Copper tubing is used extensively in the Air Conditioning and Refrigeration industry (ACR). Copper has a high heat conductivity, which makes it quite ideal for heat transfer applications such as Air Conditioning. It also has the heat transfer effectiveness nearly eight times that of aluminum tubing. For some applications, heat transfer fins are not even necessary. In this case, special arrangements of tubing called tubing coils are needed to save space and maximize the heat transfer rate. Oftentimes, an arrangement in a repeated S-shape will yield a pancake coil, which allows air to move more easily through the coil in order to remove the heat.
The best coils are constructed from a single bent piece of continuous copper tubing. Fittings are certainly acceptable to join multiple copper tubing lengths together, but for high pressure applications like Air Conditioning, a much tighter connection may be required between tubing lengths than just fittings alone. If multiple lengths are required, soldering and brazing may be necessary.
Brazing and Soldering for Extended Lengths:
Soldering involves a significant amount of heat aimed at the fitting against the tube. Heat must be evenly distributed about the circumference of the tube and the fitting, allowing for a consistent join. Combining fittings with tubing by brazing rather than simple thread joining renders the tube contiguous and reduces the risk of leaks. If the coils being used are very long, it is best to use true contiguous tube while avoiding fittings altogether in order to reduce fluid and air drag inside and outside the tube.
Benefits of Using Copper Tubing In Your Coils:
Copper tubing is considered one of the best options for a plethora of applications because of its various benefits, including long term performance, corrosion resistance, large availability of fittings and connectors, and its relatively simple requirements for recycling profitably.