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Cleaning Intertherm unit floor ducts

Posted: Thu Jul 21, 2011 6:39 am
by homebuff
Greetings to all!
I have a 16x60 MH with a intertherm gas ac unit with a downflow system.
The floor ducts extend from one end of house to other about 40 ft in lemth.
I want someone to give me some tips on how to clean them out throughly of all the junk & mold that has accumlated in it in the past years.
Tried pvc pipe & taking duct tape & tape pvc pipes together so its flexible enough to work with channeling it down the duct work but its still too stiff.
Got ahold of a mold cleaning professional company & asked them what they charged just to clean out my ducts & they wanted $345.00 to clean it.
Too much for my pocketbook just to clean them out.
I just want a easy method so I can get rid of the mold & debris lingering in the duct work so my wife & I can breath more easily.
We both get up in the morning right off sneezing for a short bit & she has Fibro anyway which causes her to have allergies.
Allergies don't affect me as much as her.
Thank's for any tips!

Re: Cleaning Intertherm unit floor ducts

Posted: Fri Jul 22, 2011 1:50 am
by DaveyB
Although I haven't done this myself (I was lucky in that my ducts are pretty clean anyway), if you are taking the air system down for maintenance, would there be a problem with pouring in several buckets of hot water with a high concentration of disinfectant, then using a pressure hose to clean them further?

Some of the water will leak from the joints (which would show you where any major air leaks are) and the rest could be sucked back out using a wet/dry shop vac (Home Depot rent these out).

As for scrubbing the inside of the ducts, I'm picturing something like an automatic swimming pool scrubber ... either that or zip down to the local workhouse and rent an urchin for the day (a la Oliver Twist) :twisted:

Just as a wild stab at a workaround, what about those automatic shower cleaners? The ones where you press a button, get out of the shower and close the door, and they spray down the entire shower with a solution that cleans and disinfects all in one go. Run a cord through the duct to pull the device through, then rig it so it keeps spraying all the way through. Hose down with clean water and suck out the excess with the shop vac and you should be good.

Just some goofy ideas, but you never know what may help!


Re: Cleaning Intertherm unit floor ducts

Posted: Fri Jul 22, 2011 8:53 pm
by Bill
Hi Dave,
I don't a great answer for ya. Sorry. But i am going to toss my two cents in. First I don't recommend putting any kind of liquid in your vents. If you have "Ductboard" duct duct work under your trailer you don't want any liquid on it. That will do more harm than good. Second idea is your air filter. See if you can get a good allergy air filter for your furnace.

Re: Cleaning Intertherm unit floor ducts

Posted: Wed Jul 27, 2011 11:19 am
by Terry
Hi David,

I have cleaned the ductwork in my mobile home and am very pleased with the outcome. I did all the work myself, so not much expense was involved. My home is a 1994 Belmont Homes 16 X 80 and the duct work is a straight run from one end to the other and is made of aluminum. My method of cleaning may not work for other types of ducts. This may cause some damage to the ductwork, but mine were already in need of some repair so I didn’t have much to lose by trying this. I will share my process in case anyone else wants to attempt this, but it is very labor intensive and time consuming if you do it by yourself. If you can find a helper to assist you with this, it won’t take as long and be easier. It took me all day by myself, but I didn’t rush anything and took my time to do it right the first time. Sorry this is going to be a long post, but I will try to cover everything that may help. Pick a cool day to do this, as the system will have to be turned off during this process and the house may get too uncomfortable during hot weather.

This cleaning method and equipment I used was just something that I just came up with out of pure frustration of not being able to find a HVAC company that cleaned mobile home ductwork. It may sound silly, but it worked for me. A shop vac, a swimming pool vacuum hose, a 9” paint roller frame, commercial size mop heads, zip ties, a fish tape reel, flashlight, hand held mirror, a disinfecting cleaner that kills mold, mildew and bacteria, a bucket & some water.

I drilled a hole in the handle of the paint roller frame and ran a small bolt through it. This is so the fish tape hook will have some place to lock on to. Attach a mop head to the width of the paint roller frame with zip ties so it won’t come off. Mix the cleaner and water in the bucket. Plan on changing the water solution many times, as there will be lots of dirt removed.

To get started, I removed all the floor register grilles in my house and then vacuumed out as much visible dirt as I could reach. Then, starting at one end I ran the fish tape through the floor opening until it reached the next opening in line. I attached the end of the swimming pool hose to the fish tape, and pulled the hose down into the ductwork to the end. Switched on the shop vac and dragged the swimming pool hose backward, moving and turning the hose to cause it to move from side to side inside the duct. I repeated this process a couple of times on each section until I worked my way to the other end of the house. It was amazing at how much debris, dust, and filth that came out in the shop vac by doing this.

Using the fish tape again, feed it back through a floor opening to the end of the duct. Work only the length of one opening to the other. Attach the paint roller frame/mop head to the end of the fish tape with the hook on the bolt to hold it. Wet the mop with the cleaning solution and wring out as much as possible. I slowly and carefully inserted the mop and handle through the floor opening. It was difficult to do this, as there isn’t much room. You may have to cut off part of the paint roller frame handle if it is too long to navigate through the small floor opening. I went back and pulled the wet mop slowly until it I could reach in and get it out. This was repeated 3 or 4 times on each section, until the mop came through clean. The mop head will be filthy and must be cleaned after each pass. Keep the water and cleaning solution changed frequently. You can use the flashlight and hand mirror angled into the floor opening to view the duct to see if any spots were missed. Keep in mind that this will not clean the inside top of the ductwork, but only the bottom and part of the sides where most of the dirt is anyway. I did this over and over from room to room until I reached the other end of the ductwork. It is possible that the mop head could get hung up in there or come loose from the fish tape. That's why it is very important to make sure that everything is tightly secured when doing this.

