Executive Summary

SGL Group is one of the world's leading manufacturers of carbon-based products and has a global structure with forty five production facilities throughout the world. Twenty four of these sites are in Europe, twelve in North America and nine in Asia. The Company also has a service network covering over a hundred countries.

One of SGL Group’s products, Ecophit® L lightweight construction paneling, is a homogeneous, binder-free material made from expanded natural graphite that has a high thermal conductivity that is conductive to energy efficient HVAC systems such as radiant ceiling cooling systems.

This product provides energy savings which, in turn, reduce greenhouse gas emissions, and noise levels, while improving thermal comfort, air quality, and fire resistance. It is binder free with no VOC content, and can be manufactured using recycled graphite.

Wiesbaden, Germany based SGL Group worked with GB to complete a review of their Ecophit® L lightweight construction panel product.

GB’s team of LEED® Accredited Professionals performed a benchmark analysis of SGL Group’s Ecophit® L lightweight construction panels and determined that their products may:

- Improve Building Durability
- Reduce Demand for Raw Materials
- Conserve Energy and Electricity
- Improve Indoor Environmental Quality
- Reduce Greenhouse Gas (GhG) Emissions

GB believes that several characteristics of SGL Group’s Ecophit® L lightweight construction panels are congruent with green building principles and, as such, the products may be considered applicable to high-performance buildings and may contribute meaningfully to green building projects that pursue LEED® Certification. (A full PDF version of this report may be downloaded by clicking the link at the bottom of this page.)

Details

Carbon is a non-metallic element that is the most abundant material on Earth. Graphite is an allotrope of carbon, meaning that it is the same element as carbon but in a different physical form. Diamonds and charcoal are other allotropes of carbon. However, while a diamond is a very poor conductor of energy, graphite is an excellent conductor. Its conductivity makes graphite an outstanding material to use in products designed for building energy systems.

The base material for the Ecophit® L panel is expanded natural graphite, which is made by immersing graphite flakes in an intercalculation solution. During the production process, the graphite flakes increase in volume by a factor of 200 to 400. This expanded graphite can then be manufactured into a range of materials which are very light with high thermal and electrical conductivity. Such effects are possible because the expansion of the graphite enlarges the surface area which in turn reduces the material’s density while keeping its high conductivity.

Expanded graphite is an inert, non-flammable substance that is easily recyclable, with no binders, chemicals or emissions. This material can also shield against electromagnetic interference as well as attenuate sound and reduce noise.

APPLICATIONS

Radiant cooling systems are a type of hydronic HVAC system in which chilled water is run through pipes in the building components such as walls, ceilings and floors, which cools the room through radiation and natural convection, very similar to a “chilled beam” system.

With a radiant cooling system, thermal comfort is determined not only by the temperature of the air around you, but also a combination of the ambient air and heat being radiated to or from objects nearby. A surface which is exposed to the occupants must be cooler than the ambient air to provide radiant cooling. Occupants and other objects (coffeepots, live plants, etc.) then radiate heat to the object, causing a sense of cooling. This is similar to radiant heating, and in many cases can use the same system of piping as the heating system. Radiant floors are popular for heating, while walls are often not ideally located to give even heating to all occupants. Therefore, the most popular choice has been ceilings.1 Ecophit® lightweight graphite panels make excellent ceiling panels to enshroud these chilled water pipes because of their high thermal conductivity as well as their light weight. Often these panels are incorporated into a ceiling grid system.

This type of HVAC system only addresses the sensible heat load in the room however, and a secondary system, typically a Dedicated Outdoor Air System (DOAS), is required to handle the latent heat load.2

Improve Building Durability

A key green building principle is the improvement of building quality and durability to reduce or eliminate the frequency of building maintenance, replacement and repair. Often, the greenest buildings are those that do not need to be replaced. Durability is the ability of any building or any of its components to perform its required functions in its service environment over a period of time without unforeseen, or significant incremental cost, maintenance or repair.3 Products that help promote a durable design and ongoing performance enhancements may result in a building that will last longer, thereby avoiding future downstream waste.

