comments:
Hey OP, just trying to share the wealth. I got a 110v mini split system, and ended up purchasing a two-stage vacuum pump on amazon ($190 or so used) instead of paying $200+ for an HVAC company to come out. It was scary trying to figure it out at first, but honestly fairly simple in retrospect, so long as the system you bought is pre-charged. It's pretty much all there in the installation manual. Summary: Attach the vacuum pump to the service port with the correct adapter, turn the pump on, open valves, and let it run for 30 min. Close vacuum pump valves, turn pump off, and watch the gauges over the next hour (or overnight). If your vacuum pressure hasn't budged since you closed the valves, then your lines aren't leaking and should be good. Open the one release valve for a few seconds and then close, putting coolant into lines. Check for any signs of leak. Can't quite remember if after that I detached the vacuum pump first or opened the mini-split valves all the way, but again, it's all in the manual. It's been working great for the past two weeks. I would absolutely recommend owning the tool for ±$200. Even if you totally screw it up, you can just have an HVAC tech come out to seal and recharge the lines for way cheaper than $5k. Honestly, that guy was probably just trying to make a dig at you for buying your own unit. Don't know if they like that people are moving towards diy-able AC systems. PS: even though my run was only like 3ft from the indoor to outdoor unit, I opted to not cut the lines, and just bundled them near the outside unit. Not the prettiest setup, but I think the pre-charge volume might be calculated based on the length of the lines going in and out. Plus, I didn't want to deal with trying to flare the copper tubing. Do be careful when bending the copper tubing that comes with the kit – take it slow, and try to make sweeping bends rather than tight right angles. But honestly, I've had very little issue, other than the frustration of trying to figure it out for the first time.