Replies

1. 
   jjmcgough | Jan 18, 2000 10:47am | #1

   *
   Perfect opportunity for you to be exposed to a rampant scam perpetuated by some in the hvac industry.

   Yes, there are legitimate duct cleaning services ou there.

   How do you choose?

   I suppose if some hoser showed up with a remote cam and ran it thru your ducts and you could actually see the realtime condition, then gave you an estimate and after they were done, shot that robocam thru again, you could be assured of the deed they had accomplished.

   You will have to pay a premium for that type of professional service. Keep in mind that once you see the actual condition of your ductwork, you may instead, opt for replacing it. A real eye opener in many situations. There is some ugly shit living in some of those tunnels.

   Good Luck!

1. 
   Bob_Walker | Jan 18, 2000 05:19pm | #2

   *IMHO, the jury's still out on duct cleaning. I've had several clients who've reported great improvements in air quality & heat distribution, more who've reported no perceptible changes.I believe the EPA site has a page on it. Their (or someone else's) concern is that what you really need to get out are the bacteria, not just the dust and visible cr**, and there's some question on whether the existing process really does much about bacteria. Whoever it was, makes sense to me. (I'll never buy another house with ducts under a slab. My "asthmatic" daughter was "cured" when we moved from that house.)Costs vary so much from what I hear its tough to compare. I haven't heard enough to give any $$.Bob

1. 
   Scott_Mazur | Jan 18, 2000 08:19pm | #3

   *I suppose you can't trap everything, but wouldn't it make sense to install some serious filtering in the ductwork between the furnace and the blower (or at least before the main heating duct) to keep the ducts clean in the first place? Or does this cause its own problems?We've converted our old forced air system to radiant (gutted all the old ductwork, dust and all). I plan to re-duct with smaller branches for air exchanges and future AC. I intend to do everything in my power to trap particles at the head of the duct, or is this wishful thinking?

1. 
   Bob_Walker | Jan 21, 2000 05:07am | #4

   *Scott,<>I know just enough to be dangerous here, but I _believe_ you can cause problems with too much filtration; I've read that it can reduce airflow, static pressures etc and cause problems with the furnace.The heating guys I know like the 6" pleated paper ("media"?) filters.Bob

1. 
   Scott_Mazur | Jan 22, 2000 01:38am | #5

   *Bob, I believe your right about over-filtering furnace ducts. I've heard a few stories of my own about damage due to restricted air movement. Not something to be taken lightly.I should have clarified (thought the furnace/blower example would fit more peoples' experience). I don't actually have forced air heat (or a furnace). The ducts in our house are only for air exchange and maybe future AC.I was also thinking more along the lines of maybe a larger filter box. Like maybe double size with two sets of filters side by side. Reduced flow through each, but equal flow in total. Is it realistic to try to maintain a zero dust environment in the ducts?

2. 
   Bob_Walker | Jan 24, 2000 04:09pm | #6

   *A respiratory therapist told me that she recommends the pleated paper (media?) type filters to reduce dust and airborn particulate matter.Presumably, near zero dust conditions in the ducts is possible (I believe they take some extreme dust control measures in the computer chip manufacturing plants) but the cost is probably immense, so probably not realistic.Bob

3. 
   andrew_d | Feb 04, 2000 10:41am | #7

   *The media filters are supposed to do well, but are expensive and do load up the blower. The universal opinion I've gotten is that electrostatic filters are a disaster -- perhaps no one maintains them right.

4. 
   Bob_Walker | Feb 04, 2000 04:58pm | #8

   *<>Well, some are available for $5 (the 1" thick) and need to be changed every 3 months: $20/year. Compare to the fiberglass matt type at $1 & change monthly-- $20 v $12.The HVAC types I've asked haven't been concerned with reduced air flow (if that's what you mean by "load up the blower") but I don't have any hard information on that.Bob

5. 
   Tony_Autin | Mar 02, 2000 02:46pm | #9

   *Guys, in Louisiana, contractors use metal ducts with insulation glued to inside, except for small rigid round ducts which are wrapped outside with insulation. Wouldn't outside insulation make for easier to clean and to keep clean ductworks???

6. 
   Mike_Smith | Mar 05, 2000 10:28pm | #10

   *.. anything you do in a well designed HVAC system can be calculated, and should be calculated..all of the mfrs. of media filters test and rate their assemblies for static pressure loss.. and a good HVAC contractor can design them in so evrything functions to spec....they can then go in and demonstrate performance..my only point is that HEPA media filters are the accepted standard and still currently state of the art... they have a track record and are superior to the electro -static filters..duct sizing, configuration, elbows, restricted runs, variable speed blowers, plenms, inside insultion, exterior insulation, flex duct, registers.... all of these go into the equation for a well designed and spec'd and installed system..any HVAC contractor should be able to demonstrate how the design and specs were arrived at, wether he did the calculations himself, or had a HVAC engineer do it, or used a mfrs . HVAC software program...all of this is knoweable and it should be part of the package...similar calculations should be performed for ANY heating system, some are easier to predict, like Electric resistance and hot-water baseboard, some are harder, like Radiant Floor, and Heating with air is the hardest to calculate, especially when you also want to compromise it and use the same ductwork for Air conditioning... so the guys who want to "load " up the system are either doing it because they have an existing condition to try and work around, or they don't know or don't want to be bothered about the correct sizing. or they are just selling a worthless or overvalued fix.....hope i didn't oversimplify the issue...but that's what i know about HVAC

7. 
   ken_p | Jun 27, 2000 04:36am | #11

   *Mike,Personally, being in the trade, and having done ductcleaning, I don't think it's worth the $$.FYI In some cases I've heard, they will "spray your ducts" with a coating to prevent the debris from circulating thru the house. But this can lead to build-up and restricted airflow. EACs (electronic air cleaners) work good, but are hi-maintenance (i.e. monthly cleaning), which most homeowners ignore. Overall, "ductcleaning" is an expensive service with minimal benefits.

8. 
   Allan_Marsh | Nov 15, 2000 03:02pm | #12

   *Mike,We recently had our ducts cleaned when we put in new HVAC system. It cost about $375 for a 2000 SF house.In my case it was not a question of if there was anything in there, I stuck my head in every return or used a mirror and was not too surprised to see all the ick that was in there. The inspection tag on the ducts near the old furnace was dated 1938 and I am sure it was never done before.The crew spent a half day on the house and acually went into each duct three times (vacuum, vacuum + rotating brush, vacuum + air jet head). Then they sprayed a disinfectant in each duct. When they were done, they left me a 5 gal bucket half full of old toys, magazines, & hardware.I think it was a good value and would do it again, but I know my situation was extreme.Allan

2. 
   Mike_Milbrath | Nov 15, 2000 03:02pm | #13

   *
   Folks, Has anyone had their ducts cleaned and can
   give me an idea of the cost? ur home is around
   1300 sq. feet. We live in Northern C