New ‘intelligent agents’ lab to help improve building energy efficiency

The National Institute of Standards and Technology (NIST) is converting one of its laboratories into the equivalent of a small office building—not because of an increase in administrative overhead, but to develop and test smart software technologies designed to slash energy use in commercial buildings.

Architectural drawing of the new NIST 'intelligent agents' lab for more efficient building control systems. Credit: Kikkeri/NIST

Architectural drawing of the new NIST ‘intelligent agents’ lab for more efficient building control systems.
Credit: Kikkeri/NIST

From schools and hospitals to stores, offices and banks, commercial buildings account for a growing share of U.S. energy use—about 19 percent of the total and a third of electric power consumption.* More than four-fifths of this energy is consumed after construction by heating, cooling, lighting, powering plug-in equipment and other operations. By one estimate, day-to-day energy expenses make up 32 percent of a building’s total cost over its lifetime.**

NIST figures that these energy-eating operations can be accomplished far more efficiently and frugally with existing equipment by more intelligently coordinating their use. At the mock office building now under construction in a standard 1,000 square foot (93 square meters) modular lab space, NIST researchers will put this assertion to the test. There, they and their collaborators will investigate whether artificial intelligence tools already used in search engines, robots, routing and scheduling programs, and other technologies can work cooperatively to optimize building performance—from minimizing energy use to maximizing comfort to ensuring safety and security.

“Adapting intelligent agent technologies from other fields offers the promise of significant improvements in building operations,” explains Amanda Pertzborn, a mechanical engineer working in NIST’s Embedded Intelligence in Buildings Program. “The idea is a kind of ‘one for all approach’—use networked intelligent agents to manage and control devices and equipment subsystems to enhance the overall performance of a building rather than to optimize the operation of each component independently of all the others.”

Intelligent agents are combinations of software and hardware—sensors, mechanical devices and computing technologies—that perceive their environment, make decisions and take actions in response. They can monitor, communicate, collaborate and even learn, predict and adapt.

The energy-saving potential of this smart technology will grow with the evolution of the “smart grid” and its two-way communication capabilities, Pertzborn says. So, for example, cooperating teams of intelligent agents can parse time-of-day pricing, weather forecasts, availability of renewable energy supplies, and occupancy patterns to adjust individual equipment and systems to achieve optimal overall performance.

NIST’s simulated office building will serve as a proving ground for assessing whether intelligent agents dispersed among a structure’s multitudes of devices and subsystems can achieve this unity of purpose and work in concert. Prototypes will be tested on the most energy-intensive of building operations: heating, ventilating and air conditioning (HVAC). So-called HVAC systems in commercial buildings account for about 7 percent of total U.S. energy consumption.***

Modern HVAC systems consist of thousands of devices from local dampers, heaters, thermostats and fans to boilers, air handling units, chillers and cooling towers. When a building’s HVAC system is first installed and tested, this vast assortment of components can be tuned so that the system starts out performing at peak efficiency. Over time, however, efficiency tends to degrade from the optimum and energy use patterns of occupants change, requiring retesting and retuning the system. Intelligent agents distributed throughout a HVAC system would enable continuous tweaking to orchestrate the operation of all components so as to maintain peak performance and efficiency throughout the building’s lifetime.

Using a real building HVAC system under controlled laboratory conditions will enable meaningful comparisons of prototype intelligent agents, Pertzborn explains. Scheduled to be completed in the fall, this building-in-a-lab will consist of four zones serviced by two chillers, three air-handling units, four variable air volume units to control air flow and one ice storage tank, plus pumps, heat exchangers and other equipment.

* U.S. Department of Energy, Buildings Energy Data Book,

** Siemens, Integrated Building Optimization: A Crucial Convergence of Demand-side and Supply-side Energy Management Strategies, 2014.

*** J. Shonder, “Fact Sheets on HVAC Measures,”

How The New VTannual Rating Affects Daylighting

If you’re involved with daylighting commercial buildings, you need to know about optically complex fenestration systems and the new VTannual rating.
   Optically complex fenestration systems are technologically advanced products that use specially engineered light-bending or light-reflecting elements to harvest the wavelengths of light that we want to use to illuminate building interiors. One key example of these new types of optically complex fenestration systems is the tubular daylighting device (TDD), which collects and admits natural light into interiors more effectively than conventional daylighting options.
   Featuring progressive technologies, these optically complex systems use stringent refractive, reflective, and filtering elements to selectively harvest natural light over the course of a year. Compared with traditional skylights, windows, and less-complex TDDs, state-of-the-art TDDs use advanced optics and materials to deliver higher quality visible light with more consistent illuminance, regardless of sky condition or climate. They also significantly reduce the potential for shifting light patterns, glare, and heat transfer issues.

