This thread is for anyone working on personal projects to share their progress, and hold themselves somewhat accountable to a group of peers.
Post your project, your progress from last week, and what you hope to accomplish this week.
If you want to be pinged with a reminder asking about your project, let me know, and I'll harass you each week until you cancel the service
Jump in the discussion.
No email address required.
Notes -
I'll add a few things that may be too obvious to an expert to mention, but I've found necessary to learn :
Before doing anything involving mains electric, grab an AC tester, and use it on a known live wire to check the battery. These don't detect DC or stored capacitance, but they're really essential for DIYers who might find reason to distrust whoever labelled their circuit breakers. Taking 110v hurts like a mother, taking 220v can lay you on your ass or cause long-term damage, and there aren't no stinking GFCIs here. AC work is the least likely space to zap you, but you really want to get in this habit before you're standing in a bathroom replacing a vent fan.
Disable power to the outdoor unit (usually will have a nearby pull-breaker, but pre-00s units might only have the breaker at your main panel) and discharge the capacitor (even a known bad capacitor) before doing anything to the outdoor unit that gets near the wiring, especially anything that involves touching the capacitor. The Proper way to do it involves a tool with a 1k+ ohm resistor and an LED, but the normal way is to just use an insulated-handled screwdriver and touch every lead to every other lead, which isn't healthy for bigger caps but you're probably gonna replace it anyway. Again, you don't want to take 110v, even 'only' for the short period it takes for the cap to discharge across you.
In many residential units, the capacitor is also used to start the outdoor unit fan: if there's an audible buzzing sound and the fan either isn't working or only works sporadically, 90% odds it's the capacitor, other 10% is the fan... if you get to it soon. If you wait too long, it's both. Guess which one is more expensive and annoying to replace. Those caps will have usually have multiple leads and multiple ratings (eg, 40/10 or 35/5), which means that they run both the fan motor and the compressor motor. Take a picture before removing any leads in general, but especially with these double-check you've got them wired with the right leads on the right rated ends. These seem to be less common in newer residential units?
You can go with a much higher voltage rating for a capacitor without much trouble (>100% over will probably have shit ESR, and it probably still doesn't matter), but avoid large difference (>25% over) in capacitance if you can avoid it, screws with motor efficiency(? power factor?). Either might not be a problem, since caps are only rated +/- 25% anyway, but if it is an issue it'll be subtle. Don't go under on either. You can get customizable ones, but they don't make sense unless you're working for someone renting out a ton of apartments/houses (and I'd argue not even then). Good to know in case someone else working on your house used one, though.
A lot of older (early 90s, sometimes early 00s) indoor units will drain directly outdoors rather than into an actual drain. This is technically against code in most of the US now (not for made-up reasons, esp if you have cats, the 'water' ends up heavily contaminated with ammonia), but however it's set up, make sure to pipe the whole thing out all the way to a major drain pipe and/or the dirt.
Basement units will often have a condensation pump, usually at the end of some PVC (rarely, aquarium silicon tube) coming from your indoor unit. When clogged or where the motor's near-dead it makes a hilariously bad sound. Sometimes can clean em out and reuse, but they're <100 USD at a big box store and <50 USD from online, and if they start to go bad you're probably on the end of a bathtub graph. As above, use an AC tester when replacing them to make sure you turned the power off on the right spot before disconnecting live wires -- I've seen stupid installs where these were on entirely different breakers than the indoor unit proper (and one awful install that was running it on two live phases, wtf).
I've been told to use vinegar for keeping muck out of condensate lines and pumps. Dunno if that's a regional thing, or superstition about ammonia, or just bad advice, but it does seem to work reasonably. Also helps a ton for sump pumps. You can get specialized tabs for these so you have to look at them less, but I dunno if they're worth it outside of rooftop units.
A lot of outdoor units are obnoxiously far from any hose spigots. If that's you and you don't want to buy three hundred feet of hose, there's three options: foaming coil cleaner with a bucket, or simple green and a pump sprayer. Some people will recommend soft brushes, but I've been very hesitant because the fins are so fragile. Don't use a pressure washer on your outdoor unit. No, not even if it's got a 'gentle' setting. Yes, professional shops have battery-powered sprayers that are usable for this safely; they're like 300+ USD and you're not going to use them enough to justify it.
If you buy a used home, check the indoor unit (evaporator) coils. They should be behind a filter and thus need maintenance a lot less often, but especially if you ever had smokers in the house, they get gummed up bad, and a surprising number of people just remove filters and run without them for weeks at a time. Vacuum the intake side, spray with an indoor-safe evap cleaner on both sides of the coils. If it's cooler months already, even if the evap cleaner says it's 'AC-safe', spray gently with water: it's intended to get washed off by condensate, and you don't want to have the stuff sit for six months. This side has thicker fins, so I'm pretty comfortable brushing them with a soft (eg, workbench) brush.
If your indoor unit is getting cool temperatures, but individual rooms are not, check first if you've got dust buildup in vents, any disconnects or gaps in vent connections, and then consider a booster fan. It's stupid, but especially for attics or big houses they're surprisingly useful.
If you're trying to get a garage, trailer, or recently reno'd attic air conditioners, and you're planning to stay with it for a while, look at mini-splits. They're more upfront cost and the install is much more obnoxious compared to the typical window unit (eg, you may need a licensed electrician for the final electrical hookup), but they're amazingly effective and much more useful in winter months. Not always the right option, but worth evaluating. Don't even bother with those stupid on-wheels mini-fridge-style units unless you have absolutely no other option, they're terrible.
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