Richard Breault, Viessmann, U.S.

Commercial Products for LEED® Building Design and Construction

Viessmann White Papers: Technical updates and thought leadership from Viessmann US.

Sustainable building design has become a focal point in communities all around the world. Society is moving at an increasingly fast pace, and the United States Green Building Council (USGBC) produces new ideas, solutions, and strategies to move towards a greener environment. The LEED Green Building Rating System was created to set a standard in eco-friendly design and construction. This white paper will help guide you through the LEED certification system, and explain how particular products available on the market have the potential to help meet these criteria.

LEED at a Glance: New Construction

Why Choose to Pursue LEED?

LEED has emerged as one of the most widely accepted sustainable goals in the United States and internationally, for both public and private organizations1. Green building projects demonstrate the most cutting edge design, construction, and operation of newly constructed buildings. Reports by numerous institutions such as Grand View Research suggest that the size of the market for green building materials is forecasted to grow continuously and significantly2.

Green building design and construction is an initiative that brings advantages for developers in any industry. From an economic perspective, green building designs show significant long-term savings in utilities and operational costs. In fact, LEED Gold-Certified buildings boast 19% lower maintenance costs, 25% less energy consumption, and 11% less water, according to the U.S. Department of Energy1. In addition, preserving the community landscape, conserving natural resources, and promoting the welfare of the occupants makes a lasting social impact on a business or homeowner.

What Exactly Is LEED?

LEED® stands for Leadership in Energy and Environmental Design. While LEED does not certify individual products, the system certifies the overall characteristics of the design and construction of a building. This happens on a case by case basis. The list below includes some of the important categories of the LEED system which this document will discuss3.

Under each category is a series of prerequisites, credits, and points. After certain prerequisites are covered, points are awarded based on the completeness of available credits. After the total points are calculated, your building will be awarded a basic certification, or possibly a Silver, Gold, or Platinum rating.

How Can Viessmann Contribute to a LEED Certification?

Viessmann has committed its own design and manufacturing process to set standards in the industry and reflect values shared by the USGBC and LEED Certification System. Viessmann has proudly participated in the EU’s Eco Audit Scheme (EMAS), a rigorous environmental assessor, since 1993. Furthermore, Viessmann has received certifications for its exceptional environmental transparency and its energy management system4.
This white paper will guide you through the most relevant LEED topics when selecting a hot water boiler for your new building. By investing in Viessmann you will reap the benefits of our cutting-edge technology, reliability, and longevity, while advancing the interests of your business, your community, and the world5. Our products have great potential to make a positive difference in your LEED guided project.

Sustainable Sites - Point Potential: 1

What: Sustainable Sites Open Space Credit  | Point Potential: 1
Intent: To create exterior open spaces that encourage interaction with the environment, social interaction, passive recreation, and physical activities.

Why:  Globally, unsustainable practices have lead to severe issues, including, but not limited to, changes in our natural landscapes and oceans, deforestation, and chemical runoff. By employing sustainable building practices the negative environmental effects of these issues can be slowed or even prevented all together. Therefore it is critical to use sustainable practices in developing construction sites with integrated ecology, ecosystems, and human developments.

How:  The goal here is to maintain or arrange at least a quarter of the site’s outdoor area to be vegetated. It is ideal to preserve as much of the landscape as possible and to be mindful of both day to day and construction operations. In order to take full advantage of your site, you must consider eliminating useless space from the design of your building. This is an important step in making your site as efficient and sustainable as possible.

Minimizing indoor footprint

Some configurations offer little-to-no side clearance between boilers, eliminating considerable wasted space. These configurations include:

  • Low-Loss Distribution Manifold
  • Compact wall hung boilers to meet commercial-level loads
  • Up to 8 in one array
  • Align several Low-Loss Distribution Manifolds in series
  • Minimizes the number of penetrations through indoor walls and the roof
  • Up to 4 units can be common vented
  • Ease of entry through regular-sized doors and hallways
  • Common exhaust
  • Greatly reduces venting material

Water Efficiency - Point Potential: 8  

What: Outdoor Water Use Reduction Credit | Point Potential: 2  
Intent: To reduce outdoor water consumption.  

