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Photograph of rusty air conditioning duct register Wet or Corroded Heating or Cooling Ducts
Causes, Health Concerns, Repairs for wet air ducts

  • POST a QUESTION or COMMENT about the cause, detection, effects-of and cures for wet, flooded, ice or water contaminated ductwork

Air duct leaks, condensation, flooding or wetting = contamination:

This article describes Wet or Corroded Heating & Cooling Ducts: Cause, Health Concerns,& Repairs to correct this condition. Rusty metal ducts or corroded HVAC ducts are an indicator of improper and possibly unhealthy conditions in the building as they are almost always associated with unwanted moisture in the duct system.

Unwanted moisture in cooling ducts in particular, is an invitation to mold, bacterial, or other pathogens in the duct system and thus in the building air. We point out and include photographs of locations where you can spot unwanted HVAC or cooling system moisture and rust, cite some related health concerns, and discuss ways to avoid duct corrosion or rust. We also offer advice on what to do about rusty ductwork.

InspectAPedia tolerates no conflicts of interest. We have no relationship with advertisers, products, or services discussed at this website.

Flooded, Wet, or Iced Air Ducts, Causes & Cures for Wet or Corroded Air Conditioning Duct Work

Photograph of rusty air conditioning duct register

The photo at page top shows a very rusty air conditioning ductwork register, and a careful look into that system of metal duct work, found additional heavy rust in the duct system along with lots of debris.

The photographs shown just above are of a less obviously rusty duct system and the rust stains on the vinyl floor suggest that the water in this duct system came from the floor level.

Photograph of rusty air conditioning duct register

[Click to enlarge any image]

Article Contents

Causes of & Cures For Water or Moisture In HVAC Ducts & Air Handlers

Photograph of  heat-deterioration of Goodman Gray Flex Duct in an attic

Excessive indoor humidity and its related mold, dust mite, or bacterial hazards may be traced to either a cause or an effect of high moisture inside of an air conditioning system or even heating system duct work or air handler. Here are some common examples of sources of condensation or actual water leaks in HVAC duct systems:

Sagging air duct (C) Daniel Friedman

See DUCT ROUTING & SUPPORT

Sagging air duct (C) Daniel Friedman

Excessive indoor humidity traced to wet air ducts caused by high velocity air conditioning system coil condensation blow-off

Reader Comment: Mike / DFW

For years I've been trying to figure out the excessive humidity problem in my home too. I finally found it after working with foundation people, plumbers, a/c techs -- nobody could figure it out, but I finally did. When the cooling kicks on, the moisture level skyrockets. It has affected the inside of my home tremendously. We thought it was the a/c drain.

They re-routed it, made sure it was draining well and clear. It is. Leak near or under the foundation. We checked everything-that wasn't it.

What's happening is the fan is actually sucking the moisture out of the evaporator coils before the condensation off the coils can drain away. The design of this Lennox horizontal system in the attic is such that the small space right above and right below the squirrel type fan, creates a venturi effect, increasing the velocity of the air being sucked into the fan.

The velocity of the air is so strong that the coils (about 12 in. away) have the moisture sucked right off of them and into the fan, which, of course is then blown into the ducting. I'm not sure if this is an engineering design problem, if the a/c co. wired the fan to a speed that's too high, or if perhaps a part is missing that is supposed to prevent this.

Regardless, the inside of the unit is now so covered with mildew and mold and the electrical connections on the heating elements as well as all the electrical connections on the inside of the unit, are so corroded and rusted, it's a wonder that love thing works at all. (This also probably explains why sometimes the heat works and sometimes it doesn't.

The a/c repair guys have never been able to figure out why. They always seem to think it's the thermostat It's not. It's new and has recently been completely re-wired when I moved it from an outside wall to an inside wall.)

Anyway, that's where MY moisture problem is coming from. Good luck! - Mike / DFW 12/13/2012

Reply:

Mike, gold star to you for good detective work. Like other areas in the Southern U.S., Dallas/Fort Worth experiences seasonal periods of high humidity that can result in an extraction rate of water from building air faster than the design of the air handler and condensate drain system can handle it.