A radiant panel cooling HVAC system is a basic air-and-water system. First costs are competitive with other systems, and a life-cycle cost analysis often shows that the long life of the equipment makes it the least expensive in the long run.4

Reduce Demand for Raw Materials

By incorporating recycled content into building materials, green builders may not only reduce the impact that results from the extraction and processing of raw materials, but also reduce the volume of solid waste that is produced as a byproduct of our built environment.

Graphite is a material that can be recycled fairly easily and used over again without losing its material properties. For special applications, recycled Ecophit® products may be used as additives, including for the Ecophit® L construction panel.

Conserve Energy and Electricity

According to the U.S. Department of Energy, residential and commercial buildings are responsible for approximately 39% of the energy consumed in the United States. In the European Union (EU), approximately 50% of the energy consumed is by residential and commercial (services) buildings.5 HVAC systems consume a large percentage of total building energy usage, and it is estimated that a significant portion of this energy use would be unnecessary if all buildings used energy-efficient HVAC systems.

Cooling of non-residential buildings equipped with all-air HVAC systems contributes significantly to electrical energy consumption and to peak power demand. Part of the energy used to cool buildings is consumed by the fans that transport cool air through the ducts. This energy heats the conditioned air, and therefore adds to the internal thermal cooling peak load.

Total HVAC energy usage and peak demand in cooling may be reduced by up to 12-45%;6 this is corroborated by studies by the Lawrence Berkley National Laboratory7 and reports by ASHRAE2. With a radiant cooling system, one can maintain the air warmer than an all-air system, since one is using the radiant cooling to cool people, not the air, and the cost of pumping the water is much less than moving the required air with fans. Radiant ceilings, used in combination with a DOAS, could reduce commercial building HVAC energy consumption by about 0.6 quads relative to VAV systems.8 Indeed, depending on geographic location, savings may range from 15%-45%, averaging a 30% reduction in total HVAC energy usage and 27% reduction in demand.7 In many cases, the initial cost of installation can actually be lower when all design impacts are taken into account. The requirement for fans, ducting, and plenums is much lower with radiant systems.

Thermal Energy Storage (TES) is a type of Demand Management system that can help a building owner save on energy demand costs. While TES systems don’t actually save much facility energy in the form of BTUs, they will produce and “store” heat energy (hot or cold) during off-peak hours (i.e. at night) in order to use this energy during peak hours, thus reducing the energy demand and associated demand charges. If peak loads were reduced across the board, smaller, more efficient power plants could be used, thus reducing air pollution, greenhouse gas emissions while providing better energy quality and security.
The sustainable benefits of TES systems may be measured at the source of electrical generation. Research from a 1996 California Energy Commission report finds that there is approximately 20% savings in raw fuel consumption (coal) when electricity is produced during off peak hours9.
The thermal storage capacity of the coolant in radiant panel cooling systems helps to shift the peak cooling load to later hours. Because of the hydronic energy transport, this cooling system has the potential to interact with thermal energy storage systems and looped heat pump systems.10

Improve Indoor Environmental Quality

Providing a comfortable thermal environment while improving indoor environmental quality enhances occupant health, productivity and well-being and is an essential goal for any green building. The U.S. Environmental Protection Agency (EPA) estimates that indoor pollution and/or contaminant levels may be two to five times (and potentially up to one hundred times) greater than outdoor levels. Potential threats to indoor environmental quality include the presence of hazardous chemicals, high concentrations of airborne fibers, and smoke, mildew, mold and/or fungus contamination, as well as excessive noise.

Metal radiant acoustic panels work almost silently and can provide heating, cooling, insulation and sound attenuation. They are easily maintained and have a life expectancy in excess of 30 years. These systems are quiet, comfortable, draft-free, easy to control, and it responds quickly. Metal ceiling panels can be perforated so that the ceiling becomes sound absorbent when acoustical material is installed on the back of the panels. The acoustical blanket is also required for thermal reasons, so that the reverse loss or upward flow of heat from the metal ceiling panels is minimized. Hydronic ceiling panels have a low thermal resistance and respond quickly to changes in space conditions. Although piping embedded in walls is not as widely used as floor and ceiling panels, it can be constructed by any of the methods outlined for ceilings or floors. Its design is similar to other hydronic panels.4

