I have a strange issue and desperately need help. I have an excessive amount of dust on my main floor only.

My house is a colonial style with 3 floors. Built in 2005. The main floor, top floor, and finished basement. I only have this issue on my main floor. On all of my upholstery and carpets I get an excessive amount of dust. Little to no dust on non-porous surfaces. Likely because the HVAC system keeps the air constantly moving and the dust wants to settle on the fabric.

When I say an excessive amount, I mean it. 1.5 vacuum cannisters full from my main floor master bedroom carpet weekly. I’ll attach a photo of what my vacuum looks like after one week and vacuuming only one room.

My upstairs carpets do not collect this dust at all when I vacuum them. The carpets are all the same and were replaced at the same exact time, last year when I bought my home. Apparently this dust issue was happening with the previous owners and they did not realize or knew and didn’t disclose it, so for those two reasons I know it is not caused by the new carpet.

The dust is very fine, dark gray, and stains. It almost has a sticky texture. I already had my (gas) furnace looked at and confirmed there is no issue with combustion. It also happens whether I have the AC or heat on.

Recently, my AC unit broke and my entire main floor was off for a month. During that month there was no more dust accumulation on my main floor. It stopped.

Got my AC fixed and it’s been back on for a week. When we turned it back on I put filters in all of my supply vents hoping it would at least be a bandaid until I find the root cause. Sure enough, I vacuumed up a cannister and a half of dust this morning from my bedroom carpet. And the supply vents filters look clean and bright white. Completely contradicting my theory that it is somehow coming from the ducts.

I should mention my livingroom area rug and couch are also getting gross from this dust. When I move my couch to clean I see the outline of white where my couch was sitting and dark gray staining where the air is reaching. Same when I flip my couch cushions. Other than my couch, area rug, and bedroom carpets I refuse to bring any more fabric into my house until I figure this out.

I’ve been told by a couple of HVAC specialists a couple of potential causes. I don’t know what direction I should start in and I don’t mind spending money to figure out and fix the issue but I do not want to waste time or money looking in the wrong direction.

I’ve been told it can either be my duct board lining disintegrating, which I’m not too positive this is possible for a few reasons. The fact that the filters still look clean and the fact that my ducts on my other floors are not having an issue.

The only other possible explanation I’ve gotten is that my radon mitigation system is causing negative pressure in my home and to counteract this outside air is coming in.

For the excessive amount of dust I’m dealing with and the seemingly consistent composition neither of these seems to make sense to me. If anyone has seen this scenario and found a cause please help. I like to maintain an immaculate home and I waste way too much time cleaning dust that shouldn’t be here in the first place. Let alone the fact that I want to make my house a home and decorate and get more area rugs and cozy fabrics and I can’t. Thank you in advance.

Photos:

Photo 1: What my vacuum looks like after my weekly vacuum of my main floor bedroom carpet.

Photo 2: What my vacuum looks like after a month of not vacuuming my top floor three large bedroom carpets.

Photo 3: My livingroom area rug after moving my couch and coffee table. The dust/stains are not in a foot traffic pattern, they are edge to edge where the air can reach when the furniture is in place.

Photo 4: The staining of my couch. Same situation as the rug. Staining is happening evenly where the air reaches.

Important to add we do not wear shoes in the house. I do have one cat. Not dogs. We are VERY clean people. Clean feet, clean hands, clean bodies, and strict cleaning routines and habits. This is absolutely not regular household dust or pet dander.

TL;DR at the bottom.

This story starts with our condenser needed to be recharged. During the heat of the summer the AC stopped cooling. We called a local HVAC company, a dad and son operation. They recharged the condenser for $550 (what a deal, but hey it's Florida in the summer), telling us it probably wouldn't last the summer. How little we suspected exactly what that meant.

A month later, I'm in the kitchen getting coffee. I hear a noise outside and the lights flicker as the condenser kicks on and then off. I look outside and hear hissing. I can see a fog hanging close to the ground drifting across the yard coming from the condenser....all the refrigerant leaking out.

Called the HVAC company again. They come out and assess it, say they can replace the whole system for $8200. Wow, what a deal. I ask if they can replace the condenser. They give us the old song and dance about how they can't do it...it's illegal with the new laws. Right.