Current rating issues
So how do building designers know which optically complex system offers the best performance for their particular projects? Currently, visible light transmittance (VT) is a factor commonly used by architects, engineers, and contractors to predict a daylighting system’s light output. It’s also a performance rating that is measured using testing and rating protocols established by the National Fenestration Rating Council (NFRC), Greenbelt, MD.
   The issue with the VT rating is that it doesn’t sufficiently account for the light-collection control that can be designed into optically complex fenestration products. These systems are engineered to filter out undesirable wavelengths—such as fabric-fading ultraviolet, heat-carrying infrared, and overpowering midday sunlight—so the collection and transmission of light varies, by design, throughout the day and year. This variance makes product comparisons difficult and the simple VT measurement a poor performance indicator.

Devising a new rating
Measuring simple VT involves direct-normal testing where a single beam of light is aimed into the optically complex system from directly overhead. There are two problems with the test. First, natural light transmits through a surface at a variety of angles throughout the day (depending on the sun’s position in the sky), not just in a perpendicular fashion. Second, this method doesn’t allow the benefits of technology to come into play, such as dome optics or optical tubing reflectance. Every daylighting system performs relatively the same when using this testing protocol, so it does not offer an accurate depiction of a product’s real-life performance. As a result, it doesn’t provide a valuable resource to the consumer when trying to select the best product for a particular application.
   To select the best daylighting system for a given project, commercial building designers must be able to compare product performance with respect to daylighting configuration and geographic location as well as climatic and seasonal variations. Until now, the lack of standard performance metrics that adequately address this new breed of daylighting systems has made the simple comparison and selection of optically complex systems virtually impossible.
   Enter the NFRC Tubular Daylighting Device Task Group. Consisting of members from the NFRC, including technical representatives from the Lawrence Berkeley National Laboratory (Berkeley, CA), testing laboratories, and several major TDD manufacturers, this collaboration has worked for more than four years to develop a new performance testing protocol for collecting and rating visible transmittance data for optically complex systems.
   The outcome of the group’s efforts was a new annualized visual transmittance rating protocol (VTannual), which was implemented by the NFRC in late 2013. The new VTannual protocol offers a more meaningful performance rating that provides an extremely accurate view of how an optically complex system will perform in real-life situations. It will allow building designers to make a true “apples to apples” comparison between daylighting products so they can choose the best system to meet their project goals.

This illustration is a graphical representation of solar angles defined and utilized within the NFRC VTannual rating protocol. Illustration courtesy of NFRC.

This illustration is a graphical representation of solar angles defined and utilized within the NFRC VTannual rating protocol. Illustration courtesy of NFRC.

Calculating VTannual
To calculate the VTannual rating, a specially designed apparatus measures a daylighting product’s:

  • Annual visible transmittance: the annualized amount of daylight transferred through a surface into an interior space.
  • Zonal time (ZT) weighting factors, which are a function that determines the percentage of time the sun spends within a specific patch of sky.

   The apparatus does this by collecting clear-sky, visible-light-transmittance data for a series of vertical planes of data in 10-deg. increments. The measurements span vertical angles for solar altitudes (angles of the sun above the horizon) ranging from 20 to 70 deg. at three specific solar azimuth angles (the compass direction from which the sunlight is coming, i.e., east or west relative to due south) of 0, 30, and 60 deg.

Figure 3 (Figure 2 is not shown) is a depiction of solar altitude angles as measured with respect to the opening of the moveable test apparatus. Illustration courtesy of NFRC.

Figure 3 (Figure 2 is not shown) is a depiction of solar altitude angles as measured with respect to the opening of the moveable test apparatus. Illustration courtesy of NFRC.

