Rooftop Units: Advanced Controls Save Energy

Packaged rooftop units (RTUs) are currently used in 37% of U.S. commercial buildings, according to the National Renewable Energy Laboratory, representing about half of total commercial building space. Many of these units are older and less efficient than today's models. However, replacing them can be expensive and may not be an option, especially if the existing unit is still functioning properly.

Advanced rooftop unit controls (ARCs) can be a cost-effective energy-saving retrofit solution. Such controls are designed to optimize the performance of RTUs by improving their operation and reducing energy waste. They achieve this through various innovative features and technologies.

Variable speed drives (VSDs). ARCs often incorporate VSDs, which adjust the speed of the RTU's supply fan according to demand. This allows the system to operate at lower speeds when ventilation-only operation is sufficient, saving energy.

Demand control ventilation. Sensors monitor indoor air quality and adjust the ventilation rates accordingly. By providing the right amount of fresh air based on occupancy and actual needs, these controls minimize energy waste.

Automated fault detection and diagnostics. This feature automatically identifies problems within the unit, such as faulty sensors or malfunctioning components. This alerts maintenance staff of any issues quickly, allowing them to implement timely repairs, improving system reliability and efficiency.

Advanced scheduling and setback. These controls allow for precise scheduling of equipment operation. This ensures a proper balance of energy efficiency and comfort during operating hours while adjusting temperatures to save energy when the building is unoccupied, further reducing heating and cooling costs.

Remote monitoring and control. ARCs typically offer remote access capabilities, enabling staff to monitor and control the unit from a central platform. This allows for adjustments in real-time, quick troubleshooting and easily accessible data for decision making.

The implementation of ARCs can lead to significant energy savings, improved comfort, extended equipment life and lower maintenance costs. The benefits make ARCs an attractive and cost-effective solution for facilities looking to increase energy efficiency and reduce operating costs.