HVAC systems improve indoor and vehicular thermal comfort by providing ventilation, reducing air infiltration, and maintaining pressure relationships between spaces. These systems are important in the design of medium to large buildings, in marine environments to provide safe and healthy building conditions with regulated humidity and temperature control, and in vehicles.
Aluminum vs. Copper
Rising energy costs and increased global sensitivity to environmental issues have caused manufacturers of HVAC equipment to seek out ways to make their systems more efficient. While copper has been their material of choice for decades because it is ductile, easy to join, and offers excellent heat transfer properties, manufacturers are converting from copper to aluminum for several reasons.
Aluminum is an excellent alternative to copper in HVAC systems. Both metals have good heat transfer properties, but aluminum offers a key advantage to copper on a surface-to-weight ratio: a pound of aluminum yields nearly three times as many parts as a pound of copper. For applications where weight is a concern, aluminum is up to 70% lighter than copper.
One of the biggest hurdles in converting from copper to aluminum was the inability to braze aluminum alloys effectively and inexpensively. However, new aluminum alloys offer good brazeability. Alloy 6082, for example, offers good weldability, brazeability, corrosion resistance, formability and machinability make it useful for rod, bar and machining stock, seamless aluminum tubing, structural profiles and custom profiles.
Infinitely recyclable aluminum is not prone to scarcity or fluctuations in commodity prices. There is a potential for saving as much as 35% by using aluminum instead of copper.
In terms of tensile strength, aluminum alloy 6101 is commonly used for bus bars today and has a tensile strength approaching copper. Alloy 6101-T63 has a tensile strength of 27,000 psi and will operate as satisfactorily as copper.
Galvanic corrosion is a common problem with all copper tubing. Aluminum offers excellent resistance to solvents and fuels, but is not recommended for exposure to other types of chemicals, including salt, bleach, acid or chlorine. However, certain specialty aluminum alloys have been developed to provide a higher degree of corrosion protection.
Vehicle makers, in particular, have taken new approaches by using aluminum for structural parts. Steel frames are being shifted to lighter aluminum extrusion frames to provide the support with less weight. Aluminum is now second only to steel as the most used material in vehicles for framing structures, bumpers, suspension, powertrain components, brake/HVAC components, impact protection, cylinder blocks, brake modules, trim and other components.
Hydro Extrusion is North America’s premier supplier of aluminum pipe and tube for virtually any type of application ranging from high pressure and mechanical to architectural and framing. With advancements in aluminum alloys and related technologies, our vast resources and unparalleled technical competencies allow us to produce the most comprehensive line of products in the extrusion industry.
Our HVAC and other aluminum tubing are available in square, rectangular and round shapes in a range of sizes based on the outside dimensions. The tube’s strength is a factor of the aluminum alloy used, the thickness of the walls, and the size of the tube. For expert engineering, design, fabrication and finishing services that will take your product from concept to completion, get in touch with Hydro for innovative solutions.