   Ultimately, 18 distinct points of paired data are collected, then factored in with the historical position of the sun for a preselected site location which, for the NFRC rating, will be a standard Middle America location at 40 deg. north latitude, i.e., Boulder, CO. These can then be used to generate functional, annualized, visible-light-transmittance ratings for any site location in the world, accounting for how an optically complex product is designed to selectively increase or reduce light collection for specific times of the day and year.
   It’s important to note that the VTannual rating is based on clear-sky conditions only. Thus, the new rating will be less useful for people who live in predominantly overcast or cloudy climates.

Obtaining a rating
To obtain a VTannual rating, a manufacturer works with a third party testing organization to conduct the test. The results are then sent to an independent inspection agency to review and verify the test data and rating results. If the data are deemed to be accurate and conform with the testing standard, an NFRC label with the rating is issued to the manufacturer for use on its packaging. The data are also uploaded to the NFRC Certified Product Database.
   The VTannual rating is designated as a single number that represents the annual average clear-sky visible transmittance of a daylighting product for a standard Middle America location. This accounts for the actual time-weighted path the sun travels during the course of the year, and is expressed as a number between 0 and 1. This differs from the static direct-normal VT rating, also expressed as a number between 0 and 1, which, for a skylight, represents the ideal maximum light transmittance of a product when the sun is directly overhead, a condition that never happens for all but a few hours each year for sites within the tropics near the equator.

Taking a new approach
Optically complex systems are forcing a paradigm shift in commercial-building design. With their ability to collect, filter, and redirect daylight, they have made it easier for natural light to become the primary daytime illumination source, with electric lighting taking a supplementary role. These systems are not your average TDDs, but fully vetted lighting equipment that has been proven to perform.
   The adoption of the VTannual rating protocol is a crucial part of this new approach to commercial lighting. It is a significant advancement in how fenestration products are evaluated because it allows those involved with building design to make educated decisions based on a product’s real-life performance, and eventually the data collected in the NFRC VTannual rating process may even allow annual performance values to be calculated relative to the building’s actual geographic location.
   Architects can now make direct comparisons, which allows them to specify and select the best product for the application. They can even calculate how much useful light is available, making it possible to estimate how much electric light is needed to make up for any deficiencies during any hour of the year. Look for the new performance rating on NFRC labels starting in the Fall of 2014.

Neall Digert, Ph.D., MIES, is vice president of product enterprise, Solatube International Inc., Vista, CA.

Five Myths of Tubular Daylighting Devices

Are these myths preventing you from specifying/purchasing tubular daylighting devices for your commercial facility?

Michael Sather, commercial marketing manager at Solatube International Inc., Vista, CA

Michael Sather, commercial marketing manager at Solatube International Inc., Vista, CA

Many people are familiar with the concept of tubular daylighting devices (TDDs), often generically referred to by more informal names such as solar tubes, sun tunnels, light pipes, or tube lights. The general concept is simple: A dome, attached to a roof with a self-mounted flashing or mounted on a curb, captures sunlight, transfers it into the building through a highly reflective tube, and delivers it into the interior space through a diffuser lens mounted at the ceiling level or at the end of the tube in an open ceiling.
   In the past 13 years, TDDs have revolutionized the way buildings are illuminated. When applied correctly, a building can be fully daylit using only the natural light supplied by the TDDs for 90% or more of the occupied hours of the year, relying on electric lights only as a backup during extremely overcast days or at night.
   That said, how do you know if TDDs are the right choice for daylighting your project? What key aspects should you consider when selecting the best TDD for a specific application? To help answer these questions and give you a better understanding of this product category, let’s explore five myths of TDDs.

When applied correctly, a building can be fully daylit using only the natural light supplied by the TDDs for 90% or more of the occupied hours of the year, relying on the electric lights only as a backup during extremely overcast days or at night.

When applied correctly, a building can be fully daylit using only the natural light supplied by the TDDs for 90% or more of the occupied hours of the year, relying on the electric lights only as a backup during extremely overcast days or at night.

Myth 1: Tubular daylighting devices are only for residential applications or small spaces.
The original TDDs that appeared in the U.S. market in the early 1990s were strictly designed for residential spaces. In the past two decades, the TDD category grew to rival and eventually surpass traditional skylights for residential applications.
   Building on that residential-market success, the world’s first commercial-grade TDD appeared on the scene in the year 2000. This new technology boasted a 21-in.-dia. tube and a transition box for a grid ceiling system, which allowed a round tube to accommodate a square diffuser, simply by replacing a 2 x 2-ft. ceiling tile. Open-ceiling models also debuted at this time and featured a diffuser lens attached directly to the tube bottom. As a result, the approach to daylighting commercial buildings was greatly simplified and the daylight fixture concept was born.

