Careful Where You Put Your Insulation

Fan bearing protection is always a high priority, especially with high-temperature fans. That’s because most high-temperature fan failures happen at the inboard bearing. But why? What’s special about that spot? To understand that, you need to understand some nuances of high-temperature fan design and common mistakes made during installation.

High-Temperature Fan Design for Fan Bearing Protection

High-temperature fans reach heat levels that no bearing should reach. That means you need to incorporate an unobstructed cooling mechanism. The first line of defense is the inboard bearing, located closest to the fan housing, often the first place a high-temperature fan will fail. It’s essential to incorporate fan bearing protection to keep that bearing below the required threshold.

We design our high-temperature fans with two components to help with that:

  • Air slots in the guard surrounding the inlet airflow to allow the cooler outside air in.
  • A cooling wheel between the housing and the inboard bearing, designed with fins that draw the cool air across the inboard bearing and then blow the air out through the slots in the guard.

On face value, the combination of guard air slots and cooling wheel fins provide the appropriate fan bearing protection to avoid overheating the inboard bearing. However, that’s not the end of the story in most installations.

Fan Bearing Protection with Insulated High-Temperature Fans

This kind of fan is often installed in a high-traffic area where fan insulation is common and recommended. The problem that often occurs is that the insulation can get in the way of fan bearing protection if you’re not careful.

It’s easy to install the installation in such a way that it covers up too much of the guard. If that happens, the insulation would block the path for the air to come off of the cooling wheel. Without the cool air successfully crossing the inboard bearing, the bearing will overheat quickly.

The Bottom Line on High-Temperature Fan Bearing Protection

The guard slots are there for a reason. So is the high-temperature fan insulation. Both can work together, but it’s critical that you take care during installation to keep the air slots open, allowing for proper fan bearing protection.

Hear it from an Application Engineer

Senior Application Engineer Chet White demonstrates how to ensure high-temperature fan bearing protection in this less-than-two-minutes video.

When you need to specify a centrifugal fan or blower for your industrial process application, or if you need centrifugal fan or blower maintenance, repair, or retrofit, reach out and connect with one of our application engineers to discuss the details of your project.

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