Applications
Seresco OA Series Dedicated 100% Outdoor Air Dehumidification System (DOAS) complete with WebSentry® Internet Control.
Most local codes have adopted ASHRAE Standard 62s outdoor air requirements for improved air quality in facilities. During humid times of the year significant amounts of moisture would be introduced to the facility from this outdoor air. Traditional air conditioning systems are not able to deal with this moisture load and consequently the space IAQ can suffer from the resulting higher Relative humidity levels that promote mold, mildew and virus growth.
Dehumidification of the outdoor air prior to its introducing to the space is the most effective and energy efficient means of treating outdoor air. A dedicated outdoor air dehumidification system (DOAS) is used for this specific duty to deliver a neutral dew point condition of 50-55°F with a supply temperature of 70-75°F.
Seresco’s OA Series of DOAS units have been designed specifically for outdoor air conditioning. They dehumidify the humid outdoor air and provide precise dew point control during peak summer loads as well as part load conditions. The off peak performance of a DOAS unit is at least as important as the peak condition performance as this is when the air conditioning system cycles and has virtually no latent (moisture) removal capabilities. DOAS units have to be able to deliver dehumidified and reheated air year round.
The Seresco OA Series DOAS units have been designed with environmentally friendly R410A refrigerant and to deliver truly neutral air to the building or HVAC system. Once the air has been cooled to satisfy the dehumidification requirement it needs to be reheated to a neutral comfort condition. The OA series unit use compressor waste heat to accomplish this. Hot gas reheat helps designers comply with ASHRAE’s Energy Conservation Standard 90.1 which requires that systems cannot use new energy to reheat the air. Using new energy to reheat air in order to keep from over cooling the space is a significant operating cost penalty for the operator.
Seresco OA series units efficiently control the supply dew point and supply dry bulb temperatures using adaptive control strategies combined with sophisticated electronics and the latest in internet technology, Seresco is the only company that can monitor 24/7 every unit sold through an internet connection on the unit. All operation of the units is monitored. Any changes in component performance can be spotted from trending graphs. Possible component failures will be detected even before they happen and corrective action taken before the customer can experience any equipment downtime.
The Seresco OA Series are available as vertical (up to 13 HP) and horizontal indoor splits systems, geothermal loop cooled, cooling tower loop cooled or as outdoor packages. Units up the model OA-014 will pass through a 30” doorway.
The units have an optional night time recirculation mode to help maintain space RH levels during unoccupied hours. Units can be equipped with recirculation/outdoor air mixing boxes on the inlet and have several occupied periods can be set up at the keypad.
The indoor split units have the compressors in the air handler and do not use condensing units. Keeping the compressors inside the indoor portion of the system increases the system reliability while significantly simplifying the installation and the refrigeration system complexity.