Had a contractor install a Central AC unit and he soldered the copper tubing leading from the unit (outside),,into our basement where it connects to our furnace (blower). Is there any industry guideline that still accepts this method of installation. I hear there is a more effective, efficient way of installing this without soldering the pipes
Soldering or brazing is the best way to connect the piping to the units. Most units produced for residential use is designed to be brazed by the installer when installing. Another type of fitting that does not use brazing is Flare fittings. This is when a fitting is put on the copper and the copper is then flared creating a female flare fitting. The other side of the tubing would be a male flared fitting where the two are joined. The result is a reasonably leak free fitting. There is a new type of fitting that can join copper pipes with compression. I can't remember the name of the company that makes them but you have to have a special tool and special fittings for use with that tool. The tool is expensive but seems reasonable but the connections are very expensive and you have to order them, unlike copper fittings that you can get at any HVAC supply house. My concern was being able to get the tool into tight areas which are common on AC units. Because most units are designed for brazing in the first place, you would actually have to braze flare fittings onto the unit before you could connect them with a flare joint. Flare joints are good but not as reliable as brazing. As far as the compression fitting (its not really just compression because the fittings have several parts and you have to apply a chemical and then use the tool) the copper needs to be round and needs the exact sized fitting. It to is not as reliable as brazing and is much more expensive. Answer: Brazing is the most common connection and the most reliable. As far as industry guidelinesbrazing is the industry standard.
How, pray tell, would you properly connect the copper piping without solder? Yes, this is the way it's done. Tip your installers.
Some new systems are in three parts that are already charged with refrigerant and only require the fastening of the tubing to the condenser and evaporator (A coils) with special fittings that as they are tightened they pierce a seal and the system is charged and ready to go. There is no industry guideline that still accepts the soldering ( brazing with silver solder) of copper tubing. It is the only proper effective way of installing the units short of the charged systems that I have mentioned above. Flair fittings can vibrate loose and cause leaks. You cannot use compression fittings as they will also vibrate loose and at high pressures can even come apart.