HVAC systems are designed to maintain indoor air quality and provide thermal space conditioning. All-Air VAV Systems use the air to perform both tasks and achieve the task of thermal space conditioning by convection only. As mentioned above, radiant cooling panel systems achieve this task through a combination of radiation and convection. By providing cooling to the space surfaces rather than directly to the air, radiant cooling panel systems allow the separation of the tasks of ventilation and thermal space conditioning. While the primary air distribution is used to fulfill the ventilation requirements for a high level of indoor air quality, the secondary water distribution system provides thermal conditioning to the building. Radiant cooling panel systems significantly reduce the amount of air transported through buildings, as the ventilation is provided by outside air systems without the recirculating air. Due to the physical properties of water, radiant cooling panel systems remove a given amount of thermal energy and use less than 5% of the otherwise necessary fan energy. The separation of tasks not only improves comfort conditions, but increases indoor air quality and improves the control and zoning of the system as well. Radiant cooling panel systems combine temperature control of the room surfaces with the use of central air handling systems.9

Only a small fraction of the fresh outdoor supply air is necessary to ventilate the buildings in order to maintain a high level of indoor air quality. For conventional HVAC systems the difference in volume between supply air and outside air is made up by recirculated air. The recirculated air is necessary in these systems to keep the temperature difference between supply air and room air in the comfort range. The additional amount of supply air, however, often causes draft as well as indoor air quality problems due to the distribution of pollutants throughout the building.

According to the 2000 ASHRAE HVAC Systems and Equipment Handbook, some of the principle advantages of radiant panel systems for human thermal comfort are:

• Comfort levels can be better than those of other conditioning systems because radiant loads are satisfied directly and air motion in the space is at normal ventilation levels.
• Supply air quantities usually do not exceed those required for ventilation and dehumidification.
• Wet surface cooling coils are eliminated from the occupied space, reducing the potential for septic contamination.
• Radiant panel heating and cooling and minimum supply air quantities provide a draft-free environment.
• Noise associated with fan-coil or induction units is eliminated.

In many instances, variable air volume (VAV) systems, supply less than the required outdoor air to a given space because of imbalance in the systems. The only air supplied in the radiant systems is outside air, so you are not circulating lots of stale air, and you can keep a constant or easily controllable volume of fresh air coming in with much less fan power, ducting, and noise. All-air systems have notoriously high rates of occupant complaints. The record in Europe so far suggests that occupant complaints in radiantly cooled buildings are far lower than those with all-air systems. This is probably largely due to the fact that with most radiant cooling systems, it is easier to have greater control of individual areas than with all-air systems.1

In fact, a DOAS used in conjunction with a radiant cooling panel can meet ASHRAE Standard 62 ventilation requirements with less ventilation airflow due to its inherent precision in delivering the required ventilation flows in the aggregate and to individual zones in the building.8

Reduce Greenhouse Gas (GhG) Emissions

The vast majority of electricity consumed in the world is initially generated through the burning of fossil fuels, such as coal, at conventional power plants. A byproduct of the operation of coal‐fired power plants is the production of a significant amount of greenhouse gases (GhG) and other harmful pollutants.

Globally, the primary sources of greenhouse gas emissions are the energy supply sector (26%) and industry (19%). Residential and Commercial buildings contribute approximately 8% to worldwide GhG emissions. Carbon dioxide from fossil fuel use accounts for 57% of all global GhG emissions,11 and in the United States alone this percentage is even higher (85%). The process of generating electricity is the single largest source of CO2 emissions in the U.S., representing 41 percent of all CO2 emissions.12

According to the U.S. Green Building Council and the U.S. Environmental Protection Agency, for each megawatt of coal generated electricity produced, an average of 2,249 pounds of carbon dioxide, 13 pounds of sulfur dioxide and 6 pounds of nitrogen oxides are released into the atmosphere. Indeed, more than 65% of the sulfur dioxide pollution in the U.S., or approximately 13 million tons per year, is the result of coal fired power generation.

Radiant panel cooling systems are more sustainable than conventional systems because they allow for reduced equipment and power plant size, which can in turn reduce the amount of pollutants produced in electrical generation as well as greenhouse gas emissions. As mentioned previously, if peak loads were reduced across the board, smaller, more efficient power plants could be used, thus reducing air pollution, greenhouse gas emissions while providing better energy quality and security.