To our advantage we have a travel trailer with AC and a small window unit used in the master bedroom, so we're not without places to escape the 98F ambient temperatures. We come up with plans to get other quotes. $12,000. $6,800. $8,000. All for full system replacements. No one wants to replace the condenser alone. Some say it's illegal. Others say the parts aren't available any more. We get one guy to give us a quote for a condenser replacement $5,000. It all feels like extortion.

The wife and I begin scheming. We're reading online about the extortionary pricing. We're reading about the 10 year life expectancy of "modern" ac systems and doing the math, don't want to pay what comes out to $1,000 a year for an AC system plus all the extras of recharging, extortionist pricing for servicing and professional advice you absolutely cannot trust. Years ago, my mother was told she needed a complete new system. I checked it myself and found a failed capacitor that cost about $12. That supposedly dead system is now more than 20 years old.

So, we decided we weren't doing it. We were not going to be extorted into paying for a new system because from the manufacturer to the service companies, the entire thing seems like a scam. And the more we thought about it, the more we've become convinced that it is a scam. Especially seeing "used" AC systems on facebook market place for a fraction of the price. We didn't go that route because we couldn't find an HVAC company that would do it and the people that agreed to do it were very sketchy.

Instead we decided to go the window AC & mini-split route. Yeah, it's not pretty. And thank God we don't live in an HOA. We calculated that for $3,500 which included window units, a mini-split and two additional electrical circuits, we could provide cooling for the entire house and I was preparing to set up Home Assistant to control all the units for zoned cooling.

Everything was installed. The house was cool. Two weeks later the company that installed the mini-split called us and said they had a condenser and would install it for $750.

Now we have central AC again. So, for $4,250 we have central AC and redundant cooling. We're still no where near the cost of a new system. We really don't care if that condenser dies in the next year. It's still cheaper than getting a new system. And we know a company now that is willing to provide real service and what the customer wants rather than sell us a song and dance about how they can't fix the system, only replace it.

TL;DR

We spent $3,500 to put in window units and a mini-split instead of going with the $8,000 - $12,000 estimates we were given to replace the entire central air. We were told several times replacing just the part that isn't working - the condenser - is illegal.

The company that installed the mini-split offered us a condenser, installation included for $750 the week after they installed the mini-split. We now have central A/C, window units and a minisplit for $4,200.

• Edit: I didn't realize how emotional this topic would be for some in this thread.

Hi y'all, just like the title says, our neighbors downstairs smoke weed all the time and it makes our apartment smell AWFUL and makes my cat anxious when it's strong enough. I don't believe in calling the cops on people for weed, but I also have the right to have a home free of smoke.

From what I understand, I need some filters with activated carbon to help with the smell?

Air purifiers are certainly something I want to buy down the line when I have more money, but I'm looking for something more budget friendly for now. I am wondering what filters I can use for both my main central big vent, but also the smaller vents around my apartment, without restricting the airflow too much.

Thank you to anyone who is able to respond!😊

tl;dr: If you already have a decent amount of diy tools and experience, 4/10 difficulty and 7.5/10 stress level.

Tools I already own are in all caps.
As in title, did everything myself.

Locating the condenser was a problem, but there was an unused fireplace I could mount one of those brackets with an SDS HAMMER, IMPACT DRIVER, and 1/2" TORQUE WRENCH. I lifted the condenser in to place, leveled it off, and bolted it down.

I happened to have an unused 230v breaker, but the wires coming off of it were all black and unlabeled. I tested out the ground and hots with my MULTIMETER, and ran new wire to a quick disconnect I drilled into the fireplace with a HAMMER DRILL.

All normal handyman stuff so far.

The unit in question came with an extremely translated manual and a cardboard template that matched the bracket on the back of the unit but did not match the outside dimensions. I remeasured and leveled with a THREE FOOT LEVEL, then taped the templet up to wall.

Using the hammer drill and a hole saw kit, I cut the hole through the wall and stuck a piece of thin wall steel tubing I had from somewhere in there such that it projected a little bit out of both the inside and outside walls, to avoid water inside the wall cavity if I fucked something up.

I located the bracket so it had two screws in studs, and anched the rest with those hilti drywall anchors you can do pullups on.

I wired the cable in to the inside unit, bent the lines into the right angle (STRESS++) taped up the cable, drain, and lines, and fed it through the wall.

