In my house in Newton, MA I did not have any single problem with the AC Drain line. Moved permanently in Florida in apartment complex and now AC Drain line clogs about once a year despite I am using anticlog tablets. I came across iFlo device but I cannot use it in my case because it works on gravity and requres a lot more space than is available (height is only 15"). But they gave me an idea. All what is needed - is a small pump and bottle of white vinegar. I have no probldm to create DIY vinegar dispenser and automate it with HE. But I cannot find a reliable and trusted data how much vinegar to dispense and how often this should be done.
Any comments and ideas are very welcome.
I hear you, don't have suggestions but please post updates if you pursue something!
A few years back I moved from PA to FL and experienced the same annual, or even semi-annual clogging. So far the Gallo Gun has worked very well, but I do feel a tad silly for not even having thought of automating a sanitizer.
I guess that's because despite my experiments with both vinegar and bleach I still need the gun. But if sanitizer is applied way more frequently, perhaps this could actually be pretty great.
This project will be DIY.
I already ordered Peristaltic Pump and Contactless Liquid Level Sensor from Amazon (should be delivered in a few days), The controller will be ZEN 17 (I already have few spares). And of course, it will be a related RM Rule. Putting all this things together is not a problem.
The problem is - How much Vinegar (or something else?) should be dispensed and how often. I am trying to find this out but so far did not find any solid and reliable data. All suggestions are very fussy. Unless I will find some good recommendation(s) I guess, I will start with dispensing 100mL of Vinegar every day and see what happens. Unfortunately this will require a (very) long time to see how this will work. I am sure, eventually this should/will work.
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What’s in the tablets that go in the condensate pan and dissolve as water drips into the pan?
It’s possible there’s info available about roughly what concentration of the chemical is expected as it dissolves in the pan. That would give you something to shoot for when creating your own solution out of vinegar.
Alternatively, start low and monitor for a while to see if it’s helping. 5% acetic acid is pretty standard for common household vinegar. If that’s not doing anything, bump up by 5-10% and repeat?
Yes, I saw a recommendations to dissolve these tablets but again, all these info is very fussy.
This is exactly my current plan.
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I pour 1/2 cup of white vinegar down the evaporator drain every month. This is in Louisiana - so similar conditions to Florida. In my old house, the drain was about 10 ft long and never clogged. In my current house, the drain is about 20 ft long. I've stuck with the 1/2 cup.
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Thank you for the info and experience. So far this is most popular suggestion.
In my case the drain line is about 3-4ft long before it connects to the main building ac drain line. I am in big (400 units) apartment complex. The AC is central chilled water with fancoil units in each apartment. Almost on a daily basis somebody has a cloged ac drain line. As of today I am using tablets adding them every 4-6 weeks per ac maintenance guy suggestion. To begin with this is very annoying task and I aready had drain line clogged 2-3 times over 4+ years. Now I am going to automate this task. My current plan is to dispense white distilled vinegar on a daily basis but I still didn't figure out how much. I will start with 50mL/day and see how this will go.
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It is unfortunate that many residents of your complex don't take care of their A/C drain the way you do. I'm really not sure what the right approach in that situation would be. In my opinion, if there's a homeowner's association, or a condo association, they should pay for the drains to be maintained on a monthly basis during A/C season.
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Here in South Florida the AC season is all around a year. The building ac drain line is OK and (I hope) regularly maintained. I was talking about that short runs in each unit. For some reason these short runs are clogging to...o often. But this is clearly unit owners responsibility.
I installed a clear filter housing at the top of the condensate drain pipe just outside the unit's pan. I use this as a sight gauge. I also drilled a syringe access port in the side of the housing and inject 50ml of 50/50 solution of chlorine bleach & water every 3-4 months.
I happened to see the Iflo commercials over the weekend while getting updates on the hurricane and thought I should rig up some automation.
That is a lot of vinegar. I think if you did 100mL per month you would probably be fine. If you want an even better solution then do 100mL bleach per month.
In the past, when evaporator coils were made from copper, bleach worked fine. Copper reacts very slowly with bleach. These days, aluminum is frequently used for coils. And it reacts pretty quickly with bleach.
So I've moved away from recommending bleach - any errors in the HVAC condensate drain installation can result in chlorine fumes being sucked back to the evaporator.
Vinegar works well. An alkaline solution made with baking soda also works. And they're both relatively inert with respect to metals.
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Being cautious is typically not a bad thing. I'll stand by though that 100mL per day is not even in the ballpark of necessary.
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@aaiyar @robl3577 Thank you for the ideas.
The bulding is 50 years old and I have no idea what materials were used for that drain pipes. I did replace the AC unit, so a little piece of the drain pipe in my apartment is a plastic. I decided to use a vinegar because I didn't want to destroy something in a building. I am sure, dispensing small amount more often is better than dispensing a cup once a month. But I am still confused how often and how much to dispense.
Meanwhile my DIY vinegar dispenser is almost ready. I tested a pump and level detector. Everything is working exactly as expected. The controller is ZEN17.
My HVAC guy has always told me to just a few drops of bleach to the drain line a couple times a year. Now I'm confused, isn't the drain line AFTER the coils? need less to say I have never really done this, and never had an issue (North Texas). They usually add something to the drain line during the spring and fall maintenance checks.
The whole air handler on that side of the coils is basically in a negative pressure situation because the fan is sucking air up through the coils. So, since the drain line is down there as well, it is pulling air from there too. That being said, I'd place a large bet that adding bleach a few times per year isn't going to harm it.
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I think you've taken on a cool project and I'm looking forward to seeing the results just because I'm kind of a geek for these things.
What you are fighting is biofilm accumulation. Basically just microbial activity. It takes time for these things to accumulate. If you kill it and flush it through, then you don't need to do it again for at least a month. Let a glass of water sit out on the counter for a few weeks and see how long it takes to start growing "stuff". Well, if you are on city water that may not be a good test because there will be chlorine in the water that prevents microbial activity for at least a few days. Try it with some rain water.
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Spot on. It’s an algal biofilm. And typically string or hair algae.
Another thing for @vitaliy_kh to consider is to use his peristaltic pump to pump in a diluted algaecide. Something like AlgaeFix. I add about 60 mL of that to kill algae in a 600-700 gallon pond. And it clears up the pond in 24 hours. Adding something like 0.5 mL every few days would be able to keep a shared drain line clear of algae.
The only concern with that approach is that the condensate drain should go to a water treatment facility, and not be directly dumped into a local body of water.
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This cannot be mixed with vinegar and must be done separately. Right?
Not sure. I would do it separately.
