Things people ask us.

Work the air side before the process side, because most of what we see is airflow rather than heat transfer.

Start with the obvious losses. Fouled finned tubes, louvers that are partly closed or seized, bug screens packed with debris, and anything parked under a forced draft unit blocking the inlet.

Then the fan. Blade pitch drifting off spec, worn or slipping belts, missing or damaged tip seals letting air spill back around the blade tips, and fans that were running backwards when the motor started.

Then recirculation. If the air temperature at the fan inlet reads well above ambient, hot air is finding its way back around. It shows up most on forced draft units with low exit velocity on a still day.

Then the process side. Fouling inside the tubes, or a duty that has simply grown past what the unit was sized for years ago.

No. We don't take on new builds. Everything we do is for equipment already in service: finding out why it isn't cooling the way it should, then optimizing it or replacing what's worn.

Building new? Your OEM can still fit the DG-II Anti Rotation Device® and E-Bell™ from day one. We supply both to OEMs.

Effectively a giant radiator for an industrial plant. It pulls heat out of a process by moving ambient air across finned tubes, with no cooling water needed. Air Cooled Condensers are the largest of them, running dry process with fans up to 32 feet across.

Which side of the tube bundle the fan sits on. Forced draft puts the fan below the bundle, pushing ambient air up through the tubes. Induced draft puts it above, pulling air through from the top.

That one decision drives fan power, air distribution, recirculation and how easily you can reach the drive to service it. There's a fuller comparison further up the page.

Neither, in general. Both are covered by API 661 and each trades something away.

Forced draft puts the fan, drive and motor under the bundle where you can reach them and where they run in cool air, so bearings and belts live longer. The fan handles denser air, so it takes less horsepower for the same duty. The trade is weaker air distribution across the bundle and a low exit velocity off the top, which invites hot air recirculation on a still day.

Induced draft gives more even distribution and roughly double the exit velocity, so recirculation drops off sharply, and the plenum shades the tubes from sun and hail. The trade is that the fan, belts and bearings sit in the hot exit air, it takes more horsepower for the same air mass, and the drive is up on the deck when it needs service.

Which suits a given service depends on process temperature, plot space, and what the site can actually maintain.

Shut one fan off and the fans beside it keep pushing air through the cell. That backdraft spins the stopped fan in reverse.

Starting a motor into a fan that's already turning the wrong way causes belt and gearbox shock, blown fuses, and a hazard for anyone working nearby. Nick walks through it on video.

It stops the fan windmilling backwards when the motor is off. It fits the fan pulley bushing, works with QD and TL styles, and with the C-ring it fits any fan shaft that stands proud of the pulley by an inch or more.

Nick Agius designed and patented it under 5,562,418, 2,665,772 and 2,127,726. Fan-Div is the exclusive Canadian distributor.

Air approaching a fan has to be gathered from every direction and accelerated to the velocity at the plane of the fan, and some of it is arriving at ninety degrees to the fan axis. Without a smooth transition, the air can't turn fast enough and it starves the blade where it matters most, out near the tip, where most of the work is done. That alone can cost up to 5% of fan efficiency.

An inlet bell gives the air that transition. The E-Bell™ is the deeper elliptical version, the world's first fiberglass adjustable sectional inlet bell, and it does three things.

It moves more air. The profile prevents vena contracta at the blade tips, so the blade is fed properly where it does most of its work.

It runs quieter. Cleaner air onto the tip means less tip noise, which is why the E-Bell™ gets specified where noise limits are tight.

It cuts hot air recirculation. The bell is deep enough to act as a barrier to air coming back down and around into the fan inlet. Recirculation is a persistent problem on SAGD sites and gas plants, and the bell helps with it without anything extra bolted on.

Fan-Div is the global distributor of the E-Bell™.

Fan-Div is the exclusive Canadian distributor of the DG-II Anti Rotation Device®, designed and patented by Nick Agius, who is now Fan-Div's Founding Partner. Call 1-877-FAN-DIV-1 or request more info.

Fan-Div is the global distributor of the E-Bell™ inlet bell, created by Nick Agius. We supply it for fans already in service and to OEMs building new units.

On an older unit, rule out one specific cause early. Through the 1980s Hudson built forced draft air coolers with two fan ring struts rather than four, on the reasoning that the machinery mount already acts as a strut in the parallel direction. Some of those units vibrate in exactly that direction, and Hudson's own fan engineering group recommends adding the two missing struts. They went back to supplying four on all air cooler fans afterwards.

Beyond that, check pitch consistency blade to blade, bearing condition, belt tension and sheave alignment, and whether anything has been swapped out without rebalancing the fan.

Older fan assemblies should be evaluated based on their condition and design, not just whether replacement parts are still available. Aging cast aluminum blades and hubs, worn or hardened bushings, obsolete attachment systems, corrosion and fatigue can all increase the risk of a fan failure.

A fan failure can cause significant equipment damage and create a serious safety hazard. Simply replacing a damaged blade or component may not address the underlying issue with an aging or obsolete fan design.

Send us the existing fan BOM, spec sheet or photos and we can review and determine whether it makes sense to repair it or upgrade to a modern fan assembly. A replacement fan can also be properly selected and pitched for the actual operating requirements rather than simply matching the existing setup.

The most important thing is not mixing incompatible greases. Grease soap and base compatibility matters, so always confirm compatibility before changing or mixing grease types. A double-base calcium-lithium complex grease can also provide a common grease option for both fan shaft and motor bearings.

Most fan shaft bearings are purgeable. For equipment operating continuously, they should generally be re-greased approximately every 30 days. Regular greasing rounds also give technicians an opportunity to listen to, feel and inspect the equipment while it is running, helping identify unusual noise, vibration, heat or other developing issues before they become failures.

Motor bearings are different. Do not over-grease motor bearings. Excess grease can enter the motor windings and contribute to premature failure, so motor bearings typically require smaller quantities at longer intervals.

Factory grease by bearing brand, intervals, quantities and solid lube: see our ACHE bearing lubrication guide. For bearing selection on vertical shafts, see fan shaft bearings.

They can. Emissions Reduction Alberta's SEMI program lists fan and pump systems, and high efficiency motors with VFDs, among the retrofits it helps fund at Alberta industrial and oil and gas facilities. Two things matter: the project has to be approved before you buy anything, and funding is limited. We work with AWE Solutions, who handle the funding side. Talk to us first and we'll scope the fan upgrade and bring them in.