Specular reflectance, which refers to a concentrated bundle of light transferred down the tube through the diffuser, is the key factor in determining how effective a TDD is at delivering light to an interior.

Specular reflectance, which refers to a concentrated bundle of light transferred down the tube through the diffuser, is the key factor in determining how effective a TDD is at delivering light to an interior.

Myth 2: Tubular daylighting devices are only for the top floor.
Specular reflectance, which refers to a concentrated bundle of light transferred down the tube through the diffuser, is the key factor in determining how effective a TDD is at delivering light to an interior. It is often confused with total reflectance, which refers to scattered light that is reflected in every direction. Total reflection is not an indicator of throughput since this would include light reflecting back up the tube.
   When daylight moves through a TDD, it reflects (or bounces) off the tubing surface. With each bounce, a small amount of that light is lost. For each 90-deg. turn, only about 5% of the light is lost. This makes possible tube runs of great distances, spanning multiple floors, running down chases in the walls, and using multiple 90-deg. turns to be able to deliver daylight deep into the interior of multistory buildings.

When daylight moves through a TDD, it reflects (or bounces) off the tubing surface. With each bounce, a small amount of that light is lost. For each 90-deg. turn, approximately only 5% of the light is lost.

When daylight moves through a TDD, it reflects (or bounces) off the tubing surface. With each bounce, a small amount of that light is lost. For each 90-deg. turn, approximately only 5% of the light is lost.

Myth 3: Tubular daylighting devices are only effective at certain times of the day or year.
Factors affecting seasonal consistency are a combination of specular reflectance, dome optics, spectral selectivity, color temperature maintenance (CTM), and solar heat gain. Lower end TDDs will have a greater difference in daily and seasonal variation due to a lack of the above mentioned properties.
   Advanced TDDs offer daily and seasonal consistency by incorporating dome technologies with passive internal reflectors or Fresnel-lens optics to help efficiently collect low-angle sunlight. This can greatly increase performance in the early morning or late day. During the winter months, when the sun is low in the sky, this is an especially important consideration in Northern latitudes.

Myth 4: Tubular daylighting devices are unpredictable.
While dome optics and tubing material will play a major role in the predictability and consistency of a TDD, you must also take into account the overall design. Even the most advanced TDDs can be designed incorrectly into a space. If you use too many units, the results can be overwhelming; if you use too few, the results can be disappointing. Most TDD manufacturers offer daylight dimming devices that provide total control over the amount of daylight entering the space.

Myth 5: All tubular daylighting devices are the same.
This statement is equivalent to saying all cars are the same. To ensure you select the right TDD for your particular project needs, there are three main considerations: the manufacturer, the product, and the partner:

  • The manufacturer. Significant differences exist in the product offerings and core focus of companies manufacturing TDDs. Some manufacturers specialize in TDDs as their sole business, whereas other companies may only offer TDDs as a small part of their overall product line.
  • The product. Be sure to specify a product that meets the needs of the space. Most TDD manufacturers will offer a wide range of models and component options to create the right configuration for the specific application and climate.
  • The partner. Once a manufacturer is selected, it is probably best to make sure there is a factory-trained distributor or representative to assist with the project. Most TDD manufacturers will have a partner who works with you at a local level from project conception through completion to help you meet your daylighting goals and stay within your budget. These companies typically offer installation services as well as installation training for subcontractors to ensure your project is a success.

Michael Sather is the commercial marketing manager at Solatube International Inc., Vista, CA.

Load Share to Heat Pools, Water

Instead of exhausting building heat generated during daily activity, a thermal-load-sharing system can direct that heat to pools, spas, and water heaters.

Jay Egg, Egg Geothermal

Jay Egg, Egg Geothermal

Spring is here, and the cooling season is quickly approaching. Pools around the country that have been decommissioned during the winter are likely to stay that way well into June, unless some type of pool heating is implemented.

But heating open bodies of water with conventional HVAC heat sources can be a rather expensive undertaking, particularly in northern climates, forcing designers and owners to look for a relatively inexpensive heat source. Let’s look at the options.

