Which type of fan, and what model should I use?

 

First, determine which type of fan to use based on whether it is an Open Ceiling, Drop Ceiling (and In-Ceiling), or Spot Cooling application. The In-Ceiling includes suspended clouds and, sometimes, hard lids, too.

Then determine which fan model to use based on ceiling height. The design number used with each fan is the hanging height at which air will hit the floor at a minimum of 100 feet per minute when the fan is operated on high speed. And every ZOO Fan is variable-speed controllable, allowing for precision adjustment.

Because ZOO Fans are the only small destratification fans designed by actual fan engineers, it turns out they perform even better than expected. So whether you’re working with drop ceilings from 8’ to 50’ or open ceilings from 10’ to 140’, there’s a ZOO fans designed for the job.

How many fans?

 

For more detailed information, please click here.

Why variable speed?

 

Even within the same facility, conditions may vary from one location to another, and the same location can change season-to-season, so it’s great to be able to adjust the speed of the fan—or, in the case of spot cooling, it’s important to be able to turn the fan speed up or down because some people like more air than others.

What’s the Optimal Fan Speed?

 

ASHRAE standards suggest that air movement of 40 feet per minute (fpm), or less, is difficult to detect and is very comfortable. At their maximum prescribed height, the terminal velocity of the air column produced by ZOO Fans falls above this range, in the slightly more noticeable, yet still quite comfortable range of 90-100 fpm. ASHRAE standards suggest an upper limit of 160 fpm for people who are lightly clothed, performing primarily sedentary activities. For intermediary ceilings heights or to adjust for localized conditions or comfort, simply adjust the speed of the fan.

Can ZOO Fans Help Earn LEED Credits?

 

YES! Significantly reduce the use of ducting on new construction, save energy and reduce operating costs. Please review our LEED page to see how.

One of your competitors claims your fans don’t work—what about that? Can engineers, contractors and end-users have confidence that ZOO Fans will perform as described?

 

Don’t just take our word for it! ZOO Fans are the only small destratification fans that have performance numbers from third-party testing in an independent, industry-certified laboratory. ZOO Fans’ performance ratings are based on the overall performance of the fan motor in its housing! This is an important advantage of the patented ZOO Fans’ design. Our competitors know this, so to try and make up for their inferior design they quote the performance of their motor only, in free air, not in its housing. Narrowing tailpipes, nozzles, and poorly designed fins and stators can significantly reduce air flow—to appreciate just how much, click here for a comparison. With ZOO Fans’ patented design and third-party performance testing, you can be confident our fans will perform as specified. Guaranteed!

Should the fans run 24/7 or just when the building is occupied?

 

Destratifying an air mass consumes more energy than simply maintaining equilibrium once it is achieved. If you are managing the speed of the fans with a building automation system, setting the temperature differential between floor and ceiling as the driver for fan speed is one way to effectively manage their operation. Alternatively, run the fans on full to determine the minimum temperature differential that can be achieved, then continue to turn the fans down until you reach the minimum speed that will maintain this differential—then “set ‘em and forget ‘em!”

Again, the key is to maintain temperature equilibrium as closely as possible—this will yield the greatest creature comfort and the greatest HVAC savings. Instead of turning the fans speed up and down, running the fans constantly at a lower speed will lower the operating costs of the ZOO fans themselves without impacting performance.

For example, a fan running at 2/3 speed generates 2/3 the CFM but consumes only 1/2 the power. A fan operating at 1/2 speed consumes only 1/3 the power. Another way of looking at it is that running a fan 24/7 at 2/3 speed consumes the same energy as running it for 12 hours on full power; running a fan at 1/2 speed 24/7 is the same as running it for 8 hours on full power.

Once a space is balanced, depending on its use 0.75 air-turns per hour will.

The building has radiant heat, so why would destratification fans help?

 

Radiant heaters end up heating something that re-radiates that heat. In addition, the heaters themselves generate quite a bit of heat. And much of it ends up at the ceiling.

In a tube heater, radiant heat is produced by a steel tube (length from 10-70 feet) that is heated to temperatures ranging from 350-1050°F. In a luminous (high intensity) heater, the radiant heat is produced by a ceramic surface (comprised of varying numbers of ceramic tiles) at 1750°F. Note that infrared heaters are also often called ‘radiant’ heaters.

The infrared energy is absorbed by the floor and objects at floor level, including fixtures, inventory, machinery and occupants, all of which become warm and, in turn, heat the air in the building. And they continue to release heat to the air, even after the infrared heaters are turned off. There could be significant differences in the infrared output, based on the burner material, configuration, operating temperature, mounting angles, combustion air input and reflector design. On average, more than 50% of the heat generated by infrared heaters is convection heat, and in some inferior models the percentage of convection heat is as high as 65%. ZOO fans return this otherwise wasted heat down to the floor, allowing radiant systems to run less, eliminating hot and cold spots, and increasing thermal comfort.

