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HVAC Cleaning or Duct Replacement?

Busybee Member Posts: 2
edited March 2020 in THE MAIN WALL
The smell of cigarettes permeates throughout the entire house. The chainsmoker is no longer in the house.

It appears as though much of the smell is coming from the HVAC system (I smell it more when the heat is on, rather than the A.C.). If I leave clothes on the bed my clothes smell like cigarettes. The smoker wasn't really in that room.

HVAC system Information:
Both the A.C. and heat blow out from wall registers.
Most rooms have two registers on the lower part of the wall and two near the ceiling.
Some rooms have mini intakes too.
All registers and returns are caulked in-place.
All flexible duct work is in the attic.
There is one large return off the kitchen (between the family room and kitchen). The smoker spent most of the time in the family room (near the return).

Source of conflict:
I received conflicting information from installers and duct cleaning services. One promotes cleaning the other promotes replacement of ducts. Most of the companies don't do both. The HVAC cleaning services say that cleaning the system is sufficient; although, none will guarantee that the smell will be out in one cleaning or completely.

My end goal is to have clean, fresh air in the house. I don't want to simply mask the smell or use toxic chemicals to clean the system which may be equally as dangerous as the nicotine smell. The person living in the house has a cancer history, so that is of concern. I am getting the house primed, sealed, and repainted (specifically for cigarette odor), carpet replaced and cleaned in some rooms, and window treatments (cleaned and/or replaced). I realize that the chemicals are not only in the HVAC system.

Here is what one HVAC cleaning service recommended:
Cleaning and anti-microbial sanitizing of a total of: (1) Furnace/Air Handling Units, (1) A/C Coil, all interior surfaces of the duct work, all main, return trunk lines, and cleaning and sanitizing of all vents associated with the hvac system. Includes: nicotine odor sealer of the duct work, before/after verification photos, and Free Static Agent Application for sanitizing.

Additional concerns:
A lot of the HVAC cleaning services say that they will only clean the returns and registers in-place given that both are caulked around. It doesn't make sense to clean one side of the registers and returns and not the backsides. I could imagine there is just as much cigarette chemicals on the backsides as well. How can flexible ducts be cleaned from nicotine and other various cigarette chemicals when they can't be scrubbed like hard surfaces without damaging the ducts? I know from cleaning some of the blinds that I really had to use a lot of elbow grease and wipe with a diluted bleach solution to get some of the discoloration off (multiple times).

What do you recommend? Cleaning or replacement of contaminated ducts?


  • Jamie Hall
    Jamie Hall Member Posts: 22,147
    Two observations. Well, maybe more.

    First, I doubt that duct cleaning alone will get rid of the smell completely. It may well reduce it, but if one is sensitive to it for whatever reason, I imagine it will still be noticeable.

    Second, when you paint... everything that doesn't move... use a top quality odour and stain sealing primer first, such as BIN. Just paint alone will not mask the odour. You may find that you need two coats of the stuff. Unless a carpet has intrinsically high value, such as a hand made oriental, scrap it. Just cleaning usually won't do it. There are companies (a very few...) who will take a hand made oriental and get it really truly clean. You can't do it on site -- these are off site facilities. And it is pricey.

    Third, the odour itself is not hazardous. Objectionable, yes. Hazardous, no.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • unclejohn
    unclejohn Member Posts: 1,833
    Call a fire restoration company they should know.
  • Larry Weingarten
    Larry Weingarten Member Posts: 3,141
    Hello, In addition to what Jamie says, you might look into better filtration for the furnace. HEPA filter and possibly something with carbon in it. Here's a link I found: https://specialtyairpurifiers.com/air-filters/best-ac-furnace-filter-odor/

    Also, individual room air purifiers might be worth looking into. A link: https://www.air-quality-eng.com/applications/residential-air-purifiers/

    Yours, Larry
    HVACNUT Member Posts: 5,476
    All of the above, plus dehumidification, UV, ionization, carbon filter.
    Has any inspected the air handler for mold?
    EBEBRATT-Ed Member Posts: 14,534

    I would get a quote on cleaning and also on replacement.

