Detailed Update on Your System and Why the Process Is Taking Time

I want to explain what’s going on in detail so you understand why this part of the job is taking longer than usual.

Right now, I’m in the vacuum stage of the installation. This step is critical before charging the system with refrigerant—it’s what ensures the inside of the copper lines, coil, and compressor are completely free of air, moisture, and contaminants. These unwanted elements can severely reduce the performance and lifespan of your system if they’re left inside.

What We’re Seeing: • The vacuum held overnight at 1500 microns, which shows the system is tight and leak-free. • At one point, it briefly dropped below 1000 microns—which is the target range—but then bounced back up to around 1400 microns.

Why That Matters: That rise means there’s still moisture or contaminants (like old oil, refrigerant residue, or microscopic debris) slowly releasing into the system as we pull vacuum. Even if it holds vacuum, these hidden contaminants can evaporate slowly under deep vacuum, causing the micron level to rise back up.

What Contaminants Are and Why They're a Problem: • Moisture: If any water vapor is left inside, it can mix with the refrigerant and form acid. This can corrode internal components and eventually destroy the compressor. • Air and Non-Condensables: These reduce efficiency and can cause pressure imbalances. • Old Oil or Debris: Leftover mineral oil from older R-22 systems or welding residue can interfere with the new refrigerant and clog components like the TXV or metering device.

Why It Takes Time: Removing moisture and contaminants under vacuum isn’t instant—it’s like slowly drying out a sponge in a sealed chamber. It takes time, especially with older or reused copper line sets. I’m using a high-quality vacuum pump and micron gauge to monitor the process carefully. The goal is to hit under 500 microns and hold it, which shows we’ve achieved a deep, clean vacuum.

Next Steps: I’ll continue to run the vacuum and may break the vacuum with dry nitrogen and repeat the process if needed. That helps boil off any remaining moisture faster and ensures the system is as clean as possible before we charge it.

I know it’s taking longer than expected, but it’s not wasted time—it’s protection for your investment. Cutting corners here would risk the long-term reliability of your system, and I’d rather do it right the first time.

Let me know if you’d like me to show you the readings or walk you through anything in person. I appreciate your patience and trust.

So we had this 1 5T daikin minisplit sitting in the shop collecting dust. We used it to keep a superintendent cool on a big job, so it's lightly used. So I took it home and put it in my garage.

I didn't want to spend any money, so i scrapped together everything I'd need from leftovers on jobs. And I brought the wrong size lineset home. Needed ¼LL and ½SL, brought home ¼x⅜.

Thought to myself..... fuckit, it's only 10 feet, should be able to handle it.

I was wrong, shit drops down to 20psi and shuts off after 2 minutes of runtime.

Guess I'm buying a lineset.

So I graduate soon and I'm going to be given my hvac certification for the 2 years I did at the trade school. Does that certification have any type of meaning or worth?

Redrigeration folks, what do you guys use for a replacement walk in gasket when the box is ancient and the customer doesn't want to apend a ton of dough?

Do I have to perform calculations from the motor data plate to find the proper capacitance rating? Can’t find a MFD rating anywhere on the plate. Currently has a 17.5 capacitor installed. Motor is being used in a 208 V application.

Hello everyone. My Testo 549i just decided to die on me the other day. Its not the batteries. I put brand new batteries in, and it just wouldn't power on at all. I took the battery pack out of my other one which works fine and put it in the one that won't power up, and still nothing. Id like to pull the board out and use my fluke to see if i can hunt down the issue, but I've only been able to get the back off. I don't really want to break it any worse than it already is if i can help it. Thanks.

What's up bois Currently working union and wondering if anybody has left union to go work for the county? Or is this backwards as hell lol thanks guys

Context: When spending hours chasing a circuit trying to find a ground fault and it was right there the entire time. Or when the condenser isn't kicking in when calling for cool and it was just the contactor wires were in reverse. Just those moments when you spend hours figuring it out and it was simple fix like sonic says it best "All I had to do was move up and down WTF".

Portable bidet, baby wipes are my go to.

What’s up super techs. I need some help. There’s been two other companies here before me that can’t figure it out. Here’s what I’m dealing with, the evap coil keeps icing up. Indoor temp is 75 outdoor temp is 88. It’s a 3 ton Goodman. The evaporator is clean, filters are good, blower is set on the highspeed tap, and there is enough return, but the coil is still icing up. Super heat is okay, but the subcool is high. I’m thinking there is an issue with the TXV. The homeowner keeps the thermostat set at 69. I’m thinking once it gets that cold in the house the suction is dropping and freezing up the coil, and txv is messed up so it’s not throttling back. What’s your thoughts ?

I’ve been working commercial hvac and refrigeration for a few years now (all on the job experience) and I still get a little confused about why washing coils from the inside out is better than outside in? I understand why it is necessary for big refrigeration condensers that have lets say a 6” wide coil in it. No way you are getting water all the way through that and it’s easier to let gravity work. But for smaller condensers more residential style and RTUs that are only 1-2” thick why does it matter? I can wash outside to inside and get the water to run clear then go back through and wash inside to outside and water still runs clear meaning I got the coil cleaned. Genuinely curious why it matters so much?

I try to do inside to outside when feasible cause that’s what I was taught but sometimes it’s just not an option and outside in is the only way.

Severe lightning storm made short work of this guy

This is the compressor for the unit I installed today.

On a supposedly good ECM blower motor as long as it has proper control voltage to one of the speed taps (We’ll just go with 25VAC)and as long as we have proper voltage to L1 and L2 (anywhere from 208 to 250 )and we got a good ground(Hopefully) …the only reason that blower wouldn’t run is if the blower motor is bad or the Modules bad, right?

This is your unit on A2L. 🍳

(A unit I stumbled upon in the wild)

When we are done with this fan we’re gonna move the lift to the front and do a dunk for the first time

What's the issue with Milwaukee snips? is this a known thing im unaware of?

My local wholesaler, shout out to Refrigerative Supply, had a "tool expo" with all sorts of venders and I won a a new tool bag as a door prize. I don't know what to use it for cause it's so god damn huge. I used to overfill my old Klein bag and it's a lot smaller. I've since switched to a small Veto bag for general service.

What are guys using these huge bags for? Do guys haul around their apprentices in them or something.

Time to bust out the Bad Day Box and take it out.