More about dehumidification problems traced to central air conditioning systems can be read

at DEHUMIDIFICATION PROBLEMS.

Do you think that the root problem, then, is an improper duct or plenum size or design or a mismatch between blower fan capacity and the HVAC duct system?

Are Rusty, Previously-Wet, Iced, or Dirty Air Conditioning Ducts a Health Concern?

Wet rusted spiral ducts © D Friedman at InspectApedia.com

Not necessarily:

To avoid inappropriate anxiety on the part of any readers we state up front that it is normal for some dust and debris to accumulate on the inside of heating or air conditioning ducts, and this material is not necessarily a hazard to building occupants.

But when ducts have also been wet, or when ducts are constructed of materials like fiberglass insulation that have been damaged or can't be cleaned, some potential health or respiratory issues may be present, as we discuss further here.

Our flooded air duct photo (above left) shows ductwork with a layer of mud - this home was flooded to a level that included ceiling-mounted basement air ducts. The ducts needed to be cleaned and sanitized.

Soil particles themselves may not be a serious health hazard but area flooding often brings pathogens (such as bacteria or viruses found in sewage) into buildings and can form a serious health hazard. Details are

at FLOOD DAMAGE in DUCT WORK.

Rust flakes

from rusty heating or air conditioning ducts themselves are unlikely to be much of a health hazard - these particles are pretty big, not easily airborne, and probably won't be found at high levels in indoor air except in unusual circumstances. But rust in ducts is a problem indicator, showing quite clearly that the duct system has been wet.

Dust & normal air duct debris:

The chief components of house dust, which will certainly collect within a duct system include fabric fibers and skin cells, often also including starch fragments and other organic debris.

Watch out:  The combination of organic debris within a duct system and water (indicated by rusty ducts or duct registers) indicates a possible risk of mold or bacterial hazards within the air conditioning or heating system. Since blowing air through the system can pick up and distribute these hazards to occupants of the building, wet or previously-wet duct work is a potential health hazard to building occupants.

Wet HVAC Ductwork Actual Risk Assessment

The actual health hazard level from wet or previously wet air conditioning or heating ducts in a building depends on these factors:

Wet spot in flex duct © D Friedman at InspectApedia.com

What To Do About Rusty HVAC Ducts, Wet or Previously Wet Fiberglass Ducts or Flex-Duct

Wet rusted spiral ducts © D Friedman at InspectApedia.com

Use of Sprays, Sealants, Sanitizers in HVAC Duct Systems

rusted metal ductwork (C) Daniel Friedman

Reader Question: considering buying a house with very corroded in-floor rusty ductwork - can we just spray-seal the duct interiors?

I am considering buying a 20 year old house which has underground ducting serving both refrigerated air and heat.

I had a duct inspection which revealed severely corroded and rusted ducts with some holes through the ducting.

I have heard of a product by the Duct Seal Technologies in which the inside of the ducts are sprayed with a coating of kevlar fibers and some bonding agent. Do you know anything about this process?

Thanks, Doug Spence - Spence 6/19/2011

Reply: in-slab HVAC ducts are asking for trouble from flooding, vermin, water, mold, etc.

Spence:

About buried or in-floor HVAC ducts: as we suggest in the article above, even if you could reliably reline your in-ground or under-slab air ducts (and how without a detailed inspection would we know that the re-coating or relining was complete, and that it remained intact?) there remains a concern with radon gas or water leaks into the duct system.

And we are doubtful about the reliability of this approach: spray-on coatings don't bond well to dirty, rusted, corroded surfaces and may fail to seal large penetrations or holes; And even a well-sealed spray-coated in-slab HVAC duct, if subjected to future flooding from ground water or plumbing leaks, or invasion by rodents or other pests, is simply going to have new contamination in its interior.

See DUCTWORK CONTAMINATION

A better, but usually much more costly and disruptive solution is to eliminate the in-slab ductwork by rerouting it through the building.