Solar-thermal is the most energy efficient and renewable source for potable water and pool heating, but solar depends on cooperative weather. Cloudy and cool days can mean a cold pool, necessitating the need for backup heating sources much of the year.

Fossil fuel heating of potable water, pools, and spas is an old favorite. First cost is relatively low, but that comes at a higher price environmentally and monetarily as you move forward. In addition to high costs for propane and other fuels, safety issues are involved when fossil fuels are used as a heat source.

Electric-resistance heating uses raw electricity to warm heating elements over which the water passes, providing a clean and safe water-heating alternative. But it can be extremely expensive. Using the coefficient of performance (COP) rating system (used internationally) for heating equipment, electric heating has a COP of 1.0, meaning that 1 unit of heat is provided for each unit of electricity, a one-to-one ratio, or 100% efficient in the COP rating system.

Air-source heat pumps, designed for pool and potable-water heating, are environmentally friendly and pump outside air into a pool or hot-water tank. However, they too rely somewhat on cooperative weather conditions, i.e., air temperatures being warm enough to facilitate efficient heat extraction. Air-source heat-pump efficiencies are in the 3.0 COP (300% efficient) range.

For swimming pool and spa heating, the best scenario is attained with geothermal-sourced water-to-water heat pumps, pulling heat from a dependable, steady, and renewable energy source; the earth. Geothermal heat pumps can be about 5.0 COP (500% efficient).

Outside temperatures fluctuate with the changing seasons, but underground temperatures don’t change nearly as dramatically, thanks to the mass of the earth. Some 4 to 6 ft. below the ground, the temperature remains relatively constant year round (about 50 F to 75 F in the U.S.).

A geothermal-sourced water-to-water heat pump, which can work in tandem with a geothermal HVAC system, typically consists of water-sourced heat pump and a buried system of pipes called an earth loop, and/or a pump to send fluid to a reinjection (Class V thermal exchange process) well. This geothermal source can be shared between the building’s HVAC and water-heating systems.

Think of it like this: While providing power to run your building’s HVAC cooling system, you are also providing the energy to run computers, lighting, servers, copiers, and domestic water heating. Then the building’s HVAC system must use power to remove the heat created by all of these internal gains, on top of the occupant loads (one occupant presents a load of 1,200 BTU each hour). You pay for energy twice to remove this waste heat through the process of cooling your building. Why not channel that heat to where it’s needed?

Among the benefits that you can realize from a geothermal HVAC system is the ability to channel and use this waste heat energy. That’s because, unlike widely used cooling towers and air-sourced cooling equipment (those that have an outside condenser that discharges waste heat), geothermal systems discharge the heat through a liquid heat exchanger (such as with a chiller-cooling tower combination). The heat is entrained in the discharge water line. Most manufacturers of geothermal heat pumps even have a factory installed hot water generator available. This option gives you two extra connections, labeled DHW (Domestic Hot Water) “In” and “Out,” that may be connected to almost any hot-water tank.

There are thousands of geothermal heated pools around in the US. There is a good chance that the local YMCA, hotel, health club, or community pool near you already has geothermal sourced pool heating. Surprisingly, many of these still have air sourced cooling systems that could be converted to geothermal (and likely will be) during the normal course of HVAC equipment attrition and upgrade. When specifying a geothermal HVAC system, consider including a thermal-load-sharing system to make maximum use of building heat.

Jay Egg is a geothermal consultant, writer, and the owner of EggGeothermal, Kissimmee, FL. He has co-authored two textbooks on geothermal HVAC systems published by McGraw-Hill Professional. He can be reached at

Slash Geothermal Costs With Free Money

Couple inherent energy cost savings with incentive dollars to make a huge dent in the cost of a geothermal system.

Jay Egg, Egg Geothermal

Jay Egg, Egg Geothermal

The economics of purchasing and operating a geothermal HVAC system are not solely reliant on paying notable upfront costs and then counting on energy-cost savings to recoup those costs in the first few years of operation. In fact, much of the upfront costs can be quickly offset by taking advantage of a variety of available incentives.

To start the discussion, let’s simply list the various incentives that are available to residential and commercial consumers. Residential options are included for comparison purposes. Here is a list of the most readily available options:

  • 30% Federal tax credit, uncapped.


  • 10% Federal tax credit, uncapped
  • Maximum Accelerated Cost Recovery System (MACRS)–benefit as high as 38%, uncapped.

