OT - Window AC Troubleshooting / Repair

oldgeezeystax

Hiya!

I've noticed that some of you that frequent this forum are in the HVAC industry, I was hoping you could talk me through troubleshooting/repair one of my window ac units or let me know if I just need to buy a new one.  The story goes:

We pull our AC units out each fall because Maryland winters can get pretty freaking cold.  This past weekend I dragged the units out of storage and installed them without too much trouble but the one in our bedroom doesn’t seem to be working very well.  Last night was the first night it ran and the fan was extremely noisy at times and it sounds like it’s crunching something (this morning I saw some small ice fragments in the bottom of the fan area), the air also felt more humid than I feel like it should.

 I don’t know much about AC units but the instructions to clean & straighten the fins looks pretty straight forward, could just doing that and some lubrication help with my issues or is there more than that?  I realize this probably isn’t enough detail to really diagnose anything but any help you can provide is appreciated!

Eggcelsior

@nphuskerfl gets paid to do this in real life, unlike most of the rest of us chuckleheads. Hopefully he'll mosey on over soon.

DoubleEgger

If the unit is freezing over, it usually means that the unit is low on refrigerant and/or the coil is dirty. 

johnmitchell

If it was me I would mosey over to the local box store.. Good luck !!!

NPHuskerFL

Window Shakers are typically more trouble than they are worth. But, a fin comb can help in straightening the condensing coil or evaporator coil fins. Several things will cause frost/ice to form like yours is doing. Starting from simplistic and moving forward...Lack of airflow caused by a dirty air filter, dirty evaporator coil, dirty fan blades on the evaporator intake motor's "squirrel cage", evaporator intake motor going bad and lastly a loss of refrigerant. Refrigerant should really be the last thing to look at because it is likely considered a critically charged system because it's so small. Hope that helps.  

Short answer. If you can DIY go for it. If you have to hire somebody like myself just replace it because once you pay T&M it's a wash as opposed to just replacing it. 

Edit: T&M= Time(Labor) + Materials

NPHuskerFL

@Eggcelsior Thanks brotha.

egger ave

Some of the new window units are more energy efficient too. If your old units are more than 5 years old it might be worth it to replace them depending on how you run them them. Some of the split ac units are very efficient too. No duct work to install.

oldgeezeystax

Thanks all!
May as well try a little diy before I send the unit to its little window in the sky. So basically open it up and clean it out as best I can? If that doesn't help, I'll chalk it up to a bad motor or lack of refrigerant as it probably won't be worth tinkering with anymore.

@NPHuskerFL thanks for talking shop, I'm sure it's not the most fun thing for you to talk about... But since we're here have you worked with any of the mini spilt systems (Mitsubishi, Fujitsu, etc.)? My neighbor got a Mitsubishi and loves it but online reviews are all over the place. We have a 1940s cape cod and a mini spilt seems like a decent retro fit option instead of messing with these window units every year.

NPHuskerFL

Yes I've installed and repaired mini splits. They are practical when duct work cannot be installed. We just installed a system with 6 evaporators and one condensing unit. Quite versatile.  Biggest factor is finding a contractor that truly knows how to do it properly and not just 1/2ass it. Brand wise I'd say Mitsubishi