If you go ahead with the process I'd recommend first an inspection for evidence of a history of duct flooding, and an annual inspection of the duct condition until you are confident of its dryness and cleanliness.

Also take a look at TRANSITE PIPE AIR DUCT ASBESTOS RISKS for more examples of problems with heating or air conditioning ducts found in slabs.

 




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Reader Comments, Questions & Answers About The Article Above

Below you will find questions and answers previously posted on this page at its page bottom reader comment box.

Reader Q&A - also see RECOMMENDED ARTICLES & FAQs

Question: what is causing fan motor and shaft rust in my Unico Mini Duct System

JL 2021/07/01

I have Unico mini-duct system in my attic. Every winter, the fan motor and shaft accumulate rust. I live in a very cold climate in winter (Vermont). Last year, I had the motor replaced and this spring, there was rust on the motor again (no visible rust last Fall when I closed the unit up for the winter). I had the New England Unico rep at my house when we closed up the unit for winter to ensure it was properly winterized.

Specifically, the plugs were put into all the outlets and a piece of insulation board wrapped inside a plastic garbage bag was placed tightly into the air return. In addition, I had an additional 18 inches of cellulose blown into the attic last fall and the attic entrance / jacob’s ladder was sealed up properly and a new roof put on (both last Fall).

The condensate drain used to drain into the sewer vent but that was moved last summer to instead drain to the outside of the house directly via a PVC drain pipe. Note there is just a small v-shaped trap on that PVC drain but my contractor thinks that is fine given it drains to the outside.

So, the current theory is the rust is occurring due to moisture in the attic in the winter, but there are no other signs of moisture in the attic. The laundry room is almost directly below the attic A/C unit and the dryer vents to that outside wall.

A friend suggested that dryer vent could be blowing warm air that rises up into the soffit vents and finds its way into the attic, but I think this is not likely the problem given I have no other signs of moisture in the attic plus the fact that the A/C unit is pretty tightly sealed up itself to avoid leaking air when it is operating.

This Q&A were posted originally at AIR HANDLER / BLOWER UNITS

Moderator reply: track down source of moisture, rust, corrosion in air handler

From your description of near-heroic measures to try to close off your attic duct system in winter one might guess that you've had reason to be concerned for moisture or ice accumulation in ductwork in the past.

What you've been doing sounds reasonable to me.

But I've also seen that the natural wish of warm air to rise into cool spaces means that even the smallest air leak into the duct system from anywhere will invite moist air and condensation and thus moisture collection during cold weather.

Because the ductwork is out of use there's no air circulation through the A/C system so no moisture removal; so any moisture accumluates, and can be corrosive.

I've even seen so much moisture accumulate in attic ducts as to form thick ice that later melts and shows up as a "leak" that has been mistaken for roof leaks.

If air is leaking directly into the duct system from anywhere in the warmed building during winter, that could explain why you see duct or attic AHU moisture signs but not other moisture or condensation signs in the rest of the attic.

Your friend's idea about the dryer vent is interesting and helpful as a model: look for sources of warm air leakage into the duct system from anywhere in the building.

Two articles you'll want to review are

WATER & ICE IN DUCT WORK

WET CORRODED DUCT WORK -- I will copy our discussion to that article and will welcome your further comments, questions, suggestions here or there.

Reader follow-up:

Thanks for the reply.

I have had some condensation in past years around the air outlets (I.e. on the ceiling around the outlets) during very cold spells. That is one reason I had more insulation put in the attic last Fall when the roof was being replaced. Now most of the ducts in the attic are buried in insulation. No issues like that this past winter after adding the insulation.

The links you sent me don’t work for me. Can you please double-check them?

The most likely place I can think of where air from the heated part of the house would be the return. Can you think of any special material the return should be made of or method of sealing (beyond what I’m doing)?

Regarding the condensate drain, do you think I need a bigger drain with antifreeze in it during the winter to keep air from getting into the unit in winter? Keep in mind it is currently just a small V-shaped PVC trap that drains outside.

