Gas and Oil Home Heating Furnaces - Air Duct Cleaning

I have NEVER had my air ducts cleaned-own a two-story townhouse approx. 1650 sq. ft. What do I need to know when estimator comes out? Can you tell me the approximate cost for this? ( I am in CA) A/C upstairs does not cool well. Could that be because of dirty air ducts? HELP!!

do you think your ducts need cleaning? improper cooling may not necessarily mean clogged ducts. have some hvac contractors out to look at your system and make recommendations, this is free. we have a brand new $9,000 duct cleaning setup, and used it once on the boss's house, did not clean a single duct after that.......tell you something? might put it on e-bay!

Hello Gorham. Welcome to our Heating and Cooling forum and the Do-It-Yourself Web Site.

Cleaning the ducting to improve the cooling ability for the upper level will not provide the solution. There are several other possibilities that can cause what seems like a lack of cooling.

It's possible there may be a ducting air leak or a duct may have become disconnected and or restricted in some other physical manner. To check this would require an inspection of the ducting system from the furnaces location to the registers connection.

Under all normal circumstantances, the upper levels of any multi level home, the upper levels will always be warmer because cooler air settles while warmer air rises.

This being the case, there most likely isn't anything mechanically nor physically wrong with the heating and cooling unit. Cleaning the ducting would provide no improvement in this situation.

Nor could the problem be easily or inexpensively corrected without installing an additional & seperate upper level unit. Doing so is often referred to as zoning and may not be practical nor cost effective in a condo/townhouse/apartment dwelling.

Forum Host & Moderator.
TCB4U2B2B Company Enterprises.
Fast, Fair, Friendly & Highly Efficient Service.....:)
Energy Conservation Consultants & Gas Appliance Diagnostics Technician.

If the upstaris isn't cooling well, you can try increasing the blower speed or getting it increased if you don't do that yourself.

Just remember that the more air gets pulled over the coil, the warmer the air coming out will become.

If your subcooling is less than 15F, than it's not a good idea to increase the speed. But if it's like 25F or higher, go for it!

As long as the system is properly sized, there is nothing wronge with pushing the system a little harder.

Subcooling is the differance between the air temps of the air coming in and out of the air handler.


So if the air coming in is 72F, and the air coming out if 55F, the subcooling is 17F

Cleaning the air ducts is not likely going to increase airflow to the 2nd floor, unless there is serious obstruction from construction debris or insulation.

Duct cleaning is done more for over-all hygiene of the HVAC system and indoor-air-quality (IAQ). A good technician will also clean the heating (blower, burners and heat exchanger(s))and cooling elements (coils) that may impact performance.

To address another post on this page..... If your Company spent $9000.00 on duct cleaning equipment, and it doesn't work, then it is likely due to the wrong equipment (systems run from $5000.00 to $75000.00 for a good truck mount) and more likely due to incorrect procedures. The best equipment in the world is only half as good as the technician using the equipment. The process and tools used to clean the system is vital to getting it clean. So many out there are buying bottom end equipment thinking it is an easy buck. Many HVAC contractors boo hoo the whole concept. If they could see what I have pulled from thousands of systems, they would think again!!

Another note -

When you are selecting an airduct cleaning contractor, be carefull. There are many hounds out there just as in any service business. Two things to remember; 1) Most homes take a minimum of 3-4 hours to complete. Larger homes can take 6-8 hours. If they are finished before then, they likely missed ALOT. 2) Stay away from Companies claiming to clean your system for $79.00 - They are in business to upsell the service on site (much like the $49.00 carpets cleaning). They are also using equipment that is usually not able to move enough air to assist the technician in getting the system clean. Make sure you have a garanteed bid on cleaning the entire system before they begin.

Best of luck -

Pat Hopkins

If you do get your duct work clean, make sure that the vacuum equipitment used either exausts the air outside or cleans the exaust with a HEPA filter.

If improper filteration is used, the dust mites, spores and hardfull pollutents will get blown back into the air that you breath.

Most vacuums pollute indoor air (excluding central vacs) believe it or not!

Jonathan -

You are absolutely right about the release of pollution while vacuuming.

Most any air duct cleaner worth hiring will have a filtration and containment box OUTSIDE the home. There are portable units that allow access to areas that otherwise may not get reached, but these units are far less powerful and they do release into the living/work areas. They claim to have HEPA filtration, but I am just not comfortable with the whole concept.

One way to reduce air-borne pollutants while vacuuming, is to istall a high-efficiency furnace filter (electrostatic or high-efficiency pleated) and run the fan switch for the central system for several hours during and after vacuuming. Some of the particles that get past good vacuum cleaners are so small that they can remain elelvated for 2-3 days. Running the system gives the debris a place to go (thru the return air vent and captured by a quality filter). If you are using a 79 cent filter from the hardware store, don't bother.

For more info on high-efficiency filters, feel free to e-mail me.

The best solution to the pollution from vacuuming is a central vacuum. All of the dirt goes into the unit in the garage so it's out of the living space. The air with particuletts (pollution) gets excuased to the outdoor air.

Venting outside always beets a filter!

With a central VAC, vacuuming does what it is supposto to, it improves air quality, reduces allergens and allergic reactions.