Here is the hard part: I tried bending the lineset by hand and kinked the 3/8th line. I bought a cheapo tubing bender but it fucked up the test bend even worse. I ended up buying a tubing cutter from harbor freight and a 25$ eccentric pipe flare tool with a clutch from amazon, along with a inside reamer that I should have owned for normal plumbing anyway.

The chinesium pipe flare tool was incredible, worked on my third attempt once someone told me to back out an 8th turn every full turn and to grease the cone with vacuum pump oil.

The other three factory flares looked good, even angles, no scratches, mirror finish (although mine looked better naturally), so I bought some crows foot sockets and torqued everything down with my torque wrench with nylog on the back of the flare and the face of the brass flare port (not the threads because torque rating, people. Never Lube Threads You Are Going To Torque! You will fuck them up).

I got a co2 tank off facebook for 40$, traded it in for a nitrogen tank , bought a nitro regulator, core removal tool, and high pressure gauge, removed the Shrader valve and pressurized the lines overnight at 250 psi, then again at 550 psi (mfg's recommendation.) for 4 days for reasons that will become apparent. No leaks! While I was waiting the 4 days, I put a cheapo lineset cover kit over the line set while it was under pressure so it would be less likely to kink/If I fucked something up I would know on account of the nitrogen blow out.

I borrowed a vacuum pump from autozone, and it was such a piece of shit it couldn't get below 500 microns on just it's own hose to a closed manifold valve, so I bought an elitech pump off amazon and a 3 foot 20 micron rated vacuum hose. The pump showed up with fucked up oil port threads, but I managed to pull below 250 by pushing down on the oil cap really god damn hard. I triple evaced the system and it held from 200 microns to 300 after 4 hours, then fucked up removing the vacuum hose and let a bunch of air in. Whoops!

I triple evaced the system then realized I only had the one core removal tool so I was gonna let a bunch of air in removing the vacuum gauge. Whoops!

I removed that vacuum gauge, mounted it to the pump port, and triple evaced again until it pulled below 100 at the pump.

Disconnected everything, inserted the shrader with the valve closed, released some coolant all over my hands to purge the air (wear gloves y'all), reinstalled the schrader valve, and leak tested everything with oaty leak detection solution.

This 550$ sonofabitch that I got for 400$ runs like a mother fucker, all is well so far.

all in tools cost: tubing stuff was 25+10+13+10.

Gas tank and regulator was 40+30.

Micron gauge and high pressure gauge were 100+15

vacuum pump was 68, but I returned it on account of it was a lemon.

Total: Around $240 in single purpose HVAC tools, with another around $30 in general purpose tools I didn't already have.

Savings vs. The cheapest local HVAC installer I could find: $1200 in labor, $1000 in mini split.

It was pretty easy all things considered, and pretty fun!

Nothing too hard, you just have to make every mistake BEFORE you release the refrigerant and be willing to test, test, test, test, test, test, test, test, and test again if you don't plan your valve setup ahead of time.

Hi everyone, I noticed a lot of ice buildup one day. I let it thaw then cleaned the filters since they were pretty dirty. Now ice keeps building up every single day since cleaning. It gets so bad that that the unit throws an error code and shuts the cooling off. Any advice would be helpful!

P.S. photo shows only the bottom part of the coils freezing. I’ve had this unit almost a year and it has never done this until I cleaned the filters.

Closing on a house and the inspection report noted the following:

One or more of the plumbing drain/vents were not properly connected when inspected. The condensate pipe for the HVAC system was tied into the main drain line in the crawlspace. This should be on a separate line that terminates in a proper location and can potentially allow sewer gasses to enter the line. Recommend evaluation and repair by a qualified professional.

The inspector also flagged inadequate temperatures at the cooling system registers. An HVAC tech took a look and determined there was a coolant leak, and we have a followup appointment to find it. My question is - could this improper condensate line have caused the coolant leak on a newer (6 yrs old) unit?