One last question: is it possible the corrosion actually occurs during the summer/fall when the unit is operating but doesn’t turn into visible rust over time (e.g. winter)?

Thanks again! - JL

Moderator reply: example of how to use InspectApedia.com on-page search box results

[Click to enlarge any image]

Example of how to use InspectApedia search results (C) InspectApedia.com

RE your question:

Can you think of any special material the return should be made of or method of sealing (beyond what I’m doing)?

-- If you are sealing the return duct at its inlet grille then that is normally sufficient; but you might want to inspect the duct system to be sure there are no obvious air leaks into it from elsewhere.

-- Something sounds wrong about all of this: when we close off duct inlets and outlets we should be closing off any significant air drafts into the ductwork during the off-season; So I keep thinking we're missing a significant airflow passage.

Regarding the condensate drain, do you think I need a bigger drain with antifreeze in it during the winter to keep air from getting into the unit in winter? Keep in mind it is currently just a small V-shaped PVC trap that drains outside.

-- The condensate drain trap may indeed dry out over winter; you could try mineral oil in the trap when the system is shut off - less of a contaminant than antifreeze;

One last question: is it possible the corrosion actually occurs during the summer/fall when the unit is operating but doesn’t turn into visible rust over time (e.g. winter)?

-- It is certainly possible that moisture is accumulating in the duct system during the in-use season and lying there corroding-away over the winter; It's common for water to blow off of the cooling coil into the supply ducts from that point onwards.

-- Sags in ductwork also pool condensate;

Reader follow-up:

Thanks for all the info. Your last point made me ponder something everyone has said should not be an issue but let me run it by you: I have 2 outlets over my 2-story foyer that require an extension ladder to plug / unplug so I stopped opening them several years ago.

Do you think it is possible that because the air isn't moving through those lines (remember this is a Unico high velocity mini-duct system) that there could be condensation sitting in those lines that could find its way back to the blower fan in the winter? FYI: I typically run the blower fan (i.e. not calling for cooling) for at least 24 hours before closing up the system for winter.

This is usually in October when the nights are cool and I'm no longer using the system daily for cooling. Could that be leading to warm moist air in the ducts that later causes the rusting on the blower fan once I close the system for winter?

My technician is supposed to come to replace the blower fan and motor today so I'll run some of these ideas by him as well. - JL

Moderator reply:

I'll be very interested in your report of what your on-site service tech has to say, as nobody can see as much by text and web posts;

But in general, for an outdoor receptacle to be responsible for rust and moisture in an HVAC duct system you'd have to have a pretty unusual circumstance in which sufficient volume of humid outdoor air is somehow conducted from an electrical box or the cutout opening for the box into the duct system. There should be no direct path through which that's possible. Visual inspection still is sensible.

Reader follow-up:

My technician agreed to problem cannot be caused by the dryer venting back up into the attic. The Unico system is pretty air tight due to it being a high velocity system.

He also did not think the two outlets that I never open would be the source of condensation for the winter months. Nor did he think running the fan in October just before I close it up could cause excess moisture to accumulate since the air is pretty dry in Vermont (low humidity) in October. So we still have a mystery. He said the unit was completely dry inside today despite the fact it was hot and very humid here yesterday. - JL

So we still have a mystery. Thanks for your suggestions and comments though. If we ever figure this out, I’ll let you know.

Moderator reply:

Thanks for the follow-up, do keep us posted, as what you find will certainly help other people too.

In investigating, start at the point of most-concern such as rust or corrosion, and follow the water or water indicators, stains, signs, rust patterns, etc.

 

On 2020-08-3 by (mod) - evaluate rust in metal HVAC ducts & registersRust-

Anna

Your original photo (further below) shows rust in the heating or AC duct register boxes that in turn are connected to plastic flex duct.

The second photo shows trivial rust; the first image you posted shows more rust and may be a concern - look for a spill or a leak source.

Those stains suggest there has been water in the ductwork - risking hidden mold or bacterial health concerns.