The use of Ecophit® L panels reduces natural gas and electricity demand and, therefore, reduces the amount of GhG emissions released into the atmosphere from fossil fuel fired power generation.

LEED® Credits

To earn certification under the Leadership in Energy and Environmental Design (LEED®) rating systems, projects must not only satisfy all LEED® system prerequisites, but also earn a minimum number of points. Projects may earn a range of sequentially higher LEED® certification ratings as determined by their compliance, as well as exemplary performance, in the credit categories within each system.

When applied properly, Green Buildings believes that SGL Group’s Ecophit® L panels may contribute materially toward earning points in a LEED® certification in certain prerequisite(s) and/or credit(s) listed in Tables 1 and 2 under the:

- LEED® Green Building Design and Construction Rating System (BD+C, 2009, which includes New Construction & Major Renovations, Core & Shell and Schools)

- LEED® for Healthcare Rating System.

Please note that no individual material or product enables a credit or certification within the LEED® rating system due to the fact that each category is dependent on the aggregate of all materials and their proportionate relationship to the total dollar cost of all materials. See individual product data sheets for details and check with local sales representative for appropriate product applications and eligibility.

LEED BD+C (New Construction & Major Renovations, Core & Shell, Commercial Interiors and Schools) Contribution Chart

Energy & Atmosphere (EA)
LEED Credit and Category	LEED Requirement	Product Contribution
Prerequisite 2: Minimum Energy Performance	Demonstrate a 10% improvement in the proposed building performance rating for new buildings and 5% in major renovations when compared with the baseline building performance rating as calculated per ASHRAE 90.1-2007 Appendix G using a computer simulation.	Radiant panel cooling systems with Ecophit reduce the energy as well as peak demand associated with heating and cooling a building.
MR Credit 5: Regional Materials (1-19 Points, New Construction/Schools OR 3-21 Points, Core & Shell)	Demonstrate a percentage improvement over the prerequisite amount in the proposed building performance rating compared to the baseline building using a computer simulation.	Radiant panel cooling systems with Ecophit reduce the energy as well as peak demand associated with heating and cooling a building.
Prerequisite 3: Minimum Energy Performance	Zero use of chlorofluorocarbon (CFC)-based refrigerants in new base building heating, ventilating, air conditioning and refrigeration (HVAC&R) systems.	Radiant panel cooling systems with Ecophit do not use any type of refrigerant, they use water.
Credit 4: Enhanced Refrigeration Management (2 Points)	Do not use refrigerants or select refrigerants and heating, ventilation, air conditioning and refrigeration (HVAC&R) equipment that minimize or eliminate the emission of compounds that contribute to ozone depletion and climate change.	Radiant panel cooling systems with Ecophit do not use any type of refrigerant, they use water.
Materials & Resources (MR)
Credit 4: Recycled Content (1-2 Points)	Use materials with recycled content such that the sum of post-consumer recycled content plus ½ of the pre-consumer content constitutes at least 10 or 20%, based on cost, of the total value of the materials in the project.	For special applications, recycled Ecophit® products can be used as additives, including for the Ecophit® L construction panel.