Commercial and residential:

  • Property Assessed Clean Energy (PACE) funding funds entire geothermal HVAC projects for property taxpayers
  • State and local government incentives (varies by region)
  • Utility incentives and funding (On-Bill financing)
  • Geothermal utility services (ORCA Energy).

Many of the incentives/benefits cover the entire cost of a new geothermal HVAC system or retrofit/improvements to an HVAC system. These improvements can include the following:

  • Geothermal source (ground loop/pond loop/Class V well system or standing column well
  • Geothermal (water sourced) chiller/heat pump equipment
  • Ductwork, distribution piping, and specialties
  • 100% fresh-air equipment (geothermal water sourced)
  • Controls and indoor air quality (IAQ) items
  • Electrical service connections
  • Excavation & recovery costs
  • Engineering drawings, permits, and fees.

Federal incentives for geothermal HVAC systems that are currently in effect through the year 2016 include different criteria for commercial and residential.

If the project is residential, all that is required is that the client be a taxpayer and fill out IRS form 5695. The customer will realize 30% of the entire cost of the geothermal HVAC system in direct tax credits. The credits can be rolled over from year-to-year until the full incentive is earned. For example, a $30,000 HVAC system, purchased in 2014, will generate a $9,000 tax credit on the very next tax filing, through 2016.

The reason I included residential is for comparison. If the customer is a commercial entity who owns the commercial property, that entity receives a 10% Federal tax credit. That doesn’t appear to be favorable until the rest of the story is considered. When MACRS is applied, the geothermal HVAC system is depreciated in an accelerated manner from 27 yr. down to an abbreviated 5 yr. A 50% bonus depreciation is also applied to the first year. This 50% bonus has been extended and modified several times since 2008, most recently in January 2013 by the American Taxpayer Relief Act of 2012.

By taking advantage of the commercial/corporate geothermal HVAC tax credits and incentives, an expenditure of $1 million for a geothermal HVAC system will net tax incentives amounting to $480,000 over 5 yr. under current program guidelines. A 48% tax incentive for corporate clients is clearly favorable to the 30% tax credit for residential clients.

PACE is a Federal program, currently available in 31 states, designed for residential and commercial consumers. The program works best for commercial customers in participating areas. PACE is arranged by local government and pays for 100% of the project’s costs. Payback is accomplished through property-tax assessments. Though PACE is also available for the residential sector, the housing market reverses in 2010 brought that funding to a halt. Commercial PACE programs have accelerated and, as of February 2013, 16 commercial PACE programs in seven states are accepting applications to fund geothermal HVAC and other energy-efficient projects.

On-Bill financing provides a way for consumers to repay the capital costs of retrofit geothermal HVAC systems as part of their monthly electric bill.

Electrical service providers have made energy-efficiency retrofits available to consumers for years. The utility companies use their reserves or third-party capital providers to cover the cost of the efficiency upgrade projects. Consumers/businesses are then obliged to pay the costs back over a period of 20 yr. on their electric utility invoice. These programs seem to be gaining favor and continue to grow, as shown by House Bill 1428, MD., “Public Utilities-Geothermal Heating and Cooling On-Bill Financing-Pilot Program,” initiated in February, 2013.

Third-party capital providers have emerged with programs such as “In-Electric Rate Funding,” introduced in January 2013 by Constellation Energy.

Geothermal Utility Services are a promising program that has been party to a market penetration of almost 40% of heating system replacements in Canada in 2011 according to the Canadian GeoExchange Coalition. Geothermal Utility Services, such as Canadian based GeoTility, and its US sister company, OrcaEnergy, cover the cost of the exterior geothermal ground heat exchanger/well system. The consumer then pays a one-time connection fee and a predetermined monthly utility charge to the geothermal utility. The consumer is then only concerned with the cost of the geothermal heat pump/chiller upgrade and is still eligible for many of the other programs mentioned, including the federal tax incentives (U.S.).

But, how much more do geothermal HVAC systems cost than standard HVAC systems? That subject is covered in the Commercial Conversation podcast, “Breaking New Ground With Geothermal.”

Briefly, standard HVAC systems may cost about $3,000/ton, compared with geothermal HVAC systems that may cost $5,000 to $6,000/ton at the lower range tonnage (less than 500 tons). As the tonnage goes up, the cost per ton goes down until, in many cases, a geothermal HVAC system can have a competitive first cost comparable to a standard HVAC system.