On 2020-08-26 by Anna

I just posted about rust in a vent with plastic lined duct, but wanted to share other images for context

I am purchasing a condo and see that there is corrosion in the first floor vents. One is worse than the rest (photos attached- 2 of the bad one and one of another). I've been reading this thread and see the recommendation to investigate any rust or corrosion.

When I look at what these vent attaches to, I see what looks like something lined with black plastic. I would like to know 1) What kind of duct is this and is there still a concern for rust in the vents? 2) would you still recommend a scope of the vents, and 3) does this vent need to be treated in anyway?

The hardwood floors were recently redone and there was concern that product spill in the vents caused the corrosion, but the flooring company says that is impossible. Could this be caused by that?

 

On 2019-12-09 by (mod)

Panther

I can't say from the photo whether that's normal dirt in older HVAC returns and ducts or rather water damage and mold; if the drywall is damaged look carefully to see if it is from water damage, mechanical damage, or simply the effects of rough cuts made during installation.

Gypsum board doesn't literally "rot" (as might wood) but it can be water damaged and become soft.
In your photo I don't see water stains. That would be a useful diagnostic clue.

On 2019-12-08 y pantherprincess555

All my air returns look like this and rotted sheetrock behind them. White film and mites all over my home.


 

On 2019-08-27 by (mod) - venting to fix a ductwork condensation problem? Really?

Linda

I want to help but am totally baffled by the question and by what the service tech told you. I have not idea why there should be a "vent" cut into ductwork - it sounds very odd to me and is by no means a common, standard, or recommended practice.

Ducts "going in to a furnace", would mean that these are the air return ducts bringing building air into the air handler to be heated (in heat mode) or cooled in air conditioning mode.

Sources of water in ductwork are discussed in the article above; some examples (not an exhaustive list) of causes of water or condensate in or on air conditioning or heating ductwork include:

If there is water inside the duct work it may be due to improper condensate drainage from the air conditioner.

Condensation might also appear on air conditioning SUPPLY ducts (leaving the air handler after the air conditioning cooling coil has cooled air therein) if the ducts are not properly insulated.

On occasion condensate may blow off of the cooling coil and into the supply air plenum or ductwork.

Rarely there are also external sources of water inside ductwork such as a plumbing leak that drips onto and into ductwork or

finally, ducts that run in floor slabs below grade, into which ground water leaks.

On 2019-08-24 by Linda - ducts going in to the furnace was dripping and sweating - AC tech said ductwork needs to be vented

The ducts going in to the furnace was dripping and sweating an air conditioner tech said it was because there should be a vent in the duct work that is coming out of the furnace that is running across the ceiling in the same room.

So he put a hole in the duct, which did stop it from dripping. Should there be a hold in it? Is this correct? My furnace is very old.

Reader Question: Mold on ceiling traced to condensation in the ductwork?

I have a condo that the garage is below the living space. My tenant noticed there is mold on the garage ceiling. One of the neighbors said they had the same problem and she had it fixed. She was told it was condensation in the ductwork. Water was damaging the drywall and leaking downward.

Of course, mine is worse. What is causing this? Could this be a problem in the construction? The units may be about 10 years old. - Carol 6/20/12

Reply:

Water in flex duct (C) Daniel Friedman

Carol from the very limited information your note alone I can't be confident in a "guess" at what the problem is in your home and can only answer in general. An A/C duct that is not insulated is more likely to produce condensation inside the ductwork than otherwise, especially in humid weather.

Such condensate, if it collects in the ductwork where it does not belong, instead of in the air handler where it is drained away, can wet duct insulation (if there is some), and can leak onto or into building surfaces.

Moldy drywall is best removed and replaced, allowing you also to check to be sure the wall cavity was not also wet (and moldy).

Ask your HVAC service company to inspect the ductwork, fix the cause of condensation, help you decide if the interior of the ductwork needs cleaning AND IF it can be cleaned at all (fiberglass duct interiors don't tolerate cleaning). WHen that problem is cured, then address the rest of the building.