Credit 5: Regional Materials (1-2 Points)	Use building materials or products that have been extracted, harvested or recovered, as well as manufactured, within 500 miles of the project site for a minimum of 10 or 20%, based on cost, of the total materials value.	SGL Group has numerous manufacturing facilities around the world. Project site distances would have to be calculated for eligible Points.
Indoor Environmental Quality (EQ)
Prerequisite 1: Minimum Indoor Air Quality Performance	Meet the minimum requirements of Sections 4 through 7 of ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality	A DOAS used in conjunction with a radiant cooling panel with Ecophit can meet or exceed ASHRAE Standard 62 ventilation requirements with little affect on energy efficiency.
Credit 2: Increased Ventilation	Increase breathing zone outdoor air ventilation rates to all occupied spaces by at least 30% above the minimum rates required by ASHRAE Standard 62.1-2007	A DOAS used in conjunction with a radiant cooling panel with Ecophit can meet or exceed ASHRAE Standard 62 ventilation requirements with little affect on energy efficiency.
Credit 6.2: Controllability of Systems - Thermal Comfort (1 Point)	Provide individual comfort controls for 50% (minimum) of the building occupants to enable adjustments to meet individual needs and preferences.	Most radiant panel cooling systems have greater control of individual areas than with all-air VAV systems.
Credit 7.1: Thermal Comfort - Design (1 Point)	Design HVAC systems and the building envelope to meet the requirements of ASHRAE Standard 55-2004, Thermal Environmental Conditions for Human Occupancy.	Comfort levels can be better controlled than those of other conditioning systems because radiant loads are satisfied directly and air motion in the space is at normal ventilation levels.
Credit 7.2: Thermal Comfort - Verification (1 Point in addition to CR 7.1)	Achieve IEQ Credit 7.1: Thermal Comfort—Design Provide a permanent monitoring system to ensure that building performance meets the desired comfort criteria as determined by IEQ Credit 7.1: Thermal Comfort—Design. Agree to conduct a thermal comfort survey of building occupants within 6 to 18 months after occupancy.	Comfort levels can be better controlled than those of other conditioning systems because radiant loads are satisfied directly and air motion in the space is at normal ventilation levels.
Prerequisite 3: Minimum Acoustical Performance (LEED BD+C for Schools)	Design classrooms/core learning spaces to include sufficient sound-absorptive finishes to comply with ANSI standards and meet maximum background noise levels for HVAC systems of 45 dBA.	Radiant panel cooling systems are much quieter than all-air VAV systems because of the lack of mechanical equipment.
Credit 9: Enhanced Acoustical Performance (LEED BD+C for Schools - 1 Point)	Design classrooms/core learning spaces to include sufficient sound-absorptive finishes to comply with ANSI standards to an STC rating of 35 and meet maximum background noise levels for HVAC systems of 40 dBA.	Radiant panel cooling systems are much quieter than all-air VAV systems because of the lack of mechanical equipment.
Innovation in Design (ID)
Credit 1: (1-5 Points)	Achieve significant, measurable environmental performance using a strategy not addressed in the LEED® 2009 for New Construction and Major Renovations Rating System. One point is awarded for each innovation achieved. No more than 5 points under IDc1 may be earned through PATH 1—Innovation in Design	Radiant panel ceiling cooling HVAC systems using Ecophit® lightweight panels which reduce building energy usage and improve indoor environmental quality may qualify for points in this category.

