I need to hook up some new copper air conditioning lines to a split system.I have been told several different methods to achive this? do you use regular plumbing solder? 5% or 15% silver brazing rods ? what type of flux? Is silver solder the same as stay-brite which is the same as regular plumbing solder? I tried to braze copper tubing using a copper phostphorous brazing rod and mapp gas and the result was unsatisfactory.Any tips or help appreciated
Todd
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Replies
HELLO TODD,
BRAZING IS WHAT YOU NEED TO DO AND THIS IS A HIGH TEMPERATURE OPERATION. ANY GRADE OF SILFOSS WILL DO ALTHOUGH 15 % IS EASIER TO USE THAN LESSER SILVER CONTENT. COPPER TO COPPER NO FLUX IX NEEDDED
What do you think of the new mini-split units that have flared line sets? The lines still need to be evacuated, but no brazing, just a couple of wrenches. Sounds a lot more DIY friendly.
Here are 2 responses, first, as from a typical hvac-talk.com 'pro', the second from a diy peerspective.
1. HVAC pro response: Don t quit your day job. Todd, you better hire a good hvac technician, you have no idea what you are doing. You need a EPA license to even open a split system unless you are using 410A - do you even know what 410A is or what R22 is? The tech is going to cost you lots, dont ask how much, hvac site does not allow monetary considerations.
2. DIY response : assume your system is R22, which is EPA regulated. so go online and take a $25 test to get a 609 license which will allow legal diy R22 purchase and work but not for hire (608 if you wnat to hire out). Then, scrounge around, you need pressure gauges, N2, O2, acet. bottles and regualtors and torches. (You need the N2 to be in the lines when they are brazed, 5% is fine for all copper, 15% to any brass fittings). Mapp gas and air torch will not work. Solder fatigues and will crack within a few months and give big leaks. Be sure you have your yellow top recovery tank and evac pump and vacuum pump capable of 500 microns at least. If you cannot follow the reasons for all the above, you also need to spend a 'few' hours reading a few hvac textbooks on superheat, subcooling. You do not need to know the enthalpy table for what it sounds like you want to do, but familiarity with some T-S diagram would help.
BTW, #2 is what I do/did, did take some time to learn, including driving a piston rod thru a piston when an oil slug hit a compressor due to incorrectly sloped lines <G>