I'm also looking forward to reading feedback about this. I've thought about it for many years. We have had dogs and life happening, and dust seems to gather rather quickly.

We also have allergies and controlled asthma.

If it's worth it, I would spend the money.

If you have metal ductwork without internal insulation, it might help. Flex-duct - forget it. If you've had a return filter on the system all this time, you might be surprised how little is "hanging out" in your ducts. If possible, have the ducts inspected and then decide if they need to be cleaned.

If you have changed your air filter on a regular basis then your duct work should be clean. If your duct work really needs cleaning then you need to hire someone who can bring in the equipment to do it properly. For $199 they are going to spend an hour vacuuming vents which is something you can do with a household vacuum cleaner.

sktn77a - we do have metal ductwork and have always use pleated filters (at least merv 8) that are changed every 2 months. Is this standard pleated filter the 'return filter' you're referring to?

mike_home - the company I mentioned is reputable and does excellent work, but your comment prompted an inquiry call from me. They said it would take 1/2 a day to complete the work. My home is 11 vents/2 returns and 1,500 sq ft. Sounds like they intend to spend a reasonable amount of time.

"If you have changed your air filter on a regular basis then your duct work should be clean. "

This is true assuming that the return side of the system on the blower side is not allowing a lot of crud into the system.

ionized_gw, where would the crud be coming from? I'm assuming you mean that if the unit is installed properly and adequately sealed it shouldn't be sucking crud in from outside sources. Right?

Leaking return duct on the blower side of the filter will draw in anything that is in the air from the outside of the return duct.

Probably not

Answer

Use Search. Lots of answers.

You are ahead of the majority since you have always used pleated filters. If the ducts are dirty,either the filters don't fit or as ionized mentioned the return air leaks between filter and fan. Is the furnace handling air circulation for cooling? It requires different maintainance if furnace also serves cooling.

I am skeptical that a duct cleaning company would come to your house and work for 4 hours for $199. Sometimes these outfits use a low ball price to get in the door and then start quoting extra charges.

If you have this done, I would be curious to know what you thought of the service and how much dust was removed.

There can be substantial mold growth inside the hard surface (e.g sheet metal) ducts or on other components of your heating and cooling system. Air ducts will get dirty over time and should be cleaned occasionally. In my opinion, preventing water and dirt from entering the system is the most effective way to prevent contamination.

If you find any mold growth in your system then mold removal service will be a good choice to stop it. If both of you have allergy problems then it will be better you conduct an air quality test in your home. From the results of this test you can decide what type of cleaning treatment is needed.

It's a scam. Dust, if any, in the ducts isn't going anywhere. Disturbing what's there will only spread it around. If you have mold growing in your ducts you need to address the problem, not engage in periodic cleanings. You shouldn't ever have water in your ducts, which is what mold needs to survive.

I wonder if our heater could be sucking in air from the attic, which is filled with dusty blown in cellulose that is treated with flame retardant. When I went up into the attic, there is a 6 inch vent going out the roof, and a 6 inch vent that opens into the attic, with a wire mesh covering it, that sits about 2 inches above the pile of insulation. Is that what is taking in combustion air? We are in California. See photo.

In my 45+ years, I have always had forced hot air heat and have never cleaned the ducts. Never had a problem with mold or dust.

Take a flash light and look into the vents in your house. You might be surprised that many of them are clean. I only have one that has dust around it and i can just take the grill off and wipe it out.

And yes, the one with the cover is for combustion. I have 2 of those next to my furnace that go into the attic, but i dont know if they have wire mesh on top of them.

It seems that a duct taking combustion air from the attic space would be a source of cellulose dust coming into the house. I really hate cellulose insulation, because it's full of flame retardant. Can I take combustion air from outside the house? Or inside the house, or garage? I may repost this question as it's own thread.

What is the make and model number of the furnace? High efficiency furnaces should be taking outside air. The person who installed this did not want to be bothered.

@mike_home, It's an American Standard Freedom 80 Single Stage. The duct work is from the 1970, but the furnace is newer. And that combustion air pipe doesn't actually connect to the furnace. I just looked in the closet, and that pipe just provides an open path from the attic to the ceiling of the closet that the furnace is in. It's not connected to the furnace in any way. Does that mean it could just be plugged up?

