First-Cost Savings With Underfloor Air Distribution

The Benefits of UFAD Systems That You Can Take to the Bank

In the quest for more efficient and adaptable building designs, underfloor air distribution (UFAD) systems have emerged as a promising alternative to traditional overhead (OH) HVAC systems. Two comprehensive studies – one by the Center for the Built Environment (CBE) at UC Berkeley and another by Global IFS and Dynamic Systems Inc. – provide valuable insights into how UFAD systems can save on first costs while offering a variety of operational benefits.

In this blog post, we’re going to explore the findings of these studies and the cost-saving potential of UFAD systems.

Analysis from the Center for the Built Environment

The CBE study provides a detailed analysis of the first cost trade-offs between UFAD systems and conventional OH systems using a cost model that compares the two systems across various parameters. This study focuses solely on a UFAD system using fan-powered UFAD boxes (similar to Price’s FDU) ducted to floor supply grilles (in the style of Price’s LFP and LFG models). This solution is still used today, though it’s becoming less common with the evolution of perimeter heating and cooling solutions, such as the LNT, LFT and LCT from Price.

Cost Model Insights

The model evaluates first and life-cycle costs, focusing on nine categories, including HVAC systems, electrical systems and raised floors. It finds that UFAD systems generally have higher first costs compared to OH systems, with a cost premium of approximately $3.50 per square foot.

However, the study goes on to explore various factors affecting costs, including building geometry, HVAC configurations, and material and labor rates. It finds that UFAD systems can, in fact, achieve cost savings under certain conditions:

• Reduced Airflow Rates: Lowering the design airflow for UFAD systems can lead to significant cost savings. The study shows that reducing the perimeter heating airflow rate by up to 30% can bring UFAD systems close to cost parity with OH systems.
• Modular Wiring: Implementing modular wiring solutions – a common option with Price UFAD systems – can reduce installation costs and improve flexibility. The study highlights that modular wiring can save on labor costs and simplify future modifications.
• Building Geometry: Factors such as floor plate size and wall thermal quality can impact the cost-effectiveness of UFAD systems. Larger floor plates and better wall thermal quality can reduce the cost premium of UFAD systems.
• High-Quality OH Systems: When compared to high-end OH systems, UFAD systems can offer substantial savings. The study indicates that UFAD systems are very cost-competitive when compared to premium OH systems.

Integrated Scenarios

The CBE study also explores integrated scenarios where multiple cost-saving strategies are combined. These scenarios demonstrate that UFAD systems can achieve overall savings compared to OH systems with the following conditions:

• Concrete Buildings with Exposed Ceilings: Using concrete structures with exposed ceilings can reduce floor-to-floor heights and save on construction costs.
• Modular Wiring and Reduced Airflow: Combining modular wiring with reduced airflow rates can further enhance the cost-effectiveness of UFAD systems.

Case Study: Dynamic Systems Inc.

Dynamic Systems Inc. (DSI) implemented a UFAD system in its new building in Buda, TX. The case study from Global IFS, a leading provider of premium raised-access flooring solutions, focuses on the first-cost savings achieved through this innovative approach. This system uses perimeter convectors (similar to the LNT from Price) that reduce ductwork and the complexity of the system, which helps save on costs. This is a more common approach to designing UFAD systems today.

Reduced HVAC Construction Costs

The UFAD system reduced DSI’s HVAC first-cost by nearly $30,000 (or $1.43 per square foot) compared to traditional OH systems. This was achieved through several factors:

• Floor-to-Floor Height Reduction: UFAD systems allow for reduced floor-to-floor heights, which can lower construction costs by minimizing the amount of building materials needed.
• Simplified HVAC Installation: The UFAD system’s design simplifies HVAC installation, reducing labor and material costs.
• Elimination of Overhead Ductwork: By eliminating the need for extensive overhead ductwork using fan columns (such as Price’s PFC) and trench heating and cooling systems, UFAD systems reduce the complexity and cost of HVAC installations.

Operational Benefits

Beyond cost savings, the UFAD system provided other benefits:

• Energy Efficiency: The building reported 35% less energy consumption per square foot compared to that of traditional systems, leading to significant utility cost savings.
• Improved Indoor Environment: Occupants experienced better comfort and productivity due to improved ventilation and reduced HVAC noise.

Both the CBE analysis and the DSI case study underscore the potential for UFAD systems to save on first costs compared to traditional OH systems. Additionally, their long-term advantages in energy efficiency, indoor air quality and operational flexibility make them a compelling choice for modern building designs. By carefully considering the factors that influence costs and implementing strategic design choices, building owners and developers can leverage UFAD systems to create healthier, more efficient and adaptable spaces.

Are you considering UFAD systems for your next building project? Contact us at sustainable@priceindustries.com to learn more about how UFAD systems can benefit your budget and optimize your building’s performance.