Case study: A Ford dealer in Lexington, KY installed ZOO Fans in their drive-through service area, where they have radiant heat. (You can see a picture of the installation under the “Gallery” tab on our website.) Customers and employees immediately commented that it was noticeably more comfortable. The service manage is pleased with the dry floors, happier employees, and savings of 25-30% on his heating bill.

I understand the value of bringing the heat down from the ceiling in cold weather, but why run destratification fans with air conditioning in hot weather?

 

Great question. Bringing air down from the ceiling during cold weather is intuitive because we all know that heat rises. The benefits of bringing cold, conditioned air to the floor during warm weather, reducing the introduction of hot make-up air, and maintaining constant background air circulation are well-known to HVAC technicians and engineers in hot-weather climates, too.

Most commercial AC systems deliver conditioned air at the ceiling and rely on air handlers/blowers to circulate the cold air, either in a “blast the air to the floor” or a “top-down, flood the upper reaches and push it all to the floor” cooling strategy.   The second the air handler goes off, that nice cool conditioned air stops cold. Boom. We’ve all felt it—no more air circulation.

But wait! Cold air sinks! Indeed, it does, but unless it is pushed downward, this cold air will stall and gradually exchange its cooler, drier characteristics with those of the warmer, moister air mass. By the time it makes its way down to the floor, it doesn’t feel cool anymore.

We’ve all experienced what happens in a movie theater, auditorium or even in larger arenas—it’s cold when the A/C is running, hot and stuffy when it’s not. Once the air handler goes off, you don’t continue to feel cold air from the system. Instead, the air stagnates and the temperature and humidity begin to rise.

Don’t run big, expensive blowers and air handlers to keep the air circulating—let energy-efficient, fractional horse-power ZOO fans do the job more economically and more effectively. Keep temperatures even, eliminate hot and cold spots, and noticeably improve comfort. Reduce the constant on/off cycling of the compressor and the air handler, reduce the introduction of outside make-up air, and noticeably reduce operating costs.

The thermostat stays satisfied longer, and so do the people. And because AC can be so expensive to operate, a reduction of just 10-15% on overall AC costs—energy, equipment, and maintenance—means the savings will add up fast!

Why zoo fans instead of traditional ceiling fans, or even a big fan? Don’t they do the same thing?

 

One way to think about mixing air in a large space it is to relate it to mixing water in a swimming pool. Older pools used to use just one or two points-of-entry for introducing heated water, and you could always tell where they were because people were gathered around them when the water was cold. Modern pool designs call for a number of small diffusers spread over the bottom of the pool. Why? Because it is usually more effective to utilize a larger number of smaller, more efficient mixing points than it is to use one or two big ones. Tornados would be an obvious exception!

In addition, many installations have overhead obstructions that make it impossible to install a big fan, or perhaps the aesthetics of a large ceiling fan don’t fit with the building’s design. That said, if a space is non-conditioned, there are no overhead obstructions, and wind speed is not an issue in your facility paddle fans can be an effective way to provide evaporative cooling. For spot cooling—to provide localized evaporative cooling to a specific work area or to dissipate heat from localized operations—ZOO Fans can be an ideal solution.

I understand the value of bringing heat down in the winter, but what’s the point of mixing that warmer air in the summer?

 

Great question. Bringing air down from the ceiling during cold weather is intuitive because we all know that heat rises. The benefits of bringing cold, conditioned air to the floor during warm weather, reducing the introduction of hot make-up air, and maintaining overall circulation are well-known to HVAC technicians and engineers in hot-weather climates. Many commercial systems bring the A/C into the building at the ceiling and, depending on the design, rely on the air handler to: 1) push the cool air to the floor, often creating drafts and hot-and-cold spots, or 2) flood the upper reaches with cool air in a “top down” cooling strategy. In fact, unless this cold, conditioned air is pushed downward, it will stall and gradually exchange its cooler, drier characteristics with those of the warmer, moister air mass. We’ve all experienced what happens in a movie theater: it’s cold when the A/C is running, hot and stuffy when it’s not. With ZOO Fans, the air handlers run less, there is less hot make-up air introduced to the system, and the constant air circulation noticeably improves comfort!

Why zoo fans instead of traditional ceiling fans, or even a big fan? Don’t they do the same thing?

 

One way to think about mixing air in a large space it is to relate it to mixing water in a swimming pool. Older pools used to use just one or two points-of-entry for introducing heated water, and you could always tell where they were because people were gathered around them when the water was cold. Modern pool designs call for a number of small diffusers spread over the bottom of the pool. Why? Because it is usually more effective to utilize a larger number of smaller, more efficient mixing points than it is to use one or two big ones. Tornados would be an obvious exception!

In addition, many installations have overhead obstructions that make it impossible to install a big fan, or perhaps the aesthetics of a large ceiling fan don’t fit with the building’s design. That said, if a space is non-conditioned, there are no overhead obstructions, and wind speed is not an issue in your facility paddle fans can be an effective way to provide evaporative cooling. For spot cooling—to provide localized evaporative cooling to a specific work area or to dissipate heat from localized operations—ZOO Fans can bean ideal solution.