Who can resist the mouth-watering aroma of charbroiled steak, frying bacon or roasted green chilies? Apparently a lot of people can when those unwelcome odors permeate the guest rooms of a luxury resort casino for 24 hours a day. That unfortunate situation confronted the Sandia Pueblo Tribe's Sandia Resort and Casino in Albuquerque, N. M.

After the stand-alone facility added a hotel above the gaming area, they quickly discovered the new rooms were directly downwind from multiple kitchen exhaust fans. Not long after opening, guests expressed their opinions to management. Said Paul Collins, superintendent of facilities, "Guest complaints about food odors from the kitchens stopped immediately after we installed the [air cleaners]. We've also gotten some relief on maintenance, and don't spend nearly as much time on upkeep and cleaning as we used to with the old systems."

New rooms overlook kitchen exhausts

Eleven Smog-Hog pollution control systems have ended guest complaints about kitchen smoke and odors in guest rooms at the resort. Factory-finished to blend with the building’s architecture, the systems also reduced maintenance costs.

The 228-guest room resort operates 24 hours a day Friday through Sunday, and 20 hours a day the rest of the week, so multiple kitchens and restaurants are functioning nearly all the time, only minimally shut down for cleaning and for prepping the next meal. The kitchen exhaust fans and grease catchers installed during the facility's initial construction seemed adequate, but they did little to control odors and required frequent, time-consuming maintenance. The original rooftop units had not been designed with building aesthetics in mind. None of this was a big concern until Sandia added a hotel overlooking this rooftop and downwind from its exhaust fans.

"Our original exhaust fans worked to some extent," said Collins, "but 'some' was no longer good enough, and guests told us." This was because exhaust fans simply pushed odors to another location, rather than remove or destroy them. SRequirements for a new kitchen exhaust air cleaning and ventilation system included odor control, continuous operation, automated cleaning, minimal maintenance and a color scheme that blended with the building's façade. The resort wanted a customized system that could be retrofitted into the existing building structure and operating schedule. 

Down to two choices

Shown on the roof of the resort, the Smog-Hog is a two-stage ESP.

Management had two types of technology to choose from in selecting a new system: an electrostatic precipitator (ESP) or media filtration.

Media filtration systems were available in multi-stage configurations: Cooking emissions would pass through a low-efficiency pre-filter, a slightly higher efficiency secondary filter, and then sometimes a final/absolute HEPA filter to finish off remaining particulates. Odor control could be added to the system using a masking agent sprayed into the exhaust, or with a carbon filter box. However, the media filters, composed of durable blended paper, were likely to clog more quickly with charbroiling and grilling applications, resulting in increased filter changes and susceptibility to fires. Neither cleanable nor reusable, the filters were a major 'sticking point' for the council.

The other option considered was a two-stage ESP, specifically the Smog-Hog from Air Cleaning Specialists Inc., Cincinnati. Within the system, cooking emissions and grease droplets receive a positive electrical charge in the first-stage ionizing section. Next, the fumes enter the second stage, which consists of two passes of grounded aluminum plates, called collection cells. The first collection pass is 95-percent efficient, and the second pass reaches 99-percent efficiency for 0.1-µm particles. A final pass through an activated charcoal section neutralizes any lingering odors. Key to the ultimate decision to go with the ESP was the potential for long-term energy savings because they operate with very low static pressure.

The supplier custom-engineered the system, developing the exhaust-cleaning requirements with the resort's facilities department and kitchen management. This ensured optimum placement of the units for proper roof loading and accessibility for routine service, as well as correct paint scheme and installation/start-up planning. The resort opted for a programmable self-cleaning system, which supplier tailored to run for one hour each day, based on downtime scheduling for the multiple kitchens. Wash manifolds would spray cleaning solution from the top and into the face of each collection pass, using special detergent and hot water tapped from the building's own supply.

The system proved successful upon startup, neutralizing guest complaints along with the odors. The ESPs "are much more effective than our prior systems," said Collins. The wash cycles and operation are all computerized. We only need to do routine maintenance and replenish cleaning solution once a month. The units have proven low-maintenance, reducing costs in that area, and we've also eliminated the cost for monthly filter changes." PE

For more information, visit the United Air Specialists' website at www.uasinc.com.