Benefits of Underfloor HVAC Technology
Katelyn Calderwood • May 7, 2018

May 7, 2018

Underfloor Technology, or Underfloor Air Distribution (UAD/UFAD) , is a method of delivering space conditioning in offices and other commercial buildings. It uses open space between a structural concrete slab and the underside of a raised access floor system to deliver conditioned air directly into an occupied zone of a building. The air is delivered through a variety of supply outlets located at floor or desk level. This method of heating and cooling is quickly growing in popularity due to its potential advantages including improved thermal comfort, increased indoor air quality, and energy use reduction.

Improved Thermal Comfort
This system gives individual users control over their local thermal environment compared to traditional systems. Because ventiliation accessibility, individual comfort preferences can be accommodated. Research evidence shows that occupant satisfaction and productivity can be increased by giving individuals greater control over their local environment. Additionally, UFAD introduces supply air at a higher temperature than overhead systems, reducing the likelihood of cold sensation.

Increased Indoor Air Quality
Three items affect the increased indoor air quality experienced by UFAD users- increased ventilation effectiveness, removal of pollutants out of the breathing zone, and the ability to effectively maintain floor plenums. Ventilation effectiveness is due to the proximity of diffusers to an individual’s breathing zone. The overall floor-to-ceiling air flow pattern provided by UAD systems more efficiently remove contaminants from occupied spaces. In other words, air from the floor sweeps pollutants up and away from the breathing zone and reducing cross-contamination. Effectiveness is also increased in cases where users have the ability to relocate/add diffusers to match use patterns of the facility. Ventilation can be increased proportionally to need without awaiting thermal demand.

Energy
Taking into consideration factors such as ventilation effectiveness, stratification savings, higher supply temperatures and split task/ambient conditioning, UAD systems can identify between 5-25% energy consumption savings due to use of higher supply air temperatures. These air temperatures allow the use of economizer cycle for longer time, especially in mild climates. For systems that have split task ambient conditioning, savings can occur if task-conditioning operation is flexible and occupancy sensors in use. In addition, UFAD conditions only use the first six feet of space in a room, reducing supply air requirements and chiller and primary fan capacity as a result.

Cost
By combining all aspects of the HVAC system into one easily accessible service plenum, flexibility is increased and potential costs are avoided associated with re-configuring building services. Facility management costs decrease due to reduced occupant comfort complaints. These benefits allow for reduction in facility staff requirements and give the team the opportunity to complete  preventive maintenance tasks.

Growth for this cost-effective technology has been relatively slow as with any unfamiliar technology. The perceived high risk to designers and building owners, lack of available information and standardized guidelines, and the perceived higher cost of a raised floor drive the resistance to implement UFAD technology.

Feeling unsure about its application?  American AgCredit applied UFAD technology  to their regional headquarters in Wichita, Kansas and experienced increased employee comfort compared with their previous facility’s traditional system. The  award winning  system design called for the use of a complementary unit that had the ability to provide very dry, comfortable, underfloor air that cooled slightly into the 60’s. American AgCredit utilized AAON DPAC units because of the product’s ability to efficiently cool all underfloor air while only dehumidifying a portion to lower humidity levels.  Learn more.

Interested in how Underfloor Technology could benefit your facility?  Contact us  to learn more.

 

Source: Center for the Built Environment:  https://www.cbe.berkeley.edu/underfloorair/techoverview.htm  

By 7004697973 November 12, 2025
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By Hibu Websites November 12, 2025
When purchasing new rooftop units (RTUs), the immediate focus often lands on the upfront costs: the purchase price and installation. However, a deeper look reveals that these initial expenses are only a small fraction of the overall financial commitment. To truly understand the long-term financial implications of your investment, it is crucial to evaluate the Total Cost of Ownership (TCO) . WHAT IS TOTAL COST OF OWNERSHIP? TCO encompasses the complete lifecycle costs of your facility and its equipment, providing a comprehensive view of both short-term and long-term expenses. Beyond the initial purchase and installation costs, TCO includes ongoing operational expenses such as energy consumption, maintenance, repairs, and eventual replacement. By adopting a TCO-focused approach, buyers can make more informed decisions that align with their financial and operational goals. WHY TCO MATTERS Uncovering Hidden Costs Many RTU-related expenses are not immediately apparent at the time of purchase. These can include: Energy Consumption: RTUs with lower energy efficiency ratings may have lower upfront costs but can lead to significantly higher energy bills over time. Maintenance and Repairs: Frequent maintenance or costly repairs for less durable units can add up quickly, impacting your budget. Downtime Costs: Breakdowns can disrupt operations, leading to additional expenses from lost productivity or temporary cooling/heating solutions. Compliance Costs: Adapting older, less efficient units to meet evolving energy regulations can result in unexpected expenditures. Optimizing Long-Term Savings Investing in energy-efficient RTUs might involve higher initial costs, but these units typically deliver substantial savings through reduced energy consumption. Over time, the lower utility bills and fewer maintenance needs can offset the upfront expense, making these models more cost-effective in the long run. Durability and Lifespan High-quality RTUs with a longer lifespan can help delay the need for replacement, further optimizing the value of your investment. Units built for durability also tend to perform more reliably, minimizing disruptions and associated costs. MAKING AN INFORMED DECISION Evaluating the TCO of RTUs allows for a side-by-side comparison of different models based on key factors such as: Energy Efficiency Ratings Maintenance Requirements Durability and Build Quality This analysis helps you strike the right balance between upfront costs and long-term value, ensuring that the unit you choose supports both your financial objectives and operational needs. THE BIGGER PICTURE: FINANCIAL & ENVIRONMENTAL IMPACT Considering TCO is not just about saving money—it’s also about making smarter, more sustainable choices. Energy-efficient RTUs not only lower operational costs but also reduce carbon footprints, aligning your investment with environmental stewardship and compliance with green building standards. Focusing solely on the initial purchase price of an RTU can be a costly mistake. By incorporating TCO into your purchasing process, you gain a holistic understanding of the unit’s true cost over its lifespan. This proactive approach minimizes surprises, maximizes cost-effectiveness, and ensures your investment delivers value for years to come. Before purchasing your next RTU, take the time to evaluate its TCO—your future budget will thank you. Contact your BCS representative to explore more on Total Cost of Ownership and how we can support your financial and operational goals.
By bldgcontrols July 9, 2018
The average American spends 93% of their life indoors. For a school aged child, that is spent largely at school. According to National Center for Education Statistics (NCES), there are almost 99,000 public K-12 schools in America and the average public-school building in the U.S. is 42 years old. Our students are spending their days […] The post The Importance of HVAC to the K-12 Learning Environment appeared first on Building Controls and Services, Inc..
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