a NADCA member for a hopefully better workmanship. We don't have any flex ducts to be careful of.

Any feedback is appreciated!
One thing I was told is normal duct cleaning can only be used for sheet metal ducts. Many houses (mine) have mostly flex duct and duct board. Those may get damaged by duct cleaning.

Also the majority of the ducts are supply ducts which are after the furnace filter. Only the return ducts are before the furnace filter.

One suggestion would be to replace the furnace filter with an Aprilaire media filter which is a 4" or 5" wide filter and does a superior job of filtering the air, less dust in the ducts. You need to install the Aprilaire media filter holder and then the filter once a year.

Now I have found one floor duct where a dog or cat or young toddler dumped assorted things down a damage grate. Hand scooping and a vacuum cleaning took care of it.
 
There is some doubt as to whether the dust levels will be lower after cleaning than they were before. The Environmental Health Officer I worked with was convinced that dust levels actually increased after cleaning. I've never seen the data so I can't say whether he was right.

I suppose the idea is that whatever debris is currently in there is packed down and forms a sort of solid surface. When you disrupt it by vacuuming some of it out (you won't get it all), the remaining dust and debris will take some time to form a new solid surface.

For what it's worth, I've never done mine.
 
and the return air would get filtered at the air handler anyway
Just thinking out loud but any "stuff" in your supply ducts will eventually blow out into your living space and eventually could get sucked back through the cold air return(s), right ? Besides, if they're doing the job, it shouldn't make any difference in adding the return ducts.
 
When we moved during high school I had terrible allergies to the cats that the prior owners had. My parents first had the carpets cleaned and/or replaced with no improvement. They then had the ducts cleaned and immediately, my allergy symptoms went away.
 
I talked to a HVAC guy I know and he said for me with 23 year old duct board I should think about replacing the duct board rather than trying to clean & coat the duct board.
 
I talked to a HVAC guy I know and he said for me with 23 year old duct board I should think about replacing the duct board rather than trying to clean & coat the duct board.

I've read similar accounts for those with flex ducts - cheaper and easier to simply replace them.

We have "proper" ducts but the supply trunks are mostly enclosed in drywall. Not sure how they will gain access to the trunks to clean them properly
 
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