Anyone read about the danfoss attack in the EU? Thats some crazy stuff. Could you imagine being the on call guy and having to deal with that? Supposedly they cranked the Temps up to 130* a lot of the places I work have zero backup. Its crazy to think a single hvac controller would be hacked so easily 😆

I am creating an estimate for replacement of 2 furnaces. unsure of the best options to make this work for them. They have a shared return that comes up through a concrete floor, main trunk is 30 x 14 inches and splits into 20 x 24 inches for each furnace, actual hole through the furnace is 16 X 24 inches. 89 kbtuh existing furnace, each furnace has the exact same static pressure measurements. 0.36 inWC when both furnaces running in high speed, -0.15 in the return and +0.22 in supply. Return pressure is only like -0.02 when other furnace is not running. Measurements taken with brand new merv 13 filters in place.

seems like there is plenty return for both furnaces, causing a massively oversized return when only one is running. There is also an individual fresh air connection to each return branch thats like 5 inches.

wondering if a constant CFM ECM motor might help with this?

I can make each return smaller from the split but major ductowork changes is not an option.

" I like Carrier and Rheem"

"Rheem is a yassified Carrier"

"Lennox is literally a minifridge, cant convince me thats a furnace"

"York looks like it bites"

"Goodman looks Jolly, safe, and reliable, like santa"

"Trane scares me"

"Trane is terrifying"

"Trane looks like it would call me a slur"

Was sent to a univent today basically a fan powered heating coil wall mount, maintenance man claimed blower motor was hot and shutoff wanted it replaced, customer supplied parts. Motors wiring diagram confused me so I just ohmed the connections found primary winding and put cap wire on the other lug it ran backwards so I swapped the primaries around. 120v 1/4hp 1ph got it running but I want to understand what the schematic was saying

tldr : whats with these schematics and how to know how to wire it correctly old one was mcquay

How often do you all check your gear? Nothing is worse than being out in the field and waisting time searching for issues that a bad hose o ring or bad micron gauge has caused.
Any tips or tricks you all use to make sure your equipment is in top working order?

Specifically looking for advice from union guys but all feedback, questions, and roasts are welcome.

TL;DR I’m going through a career identity crisis and would like feedback on where my expectations should be. I'm looking into organizing into a union and how that'll go because despite 9 years of experience I have decent gaps in knowledge

Hey fellas, I first started doing HVAC when I joined the USAF in 2017. I was active duty but I stayed at the same base all nine years so I got really good at that installation's equipment. I did go to the Middle East twice to do HVAC, and once to manage the preventative maintenance program for that base.

In general: I'm good at electrically troubleshooting and following a schematic. I know hydronics and can maintain/replace pumps, seals, gaskets, motors, etc. Same with fan motors, blades, and belts. I've installed a couple large expansion tanks

For cooling: I have A LOT of experience on maintenance and repair of FCUs, chillers, DX w/ AHUs, traditional "residential" splits, and geothermal heat pumps. I know the refrigeration cycle and roughly what state refrigerant should be at different points. I know how to measure subcool and superheat. I know how to charge via weight, subcool, (beer can feel lol) etc. One of those trips to the middle east I was installing 1-2 Carrier 410A mini splits every day for almost 9 months. My solder and brazing is solid on 3/4" and gets questionable the larger it gets. I know all the hand tools and techniques for most common jobs.

For heating: I know the basic fundamentals, but I've never even used a flue analyzer or manometer outside of training. I know the basic sequence of operation of purge, gas, ignition, flame sensor, blower, satisfied/post purge.

Where I don't have a lot of experience/knowledge is: (intermediate) heating because where I was stationed we contracted most of it out. I also don’t have any experience with cooling towers or VRF. My controls knowledge is limited to looking at the BAS's telemetry and the inputs/outputs. I've also bound sensors on Trane CGAM chillers and a couple on Carrier and York.