Watch out: mold can grow to problematic levels in fiberglass insulation in or on wet or previously wet HVAC ducts even when the ducts look clean to the naked eye. An explanation of this problem is

at FIBERGLASS INSULATION MOLD

Reader Question: dripping from the HVAC ducts

(Sept 29, 2015) Jyotika Bahree said:
Hello, we just had our evaporator coil replaced yesterday and the technicians had to alter the ductwork to put the coil in.

After the work was done, the technicians confirmed that the AC system was cooling properly. After they left, I went to our basement where our HVAC unit is located and found that there was air leaking from the duct joints where they had put the new coil in.

Thinking that the leakage did not seem normal and might compromise the cooling, I called him to ask about this. He said that they had deliberately not sealed it completely to prevent the system from "sweating" too much. Not knowing any better, I had to accept what he told me. I would like to get your opinion on this issue.

Please do let me know if this will compromise the system efficiency or if this will truly prevent the system from sweating and therefore we should do nothing.

Reply:

Look for

1. missing duct insulation

2. condensate blowing off of the cooling coil into ducts near the air handler

Question: does use of bleach or scented candles corrode our air ducts?

I was told products such as clorox, scented candles and sprays cause corrosion to air and heating lines. Is this true? - June Walker 10/2/11

Reply:

June, it's true that in areas where high levels of chlorine gas are present, such as around indoor swimming pools, corrosion of metal HVAC ducts and even evaporator coils can be a serious problem.

Scented candles? I am very doubtful that in normal use you could put enough corrosive material into the air to affect the ductwork. But indeed use of scented candles can be an indoor air quality problem source for some people such as asthmatics, and the soot deposition on indoor surfaces can be a cosmetic problem as well.

See THERMAL TRACKING & HEAT LOSS.

Question: is it ok for a window A/C unit to run continuously for 30 minutes or longer?

Is it ok for a window unit to stay on cooling for 30+ minutes or will this break the unit, see its above 96 degrees all the time outside so its hot hot and since I cleaned the evaporator coils & moved thermostat accidentally

I swear it doesn't cut off & on like before but I just don't want damage to unit and also coils were dirty before so maybe that's why it cycled quicker then anyway please help - Christie 7/25/12

Reply:

Christie,

Under normal conditions (that is for example no abnormal electrical voltage levels, proper wiring and installation) a window air conditioner could run continuously, 24-hours a day, without damage to the equipment itself. Of course if the air filter becomes debris-clogged and is not cleaned the system efficiency and effectiveness will decrease, and of course your electric bill will reflect that continued operation.

See WINDOW / WALL AIR CONDITIONERS for details.

Reader Questions about Wet Corroded Air Ducts

On 2019-07-15 by (mod) -

Shirley

If your apartment is unsafe / unhealthy and the management is not addressing the situation you may need to ask for help from your health department.

On 2019-07-15 by Shirley - There's mold, rust,lead and possibly asbestos thru out even the tile floor and the air feels humid,

My evaporative cooler or condenser and coils need cleaning from debris from gas powered leaf blowers next door twice a week.

I should get my rental payments waived till the slumlord faces her responsibility, she just don't want to pay professional costs.

These apartments should be condemned built in 1949, the slum Lord told us not to lick the paint, it's full of lead, rusty water pipes, mold I need the Environmental Protection Agency to test these apartments, they are hazard to our health, and inhabitable to live a healthy living conditions

There's mold, rust,lead and possibly asbestos thru out even the tile floor and the air feels humid, the AC is potentially not giving out cool air as time goes by we have a slum Lord that refuses to hire a professional bonded and licenced, they use exfelons to do the handiwork, and refuses to exterminate by professionals but uses the cheapest extermination using claydirt making your apartment dirty around the base iarda and window sills

My apartment below the ceiling is cracking and buckling from the ceiling to the base board

On 2019-04-21 by (mod) - What are the effects of a corroded return air duct in an air conditioning system?

Re-posting from email:

Anonymous wrote:

I was going through an article on your site on '' Return Air HVAC improvement Guide.''

But my question now is; What are the effects of a corroded return air duct in an air conditioning system?

