Customer Brief: Aprilaire

Aprilaire introduced the first evaporative flow-through-design humidifiers in 1954 and has been a technology leader ever since. CFdesign is a vital in their never-ending quest to walk the thin line between too much and too little humidity.

Doing more, Doing it better, In less time

Before purchasing CFdesign software, Aprilaire relied primarily on instincts and experience in the early design stages to project how air would flow through the humidifier.  Prospective designs were tested with plastic prototypes including the water panel inside. Engineers physically measured the amount of airflow through the device. If the measurements did not match Aprilaire’s specifications, design changes were made and another prototype constructed.  Each design, prototype and testing cycle took around three to five days. The prototypes cost approximately $1,000 each to produce.

With CFdesign Tom Anoszko, senior design engineer at Aprilaire, estimates the typical design cycle for a new model of humidifier is reduced by a third, while quality has increased.

“We are able to do many more iterations and use more creativity in our designs early in the design process,” says Anoszko. “Quality is improved because we have more time to do design iterations before committing. When we move forward with a design, we’re confident it is the right one. We have very few problems on the back end, where tooling becomes involved and it gets expensive to make changes.”

Ideal for occasional use

Anoszko says it doesn’t make sense for Aprilaire to have a CFD specialist within the company because CFD isn’t an everyday task. That puts demands on the software to be intuitive enough so that users can get productive with it quickly after not using it for long stretches.

“Any of the three of us might go months without needing CFD,” says Anoszko. “Fortunately, it’s not difficult to get back up to speed with CFdesign after not using it for several months.

Getting the right flow

In a typical simulation a SolidWorks model is launched into CFdesign. A half-inch of pressure is set on one side of the water panel and zero pressure on the other. The resulting 3D images in CFdesign clearly show the air velocity in different areas of the humidifier. The goal is to eliminate pockets of low and high velocity, maintaining a consistent flow throughout the system.

“It’s not a matter of the fastest airflow being the best,” says Anoszko. “Beyond a certain velocity, you end up blowing water off the evaporative pad. You want to hit the sweet spot where you are delivering air across the face of the water panel as efficiently as possible.”

After assessing results in CFdesign, the humidifier model is revised in SolidWorks, and the simulation is run again.  The cycle repeats until Aprilaire gets the results it wants.