    Then possibly have a couple sections of the existing duct taken down and examined to see if it can be cleaned.

    @unclejohn suggestion of a fire restoration company is a good idea
  • mikeg2015
    mikeg2015 Member Posts: 1,194
    Most of the smell will be in the walls. The fiberglass insulation. We had a former smoker house. Anytime it was closed up when we were away and especially when the attic got really hot. We could smell it.

    Duct cleaning (metal ductwork not flex) will remove a little dust that will hold the odor. Mostly return.

    Coil cleaning, pull blower and clean it.
    Then you might pull the air filter and blast a couple cans of a neutralizer in there.

    Step 1 of course if repainting the entire house including ceiling and replace all carpet. Clean hardwood really well.

    The smell isn’t hazardous. It’s just annoying and gross (no offense to smokers).

    It will improve. My mother in law and her husband used to both smoke in their house. He quit and she smiles mainly in one room and goes outside a lot. The house isn’t nearly as bad. We lived in their previous home and it was barely noticeable.
  • SuperTech
    SuperTech Member Posts: 2,022
    I've seen the effects of heavy smoking on forced air systems and it's pretty nasty. Even the best duct cleaning won't do anything but remove dust and dirt. I've seen the metal ductwork coated in brown tar, I don't think anything but replacement ductwork will completely get rid of it. Evaporator coils can easily be cleaned, I have used a product called De-solv. The blower assembly can be cleaned as well. Greased lightning works really well for removing the brown tar that coats everything.
  • ChrisJ
    ChrisJ Member Posts: 15,162
    New ductwork and equipment. The equipment is typically lined with paper covered fiberglass, you're not getting it out of that.

    If it was me and I wanted the smell gone I'd have a good contractor install all new ductwork and equipment. Use a good oversized 4" or 5" thick MERV 8 filter, anything higher isn't going to help you in my opinion. Size the ductwork for good flow, bigger is better.

    A UV light is useless and has no effect on smell. Even then, there's debates over how effective they are at doing anything in typical residential setups. I wouldn't spend money on one. Don't pay for gimmicks keep things simple that are known to work.

    Paint the rooms, clean the floors, replace carpets etc. Over a few years any remaining smell should fade if not totally disappear.
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • pecmsg
    pecmsg Member Posts: 4,388
    Flex duct CANT be cleaned.

    Givin enough time and fresh air the smell will go down. Ventilate, Ventilate, Ventilate!

    To speed it up replace the flex ducts. If the air handler is using R-22 replace it as well.

    Wall's will have to be painted like @Jamie Hall stated.

  • KC_Jones
    KC_Jones Member Posts: 5,535
    edited March 2020
    Another possibility is an Ozonator. They are designed for these applications. I used to use them all the time when detailing cars.
    2014 Weil Mclain EG-40
    EcoSteam ES-20 Advanced Boiler Control
    Boiler pictures updated 2/21/15
  • Busybee
    Busybee Member Posts: 2
    edited March 2020
    I attached photos for review. Can anyone provide additional info and explain how this type of system works. I'm not familiar with this sort of stuff.
  • pecmsg
    pecmsg Member Posts: 4,388
    That shows Flex Duct. it cant be cleaned and must be replaced.
  • pecmsg
    pecmsg Member Posts: 4,388
    I will also add the Supply Plenum on top it wrong. There should be 3' of straight trunk before any takeoffs. Depending on the model #'s a transition between the blower and the evaporator sections.
    HVACNUT Member Posts: 5,476
    Yeah looks like a cheap spider duct system.
    Rip it out and replace it with new, or preferably new trunk duct with proper branch ducts.

    In any case, make sure the contractor seals all joints with mastic tape or compound. Code might require pressure testing. And it makes for a more efficient system.