Hvac duct cleaning: Have you? How often?

Messages
7,174
Location
Michigan
Been in this house 26 years and never had the ducts cleaned. House has lots of dust even running MERV 11 one inch filters. Also have and have had many pets. I can only imagine how dirty they are.

Next week I am getting them cleaned and going to an Aprilaire 1410 5" air filter install.

My daughter just had theirs done on a house she just bought prior to installing a new furnace/air filter system. They were dirty and they found all sorts of kids toys stuffed down into them.... Lol

Do you get yours cleaned? How often? Did they look really bad... Etc?
 
Messages
4,302
Location
Ca.
I have them cleaned when I move in and stick a rented laser counter very 5 years or so up to them to determine if the air coming out is worse than what's going in.

After having a 5" filter box vs a 1" I'll never go back and always pay to upgrade.

It's the cheapie 1" low merv stuff that fills the ducts with dust.

Pets also fill your dryer vent with gunk.
 

ZZman

Thread starter
Messages
7,174
Location
Michigan
I have them cleaned when I move in and stick a rented laser counter very 5 years or so up to them to determine if the air coming out is worse than what's going in.

After having a 5" filter box vs a 1" I'll never go back and always pay to upgrade.

It's the cheapie 1" low merv stuff that fills the ducts with dust.

Pets also fill your dryer vent with gunk.
Laser counter?
 
Messages
5,370
Location
Atlanta,GA
Never. Almost all of my major ducts are squashed between the rafters in a cathedral ceiling. My house was re-roofed a few years ago and I think the roofers punctured some of these ducts so I don't want anything running through them which could cause tearing.
 
Messages
25,571
Location
Upstate NY
I would look closely at the ducts to see how dirty they look. I think in many cases the service is a ripoff. Wife had it done on older house she owned and the quoted price was not all the ducts. Maybe just the smaller ducts and not the main. Something like that. They wanted to upsell the full service at a significantly higher price.
 
Messages
1,942
Location
British Columbia, Canada
The environmental health officer I used to work with was not a fan of duct cleaning. In his experience there was more inhalable particulate in the house after duct cleaning than before.

That kind of makes sense too. If there's dirt in the ducts it's packed down. Removing some of it will disturb the rest. That's what happens with asbestos - if asbestos is intact it's generally better to possibly improve the cover, regularly monitor its condition, and otherwise leave it alone.

I've never seen any research on the topic though. I replace my filters regularly but I've never had the ducts cleaned.
 
Messages
479
Location
illinois, usa
I have metal ducts and had them clean once, many years ago. The company cut some nice holes in the supply and return trunk which I open every few years to clean if needed. I have a large return in the floor and added some filter media mainly for just large stuff.
 
Messages
5,383
Location
NJ
Laser particle counter - you can rent them from vacuum shops. they use them to check for leaks.
Laser counters are used extensively to monitor clean rooms for non-viable particles for pharmaceuticals and electronics. I'm curious the units and results you got in a home setting. ISO 5 is considered "sterile".
 

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ZZman

Thread starter
Messages
7,174
Location
Michigan
I have metal ducts and had them clean once, many years ago. The company cut some nice holes in the supply and return trunk which I open every few years to clean if needed. I have a large return in the floor and added some filter media mainly for just large stuff.
How much dust have you found checking it yourself?
 
Messages
1,283
Location
Texas, USA
A/C company replaced all my ductwork last summer. Since they piled it in the driveway, I got curious and took a look. They were actually pretty clean. Definitely nothing worth calling someone out to do. Now, my intake registers...I have to clean them all the time. 3 dogs.
 
Messages
956
Location
Under the Hood
I have them cleaned when I move in and stick a rented laser counter very 5 years or so up to them to determine if the air coming out is worse than what's going in.

After having a 5" filter box vs a 1" I'll never go back and always pay to upgrade.

It's the cheapie 1" low merv stuff that fills the ducts with dust.

Pets also fill your dryer vent with gunk.
UncleDave, question:
1) How often do you change the 5" Filter vs the 1" .... ?
2) Does changing from 1" to 5" change the differential pressure at all .... ?
Thanks for your response.
 
Messages
5,034
Location
Ohio
I had my ducts cleaned about ten years ago. A lot of drywall pieces and construction debris was swept into the ducts by some worthless builders twenty years earlier..A "good job" will usually take about 5-6 hours and cost over $500. Anything less is not a thorough job. They cut a few holes in the duct work for access and made sheet metal patches to cover the holes.
 
Messages
4,302
Location
Ca.
UncleDave, question:
1) How often do you change the 5" Filter vs the 1" .... ?
2) Does changing from 1" to 5" change the differential pressure at all .... ?
Thanks for your response.

1. I changed the 1" a couple times a year, I change the 5 " once a year.

2. the 5" filter flows a lot better at every given efficiency point.
The merv 16 5" flows better than the merv 13 1"
 
Messages
4,302
Location
Ca.
Dylos is a (relatively cheap) counter.
Laser counters are used extensively to monitor clean rooms for non-viable particles for pharmaceuticals and electronics. I'm curious the units and results you got in a home setting. ISO 5 is considered "sterile".

While I lived in LA I would rent a 5 channel unit from the local vac and air cleaner shop that used it to demonstrate air cleaners, vacuums and test for leakage.

Then I bought a cheap (250.00) Dylos unit that vanished in the move from LA to Nor Cal.

I could get zeros across the board holding it on front of a clean Hepa filter but never in a room.

I dont recall any absolute numbers, but what I looked at was the difference between inlet air at the unit and outlet air at a register when the outlet numbers ended up worse than the inlet numbers it was pretty clear the ducts were holding and releasing dust and dirt and it was time to clean them. The LA house had fairly close proximity for the freeway and the air was super dirty at certain times.

On the furnace filters I actually had 3 types, 1" that got upgraded to a 3", them when I moved North the system had a 5"

The 3" was also a marked step up from the 1" in flow and holding capacity, the filter came folded flat and expanded like an accordion it was called a Bryant EZ-flex and even at mere 13 flowed really well.

The 5" setup here is nothing short of phenomenal it even removes smoke smell from forest fires
 

JC1

Messages
5,841
Location
Oshawa, Ontario Canada
We've had them cleaned once in 18 years (maybe 9 years ago). No pets, so the duct work isn't that dirty.

Had the ducts aerosealed this past July and inspected the ducts at that time. They were clean.
 
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