As I stated above, this may cause some damage to the ductwork, but I was lucky and only had to repair factory-made mistakes inside there. Laying the mirror in the bottom of the duct at each floor opening, I inspected the connection from the floor opening into the duct. There were places that the aluminum foil tape from the factory had come off years before, and large gaps were letting the heated or cooled air escape. Some were large enough to see the floor joists reflecting in the mirror through them. It looked like the factory used an axe to chop these openings! I repaired all these gaps and resealed all factory openings cut for the floor registers. It would be a good idea to remove the grilles each year and inspect again with the mirror and flashlight, just in case some of the tape comes loose and starts leaking air out of the house.

I reinstalled all the floor register grilles and turned the system back on. The air coming through now was very clean and fresh smelling. The increase in overall air flow was just amazing! In my master bathroom and bedroom at the far end away from the furnace, there never was that good of air flow, and the temperature would always be about 10 degrees difference from the rest of the house. Now it stays about the same through out the entire house. The air flow is so strong now that it moves the shower curtain, which it never did before I did the cleaning and repairing leaks.

Not only is my home more comfortable now and has healthy clean air, my utility bill also dropped considerably. It was well worth my time and effort to do this.

I hope this information will help, as it did work for me with great results!


Re: Cleaning Intertherm unit floor ducts

Posted: Sun Sep 04, 2011 10:44 am
by homebuff
:) Thank's for that info!
lot of work on my behalf but it needs to be done anyway cleaning out all my duct work.
Lot's of small dog food crumbs & dog hair that are stuck to the bottom of the duct work & hard to get loose unless I do pur some warm ater in it to slowly soak it loose I guess is the method to follow you by.
Have no access to a swimming pool hose though but I guess I could tape a bunch of vacumm hose to one another & do it that way.
Have one more project where I have a caked on particles on the Evaporator a/c coils & need to know what type tool & method to get in there & clean it all off without damaging the coils.
It's kinda cutting down on the cooling & air flow causing the blower to cut in & out too often but the house still stays cool.
The coil & plastic tray assembly is pretty new I installed myself a couple years ago.
This is most likely going on the third year using the a/c. I installed it the same time when the outside unit compressor went down & had to install a outside 3 ton unit. The inside unit is a MGH Intertherm unit. Natural gas & a/c downflow unit.
Thank's! :)
It's a small area to work in getting inside the matal pltes to clean it off.
What type of stiff brush would be a good tool to scape the crud off the coil's?

Re: Cleaning Intertherm unit floor ducts

Posted: Mon Sep 05, 2011 5:13 pm
by Bill
Hi, Dave
Here are a couple of web sites that will help you out with cleaning your coil
That is for you coil fin's will help to clean you don't want to use a wire brush it might do more harm than good.
That is for some coil cleaner. You want to use this. ... ure=relmfu
This is a how to on coil cleaning. Should help out

Re: Cleaning Intertherm unit floor ducts

Posted: Sat Sep 10, 2011 7:42 am
by homebuff
:) Thank's for the tip sites!

Getiing close to fall so I can remove the metal sheet plates to clean the crud of the coils.
Still be a bit tight getting a small brush or what ever the other guy's use.
The caked on crud is rather loose being a newer evap coil.
The coils are pretty shiny still so not alot of buildup substance in the inside fin area.
Looks as though if I can reach my hands inside the opening I can just merely pull the caked on hair & stuff of the coil's.
Hope it makes the fan blow a little easier.
Stil have to get the proper 1/3 hp motor that's suppost to be on it & not the 3/4 hp so I will have some heat this winter & nor have to rely on floor heaters.
It blows out to hard in the winter causing the exchanger not to build up enough heat then shuts back off continously.

Re: Cleaning Intertherm unit floor ducts

Posted: Mon Sep 12, 2011 8:07 pm
by Bill
Hi Dave,
Sounds like you are on the right path. One thing to remember is that once you get your coil nice and clean is to make sure your air filter stays clean. That way you wont have to clean your coil again.
Thanks and hope this helps.

Re: Cleaning Intertherm unit floor ducts

Posted: Thu Nov 15, 2012 8:27 am
by oldtimer
This is a post I posted awhile back on how I cleaned our vents.

I cleaned my ac vents today.
This is the way I did it . I took a stiff tape measure and shoved it into one vent to the next. I bent the end over and taped it in a loop. I then tied a piece of rope to the tape and pulled it through. I then tied a heavy sweat shirt to the rope. I then dunked the shirt in a bucket of cleaning solution ( anything will do ) then pulled it through the vent. Works great. Then I moved on to the next vent.
Y'all may have heard of this or maybe not. I thought I'd pass it on to yas.
God Bless
Thank you
God Bless

Re: Cleaning Intertherm unit floor ducts

Posted: Tue Jan 29, 2013 10:26 am
by homebuff
:D I replaced the motor & now with the heat off the fan cycles on & off at long intervals for about 3 seconds in a 5 minute period in between.
The switch at the thermostat is turned off & the pilot light I turned down a bit the other day & thinking it might be building up too much heat & energizing the thermal 2 disc type switch on the fan side.
Hope someone can answer this.

Re: Cleaning Intertherm unit floor ducts

Posted: Tue Jan 29, 2013 11:06 pm
by DaleM
Fan switch is weak, replace it. Sent you a pm as well.

Re: Cleaning Intertherm unit floor ducts

Posted: Wed Jan 30, 2013 9:23 am
by homebuff
:wink: thank's Dale!
Got it!
I assume weak on the fan side & not the limit side.
Wish me luck! :D
Haven't had a chance to check the roof cap though.