In other words, when a commercial entity takes advantage of federal incentives for geothermal HVAC systems, they are realizing essentially a 48% cost reduction benefit on the entire mechanical system. One can be reasonably assured that the resultant first cost of the system can actually end up being substantially less than the first cost of a standard HVAC system.

However, the federal incentives and energy efficiency of a geothermal HVAC system, though compelling, are secondary to some of the other tangible benefits of going geothermal. Consider the following advantages that can be attained only with geothermal:

  • Elimination of outdoor equipment
  • Storm proofing (geothermal equipment is sheltered from storm events)
  • Longevity of system (a result of all indoor equipment)
  • Elimination of fresh water consumption (from commercial cooling towers)
  • Elimination of fossil-fuel consumption (on-site)
  • Superior comfort in heating and cooling modes (more on this in future columns)
  • Enabling thermal load sharing (swimming pools, domestic hot water, HVAC re-heat)
  • System efficiency, as high as 40 EER.

You can see that we are in a favorable market with the many incentives for the implementation of commercial geothermal HVAC technologies. It does take a little legwork on the part of the contractor, engineer, and consumer. Construction professionals that up-sell to geothermal HVAC have all of these resources available to them.

Jay Egg is a geothermal consultant, writer, and the owner of EggGeothermal, Kissimmee, FL. He has co-authored two textbooks on geothermal HVAC systems published by McGraw-Hill Professional. He can be reached at

PNNL and PPG to develop dynamically responsive IR window coating

pnnlThe Pacific Northwest National Laboratory (PNNL) and PPG have been awarded up to $750,000 to design a coating that can “switch” from a solar IR-reflecting state to a solar IR-transmitting state while maintaining high levels of daylight transmittance in either condition. PPG will provide an additional $78,000 in cost-sharing.

The development of such a coating would represent a major advance compared to current thermochromic window technology, which involves coatings that darken and block visible light when exposed to high volumes of IR energy, and existing electrochromic window technology, which relies on external power sources such as electricity to balance tinting and light transmittance.

The new PPG/PNNL coating technology also has the potential to be inexpensive, which will help ensure that dynamically responsive IR windows are an economical option for use in residential and commercial retrofit applications.

The two-year project is designed to develop dynamically responsive IR window coatings on a laboratory scale. If development is successful, the product could be scaled up and potentially commercialized within several years. PPG also collaborated recently with PNNL to develop and study waste-heat recovery technologies to save energy in the glass manufacturing process.

Building energy management systems sales to reach $5.6B by 2020

BuildingEnergyManagement_IconThe market for building energy management systems (BEMSs) continues to grow, driven by technology advances as well as a growing familiarity among customers with the benefits that BEMs provide. A number of new and existing companies are developing software-based platforms to help customers squeeze cost-reducing energy efficiency and operational benefits out of their building portfolios. According to a new report from Navigant Research, worldwide revenue for BEMSs will reach $5.6 billion annually by 2020, more than doubling from the 2013 level.

While many BEMS vendors have developed platforms with commercial and government customers in mind, the utility sector is playing an increasingly important role in the BEMS market, according to the report. Utilities face a growing number of regulations, such as energy efficiency resource standards in the United States, that require them to play a proactive role in reducing the energy consumption of their customer base. A BEMS deployed by a utility to its customers provides energy efficiency gains that utilities can claim in compliance with such regulations.

An Executive Summary of the report is available for free download on the Navigant Research website.

NRDC, NYU to recognize most energy-efficient commercial real estate tenants

nrdcThe Natural Resources Defense Council (NRDC) and New York University (NYU) have started a new initiative to tackle carbon pollution in the U.S. by encouraging tenants of commercial buildings to save energy. If successful, the initiative should not only reduce carbon dioxide pollution created by America’s buildings, but also save commercial real estate tenants money on their bills.

Thanks to an award from the new Real Green Research Challenge from CBRE (the world’s largest commercial real estate services firm), NRDC will collect and analyze energy usage info for commercial office tenants within CBRE’s portfolio and provide feedback on how they compare to their peers. This will allow NRDC and the commercial tenants to work together to help improve energy efficiency. (A recent NRDC case study shows that the first tenant to undertake this approach is projected to reduce energy use in its office space by nearly 30%, saving $1.8 million over the course of the 15-year lease.)