Moderator reply:

To ask about the effects of corroded return air ductwork in an A/C system is, I agree, a reasonable question in concept but unfortunately one that nevertheless cannot be answered usefully when we have not a shred of information about the air conditioning system, ducts, condtion, contamination, amount of corrosion or rust, its cause, possible pathogens in the moisture that caused it, air movement, type of building, other building conditions that impact the effects, and quite a few other questions.

To give a general ' "it's ok" or "it's dangerous" answer would have no useful reliability.

For example, sewage water leaking from an overhead sewer line into an air conditioning duct system is unsafe regardless of whether or not the duct is visibly rusty.

In sum, superficial or small amounts of corrosion or rust in an A/C or heating system air supply OR return duct may be of itself inconsequential though even then the cause of the corrosion should be considered and probably fixed - such as condensate blow-off or missing duct insulation.

But extensive corrosion inside HVAC ducts might indicate not only that the system is itself damaged and leaky (increasing operating costs and decreasing building comfort) but it might also mean that pathogens such as bacteria or mold are being blown through the system and onto occupants.

On 2018-12-13 by Mario

I have a plumbing leak that is dripping into my basement duct once I fix the leak what can I do to get the corrosion...hard water stains off and restore the look of my ducts

On 2018-10-03 by (mod) - How long does it take for rust to form in ac ducts

Days or longer, depending on the materials involved and site conditions.

It's less the rust, and more mold, bacterua, or viruses in damp ir wet conditions, that I'd want to investigate.

On 2018-10-03 by Fay

How long does it take for rust to form in ac ducks and is it hazardous to my health. I'm immune compromised. My complex is 30 years old I can see the rust on the ac grates in the apartment. What should I do?

On 2017-07-13 by (mod) - My ducts are leaking water also, how do I clean air handler?

Anon

In general water leaking out of HVAC air ducts is coming from

- condensate blow-off of the cooling coil, possibly requiring fan adjustments, a replacement of a baffle that a tech left out near the squirrel cage fan - or perhaps a baffle that was installed in the wrong location

- condensate accumlating downstream in ductwork perhaps because of missing insulation or air leaks into return ducting

Anon:

Cleaning an air handler might be considered at more than one level of work:

1. change dirty air filters regularly, usually monthly

2. remove any obvious clods of debris you can reach without disassembly - be sure power is OFF or you could be injured

3. hire a pro who removes the blower assembly, cleans it, lubricates it, cleans out the entire return air compartment, then rebuilds the system
Details are at BLOWER FAN ASSEMBLY CLEANING https://inspectapedia.com/aircond/Air-Handler-Blower-Cleaning.php

4. Cleaning a dirt-blocked cooling coil in the air handler is described at DIRTY COIL CLEANING PROCEDURES https://inspectapedia.com/aircond/Cooling_Coil_Cleaning.php


On 2017-07-13 by Anonymous

Mine are leaking water also, how do I clean air handler?

On 2016-09-14 by (mod) -

PT

The blower unit - the machine that includes a fan and controls to blow conditioned air through the duct system.

On 2016-09-14 by pt

Metal ducts that have been wet but are not severely damaged can and should be professionally cleaned. Be sure that the interior of the air handler is also inspected and cleaned - what do you mean by air handler?

On 2016-08-06 by (mod) - UV lights disinfect but don't dry ductwork

A UV light will not do the least thing about drying out wet or rusty metal ductwork; IF and I empahsize IF the light were strong enough and the airflow slow enough, a UV light might kill some microorganisms that may be found in indoor air or in wet or damp ductwork. It sounds to me that the vendor is proposing to use a tool that they know and sell rather than that the problem is being properly addressed.

I suggest a duct inspection to find and fix the cause of the moisture problem, and perhaps duct replacement of rusted sections.

On 2016-08-06 by dave

when I turn on my central a/c for the first time in the spring ...theres brown residue that comes out of the ducts...the a/c company claims its rust from the ducts in the humid hot attic space they want to install a uv light claiming this will take care of the situation ....im not buying it I feel like I'm getting scamed...any input would be appreciated


...

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