Improving indoor comfort while conserving energy has always been a priority for commercial spaces. In the past, tightly sealing buildings to prevent air infiltration was a common approach. This helped maintain the indoor temperature and reduced energy use. However, it came with unintended consequences, as occupants began experiencing dry coughs, headaches, and other health issues due to poor air quality from trapped contaminants.
The focus shifted to addressing indoor air quality by introducing fresh air from outside while controlling energy costs. This change led to the adoption of Dedicated Outdoor Air Systems (DOAS) as an effective solution for enhancing indoor air quality. Here is how DOAS can make a significant difference in commercial spaces.
What Is a Dedicated Outdoor Air System (DOAS)?
Despite its name, a Dedicated Outdoor Air System is not designed to improve outdoor air quality. Instead, it is an outdoor unit that filters, dehumidifies, and treats outside air before introducing it into the building. By acting as an air filter for the HVAC system, a DOAS ensures that the air entering the building is clean and free from outdoor pollutants.
Traditional HVAC systems often need help processing large quantities of outdoor air due to the added humidity, which can lower their efficiency. A DOAS addresses this issue by conditioning the air before it enters the indoor space, optimizing energy consumption and minimizing moisture-related problems. When used with an indoor HVAC system, a DOAS significantly enhances indoor air quality, reduces energy usage, and prevents excess humidity.
The Role of Proper Ventilation in Indoor Air Quality
Ventilation is essential for maintaining healthy indoor air quality, especially in occupied spaces where carbon dioxide (CO2) levels can rise quickly due to human breathing. While outdoor CO2 levels typically measure around 400 ppm, levels in crowded indoor environments can spike to 2,000-5,000 ppm. These elevated levels can lead to discomfort and adverse health effects without proper ventilation.
A Dedicated Outdoor Air System helps maintain low CO2 concentrations by continuously supplying fresh, dehumidified air into the building. This ensures that air quality remains healthy, supporting the well-being and productivity of occupants.
Decoupling Ventilation with DOAS: A Smarter Approach
A vital advantage of a DOAS over traditional central ventilation systems is its ability to “decouple” ventilation from temperature control. A central unit handles temperature regulation and ventilation in conventional HVAC setups, mixing outdoor air with recirculated air. This approach often needs to distribute fresh air evenly throughout the building.
A DOAS separates the ventilation process from temperature control, allowing fresh air to be delivered precisely where needed. This decoupling ensures that only occupied areas receive ventilation, resulting in energy savings in low-occupancy spaces. Additionally, it provides better control over indoor air quality by evenly distributing fresh air.
Furthermore, a DOAS efficiently handles the energy-intensive task of conditioning ventilation air, which can be challenging for standard systems during extreme temperatures or high humidity. A DOAS works alongside the HVAC system to maintain optimal temperature and humidity levels, promoting thermal comfort and healthy air quality by focusing on primary dehumidification.
Leveraging Advanced Technology for Maximum Efficiency
Dedicated Outdoor Air Systems use state-of-the-art technologies to enhance energy efficiency and air quality. Most DOAS units are packaged direct expansion (DX) systems with variable-speed or multi-stage compressors. This setup allows for precise temperature and humidity control, adapting to the building’s needs and optimizing energy use.
Many DOAS units incorporate energy recovery components like enthalpy wheels, heat exchangers, and hot gas reheat systems to further improve efficiency. These technologies recover energy from exhaust air, making the overall system more efficient even in harsh conditions. With these advancements, DOAS units ensure that buildings remain comfortable and energy-efficient while maintaining high indoor air quality.
Conclusion
With growing awareness of the health effects of indoor air quality, many facility managers and building owners are opting for Dedicated Outdoor Air Systems as a solution. DOAS improves air quality and supports energy-efficient operations, making it an ideal choice for sustainable, healthy commercial spaces. By decoupling ventilation from temperature control and utilizing advanced technologies, DOAS provides a comprehensive approach to ensuring thermal comfort, enhancing air quality, and reducing energy consumption.
Investing in a Dedicated Outdoor Air System is a smart move for businesses aiming to create a comfortable and healthy environment. Contact DRI Rotors to discover how a DOAS can help make your commercial space more energy-efficient and inviting.