Most attics are, topologically, outside of the house. Some homes have sealed attic, but the numbers are small. In those cases, the roof deck would be insulated, not the attic floor/living space ceiling. The combustion air is coming from outside. You don't want your combustion air coming from the living space if you can help it.

ionized_gw, Our attic is not the sealed kind. Since the duct is basically just a 6 inch hole between the attic and the hall closet that the heater is in, combustion air is probably coming from both the attic and the house. What is the reasoning behind not having combustion air drawn from the house interior?

The furnace needs enough oxygen for complete combustion. Houses are build so tight that outside air might be needed. This vent is in place to provide additional air.

Yes, you need that vent for extra air, Dont plug it up. It would create a vacuum effect. Like putting you hand over a vacuum pipe, in order for it to work properly it needs to be able to suck in air.

You can divide furnaces and boilers into two groups, older types only used air drawn from their immediate environment. New ones can fall into that category or into a sealed combustion category that have external air supplied directly by a pipe to the outdoors connected to the combustion chamber in the appliance. The former type depressurizes buildings which draws make-up air in from anywhere (cracks and holes in the building envelope) that air will leak through.

As people in the North progressively sealed up their homes over the past few decades, more and more problems arose with negative pressure in the homes with the old-style equipment. This can cause backdrafting and other problems. The proper way to supply combustion air in this situation is to provide a blower-driven supply of make up air that is interlocked to the combustion appliance that terminates very near the air intake of the appliance. If the blower is not turning, the appliance won't start. The trouble with make-shift ducts is that they can become blocked. In colder climates this blockage was often caused by ice. Duct from the attic would probably preclude that, but is probably not building code compliant. In any weather when the furnace is not running, you have room air (inside) exchanging with attic air (outside). It is a big leak.

@ ionized_gw and mike_home, Thank you for explaining so well. Since I'm in mild winter California, in a house built in 1971, the house is not sealed well. I think I am going to seal up that 6 inch pipe going into the attic because you're right about it being a big leak between the attic and room air. And I hate the idea of breathing air from the insulation filled attic. I also just remembered that there is also a 6" x 12" screened vent into the crawl space. I'd rather breath crawl space air than attic air. (The crawl space is also vented to outside by vents around the perimeter.

Where is the combustion air for the furnace going to come from? You must provide a combustion air supply!

@ ionized gw, There is a 6" x 12" vent in the floor that is open to the crawl space, which has vents to outside all around the perimeter, so it has that outside source of air. Or is there a issue with gas is heavier than air type thing? It seems redundant to have it open to the attic, and open to the vented crawl space. The crawl space is much more well vented than the attic.

I can't say if the floor vent is sufficient. There are formulas that are used for this, BTU vs area of air intake.

Is the furnace closet sealed and insulated from the rest of the house? If so, the entire space may be considered outside, attic, closet and crawl space. That would mean that a lot of the previous discussion about make-up air is superfluous.

@ionized, The closet has a 1 inch gap under it, over hardwood floor. Closet walls are un-insulated. Maybe adding weatherstripping would be a better alternative.

Did you just move into your home or Are you about to move into a home?

When we move into homes, it is very difficult to know how diligent the previous homeowner was about the general maintenance and upkeep of their home. If your new home operates using a duct system, then it is time to think about getting your ducts cleaned.

Taking proactive step to clean your ducts is something you can do to ensure that you have a healthy new home. This will prevent your family from suffering from health issues due to your indoor air quality; remember, as soon as you turn on your furnace or air conditioner, the air will push through the ducts, bringing all of the contaminants lining the ducts with it. Prevent years of built up dirt, debris, pet dander, fur, and other contaminants from flowing into your air, have your ducts cleaned today!

When we got our ducts cleaned, it separated one of the ducts from the vent, and I had to crawl under the house to reconnect it.

IF the ducts, supply boxes, plenum connections & return air
are mastic sealed, then nothing gets into the ducts
to be sucked out.

invest in proper sealing of duct, rather than
'cleaning' ducts.
average house has 30% duct leakage.

a 1970's house was not built tightly.
it would take a lot of effort before make up
air would be required.

I'd rather see a homeowner invest in air sealing
& duct sealing than band-aids like duct cleaning
on a leaky system that will only get dirty again.
or even uv lights to zap growth in ducts that wouldn't
occur if the ducts were properly sealed.

kinda a pet peeve of mine.

best of luck.

I had my ducts cleaned about a year ago. Don't recall exactly what I paid, but it was a similar special. They cleaned out a ton of junk, not just dust. House was built in 1949. IMO, it should be done at least once!

You can't expect much cleaning for $199 Canadian. It costs a lot more to do it properly.