NVision
NVision, Inc., a leader in 3D non-contact optical scanning and engineering, has worked with the HVAC (Heating/Ventilation/Air Conditioning) industry for more than 30 years. The company has announced that recently, its technology helped major HVAC manufacturers successfully evaluate and confirm the viability of converting copper system components to aluminium, and reverse-engineer and improve the design of air conditioning (A/C) drip pans.
The near-essential nature of A/C makes HVAC a highly competitive industry according to NVision, and affordability is essential to staying alive in the market. NVision says that to address these challenges, some A/C manufacturers are following the example of the automotive industry and converting their copper components to aluminium.
With A/C components, aluminium offers several advantages over copper according to the company. Aluminium is more abundant, which makes it less expensive, it is also lighter, but perhaps more significantly according to NVision, it is impervious to formicary corrosion, which attacks copper and copper alloy tube walls, which creates a network of microscopic tunnels culminating in pinholes and leaks in coils and piping.
One of the principal U.S. HVAC manufacturers wanted to test the viability of converting its copper A/C components to aluminium according to NVision.
“The primary impetus for the proposed conversion was to avoid formicary corrosion of pipes,” said Steve Kersen, President of NVision. “Before greenlighting the conversion, the manufacturer wanted to assess the results of converting to aluminium to ensure that all the parts would meet manufacturing specifications. To accomplish this, the new aluminium parts needed to be precision-measured to a degree that was impossible with traditional measurement tools, such as calipers.
“The HVAC company had done extensive research and understood the high level of accuracy that non-contact scanning brings to part measurement and inspection. They asked NVision to conduct first-article inspections, spot-checking parts from the first production run to confirm that they matched all the manufacturing tolerances.”
NVision engineers began scanning the converted A/C components, which required multiple non-contact scanners, including HandHeld laser and CT scanners. The NVision team measured the system’s U-shaped coils, as well as its casings, soldering joints, and more.
“Our HandHeld scanner has an accuracy of +\- 0.025 mm or 25 microns, which is one-thousandth (0.001) of an inch. As its laser light sweeps across an object's surface, it rapidly—at a speed of 60,000 or more separate measurements per second—collects massive amounts of individual location points on the surface, each with its own x,y,z coordinates and i,j,k vectors,” says Kersen. “The full dataset, or ‘point cloud,’ collected by the scanner comprises literally millions of these measurement points. With this vast amount of dimensional data, we inspected the components against all the aluminum parts in the A/C system, down to the most minute detail.”
NVision says the scanning results confirmed that the new aluminium parts met all of the manufacturer’s specifications, so it could begin to convert it’s A/C parts from copper to aluminium.
The company also worked with a second HVAC manufacturer. This manufacturer was going to modify the drip pans on five of it’s A/C units, but needed accurate CAD models of the current pans to serve as the starting point for the redesign.
After scanning the pans with a handheld laser scanner, NVision engineers used the point clouds to create STL models of each pan’s average dimensions, followed by the creation of 3D models. These were then converted CREO, which is one of the five major 3D CAD platforms according to the company. The manufacturer used these models to make the desired modifications to it’s A/C drip pans.
“I'm proud that our 3D scanning and engineering services played a role in extending the lifespan and improving the design of these A/C systems. Neither of these projects would have been as successful without the accuracy of 3D non-contact scanning,” says Kersen. “You could say that NVision is helping to improve home comfort from A to C.”