LEED for Healthcare Contribution Chart

Indoor Environmental Quality (EQ)
LEED Credit and Category	LEED Requirement	Product Contribution
Prerequisite 1: Minimum Indoor Air Quality Performance	Meet the minimum requirements of Sections 6 through 6 of ASHRAE Standard 170-2008, Ventilation of Health Care Facilities	A DOAS used in conjunction with a radiant panel cooling panel can meet or exceed ASHRAE Standard 170-2008 ventilation requirements with little affect on energy efficiency.
Credit 2: Acoustic Environment (1-2 Points)	Design the facility to meet or exceed the sound and vibration criteria outlined in the 2010 FGI Guidelines for Design and Construction of Health Care Facilities (2010 Guidelines) and the Sound and Vibration Design Guidelines for Health Care Facilities, including New Guidelines for NICUs (January 1, 2010; Version 2.0) (SV Guidelines).	Radiant panel cooling systems are much quieter than all-air VAV systems because of the lack of mechanical equipment.
Credit 6.2: Controllability of Systems - Thermal Comfort (1 Point)	Provide individual thermal comfort controls for every single occupant patient room AND provide individual thermal comfort controls for 50% (minimum) of the remaining building occupants to enable adjustments to meet individual needs and preferences AND provide comfort system controls for all shared multi-occupant spaces to enable adjustments that meet group needs and preferences.	Most radiant panel cooling systems have greater control of individual areas than with all-air VAV systems.
Credit 7: Thermal Comfort - Design and Verification (1 Point)	Design HVAC systems and the building envelope to meet the requirements of ASHRAE Standard 55-2004, Thermal Environmental Conditions for Human Occupancy. Provide a permanent monitoring system to ensure that the building performs to the desired comfort criteria as determined above. Agree to implement a thermal comfort survey of building occupants2 within a period of six to 18 months after Occupancy.	Comfort levels can be better controlled than those of other conditioning systems because radiant loads are satisfied directly and air motion in the space is at normal ventilation levels.
Materials & Resources (MR)
Credit 3: Sustainably Sources Materials and Products (1-4 Points)	One point and up to a maximum of four will be awarded for each 10% of the total value of all building materials and products used in the project (based on cost) that meet the criteria listed in the LEED® for Healthcare reference guide for salvaged/reused material, recycled material, regionally sourced material, rapidly renewing material and certified wood.	For special applications, recycled Ecophit® products can be used as additives, including for the Ecophit® L construction panel. SGL Group has numerous manufacturing facilities around the world. Project site distances would have to be calculated for eligible Points.
Energy & Atmosphere (EA)
Prerequisite 2: Minimum Energy Performance	Demonstrate a 10% improvement in the proposed building performance rating for new buildings and 5% in major renovations when compared with the baseline building performance rating as calculated per ASHRAE 90.1-2007 Appendix G using a computer simulation.	Radiant panel cooling systems reduce the energy and peak demand associated with heating and cooling a building.
Credit 1: Optimize Energy Performance (1-24 Points)	Demonstrate a percentage improvement over the prerequisite amount in the proposed building performance rating compared to the baseline building using a computer simulation.	Radiant panel cooling systems reduce the energy and peak demand associated with heating and cooling a building.
Prerequisite 3: Fundamental Refrigerant Management	Zero use of chlorofluorocarbon (CFC)-based refrigerants in new base building heating, ventilating, air conditioning and refrigeration (HVAC&R) systems.	Neither decentralized PCM based HVAC systems nor radiant panel cooling systems use any type of refrigerant.
Credit 4: Enhanced Refrigeration Management (1 Point)	Do not use refrigerants or select refrigerants and heating, ventilation, air conditioning and refrigeration (HVAC&R) equipment that minimize or eliminate the emission of compounds that contribute to ozone depletion and climate change.	Neither decentralized PCM based HVAC systems nor radiant panel cooling systems use any type of refrigerant.

Conclusion

The SGL Group Ecophit® L lightweight construction panels meet five significant criteria used in green building initiatives. Through their sustainable sourcing, recycled materials, fire resistant material qualities and excellent acoustical and air quality as well as energy efficient properties, these materials can improve building durability, maximize energy efficiency, minimize heat and/or cooling loss, improve indoor environmental quality and minimize impact on the environment through decreased usage of raw materials for building construction.

All of these characteristics make the SGL Group Ecophit® L lightweight construction panel a product that Green-Buildings.com would recommend for any project with sustainable design or performance goals or any project that is pursuing LEED® certification.

Case Study: Deutsche Bank AG "Green Towers" Renovation

Executive Summary

Deutsche Bank’s “Green Towers” became one of Europe’s most prominent green building renovations. Indeed, the project was pursued with the intention of developing the most environmentally friendly skyscrapers in the world as well as the first renovated LEED® certified skyscrapers.

Originally planned as a renovation to improve the building’s fire protection systems, the “Green Towers” project blossomed into a full analysis and sustainable renovation of the entire 121,522 m2 building.

The result is a building designed to use 50% less energy and 74% less water than before and reduce its CO2 emissions by almost 90%. The successful renovation also created a new workplace environment that enhanced productivity and employee satisfaction.

Highlights

- Project Name: Deutsche Bank “Green Towers” – Project Blue
- Location: Frankfurt, Germany
- Building Type: Commercial Office Space; Skyscraper
- Certification:
- LEED Platinum (v2.2)
- Deutsche Gesellschaft für Nachhaltiges Bauen (DGNB – German Sustainable Building Council) Certified Gold (Highest Level)
- Project Scope: Two Towers, ~35 floors each plus 4-floor base.
- Gross Floor Space: 121,522 m2; Net Floor Space 103,354 m2
- Height: 155 m
- Setting: Urban
- Built: Originally completed in 1984; Renovation completed in 2010
- Owner: Deutsche Bank AG
- Architect: Marco Bellini Architects, Milan Italy
- Energy Savings Following Renovation: 19.8 GWh

Details

Estimated GhG and Energy Savings

The building’s innovative and sustainable measures are many and include ample daylighting, coupled heating, cooling and heat recovery systems, energy efficient triple-paned windows, intelligent lighting controls, green IT solutions, natural ventilation, solar hot water heating and regenerative drive elevator technology.