What: Indoor Water Use Reduction Credit | Point Potential: 6  
Intent: To reduce indoor water consumption.  

Why:  There is not as much available fresh water as you might think; roughly 97% of Earth’s water is held in the ocean, which is not fit for human usage or consumption6. The other 3% is fresh water, however more than two-thirds of that remains locked in glaciers and ice. This section addresses creative ways to minimize water consumption and reuse water from different sources.

How:  There are numerous methods and practices to cut down on water consumption. This category addresses ways establish efficient indoor and outdoor water fittings, fixtures, and/or systems. Creative solutions for water reuse is also encouraged under this category.

Alternative water sources
Your building will have large demands to meet for water consumption. Conserving as much water as possible is certainly ideal. The condensate from inside our condensing hot water boilers is steadily captured. It has potential to be re-purposed, rather than wasted. The returned water has many potential applications for greywater reuse. Greywater is gently used water from your bathroom sinks, showers, tubs, and washing machines. It is not water that has come into contact with the toilet or from washing diapers7.

In addition to water used for plumbing, greywater can be used to help reduce the project’s Landscape Water Requirement (LWR). Condensate is initially acidic; regardless of whether it is re-purposed or disposed of, greywater must be neutralized. Refer to the subheading “Option 2. Reduced Irrigation” and Table 1 under this credit in the LEED v4 Handbook for further details.

Domestic hot water recirculation
There are also methods to show reduction in potable water usage. A program is available on Viessmann's  B2HA/B's for use with a hot water recirculation pump. Although Viessmann does not provide the full system necessary, it comes programmed and simply needs to be enabled. The effect of this system is the elimination of standby water consumption at the faucet until the hot water arrives.


Energy & Atmosphere - Point Potential: 18  

What: Optimize Energy Performance Credit | Point Potential: 18  
Intent: To achieve increasing levels if energy performance beyond the prerequisite standards to reduct environmental and economic harms associated with excessive energy use.  

Why:  Reducing fossil fuel consumption begins with the concept of maximizing energy efficiency through smart design solutions. This will reduce greenhouse gas emissions and our dependency, worldwide, on nonrenewable fuels. This section looks into energy demands for your new building and aims to both lower it, thus reducing fuel/electricity consumption, operational costs, and harmful emissions.

The prerequisite standard requires a simulation of the minimum required efficiency for your building. To achieve the credit, you must demonstrate a simulation that is 5% more efficient than this baseline. Additional points are awarded for higher percentage improvements.

How:  Viessmann’s passion for  quality assurance  not only achieves industry efficiency standards under ideal conditions, but allows for maximum efficiency performance throughout the entire calendar year. Our products boast highest in-class efficiency ratings and compliance with several organizations‘ guidelines, including:

  • ASME Boiler and Pressure Valve Code
  • ASHRAE/IESNA 90.1 2016-“Gas and Oil Fired Boilers - Minimum Efficiency Requirements.”
  • AHRI BTS-2000
  • ANSI Z21.13 test standards for US & Canada
  • CSA Certification
  • CSD1- Control and Safety Devices
  • Energy Star Rated (B2HB)

Lambda Pro Control

  • This module communicates with the ionization electrode in the  B2HA/B  boilers. It automatically adjusts air/fuel ratio to achieve maximum efficiency and/or increase or reduce the flame. This keeps the burner at optimum combustion in order to always maintain the required heating load, cutting down on fuel consumption while ensuring proper combustion.

Efficient and effective combustion
Viessmann's line of commercial boilers have a programmed 5:1 turndown ratio. Having a lower turndown ratio ensures that the  burner is evenly lit. Maintaining a stable flame is important; the burner is designed to collapse the flame at very low  fire to prevent flame tear off. As a result, constant and complete combustion takes place while the boiler is firing. This results in less byproducts which are harmful to people and the atmosphere, such as carbon monoxide, carbon dioxide, and NOx gases.
In addition, Viessmann boilers achieve maximum condensing operation, due to the high mass design. Condensate contains latent heat, which can be extracted through the heat exchanger and be put to use instead of lost. This is how the company's products achieve such consistently high efficiency ratings.

