Mini split and humidity

[46MGTC]

I've had a "no name brand" 18K mini split in my detached garage for about 9 years. It's been working fine considering what it is and what I paid for it.
Just the last few months the humidity in the garage is through the roof (this morning 89%) but the temperature is pretty much as set on the control panel.

The unit is called Ambiance Eco-Green and is a 17 seer inverter type. They are no longer in business. If there a typical failure mode where the humidity is not controlled but temperature is? Or have I got my nine years out of it?

It's been very humid here recently but I suspect no worse than some previous years.

I should add that I've looked at the condensate line outside and there is water dripping from it.

 

[finn]

Drain tube from the head unit is probably plugged. Disconnect it and team or blow it out.

Disconnect from the head end. There’s probably a trap where junk has accumulated, impeding condensate flow.

 

[Trey T]

If you can select the fan to run low instead of high, you'll get maximum humidity removal. Keep in mind, if you have air leakage, or too much air leakage, the system won't be able to keep up to provide adequate humidity removal.

 

[eddieK]

dirty coil...

 

[tyme2par4]

I would start by cleaning the coil and any filters, as well as the condensate line.
Most of the newer units have a "DRY" mode that functions as a dehumidifier. If you don't have that mode available, set the fan to low and on all the time.

If you are still maintaining temperature, it doesn't sound like there's anything functionally wrong with the unit.

 

[46MGTC]

Thanks for the help so far. I did find and turned on the dry mode and that dropped the humidity to about 55% but also dropped the temperature. When I checked in the morning after running all night it was 59 degrees in the garage. A bit too cold for me!

I cleaned the filters, blew out the coil with compressed air and blew out the condensate line. Another check in the morning it was 66% RH with the temperature set at 74F.

Is there a better way to clean the coil other than just air? Anything I should check on the outdoor unit?

 

[rlitman]

I use a foaming coil cleaner. It rinses itself clean with condensate. Spray it so that it foams into the space, and not over it.

As for cleaning the filter, while that's a good idea, it won't help with humidity. Might even make it worse. You get more dehumidification with less air flow over the coil.

 

[eddieK]

Thanks for the help so far. I did find and turned on the dry mode and that dropped the humidity to about 55% but also dropped the temperature. When I checked in the morning after running all night it was 59 degrees in the garage. A bit too cold for me!

I cleaned the filters, blew out the coil with compressed air and blew out the condensate line. Another check in the morning it was 66% RH with the temperature set at 74F.

Is there a better way to clean the coil other than just air? Anything I should check on the outdoor unit?

Evaporator coil cleaner

 

[46MGTC]

OK, just finished pass 1 of cleaning the indoor coil. That was after figuring how to crack the thing apart. I used a hand pump sprayer coil cleaner product and caught the contents of the condensate line. Pretty disgusting how black the liquid was that I captured. Been rinsing for about 20 minutes and still getting dirty water. I also bought a can of the foaming stuff and may just hit it again.

Too hot out to deal with the outdoor unit today.

 

[Jackfre]

Spray the blower wheel with the cleaner as well. I use a heavy plastic sheet and a large trash can to collect the sludge.

 

[SouthLake]

Remove the blower wheel. This will make cleaning the unit 100X easier and you will be able to clean it much more thoroughly. Pay special attention to the drip tray and how gnarly it is.

 

[46MGTC]

OK, I'm a moderately handy guy working on a couple of old MGs and general DIY. I've been looking at the front of this indoor unit and all I see is a forest of fins. There is an electrical box/ display panel on the right side and a bunch of soldered tubes on the left. I don't see any way of taking it apart to get behind the fins as they extend up to almost the very top of the unit. I can see the drip tray and I did clean some ****** from it.

How would you take this apart without disturbing the lines? There is apparently no service manual for this thing.

 

[SouthLake]

you should be able to remove the drip tray, and a few (4) screws that hold the coil allowing it some movement. then you look up at the wheel there will be a set screw, with a very long phillips driver, remove the set screw, and the wheel will come out as you gently lift the coil (only need an inch or so). this is the video i used, it was very helpful

 

[46MGTC]

Thanks for the info and the video link. I'll try to get back into this on the weekend.

 

[SouthLake]

I want to install a minisplit to use while im cleaning my mini split. Like you i decided to do this during the summer. it was a sweaty grotesque reminder of why i got the unit and how much i appreciate it. but we should really be doing this in the winter time lol good luck please report back