Trying to Provide Humidity Solutions
As most vendors would agree, historically, packaged equipment has been selected to control temperatures within a building, but the dehumidification capability of “off-the-shelf” rooftop equipment was assumed to be somewhat fixed based on the unit’s sensible heat ratio. Today, many vendors will tell you the market wants competitively priced packaged equipment that can respond to temperature and/or humidity space demands.
As one manufacturer put it, one of the greatest design challenges is to maintain comfort, including indoor humidity, for occupants year-round. The challenge becomes increasingly difficult since some occupants tend to have different comfort thresholds. This design challenge is further complicated if occupancy levels are highly variable. The sensible and latent heat removal required from the space thus varies and requires a system that can adapt.
LOOKING TO HELPAprilaire (www.aprilaire.com), for one, offered one new solution. It announced the redesign of its small bypass humidifier, the Model 550. The new unit has been renamed the Model 500. According to media relations manager Nikki Krueger, it features a modern design, similar to the Model 600; uses the same No. 10 water panel and has the same foot print as the Model 550; has quick, reversible housing, as no tools are needed for left or right discharge; and it has a reversible nameplate.
AxAir Nortec Ltd. (www.humidity.com) introduced and featured more than a few new humidity control products. On display were its NHSC, a resistive element humidifier; SETC steam exchange humidifier, designed for facilities where pressure steam is available from a boiler; and SAM-e short absorption manifold, designed for humidification applications “where the shortest possible absorption distance is required,” said the company.
On the residential side, the company introduced its Resdelux electrode steam humidifier, designed for home or condo use. It employs electronic technology designed to deliver up to 8 pounds per hour (23 gallons per day) of steam humidification, said the company. Also featured were its GS Series gas-fired humidifier; high-pressure nozzle humidification system, specifically for use in air handlers and ducts; and the NHTC electrode steam humidifier.
Bry-Air (www.bry-air.com) introduced its MiniPAC, designed specifically for small facilities “in need of reliable humidity control or mold and mildew protection,” said the company. It said its new unit, which “combats the effects of moisture in up to 8,000 square feet,” can be used in a variety of applications, including colleges and universities, restaurants, and libraries.
The 350 unit includes permanent, washable filters with removable access panels, front-mounted performance lights and test ports, round duct collars with hand-adjusted volume damper, and a desiccant rotor. No drain lines or water buckets are needed, said the company. It said humidity is automatically removed through an air duct, similar to a clothes dryer.
MEETING DESIGN CHALLENGESCarrier (www.carrier.com) specifically said it has a new product to address all design challenges. It said its new Humidi-MiZer™ adaptive dehumidification system is designed to provide flexibility and humidity control. Unlike a traditional reheat system, the company said its system derives more refrigerant subcooling from the combination outdoor and Humidi-MiZer coils. As the refrigerant entering the indoor coil is much colder than normal, the temperature of the indoor coil is well below the entering air dew point, which allows more water to be removed from the air, said the company.
“It’s not merely a reheat unit,” explained Ron Woodstock, product business manager, Light Commercial Systems, North America. “We’re actually dropping the indoor coil temperature to get more water out before the reheat. That’s a very key attribute to the performance of this unit.”
According to Woodstock, the Humidi-MiZer allows for multiple modes of operation for the rooftop unit. He said these modes are: a standard cooling-only mode, a cooling mode with a minimal amount of reheat; a cooling mode with full reheat; or a combination of these modes if the unit is equipment with multiple refrigerant circuits.
Dectron (www.dectron.com) introduced its DS-803, which it described as the “industry’s first mechanical heat recovery dehumidifier targeted at the booming indoor water park market.” Harry Topikian, vice president of business development, said the unit is a complete IAQ system that heats or cools water park spaces up to 36,000 square feet from a single unit, “while also efficiently recovering heat to produce free pool heating.”
Besides dehumidifying to a “comfortable 50 percent relative humidity,” Topikian noted that larger facilities can combine multiple units via Dectron’s proprietary microprocessor-based Supervisaire® controller/monitor, which he said are compatible with most building automation system protocols.
Desert-Aire Corp. (www.desert-aire.com) reintroduced its ExpertAire™ Series dehumidifier, a unit that the company said replaces several of its product lines, including its IH, WC, PD, and PDW products. Available in 1 to 15 tons, the unit is designed to dehumidify industrial, commercial, and residential applications, including pool rooms and libraries, manufacturing plants, and water and wastewater treatment plants.
One major improvement is the standard offering of R-410a on all sizes. Another enhancement is new coils using rifled tube and lanced fin design. According to the company, this yields more moisture removal capacity with a lower pressure drop for the blower, “providing an optimized moisture removal efficiency (MRE) value between four and six,” it said.
EXPANSIONS AND MOREDri-Steem (www.dristeem.com) announced the expansion of its XT Series electrode steam humidifier product line. According to marketing communications manager Richard Boyum, the humidifier line has increased its capacity to 200 lbs/hr. and staged (multiple-unit) maximum capacity to 400 lbs/hr. Existing models are now available in more voltages, and there are two new steam blowers allowing steam distribution in open finished spaces, noted product manager Kathryn Gaskell.
“XT Series humidifiers provide cost-effective steam humidification for use in commercial and large residential applications,” said Boyum. “Low up-front costs, minimal maintenance requirements, and efficient steam production make this humidifier one of the most affordable humidifiers to buy and operate.”
Among the innovation awards presented at the AHR expo, Munters Corp. (www.munters.com) earned an honorable mention for its HCU water source heat pump. According to the company, the desiccant wheel is reactivated with wasted heat from the condenser coil, “making it the most efficient means of removing humidity.”
Munters also featured its DryCool home dehumidifier. A dehumidification wheel downstream of the evaporator coil is designed to remove additional water from the airstream in a vapor state. In addition, the dehumidifier uses a “unique arrangement of two airstreams to accomplish the task of providing cool, dry air at high efficiencies,” said the company.
Skuttle (www.skuttle.com) featured its flow-through, drum, and steam humidifiers. At its booth, representatives informed expo attendees of the need for humidification in a home. In a company brochure, it stated, “More and more homeowners are realizing that, during the winter months, they live in a moisture-deprived ‘sick house.’ … Proper home humidification reduces static electricity, revitalizes dry skin and scratchy throats.”
“The product has been improved with better access with the hanging rods moved away from the access panels,” he noted. “There are a number of air path configurations for both the evaporator and condensing section that can be field selectable using standardized panel sizing.”
Refrigerant options are available for both R-407C and R-410A. Units with R-410A can have two-speed compressors up to 5 tons capacity. “Splittable single-package units are possible due to the use of re-sealable refrigerant fittings,” explained Beever. “These allow the units to be split without losing the refrigerant charge for installation, and then reassemble once the two sections are in place.”
In retrofit and replacement projects, Beever noted that this comes in handy when the evaporator needs to be located close to the conditioned space and the condensing section located close to an outside wall.
The company also featured its dedicated outside air systems, under the Thermo-Air label. It is a self-contained, water-cooled, vertical, 100 percent outside air system, designed for use in hotels, hospitals, schools, and retail spaces. Beever said the company expects to begin production of a horizontal unit/system later this year.
Williams Comfort Products (www.williamscomfortprod.com) introduced the Sponge, a total-space dehumidifier for residential and light commercial applications. The dehumidification system is designed to improve comfort levels, protect furnishings, and help prevent the growth of mold and other contaminants. Installed as either part of the heating and air conditioning system or as a stand-alone unit, the company said its product operates automatically as dehumidification is required.
Publication date: 02/19/2007