Are you familiar with Dedicated Outdoor Air Systems (DOAS)? Unlike traditional HVAC systems that introduce fresh air as part of the conditioning process, DOAS manage ventilation separately from heating and cooling. DOAS, placed as part of a parallel system, can address concerns of indoor air quality (IAQ), temperature and humidity ranges, and energy efficiency.
DOAS are relatively new to the U.S. but are increasing in popularity as IAQ concerns grow and ventilation codes become more stringent. DOAS deliver 100% outdoor air and handle latent loads while a parallel system handles sensible loads. This allows for perfect pairing with a Variable Refrigerant Flow (VRF) system, for example, which does not address ventilation but efficiently moves heating and cooling to every zone. Other common system pairings include chilled beams and fan coil units.
Commercial Applications
DOAS are gaining the most traction in large commercial buildings, like schools, churches, hospitals, hotels, restaurants, and big box retailers as they provide conditioned outdoor air at a low dew point, addressing ventilation and dehumidification requirements for Facility Managers. They also keep the structures properly pressurized, preventing outside pollutants and odors from entering. These facilities are reaping the benefits of improved air quality, greater energy efficiency, and more available space due to smaller system requirements. These advantages far outweigh the potential
disadvantages of higher first costs and complexity.
Benefits of DOAS
- Provides a dedicated supply of 100% fresh, outdoor air
- Prevents moisture-related indoor air quality issues, such as mold and sick building syndrome
- Separately addresses air conditioning and ventilation to save fan energy
- Removes contaminants from outdoor air before it flows into the building
- Increases energy savings
- Allows for the independent control of space temperature and humidity
- Offers the option to downsize zone level heating and cooling equipment, in many cases
Are DOAS Right for Your Project?
Studies have demonstrated the energy efficiency of these systems in large retail stores in New Orleans, Dallas, and St. Louis, yielding an energy savings of 14% to 27% annually. DOAS may be the perfect solution for a large-scale project that needs to boost fresh outside air, improve IAQ, and enhance occupant comfort, especially in the humid Florida climate. Would you like to learn more about these innovative systems? Call a member of our Estimation team.We would be happy to explain how DOAS can make a difference on your next project.
BCH Mechanical has been a trusted name in Florida construction since 1976, delivering innovative design, high quality craftsmanship and excellent customer service. BCH capabilities include HVAC, plumbing, medical gas, piping, sheet metal, LEED, Design/Build, 3D-CAD/BIM coordination, and HVAC service. Visit BCH on the web: www.bchmechanical.com.