High occupancy spaces pose a particular challenge, because sensible and latent loads do not peak at the same time. In most climates, the result is elevated indoor humidity at part-load conditions, and the right combination of cooling capacity and supply airflow may not exist in “off the shelf” packaged air conditioners. These problems with constant volume, mixed air systems can be overcome by designing it as a dedicated outdoor air system, and integrating a Trane Horizon Outdoor Air Unit.
By dehumidifying outdoor supply air before it is delivered to the interior space, latent loads are greatly reduced, providing optimal comfort and promoting energy efficient operation. Case studies have demonstrated that dehumidification has substantial preventive power. For the average high rise, a dedicated outdoor air system can potentially prevent thousands of gallons of water from entering the structure every month.
The highlight of the Horizon series expansion is the introduction of the 10- to 30-ton, 7000 CFM capacity OAG model Outdoor Air Unit. The product of a strategic redesign, it boasts a compact footprint, up to 30-percent smaller, and a sleek 61-inch cabinet profile up to 33 percent shorter, while still offering the highest heating capacity of any comparable unit on the market.
The reduction in cabinet size facilitates its use in retrofit and renovation applications, and the shorter profile makes it ideal for municipalities with code requirements regarding rooftop equipment installation aesthetics. These successful cabinet configuration upgrades are also rolling out across the entire Horizon OAU series.
The Horizon family of products also includes a complete line of Make-Up Air Units, a legacy technology that remains an essential approach to supplying fresh ventilation air to commercial and industrial facilities for which dehumidification is not a critical factor.