Navigant Research Blog

Decoupling H, V, and AC: DOAS and More

— April 14, 2014

Buildings have long been a target for energy efficiency improvements, as they consume a substantial portion of the world’s energy supply (about 40% in the United States).  More recently, the detrimental effects of poorly designed buildings have been established and buildings have been identified as an area to improve the health of occupants.  Though heating, ventilation, and air conditioning (HVAC) systems can be used to accomplish both of these goals, they typically cannot achieve both goals simultaneously.  Conventional approaches to improving indoor air quality (IAQ), such as increasing the ventilation rate or increasing filter efficiency, require using more energy, while increases to energy efficiency (such as improving a building’s seal to reduce infiltration) can have adverse impacts on IAQ.  However, addressing the requirements of heating, ventilation, and air conditioning separately have produced innovative approaches to improve health and reduce costs.

A Flawed Paradigm

Heating, ventilation, and air conditioning are generally lumped into a single system.  Why not?  For the most part, each task requires a box with fans and coils.  Using a single rooftop unit or air handling unit to provide ventilation, filter recirculated air, and produce comfortable temperatures is convenient.  Unfortunately, a single system can have a difficult time maintaining adequate control over disparate conditions.  In practice, adequately addressing IAQ takes a back seat to maintaining space temperature.

In fact, there is evidence that traditional HVAC designs systematically under-ventilate.  Thermostatically-controlled variable air volume (VAV) systems do a poor job of matching airflow to ventilation requirements, particularly in conference and meeting rooms when they are first occupied.  More people in a room increases the generation of both heat and carbon dioxide (CO2).  However, thermostats have a dead-band, an allowable deviation between the actual and desired temperature to avoid short-cycling and simultaneous heating and cooling. As a result, there is a time lag between when the space is occupied and when more than the minimum airflow is delivered.  Moreover, depending on the conditions, the 55°F supply air can offset the temperature rise quickly and return to the minimum position as the CO2 of the space continues to rise.  Theoretically, the minimum damper position should meet the ventilation requirements of a fully occupied room, but improper damper minimums or poor controls integration can lead to under-ventilation.

Separation of IAQ and Thermal Comfort

Decoupling ventilation requirements from thermal comfort through a dedicated outside air system (DOAS) is one way to address this ventilation issue and improve IAQ.  A DOAS provides 100% outside air to a building to meet the building’s ventilation needs.  Typically, it is equipped with some form of energy recovery to precool and dehumidify or preheat and humidify supply air from what is captured from exhaust air.  As a result, the system ensures adequate ventilation and prevents the spread of contaminants between spaces.  Including a DOAS in a building design improves a building’s IAQ by managing it separately from heating and cooling requirements.

However, improving IAQ does not have to be part of HVAC at all.  Introducing filters and outside air into a system that is already designed to move air is convenient, but the same effect can be accomplished by other means.  Adding plants into a space, for instance, can help reduce CO2 and ozone.

The future of IAQ might not be in HVAC, but in the building itself.  Lauzon, a North American flooring manufacturer, has developed a flooring-based solution, called Pure Genius coating, to manage volatile organic compounds (VOCs).  The coating uses photocatalytic titanium dioxide to break down VOCs into water and CO2.  Of course, when maintaining IAQ, converting VOCs to CO2 is a bit like robbing Peter to pay Paul.  However, it shows the advances that materials are making.  Solutions to the current limitations of HVAC equipment might come from outside the mechanical universe rather than from incremental engineering improvements.

 

Energy Systems Group Acquires Chevron’s Federal ESCO Unit

— April 8, 2014

On April 1, Energy Systems Group (ESG), a major U.S. energy service company (ESCO) based in Newburgh, Indiana and a subsidiary of utility holding company Vectren Corp., announced that it had acquired the federal sector energy services unit of Chevron Energy Solutions, a subsidiary of Chevron USA. The unit, which consists of 48 employees, will not only expand ESG’s projects and footprint but, more importantly, will also allow ESG to play in the U.S. federal government’s indefinite-delivery, indefinite-quantity (IDIQ) ESCO market.

That market was created in February 2009 when the U.S. Department of Energy (DOE) awarded 16 ESCOs with DOE energy savings performance contracts (ESPCs).  These 16 contracts allow the selected ESCOs to provide federal agencies with up to $5 billion of performance contracts each.  The program effectively prequalified the 16 ESCOs to perform energy efficiency services for many of the federal government’s largest facilities.

Narrowing the Competitive Field

Although ESG had been an active player in the federal ESCO market through other avenues prior to the acquisition, such as utility energy services contracts (UESCs – a twist on the traditional ESPC in which federal agencies procure performance contracts through their local utilities), the acquisition allows it to narrow the competitive field for large contracts offered only to ESCOs.  Given that the federal market represents one of the most promising segments in the challenging ESCO market, as Navigant Research wrote in its report, The U.S. Energy Service Company Market, the acquisition positions ESG to benefit from the full scale of the federal ESCO market. “The federal sector is one of our primary targets for growth in the coming years,” said Greg Collins, President of ESG, when I spoke with him.  “This acquisition strengthens our position in delivering on a wider range of federal opportunities.”

Note that other ESCOs have entered the federal market through acquisition.  For example, in 2007, SAIC (now Leidos) acquired BENHAM Companies to gain access to a broader swath of federal building customers (though, this was before the establishment of the IDIQ market).