The resulting savings include:

- 89% less CO2; roughly corresponds to the emissions of 6,000 cars each driving 12,000 km (primary energy – 55% through lower consumption and 34% through regenerative energy).13,14
- 67% less heating and cooling; roughly corresponds to the heating power required for approximately 750 family homes.
- 55% less electricity consumption; corresponds to the electricity used annually by approximately 1,900 family homes.
- A designed total of 19.8 GigaWatt hours (GWh) of energy saved.

HVAC System

The heating and cooling ceiling system with Ecophit is equipped with newly developed radiant elements for the thermal activation of the building’s mass – resulting in a 20% higher thermal output than conventional systems. As radiant cooling and heating operates by circulating water, as opposed to a forced air cooling system, the air exchange rate can be reduced from 6 to 1.5 times the volume. As a result, the new ventilation systems will consume less than half the electricity. The energy used for generating cooling will be significantly reduced through “free cooling”.

Ecophit L Lightweight Construction Panels

The HVAC system at Deutsche Bank Green Towers is assisted via heating and cooling ceilings using the SGL Group's Ecophit® L lightweight construction panels, together with concrete core cooling.

The system relies on the storage capability of the concrete on the one hand and the excellent heat transfer properties of the Ecophit® L lightweight construction panels on the other. The ultra-lightweight Ecophit® L graphite panels are employed in cooling ceiling elements located beneath the concrete ceiling. When installed, they provide very rapid distribution of the cold and heat.

During the night, when cool water flows through the elements in direct contact with the concrete ceiling, the cold is released into the concrete, where it is stored. Later, when operating during the following day, the system absorbs the thermal energy into the cool concrete, and hardly any extra energy is needed.

Nighttime cooling energy can either be obtained directly from the cooler night air or from electricity at the cheaper night (off peak) tariff. This system "actively" involves the thermal mass, i.e. the storage capacity of the concrete, in the energy management of the building.

In the Deutsche Bank towers the employment of Ecophit® L ceiling elements puts the existing concrete thermal storage system to very effective use. Advantages include:

- Convection and radiation "Gentle cooling" largely mimics naturally occurring conditions and is therefore perceived as extremely pleasant by building occupants
- The less drafty nature of the air stream, which now flows into the rooms gently and silently
- The simple use of alternative cold-water and hot-water generation systems, and
- Low flow temperatures that require only modest amounts of energy and produce considerable energy savings.

Because the Ecophit® panels also improve the thermal output per element even more, the heating or cooling surface needed for room air conditioning is considerably smaller in area than that of systems without graphite/concrete core cooling. This further reduces operating costs.

Other Features and Benefits

The windows opening parallel to the façade are equipped with motorized scissor hinges – making it possible to have natural ventilation even at wind speeds of up to 180 km/h.

The tubular lights especially designed for the office floors are equipped with high-tech prism technology – achieving a light output of 86%.

- 98% recycling rate 30,500 tons of material recycled during the renovation work and 15,000 m² of office space equipped with re-used materials
- 74% saving in annual water consumption, enough to fill 22 Olympic-sized swimming pools. Low flow fixtures as well as rainwater harvesting technologies and on-site water treatment contributed to these savings.

Toilet fixtures have a highly efficient flushing technology – using 30 percent less water than comparable modern systems.

Rainwater and grey water are collected, treated and used for the outdoor watering systems as well as the WC and urinal flushing systems throughout the entire building complex.

Conclusion

Overall the Deutsche Bank “Green Towers” demonstrates just how sustainable an existing building can become with the proper integrated planning and design. Indeed, LEED® Platinum certification, as well as its DGNB Gold certification, is the highest certification for both organizations.

The Ecophit® L lightweight panels were a significant contributor to the energy efficiency of this building and assisted in earning credits towards both the DGNB and LEED® certifications.

Download the Certification Report:

Related Products:

• EAS: Sound Absorption Panels