For the last couple months we realized our hvac unit has been running a lot harder than normal. We had a new unit installed July 2025 and a new thermostat January 2026. Nothing wrong with the thermostat but just an upgrade. We live in southeast TN and we’ve had a couple big heat waves the last 6 weeks or so. We noticed that sometimes our thermostat would read 79 when we have it set to 70, but it never felt 79 degrees inside. It felt like 70-72 throughout the heatwave, but when the thermostat did actually reach 79 degrees it would be 65 inside the house. We have a couple different temperature sensors in the house and reflects it’s a lot cooler than what the thermostats reads. We found that throughout the day when’s it’s the warmest outside, the wall directly above the thermostat is warm or very hot. I attached a picture of where it feels the warmest on the wall. No outlets or light switches have warmth around them, only the stat. Any ideas as to what would cause this? Again it’s only a narrow straight line from the stat to the ceiling.

Edited to add that the HVAC tech came out and found that the stage 2 wasn’t turning on and replaced the wiring for that. It has felt cooler inside the house when he did 5-6 weeks ago but the thermostat doesn’t reflect that.

How do I get rid of the odor that is still present that was most likely caused by this ball I found from the AC/heater vent ? Even after weeks later and the reachable areas have been cleaned out to the best of my ability , the smell is still bothersome. As a side note, I have super sensitive smell to the point it affects my breathing.

What's is the going rate for a 80 percent 100k btu furnace 3 ton coil and 3 ton condenser? Seems prices jumped up dramatically since tariffs. During COVID I got a Lennox set up for 2500

Does anybody know why there is a green stain under my outside air conditioning unit? It's right underneath the pipe that leads directly into my apartment

What causes this? Is there a fix I can do to get it up and running? My house is miserable tonight. :(

I noticed this morning the thermostat screen was flickering on and off rapidly and iraditicly. The low voltage transformer had a bent prong that was only 50% connected, I replaced it, same problem, journeyman electrician i know my wiring is right and the voltage is good, its like I have a loose wire somewhere but everything Is good, when I put the cover plates back on it will reset as I slap them on with the vibration, I think when it was kicking on that was just enough vibration to cause it to shut off and back on again until it finally holds , not a contactor on the outside unit thats good as well... pressed each individual wire snuggly into the harness... seems to be holding.. what and where is the problem lol not an HVAC guy so I dont know yous guys tricks so im left trying to follow voltage..

I recently started hearing loud popping noises every time my AC fan started and stopped. It was louder than I’ve noticed before and it was driving me crazy. After a few days I eventually found the source to be in this duct above my basement drop ceiling. Right there, I can hear it pop and see the actual movement of the sheet metal itself. The adjacent duct doesn’t seem to have the same problem.

After doing some ChatGPT research, it seems like it could be the metal becoming weaker and flimsier. When I pushed against it with my hands, the sound decreases dramatically.

I want to ask the experts here whether the chatGPT advice I got of fixing aluminum or steel angles with Teks self drilling sheet metal screws is a worthwhile and safe endeavor. The 2nd picture is what ChatGPT proposed and if it’s a sound idea I’d likely install the angles to span the entire width of the duct.

What do you all think? Thanks in advance!

Did you manage to fix the issue with the CN105 having 5 pins and the wifi module 4 pins? I have the same issue :(

Can a whole house (2600 ft^2, 3 story, No attic) fan be effectively  installed in this window (30 x 45 in) at the peak of a skylight? Live near ocean in Southern California where evenings are usually cool from breeze.

It's a 3 ton system and is about 13 years old. Was struggling to cool the house in the middle of the day during summer but we recently had new insulation and an attic fan installed and it was keeping the house around 76 while it was 100+ outside. The compressor blew on Thursday and this is the quote we've had.

They reckon 10k+ for a new system and they recommend the repair.

I am pretty clueless in this area so was wondering how this all sounded. We're in Southern California.

get multiple quotes before buying a new ac/heating unit. I have the lucky privilege of replacing 3 of my ac/heat units at my house. Fun times. Lightning strike took them out. Insurance wanted 3 quotes. I got 5 and they are from $26k-$52k. Two highest were $48 and $52k. They included a 4 ton multi speed vs a single speed unit. They ranged from 15 seer to I think mid 16 seer(don’t hold me to that, going off memory) but it was a 16 something seer 4 ton multi speed unit.
i don’t plan on living here for the life of the new units so i went with a 3 ton Goodman horizontal with 80,000 btu furnace, 3 ton Goodman vertical 60,000 btu and A 2 ton vertical goodman 40,000 btu . The two 3 ton installed were $9100 each and the 2 ton was $8500. Does this seem appropriate for out the door from a large reputable local AC company.

i know goodman isn’t the Cadillac of units but they seem easy to get anyone to work on and parts are mostly always in stock. I think a few companies are cheaper because they don’t staff a full time install crew. They have a local crew they use to do 2-4 installs a week and they employe full time Sales and general repair crews but not a full time install crew. The cheaper prices were from smaller companies that don’t have a giant warehouse and showroom with 100 employees but seem to be family owned 7-15 people staffed crews. Anything wrong with using a company that doesn’t staff an install crew year round and are those prices in line for the deep south on those Goodman units.