The federal sector has been a key focus for ESCOs in the United States over the last few years.  While the municipalities, universities, schools, and hospitals (MUSH) market remains a challenge due to the winding down of stimulus funding for municipal performance contracts and concerns about municipal debt, ESCOs have patiently awaited the boost to the market that was initiated by the Better Buildings Initiative, the $2 billion federal performance contracting program announced by President Obama in December 2011.

So far, the program has fallen short of its goal of achieving the $2 billion in contracts by the end of 2013. However, initial signs in 2014 are promising.  Many of the ESCOs I work with are reporting a strong flow of federal requests for proposals (RFPs) and, in the first quarter of 2014, over $230 million of federal IDIQ ESPCs had been awarded. By contrast, in all of 2013, only $362 million was awarded.  In addition, the CEO of Ameresco, George Sakellaris, announced in his company’s 2013 fourth quarter earnings call in early March that federal government ESCO activity was high.  Therefore, 2014 is looking strong for the ESCO market and ESG will be in a much better position to address it in the wake of this acquisition.

 

Smart Building Apps Seek Relevance

— March 20, 2014

In a world where software applications are replacing bank tellersconcierges, and even opticians, what’s the impact on the role of building engineers?  As described in Navigant Research’s Commercial Building Automation Systems report, the convergence of information technology and building control networks is yielding vast amounts of data.  Moreover, the wider adoption of open standards and the decentralization of building networks make this data widely available.  Against this backdrop, the appification of building management seems inevitable.

Still, the universe of building management applications appears to be in its infancy.  A quick search of the iTunes App Store revealed several available choices.  Apps are available from developers as large as Siemens and as small as Lorenzo Manera (I don’t know who he is, either).  The low barrier to entry in app development means that new entrants are just as capable of bringing an app to market as veteran industry players.

Most of these apps appear to turn a mobile device into another building-level control panel, providing functionalities such as monitoring and controlling heating, ventilation, and air conditioning (HVAC) and lighting or providing some level of energy management.  With the proliferation of open protocols, these types of apps have become easy to develop.  However, they all seem to be equally unsuccessful; none of the apps identified have received enough overall ratings for an average rating to be displayed.

Worthy or Worthless?

Smartphones and tablets provide a slew of sensors and far greater mobility than laptops.  Successful apps take advantage of these features, whether it’s the ability to play games anywhere or to use the embedded camera to snap a quick Instagram selfie.  Residential building automation provides several compelling ways to leverage the properties of mobile devices: occupancy can be set using geolocation, outside air temperatures can be provided through the Internet, and devices can remotely monitor and control lighting, HVAC, and security.  Moreover, an app can obviate the need for a system console.

Apps for commercial buildings, however, are a different story.  Since they’re built on top of an existing building management system (BMS), they don’t replace any equipment.  They don’t provide any more functionality than the underlying system.  The sensors on the device do not provide any useful input.  Some building management apps may aid in commissioning, but the biggest feature appears to be providing another way to monitor the BMS.  The Facility Prime app from Siemens, for example, is described on iTunes as “an ideal interface for non-facilities employees that may need access to live system data.”  Until building management apps can provide more functionality for commercial buildings, they will remain a cool toy for home automation.

 

The Future of Buildings Will Be Printed in 3D

— March 11, 2014

There is something mesmerizing about watching a 3D printer work.  Whether it’s printing in plasticsandmetalsugar, or chocolate, it is captivating to see layer after layer be laid down to create simple or sublime forms.  3D-printed (also known as additive) materials have been recognized as having novel material, physical, and even electric properties.  Impossible shapes have been created that could enable an expansion in how materials can be conceived and used.  But what does additive manufacturing mean for buildings?  The ultimate application is easy to conceive: printing buildings, molecule by molecule, creating homes with landing pads for flying cars, and a HAL-9000 built into the walls.  But that is the Future (with a capital F).  In the near future, 3D printing will change the ways buildings are maintained and built.

The first application of 3D printing will address a very old-school problem: replacing parts in aging equipment.  Buildings are incredible for their durability.  This is also true for the equipment inside buildings.  At the Hotel Boulderado in Boulder, Colorado, the city where Navigant Research is headquartered, the original elevator is still running after 100 years.  With good maintenance, some systems will last for decades beyond their intended service life.  Keeping legacy systems in place lowers capital expenses for building owners.  But it’s not always easy to replace old parts.  In some cases, the replacement parts are no longer available, either because the manufacturer has gone out of business or has simply stopped making them.  In other cases, the transport costs for replacing parts can be prohibitive.  3D printing can solve that by creating custom parts made with extreme precision.  With the portability of 3D printing, it could even be possible to send the design specs for the part to the location where they are needed and print the part onsite.

Print Me a House

Constructing buildings using 3D-printed materials is still in the visionary phase of development.  DUS Architects has launched an ambitious project to print a traditional Dutch Canal House out of polypropylene.  In a very public display, a large silver box will print walls and other structures onsite, to be assembled into the traditional canal house form over the next few years.  Starting with the façade, the buildings will be printed and assembled out of plastic, building voids into the walls for support and insulation.  This is a public demonstration of an innovative approach.  One can envision printing building materials onsite using local materials, curbing transportation costs, saving energy, and reducing carbon emissions, not to mention vastly lowering the material waste that is a part of the building manufacturing industry.  In the next few decades, we can look forward to 3D printers getting bigger and cheaper, enabling 3D-printed material to be merged with traditional approaches.  The economics of 3D printing materials for buildings are not clear, and could be a major limiting factor in most settings.  In the meantime, if you find yourself in Amsterdam, you can buy a ticket to see a house being printed.  The architects and partners have made the building site (and print shop) open to the public for a small fee.

 

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