Hello, I will try to provide as much information as possible. Thank you for your help in advance.

My property is 1425 sqft, 2-story Townhouse. In early June of this year, my outside compressor/unit completely died. I had it replaced, and all was good. Three weeks later, I notice in my utility room, which is where the coils/blower part of the system is, has a bit of water in the floor. I chalk this up to never noticing it before, and that it's probably because it's been extremely hot. I had to leave for 5 days, so I shut the unit completely off. (hindsight, that was ignorant to assume without checking.) I came home, cut it back on, and I've dealt with this for a couple of weeks until now, mopping it up with a towel occassionally. I researched it, and determined that one of the coils had ice on it--not a significant amount, but this is a build up of not being shut off for about 5 weeks straight. It has been extremely hot here in Virginia (Highs in the 90s for months straight.) I googled, and it seems the 2 most common causes are a dirty air filter or inadequate refrigerant levels. I replaced the air filter which indicates it's "up to 90 days" after being replaced 54 days ago. It was dirty, but not what I would consider "extremely" dirty... I could see light through it just fine.

I shut air conditioning off, but turned the fan to "on" to blow air across the unit and defrost it. It only took an hour for the ice to completely melt, and it trickled down into the drip tray, and out of the drain as it should. I then cut the air back on, so I'll see if I have more water when I return home this evening.

I have a few questions:
1: I don't know what dirty coils look like, to mine look clean in the pictures below?

2: Could the combination of a slightly dirty filter and extreme heat cause this? Or should I be thinking refrigerant levels?

3: Bonus. The last 2 pics are a duct upstairs that I have no idea what it is.
No air seems to come out, or in. I would assume it's a return duct for upstairs, but there's never been a filter on it, and it doesn't seem to have ANY air flow ever.

Thank you for your help! I would like to be a little more education if I have to call the HVAC guy back... if it ends up being refrigerant levels, then I am assuming they caused a leak when installing the outside unit, because I saw symptons 3 weeks later?




Question 3:

 

It's hard to say how clean the coils are. Where they collect dirt is on the inside of the A. I believe that the pictures you took show the outside of the coils. Regardless of the temperature/humidity, the system should not freeze up. I would guess that the duct you showed is a return duct. There's no way of knowing, without following it to see where its' connected, whether it's still being used. However, if it's the only return air duct on the second floor, it should be used.

 

Thanks for the reply. I'll inspect the inside of the A and check for cleanliness when I return home first.

If the return duct is being used, shouldn't it have a filter? The grate screws on too, if that indicates it doesn't require a filter. I can't locate any return ducts on the second floor outside of this one.

The temperature difference on the second floor is always significantly warmer than downstairs, even in the winter, I have to use a window unit a/c up there. When I purchased the house 3 years ago, the inspector recommended I have insulation added in the attic, but I haven't gotten around to that yet.

 

Usually, all the returns meet in a central location near the air handler and a single air filter is used, so I wouldn't expect to find a filter on that return. To see if it's "working", with the system on, hold a tissue in front of the duct (parallel with the duct). If there's airflow, the tissue should either blow out (supply), or in (return). Heat rises, so it's always going to be warmer on the second floor. Ideally, it's best to have 2 A/C units, one for each floor. If you have a single unit (most people do), you need to adjust the dampers in the long tube runs to send more airflow upstairs in the summer, and less in the winter.

 

So I checked the coils, and they didn't appear dirty at all. These pictures are before cleaning, but I had a can of cleaner so I sprayed them down good on both sides anyway. I am still getting water from the coil freezing up and then the ice melting... any ideas?



This side is the one getting ice, here's the inside of it:


Also, when finangling/wrestling the cover back on, it accidentally touched some coils and did this... they don't appear to be leaking and I didn't hit them too hard/rough, should I be concerned?

 

Usually, there are two causes of the evaporator coil freezing up: low airflow through the coil, or low refrigerant charge. If you appear to have normal airflow, then the most likely cause is insufficient refrigerant. It's possible that when they replaced the compressor/condenser unit, they didn't add enough refrigerant. When my son had a new A/C system installed in his previous home, it wasn't cooling properly. After calling the HVAC contractor back to look at it, they found that they hadn't fully charged it. After adding more refrigerant, the system started working properly, blowing nice cold air.

 

Thanks Bob! I'll give them a call.

 

Well, I called the company that installed the outside unit. I've used him several times at the recommendation of friends, and he's always been very honest and treated me well money wise. (One time a wire nut had backed off of something and the air wouldn't cut on, he figured it out in 15 minutes, but didn't charge me for a service call, only $20)

He said that since I have the thermostat set on 68-70, and as hot as it's been that I need to bump it up to 72 or 74 and set the fan to "On" instead of "Auto"... Now I realize what this will do: A: Cause the system to run less, B: run the fan continuously which will defrost the ice.

This will perhaps fix the resulting symptom of a problem, but not the problem itself?

 

I'm not an HVAC tech, just a homeowner. However, to my knowledge, an A/C system should be able to run continuously without freezing up. Personally, I think what he told you will mask the symptoms, but not actually solve the problem. In addition, leaving the fan on continuously will have the effect of increasing the humidity in the house, since it will be blowing air over the condensate pan which is full of water (similar to how a humidifier works).

Perhaps if Houston sees this he could comment (he is an HVAC technician).

 

Bob's right, no matter how hot it is, a properly functioning AC will not freeze up.

 

What is the make and model of your unit?

 

Yeah I agree--there is something wrong, I am guessing at this point most likely refrigerant levels. If I call him out, there will be service fee... if they do indeed end up low, I can say "Well, this has been happening since you installed the system 2 months ago." If it isn't that, I have to get whatever it is resolved anyway.

I'll call him back in a couple of days and say it's still doing it on with the thermostat at 72. The high is 81 here today... not 95 & humid like it has been.

 

charliewhiskey--which part? Inside or outside?

Here's a picture of the inside unit if that tells you anything. I can get model numbers for everything if that will help diagnose.

 

Well, I'm praying and crossing my fingers, but I think with the direction here I got it fixed myself. See the picture below... See the gap in the back left? A tremendous amount of air was escaping here, never being blown through the coils, and allowing warm air here, thus causing extreme condensation. 48 hours, and no water in the floor as fixing this... also, the normal condenstation drainage in the EZ Trap is not freezing cold now, back to normal slightly cool temps. The system is now cooling the house better as well.

The posts/recommendations here helping me understand the system is what drove me to find this. Thank you all for your help! I am updating this thread in the event someone later finds it and it can help them.

 

Well, turns out the issue isn't fixed... it just took longer to ice up/drain in the floor. While I was in there cleaning up, I also heard a gurgling sound from one of the lines going into the unit. I went outside, and one of the lines there had a lot of cold water in the foam insulation around it.

I am guessing at this point that it's a refrigerant leak. The company that installed my outside unit is supposed to come tomorrow... I am hoping that it is a leak or just low, caused by them installing the outside unit and it doesn't cost me anything... we'll see.

Thanks for your help guys.