Materials & Resources - Point Potential: 1  

What: Building Disclosure and Optimize Environmental Product Declarations Credit | Point Potential: 1  
Intent: To encourage the use of products and materials for which lifestyle information is available and that have environmentally, economically, and socially preferable lifestyle impacts. To reward project teams for  selecting products from manufacturers who have verified improved environmental lifecycle impacts.

Why:  Recycling technology and practices have greatly improved in recent years. With landfills all around the country reaching capacity, the demand for recyclable products is constantly increasing. This section examines the Life Cycle Assessment (LCA) of materials used in construction as well as products that will remain permanently in the building.

How:  Viessmann floor standing boilers are made of over 90% steel- a prime example of recycled materials and resource efficiency, as steel is 100% recyclable. In addition, we have been able to greatly reduce the variety of parts by applying modular strategy. This has a positive effect on storage, because overstocking is easily avoided. Packaging is also of the utmost importance. We have agreed with suppliers to use returnable systems, recyclable packaging materials, and as small a variety of materials as possible. Furthermore, we make the refractory of the  CM2  and  CA3  partially from potatoes.

Eco-friendly suppliers
To ensure that Viessmann uses the best quality materials from suppliers with shared environmental-values, a regular supplier audit is performed. As a company certified by EMAS and ISO 14001, it is ideal for suppliers to maintain the same certification. Viessmann guarantees top quality products from a sustainable standpoint based on this practice.

Durable materials
Viessmann condensing hot water boilers are equipped with titanium-infused stainless steel heat exchangers. This extremely durable material and patented design can withstand decades of use and makes maintenance very easy. Many other manufacturers sacrifice the quality of their heat exchangers by using a more reactive grade of stainless steel, which results in greater risk of corrosion issues.


Indoor Environmental Quality - Point Potential: 6  

What: Indoor Air Quality Assesment Credit | Point Potential: 3  
Intent: To establish better indoor air quality in the building after construction and during occupancy.  

What: Low Emitting Materials Credit | Point Potential: 2  
Intent: To reduce concentrations of chemical contaminants that can damage air quality, human health and productivity, and the environment.  

What: Thermal Comfort Credit | Point Potential: 1  
Intent: To promote occupants; productivity, comfort, and well-being by providing thermal comfort.  

Why:  The health, safety, and comfort of yourself and the occupants of your building must be a very high priority. It is crucial for the air indoors to be as clean, cool, and odor-free as possible. This section sets parameters for the indoor environment of the building, which regards the quality of thermal, visual, and acoustic comfort.

How:  Volatile Organic Compounds (VOCs) have a tendency to release fouls odors and in some cases gases, which can pose health risks in relatively high concentrations. Steps in the manufacturing process has shown great improvements in the reduction of VOC emissions.

  • The use of solvent-free alternatives have led to significantly less diffuse VOC emissions
  • Boiler cover plates have been powder coated since 1974, and in 1990 the boiler bodies as well. This is a cost, time, and overall eco-friendly alternative to wet painting. Wet painting contributes to more VOC emissions, regulations for storage and handling, processing times, and disposal costs.

New substances are never used without first checking if they are potentially hazardous. There are many substances that Viessmann regulates or prohibits in order to contribute to the safest and cleanest working environment possible8. All suppliers are obligated to comply with Viessmann’s policies on banned substances.

High mass boilers are hands down the best option when planning on microzoning your building. High mass means more water inside the boiler itself, which means there is no minimum flow requirement for the boiler. In addition, the larger volume of water eliminates the tendency for short cycling, and thus it operates more efficiently. Therefore, the energy produced by the boiler is more readily available to meet the varying demands around the building. Hence  “micro loads“ can be processed to meet the specific demands of the areas in your building, even though it is less than the boiler’s firing rate. In the boiler room itself, our commercial boilers also contribute to maximum comfort. Thanks to our well insulated design and highly efficient heat transfer, very little heat is lost to the boilers surrounding environment.


Innovation - Point Potential: 5  

What: Innovation Credit | Point Potential: 5  
Intent: To encourage projects to achieve exceptional or innovative performance.  

