Navigant Research Blog

New Home Bundles Energy Technology for High Efficiency

— June 4, 2014

There are numerous examples of highly energy efficient homes on the market, all featuring various types and combinations of technologies.  For instance, Garbett Homes and Vivint have created a net-zero home in Utah that features a zero rating on the Home Energy Rating System (HERS) Index.  Builder KB Home has completed a house in Lancaster, California that is designed to use net-zero energy and zero freshwater for irrigation.

Similarly, Sacramento Municipal Utility District (SMUD) has been involved in net-zero residential projects for several years.  Also, Meritage Homes offers net-zero homes at several of its communities in Arizona and Nevada.  In addition, automaker Ford has partnered with several companies for its MyEnergi Lifestyle initiative that aims to demonstrate how homeowners can lower electric bills and reduce carbon emissions with a combination of solar photovoltaic (PV) panels, smart appliances, and plug-in electric vehicles.

AC Included

A new custom home in Houston, Texas offers another angle on residential energy efficiency that leverages the relatively low cost of natural gas as a way to lower electricity costs.   The spec home features a micro-trigeneration system that is the first of its kind available for the residential market, according to the manufacturing company, M-CoGen.  At the heart of the home’s energy production is a natural gas-powered unit, which operates with a traditional micro combined heat and power (microCHP, also called residential CHP, or resCHP) system and adds cooling and storage capabilities.  The system can reduce overall electricity use by up to 70%.  By adding cooling functionality, the system carries a new moniker: micro combined cooling, heat, and power (microCCHP).  The system also incorporates a battery bank for energy storage and provides power management controls to enable the home to shed load and make decisions on time-of-day usage.

While this microCCHP system does not bring the home to net-zero functionality, it does provide homeowners with another alternative to the traditional one-way consumption model, particularly in markets where natural gas is plentiful and relatively affordable.  Whether this particular generation solution will scale to thousands of new homes remains to be seen.  Over time, though, this and the other combinations of onsite generation, storage, and energy management technology have a chance to disrupt the residential energy market, as rooftop solar PV systems have been doing for a number of years.


Johnson Controls’ Air Distribution Technologies Buy: More Than Meets the Eye

— May 12, 2014

Johnson Controls made news in April with the announcement that it will acquire Air Distribution Technologies from Canada Pension Plan Investment Board (CPPIB) for $1.6 billion.  Air Distribution Technologies makes ventilation systems under several brands, including Hart & Cooley, Ruskin, and Titus.  The move appears to be a straightforward horizontal integration that will enable Johnson Controls to capture a larger share of total construction spending.  The acquisition will allow building owners to turn to the same company for HVAC equipment, HVAC controls, security and fire safety systems, energy management, and now air distribution.  Indeed, Johnson Controls is already selling air distribution equipment through its FlexSys line of underfloor air distribution (UFAD) systems.  According to CEO Alex Molinaroli, “This investment expands Johnson Controls’ position in the buildings space with additional products that are complementary to our existing heating, ventilation, and air conditioning offerings.”

The Future of Controls Integration

However, this move could be more than a simple expansion of a product portfolio.  At this year’s Building Energy Summit, Grundfos provided a glimpse into the future of controls integration with its MAGNA3 pump line.  What is striking about these pumps is how little work they leave for a controls company (such as, say, Johnson Controls).  They include a built-in heat energy meter, an integrated temperature and differential pressure sensor, and optimized building management communication.  Additionally, wireless communication permits the pump to connect with another MAGNA3 pump, allowing multiple pumps to be controlled jointly through a single connection to a building automation system (BAS).  The wireless communication also connects to the Grundfos GO mobile app.  Much of what used to be accomplished by field integration is now shipped in the same box as the pump.

This level of controls integration may reach airside equipment, too.  Imagine a system where temperature sensors are integrated into return grilles.  UFAD systems already allow for individual diffuser control, but if a traditional air distribution system were to include diffuser-level damper control, it would enable every individual occupant to create its own ideal environment and would do so without much of the equipment needed to provide control today.  Could this model of integrated controls be the next big step in airside equipment?  The integration of Air Distribution Technologies into Johnson Controls might provide an answer.


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.  Although 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.


New Chinese Subsidies Target Improved Building Efficiency

— June 10, 2012

The Chinese government recently announced a series of subsidies and incentive schemes aimed at energy efficiency and renewable energy proliferation around the country and on June 1, it started offering subsidies for televisions and fixed-speed air conditioners.  The total volume of available subsidies will be about RMB 26 billion ($4 billion), though the program aims to use the subsidies to drive total consumption of RMB 450 billion ($70 billion).  The program represents part of a national plan to stimulate domestic consumption in 2012 by investing RMB 170 billion ($27 billion). Of that sum, more than 50% will be aimed at energy efficiency and renewable energy products under a series of subsidies (that haven’t been announced yet) and other incentive programs.

China represents the world’s largest construction industry, and about 2 billion square meters of new space are added to China’s building stock ever year, as described in Pike Research’s report entitled “Global Building Stock Database.” A surge in energy consumption has accompanied this growth and China surpassed the United States as the largest emitter of greenhouse gases a few years ago.  However, a recent report from the International Energy Agency adds that China’s carbon emissions intensity per unit of GDP fell by 15% between 2005 and 2011.

In an effort to curb its carbon emissions growth, China’s 12th Five Year Plan, released in 2011, laid out the Chinese government’s ambitions to reduce energy consumption per unit of GDP by 16% from 2010 to 2015.  This most recent wave of subsidies is aimed at helping China meet these goals by targeting specific energy-intensive appliances – televisions and air conditioners – that are responsible for a significant portion of the growth in China’s per-capita energy consumption.

As I wrote in Pike Research’s recent white paper, “Smart Buildings: Ten Trends to Watch in 2012 and Beyond,” the Asia Pacific region’s size relative to the rest of the world is not always reflected in revenues for energy efficiency technology.  Despite the region’s dynamic construction activity, it represents just 25% of the global market for building automation systems (BAS) and controls, 20% of the global market for building energy management systems (BEMS), and 17% of the global market for intelligent lighting controls.  However, as the Chinese government bolsters sales of energy efficiency equipment in the next few years through subsidies and other regulations, China’s market share for smart building technology is expected to grow, placing the building industry at the center of China’s strategy to reduce the energy intensity of its economy.


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