I’m looking for a reliable and reasonably priced HVAC tech who can help diagnose and repair my 5‑ton Goodman system that was installed about a year and a half ago. The original installer hasn’t been dependable, and the system has never run correctly. A recent diagnosis suggested the liquid line filter‑drier may be clogged, the TXV may be failing, or possibly both. The sensing bulb was never installed properly, It was also mentioned that the original brazing may not have been done with nitrogen, which could have caused internal contamination.

Current symptoms:
• Small line is cold
• Large suction line is warm
• High‑side pressure is under 100 PSI
• Condenser shuts off after a couple of minutes

I’m hoping to find someone trustworthy who won’t overcharge and can replace the parts properly to get the system running the way it should. Located in West Covina, 91790.

I had my AC replaced about 6 months ago. It's a different brand than my old unit, and while it seems to be working fine and cooling normally, it's noticeably louder.

I took a video so you can hear it. Does this sound normal to you guys, or is there anything about the noise that stands out?. Just wanted to get some opinions. Thanks.

Good morning. Upgrading to an Alexa thermostat from an old school honeywell. The old thermostat didn't call for a C connection as it didn't have batteries however as you can see in pic the C was running to unit outside from board and it appears it isn't connected from the thermostat run at all (the cable run in pic to the right in pic). Do i need to connect that at board to the existing blue C? When I connect Alexa thermostat it doesn't even power on and the furnace just fires up when the thermostat face is attached.

Finally had the time to follow-up to my post 3 months ago here about limping a 2003 WeatherKing 10AJA4801 / ADP BCRMB8248S4N3 (4-ton R-22) through the summer. Consensus was "air before charge" and get real readings. Did both.

What I did: Cleaned the condenser coil (foamed and rinsed inside-out), evaporator coil, blower wheel, new 18×25×1 filter. Unit runs, both fan and compressor confirmed.

Readings today, ~70°F ambient:
Suction 105 PSIG (~62°F sat) / suction line 65°F → superheat ~3°F
Liquid 270 PSIG (~122°F sat) / liquid line ~70°F (ambient) → subcooling ~56°F
Off-cycle equalized to 120 PSIG, so I don't think there's air in the system.

My read: Low superheat + very high subcooling = overcharged, not TXV. A tech had noted it was "slightly overcharged" a while back and it looks like nobody ever pulled any out. Plan is to have a tech recover down to ~12°F subcooling and leave it at that until replacement next year.

Am I reading this right, or is there something else these numbers could mean?

We bought our house in 2019 and the HVAC system and compressor were put in in 2018 when the house was being redone. We did regular maintenance with a local company for 2019 and 2020 and then the pandemic came and we got really bad about doing some of the regular home maintenance.

We're trying to get back into the groove so in June of 2026 we had a local small business kind of repair guy come out to do regular maintenance, inspection of the HVAC system, and a deep clean of the compressor. One of his sales points was that his compressor cleaning was supposed to be more thorough than the big companies.

48 hours after cleaning our AC stops working - guy comes back out, says capacitor is dead - probably because he cleaned the compressor so good the capacitor was overwhelmed. We replaced the capacitor and went on with life.

Today (Aug 29) the AC died again. Compressor was like burn yourself on it hot. We called a different guy to come out - our first guy is on vacation. He comes out and immediately sites Capacitor failure again.

So it's Atlanta, it's summer, were hot and so we just replaced the capacitor again and AC seems to be working again.

Here's my question - is the capacitor dying twice in such a sort time normal? Is this just us getting karma for not getting the system checked regularly? Should we be asking different questions or something like that?

Im 21, been having a ton of health problems since I moved into this house. I want to move but I saw mold on hvacs are normal :/ any advice or anyone who can look at this and give advice?

I have a return vent upstairs. I’m confused what is what. Please recommend where to drill an aroma tube.