Why:  Sustainability has become increasingly popular in recent years, which means there are countless opportunities for improvement and development to be made. This section enforces the idea that we are constantly evolving and moving towards a healthier world through green technology and practices.

How:  A number of energy cost saving solutions have been developed in order to innovate sustainable, economical advances in the heating industry. Viessmann pioneered its outdoor reset control technology decades ago, which proudly set this as an industry standard. Sensors, inside and outside, communicate with each other around the clock to automatically adjust rate of fire.

Additionally, the  Lambda Pro Control  is a truly unique addition to the  B2HA/B  line. This module has an amazing impact on the boiler’s ability to fine tune the intake. This is yet another example of technology that Viessmann has spearheaded to continue the pursuit of higher efficiency.

Boiler Redundancy
When you have an array of  B2HA/B’s or  CM2’s cascaded together, designing in redundancy allows one boiler to be shut down for maintenance while the others continue firing. Having hot water in your building is necessary, and this innovation streamlines the maintenance process. In both cases the boilers are still capable of meeting close to or up to the desired load requirements. The  CA3  Model  comes with an option to effortlessly toggle between natural gas and propane gas, with the flip of a switch.


The Viessmann Vision: Global Leaders in Sustainability

Sustainable building design has become a focal point in communities all around the world. Society is moving at an increasingly fast pace, and the United States Green Building Council (USGBC) produces new ideas, solutions, and strategies to move towards a greener environment. The LEED Green Building Rating System was created to set a standard in eco-friendly design and construction. Viessmann has aligned itself, for many years, to reflect the high ideals of energy conservation and sustainability for a healthier world.  
As a testament to our commitment to innovative, sustainable, and efficient practices, Viessmann's main facility in Allendorf, Germany has been retrofitted to reflect the ideal operations of the future. Two in-house Biogas Plants provide heat and electricity for the facility through wet and dry fermentation, using local renewable resources and waste from the countryside.

Both plants were designed by members of the Viessmann Group. The first of the plants, which was built in 2010 and operates on the dry fermentation principle, was granted research and development status. The project is currently supported by the Ministry for the Environment, Energy, Agriculture, and Nature Protection in Hessen. The Viessmann Group has a vision of a sustainable future, powered by renewables, and made possible by imagination. Bringing imagination into reality is what we do best.


Viessmann’s products and commitment to sustainability compliment and reinforce LEED’s philosophy, values, and methodology. For more information, please visit our website at  and for any inquiries or questions about LEED visit


Figure 1:  This is a complete list of all substances that Viessmann or LEED regulate. The table below includes compounds which both entities control. This is not a complete list of all substances that Viessmann or LEED regulate.

Viessmann Restriction
LEED Max. Allowable Concentration (µg/m3)
Dichlorobenzene (1.4-)r1000
Dichloroethylene (1.1)r70
Napthalene Oilsr9
Polychlorinated Napthalenesr9

Figure 1 Key

p (prohibited ) = must be excluded from deliveries to Viessmann
r (restrictions) = must be taken into account for deliveries to Viessmann
d (declarable) = use of more than 0,1 % by weight in an article must be declared against Viessmann μg/cm = micrograms per cubic meter



1: DeTorres, Dustin. “The Growth of LEED Certified Buildings.” Why Ventilation Should Be Separate From Heating and Cooling Systems, Zhender America, 5 Dec. 2014,

2: source:

3: For a full overview of LEED Categories, and for other LEED related inquiries, please visit their website at

4: Certifications to DIN EN ISO 14 001:2015-11 and DIN EN ISO 50001:2011-12, respectively.

†: The points included here are the maximum amount of points possible to receive from the given Credit. Points are awarded on a case by case basis by a LEED Accredited Professional (AP).

5: Viessmann offers a variety of commercial hot water boilers to meet your demands.

6: NOAA. Where is all of the Earth’s Water? National Ocean Service website,, accessed on 8/2/2018.

7: Greywater Action, “Greywater Reuse.“,

◊: For more information about the Lambda Pro Control, visit the product page:

8: See Figure 1 in the appendix for a shortened table of restricted VOCs. For the full list of banned substances, please visit:

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