NRDC will also be *recognizing the nation’s top commercial tenant energy performers* by developing a rating system for comparative tenant energy use that provides a quantitative foundation for identifying and promoting energy efficient practices.

NRDC’s Yerina Mugica blogs in greater detail about the new Tenant Recognition Initiative on the NRDC Staff Blog.

IKEA plugs-in solar panels at Boston-area store


This solar array–at the Stoughton, MA IKEA store–can generate nearly 600 kW of AC power.

IKEA recently installed a solar energy system at its store in Stoughton, MA. The 118,000-square-foot PV array includes 4,220 laminated panels and can generate up to 590.8 kW. The installation will produce approximately 695,000 kWh of clean electricity annually, the equivalent of reducing 479 tons of carbon dioxide (CO2), eliminating the emissions of 94 cars or powering 60 homes yearly (calculating clean energy equivalents at

This installation represents the 38th completed solar project for IKEA in the U.S., with one more location underway, making the eventual IKEA solar presence nearly 90% of its U.S. locations, with a total generation of 38 MW. IKEA owns and operates each of its solar PV energy systems atop its buildings – as opposed to a solar lease or PPA (power purchase agreement) – and globally has allocated $1.8 billion to invest in renewable energy through 2015. This investment reinforces the long-term commitment of IKEA to sustainability and confidence in photovoltaic (PV) technology. Consistent with the company’s goal of being energy independent by 2020, IKEA has installed more than 250,000 solar panels on buildings across the world and owns/operates approximately 110 wind turbines in Europe.

For the development, design and installation of the Stoughton store’s customized solar power system, IKEA contracted with REC Solar, Inc., a national leader in solar electric system design and installation with more than 9,000 systems built across the U.S.

IKEA, drawing from its Swedish heritage and respect of nature, believes it can be a good business while doing good business and aims to minimize impacts on the environment. IKEA evaluates locations regularly for conservation opportunities, integrates innovative materials into product design, works to maintain sustainable resources, and flat-packs goods for efficient distribution. U.S. sustainable efforts include: recycling waste material; incorporating key measures into buildings with energy-efficient HVAC and lighting systems, recycled construction materials, warehouse skylights, and water-conserving restrooms; and operationally, eliminating plastic bags from the check-out process, phasing-out the sale of incandescent light bulbs, facilitating recycling compact fluorescent bulbs, and by 2016 selling and using only L.E.D. bulbs. IKEA also installed electric vehicle charging stations at nine stores in the Western U.S.

More Companies Join Better Buildings Challenge

Department of EnergyThe Obama Administration announced recently that six new major U.S. companies are joining President Obama’s Better Buildings Challenge, which encourages private sector leaders across the country to commit to reducing the energy use in their facilities by at least 20 percent by 2020.  Starbucks Coffee Company, Staples, and The J.R. Simplot Company will upgrade more than 50 million square feet of combined commercial building space, including 15 manufacturing facilities. Financial allies Samas Capital and Greenwood Energy will also make $200 million in financing available for energy efficiency upgrades through this national leadership initiative. Utility partner Pacific Gas and Electric (PG&E) has also committed to offering expanded energy efficiency programs for its commercial customers, who are responsible for 30 million square feet of commercial building space.

The Better Buildings Challenge is part of the Obama Administration’s comprehensive strategy to improve the competitiveness of American industry and business, by helping companies to save money by reducing energy waste in commercial and industrial buildings.  Under the Challenge, private sector CEOs, university presidents and state and local leaders commit to taking aggressive steps to reduce the energy used in their facilities and sharing data and best practices with others around the country.  With the addition of today’s partners and allies, nearly 70 organizations have now joined the Better Buildings Challenge.  Together, these organizations account for more than 1.7 billion square feet of building space, including more than 300 manufacturing plants, and have committed almost $2 billion to support energy efficiency improvements nationwide. For more information, please visit the Better Buildings Challenge website.

The energy to operate the buildings where we work, shop, and study costs the U.S. approximately $200 billion annually. Last year, commercial and industrial buildings consumed more than 40 percent of all the energy used by the U.S. economy.  The goal of the Better Buildings Challenge is to support building upgrades to make America’s buildings 20 percent more energy efficient over the next decade, while also reducing energy costs for American businesses and local governments by more than $40 billion and creating jobs for U.S. workers.