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Expert Advice on Direct Digital Controls for Energy Efficiency and Building Performance

Written by: Austin Alvey Aguilera

Silicon Valley and the tech world find new and exciting ways to bring smart technology into every facet of our lives. Our homes, vehicles, and even our bodies (through smart devices that count our steps and heartbeat) are being made intelligent in the digital age.

This electronic revolution isn’t stopping at the entrance to the buildings we work in either. If you own, work, or manage a building built prior to the 00’s, it’s likely your HVAC is controlled with a complex pneumatic system or some other form of analog control relying on finicky valves and thermostats. The good news for the frozen receptionist at the front desk and the sweltering office manager with a south facing office window is that the digital age has come to the rescue. Don’t take my word for it – I’ve gathered experts in building HVAC and energy efficiency from around Oregon and the Midwest and asked them about bringing our buildings into the 21st century.

Candice Norton, of Resource Innovations, explains what direct digital controls (DDC) can do for a building.

“DDC systems, also known as building management systems (BMS), are a vital tool for ensuring a building is functioning correctly and at optimal capacity. Having a BMS allows facility operators to not only have more insight into how their building is operating, but also creates the opportunity for significant energy efficiency benefits if optimization sequences are implemented.”

So how exactly does a digital BMS system help improve performance? Phillip Maddi, of Burch Energy, explains that building data is the key to insights into building performance.

“...monitoring and recording numerous data points can improve system performance through constant commissioning. Upgrading to DDC from pneumatic controls provides facilities operators with better insight into equipment operation, often with remote monitoring capabilities.”

“If you can’t measure it, you can’t improve it.” - Peter Drucker

Philip emphasizes his point by quoting a phrase widely attributed to Peter Drucker who is considered by many to have built the foundations of the modern business.

If any of this has piqued your interest, you may be the owner or operator of an older building and want to know what sort of real-world benefits are on the table. Waypoint Energy’s own Sari Mira has this to say on the subject.

“Energy savings associated with retrofitting a pneumatic control system with a DDC system can vary anywhere between 10-30%.”

Sari goes on to explain that the benefits don’t stop at energy savings.

“...building owners typically see significant labor and materials savings in the form of maintenance savings as they no longer need to maintain a mechanically complex system.”

And lastly Sari points out how DDC can help that frozen receptionist and sweltering office manager we mentioned earlier.

“...DDC systems utilize electrical signals to transmit data and control commands, response time is much faster than a pneumatic system; hence, improved occupant comfort.”

I hope the benefits of a digital BMS are becoming clear. But this is the real-world and these things can’t be cheap! Karl Friesen, of KFAA Engineering, has extensive experience estimating energy savings associated with DDC retrofits in buildings. When asked, Karl provided his opinion on the cost of DDC retrofits.

“...upgrading a building’s HVAC control to a new modern DDC system has one of the biggest impact ‘bangs for the capital invested buck’ you can make in a building.”

Karl also points out that even LEED certified buildings can gain from DDC retrofits.

“...whether a building is LEED certified, old and deteriorating or renovated with energy code compliant systems, investing in all the latest HVAC equipment innovations does not lead to a highly energy efficient, high performing building. Only through leveraging the building’s ‘brain’, an up to date DDC system, to implement and maintain ‘simple operator friendly’ HVAC system optimization strategies can high performance results be achieved.”

If this is intriguing, but you find yourself wondering how this is all possible, Candice Norton answers the question: What sort of upgrades and strategies can be implemented through a DDC upgrade?

  • "Supply air temperature reset

  • Static pressure reset

  • Optimize scheduling

  • Nighttime setbacks

  • Optimum start/stop

  • Boiler lockout at max outside air temperature

  • Chiller lockout at min outside air temperature

  • Hot water loop supply temperature reset

  • Chilled water loop supply temperature reset

  • Variable flow in a water loop that includes differential pressure sensors, or temperature sensor, to allow for the loops flow to vary based on load the loop is serving

  • Demand control ventilation (DCV) using CO-2 sensors to reduce outside air ventilation during unoccupied hours

On top of improved equipment control, there are also non-energy related benefits which are more difficult to justify but still valuable. The following are just to name a few:

  • Remote access to quickly adjust setpoints for comfort complaints

  • Instant warning when equipment goes down, or other programmed alerts are triggered

  • Preventative maintenance notifications such as, scheduling when a filter needs to be replaced"

“Just because you have DDC controls does not necessarily mean you have optimized the setpoints for energy efficiency." Phillip Maddi explains, "Reviewing your setpoints to ensure automatic operation with setbacks and resets enabled will help ensure your system is getting full potential from the sophisticated controls.”

Even if you already have DDC, you may still have opportunity for improvement. Once you have the data and the power to make changes with a few clicks, you can compensate for shifts in equipment performance over time. Great, right?

There is one last item that you should keep in mind if you’re considering a DDC-related upgrade to your building. Drew Samuel, also of Resource Innovations, explains that once a building has been properly set up (commissioned), there is a smart method to maintain performance over time: MBCx. Sustainable engineering Solutions describes MBCx:

“Monitoring-based commissioning, or MBCx, is a process that utilizes automated data analytics to continuously monitor the performance of systems over the life of a building. ( . . . ) The performance of these [building HVAC] systems will then be continuously monitored and compared to the baseline information. As building performance begins to suffer (also known as “building drift”), it will automatically be detected through qualitative and quantitative means of assessments.”

If you are interested in learning more, know that you’re not alone on this journey. There are many energy efficiency programs that are designed to help with upgrades like those we’ve discussed here. These programs often utilize knowledgeable energy and building performance professionals, like those who provided quotes for this blog, to guide you to success in the age of smart gadgets and smarter buildings.

Drew Samuel put it like this:

“Customers can save money and energy by upgrading older building controls to DDC and leveraging utility-funded energy efficiency programs like prescriptive incentives and monitoring-based commissioning (MBCx) studies. In the ComEd territory, prescriptive incentives are paid out for upgrading legacy systems to DDC, commonly on a per square foot-controlled rate. Then, with the assistance of an expert engineering firm and the integration of fault detection and diagnostic (FD&D) software into their new DDC system, energy engineers can identify energy conservation measures (ECMs), also known as energy efficiency measures (EEMs), with deeper energy savings more efficiently than through traditional retro-commissioning (RCx) studies.”

Reach out to our team if you’d like to learn more about DDC control improvements, energy efficiency, or incentives!

Company Links:

Names and Titles:

Candice Norton – Resource Innovations – Lead Energy Engineer

Drew Samuel – Resource Innovations - Senior Engineering Manager

Phillip Maddi - Burch Energy – Principle Engineer

Karl Friesen – KFAA Engineering – Owner’s Rep and Lead Engineer

Sari Mira – Waypoint Energy – Senior Engineer


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