I got out in August 2026 and convinced myself that I wanted to do apartment maintenance because I was sent to work with the dorm management and I was on the admin side but would still do minor stuff before we sent it to the shops. I was wrong lol. Now I'm 2 months in to this job and even though I'm maxing out the pay range for my position ($35.50) it's not enough for where we live and our long term goals. I also HATE going into roach infested apartments EVERY SINGLE WEEK. I follow pest control on the day he comes and I can't do this every week for the foreseeable next few years.

I'm looking into the union near me and organizing in. I'm sure I'll do well if they give me a written test because I'm good at recall, facts, and test taking. I'm a little worried if they give me a practical test involving heating, but I'm not hopeless.

All this to ask: IF I get a chance to join a union, where do you guys think I'd place with what I know. 3rd-4th year apprentice? Journeyman? Thank you in advance!

TL;DR I’m going through a career identity crisis and would like feedback on where my expectations should be. I'm looking into organizing into a union and how that'll go because despite 9 years of experience I have decent gaps in knowledge

I hope any other guys who work on Daikin VRVs have better luck than I have had this week. A 5 head VRV system (Less than 3 months old) with all 4 way cassettes (FXFA36) has decided that the A1P (Controls Board) needed to die in 2 heads (Yes I did replace the A2L sensors first and the A0-17 stayed).... Guess my lead times.... Daikin Applied doesn't even have a part number for that board and my other vendor is showing a MINIMUM 100 day lead time from the factory. So as of this moment I'm praying Daikin approved warranty the whole head just so I can rob the boards out of them.... Better start praying to Krom, Zeus, Odin, Ra, or whoever you believe in yours don't just crap the bed.

I guess at least it's symmetrical:

In a bad spot, customer has no heat and no cooling due to this failed motor, carrier and all ICP suppliers around me are saying that the motor is on indefinite back order… has anyone installed a 6 ton squirrel cage blower assembly in place of the ecoblue?

Has anyone been to this class? If so, what was your experience? It’s $2300 so I would hope it must be pretty good.

VRF leak checks made easy.

Everyone knows about the unethical practices of PE firms buying up family businesses. Would it be possible for the workers to unionize and demand fair treatment not only of workers but of customers as well

Probably every PE guy out there.

https://youtu.be/hqqoo1IgIrU?is=2Sp1Nqx9th6XbuyZ

So what metering device is this system using and where is it located? I believe I have blockage and also a good possibility on non condensable as I can’t remember if we took the nitrogen test off or not… that said, what would happen if I had nitro with some trace gas in a system?

As the title says I’m taking the leap of faith in myself and leaving residential, worked it 2 years and just became burnt out from management pushing too hard, I start next week and would like to hear any tips going into it, i really have no experience working on anything larger than small rtu’s

Hi! I posted probably about a month or two ago asking about union because I didn’t think working for my dad was going to work much longer because I’m trans, and fighting like hell to get my mental health sorted out (adhd and depression). The union called me, and I have a meeting to see where I would place! I’m excited, but I’m so scared to leave my dad’s company because it’s all I know. I would love to get into a facilities gig, but here’s my question. If mornings have always been a struggle for me, would I be better served trying to get into like a 3rd shift gig at a hospital or other critical site? I’ve tried pretty much everything to get myself to function in the mornings, but nothing is working. Wanted to share my win and also ask what the best way to go in my situation was. TIA

I'm tired of having a morning meeting everyday because someone didn't take enough pictures or give enough estimates on their calls the day before.

I'm tired of having a corporate lapdog ride with me every other week for "training".

I'm tired of having to get 3 estimates and 20 pictures on every call or else.

I would say I'm tired boss, but I dont know my bosses name or where he is. Fuck private equity.

Compressor and fan is working smoother than most new systems I see lol.

No birds nest! Just 20 walnuts and a 6’ long squirrels nest! Pipe was 7’ total LOL

I've been changing a few evaporator coils and the process I changed the r410a TXVs to r22. And I have started to notice the grease on aluminum coils. I'm assuming it's some kind of anti-corrosion or bimetal type of Grease. Maybe dielectric

EDIT: This is a brand new r410a coil; exchanging the TXV before installing into a r22 system. The image shown is the r410a txv that came from the factory.