IoT Connects You to Digital HVAC Assets

IoT Connects You to Digital HVAC Assets

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The network edge represents the playground of IoT. Imagine inexpensive wireless devices directly monitoring and/or controlling critical HVAC assets. HVAC systems are key to building performance and sustainability. Welcome to the new world of Operational Technology (OT).

Conventional Information Technology (IT) paradigms focus on the core of the network. OT-centric thinking, on the other hand, begins at the edge. Consider the illustrated examples below. The IT domain includes a focus on the cloud infrastructure, while the OT domain includes a focus on physical plant equipment. These distinctly different emphases reflect the chasm between IT and OT. Thus, IoT solutions offered from an IT perspective may emphasize networking principles rather than solving actual OT problems.


Consider the current emphasis on HVAC for energy efficiency. One of the current trends relates to Asset Condition Monitoring (ACM) of critical HVAC assets. Consider the example of a Roof Top Unit (RTU), which firmly resides in the OT domain illustrated above.

What is an RTU?
RTU Example of Packaged RTU


There are two basic types of RTUs, split systems and packaged systems. Split systems typically have one main component outside and a second main component inside. Packaged systems, on the other hand, typically have all components located in a single large unit outside.

Various options exist for packaged systems, including (1) AC-only units, (2) gas/electric units that heat with gas and cool with electric, or (3) all-electric units that heat and cool with a heat pump. The RTU can have various fans and controls on it to manage supply/return air flow. With respect to the fans, various designs exist. One design features constant volume where the fan runs at full speed. Another design features variable air volume where the fan changes speeds.

What’s the Problem?

IoT responds to actual problems. Enterprises can leverage IoT hardware to manage OT issues presented in the HVAC domain.

As is well known, HVAC and lighting represent the largest percentage of the electricity consumption in commercial buildings. While every building’s consumption profile varies due to the differences in HVAC and lighting equipment, the theme remains the same. Energy efficiency efforts should primarily target HVAC and lighting sources of energy consumption.


HVAC and Lighting Costs Example of HVAC and Lighting Costs


Clearly, the motivation exists to address the efficiency of HVAC units such as RTUs. The pathway, however, remains murky. Most efforts focus on RTU maintenance programs that rely on periodically scheduled visits (e.g., every six months). Absolutely necessary, but limited. Properly maintained equipment ensures that the equipment remains functional but the extent of that functionality cannot be quantified. No insights to the actual operational efficiency of the RTUs are provided.

The Solution: Digitizing HVAC Assets

Periodic maintenance programs for RTUs can provide a written report of the checklist of maintenance actions taken by the technician. RTU repairs may also produce further written documentation. The collection of paper documentation provides limited value. Finding and locating the written records incurs high transaction costs. Additionally, the obscure content of the paper records only reflect the operational status of the RTU at snapshots in time. These limited insights cannot easily be compared to the operation of RTU assets in other buildings and locations. In general, the overhead associated with paper systems is enormous.

Digitization of RTU assets is key. In practical terms, digitization of assets involves the process of creating electronic resources from the physical RTU assets. The operational benefits to efficiency will accrue for companies today, and tomorrow.

What does the digitization of an RTU asset look like? Consider the following example where inexpensive wireless IoT devices provide the following real-time data streams to a cloud platform:

  • Supply/Return Temperature;
  • Compressor Run-Time;
  • Air flow;
  • Vibration;
  • Total RTU power consumption; and
  • Ambient Temperature/Humidity.

This collection of granular real-time cloud data enables anytime, anywhere access to a highly-functional, virtual rendering of the operational status of the RTU.

New Markets for Digital Assets

The digitization of RTU assets opens up vast new markets.

First, the historical collection of operational data enables ready comparison of RTUs across the building and portfolio. RTU analytics can provide objective measures of operational efficiency. For example, actual Energy Efficiency Ratios (EERs), kW/ton or Coefficient of Performance (COP) for an individual RTU can be compared to theoretical measures based on age of the RTU. Hard evidence of energy efficiency performance will replace conventional guesswork.

Second, the historical collection of operational data enables continuous commissioning of the RTUs. Continuous commissioning can relate to an ongoing process of resolving operating problems, improving comfort, and optimizing energy use. In general, you can’t manage what you can’t measure. Objective real-time RTU data using IoT enables a systematic approach to achieve the goals of continuous commissioning.

Third, the historical collection of operational data enables predictive maintenance. IoT provides the fuel for Artificial Intelligence (AI) and Big Data. The increased availability of real-time data will facilitate the rise of Subject Matter Experts (SMEs) that can monitor the operation of RTUs using AI tools such as machine learning. Anomaly detection and Fault Detection and Diagnostics (FDD) can signal the need for maintenance before catastrophic failures occur. Eliminating the risk of emergency repairs will have a far greater impact on your facility management budget as compared to energy efficiency savings.


The creation of digital HVAC assets has far reaching benefits in solving real-world OT problems. IoT is perfectly suited for such a domain because it provides a platform framework for delivering real-time insights. Don't accept the status quo of limited visibility. The risk of perceived obsolescence for your business is too great.

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