Solving an Acoustical Problem in a Retrofit Environment

Posted November 15, 2011 By Stan Gatland and has no comments yet.
 

Stan Gatland

Stan Gatland is Manager, Building Science Technology for CertainTeed Corporation

It can be a challenge to control the acoustics in older buildings when they are repurposed for multiple business uses.  One example is a call center situated in the middle of an office building, surrounded by cubicles of other workers and offices with many hard surfaces – glass, wallboard and wood doors. The perimeter of the call center has a low suspended ceiling with a decorative hard wood finish that amplifies and reflects the various sounds typical in an open plan office setting – loud telephone conversations and office equipment – carrying the disruptive noise throughout the floor.

The building owner had some ideas on how to improve the space but decided to work with an acoustical consultant to confirm the noisy conditions with measurements, as well as make recommendations on how to improve the space acoustically.

Acousticians commonly refer to highly sound reflective rooms as “live” or “reverberant.” Open plan office space should be designed for both good speech privacy and poor speech intelligibility.  Typically, you design for privacy at work stations and make speech unintelligible between adjacent areas by controlling background noise levels and reverberation time – the length of time it takes for a sound pressure level to decay or dissipate.

The results confirmed that background noise levels were high and intermittent and reverberation times exceeded the maximum recommendation of 0.60 seconds at most locations on the floor.

Another metric that was used to characterize the space was the speech transmission index (STI). STI is a measure of the ability to understand speech in a given space with the sound source coming from different directions or locations.

In open plan office settings, you want STI values to be low or poor meaning that people can’t understand each other from different locations.  Most locations had fair to excellent ratings creating a poor acoustical environment.

The recommendations provided by the consultant to solve the problem in this office space were:

  • Change the entire ceiling to high absorption suspended tile or use functional absorbers (hanging panels in the box like orientation)
  • Add some absorptive treatment to office doors or walls facing the open office
  • If not enough, use background masking noise.

It is expected that if the summary improvements were made it would improve comfort and maybe morale and productivity for the employees.

Time will tell. Do you have any examples of acoustical retrofit to share?

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Designing Environments for Sound Control

Posted December 27, 2010 By Stan Gatland and has 3 comments.

Stan Gatland

Traffic, door slams, vacuums, toilet flushes, TV’s – these are just some of the everyday noises that can affect your comfort.

Acoustical comfort, created through effective sound control, should be considered in all buildings. Many practical and economical solutions to sound-related problems are currently available to architects, engineers, contractors and building, and home owners.

Most noise control situations can be managed whether it’s from airborne sounds – sound that is directly transmitted from a source into the air like outside traffic, music or voices,- or structureborne sound – sound that travels through solid materials like footsteps, door slams, or plumbing vibrations.

There are four goals to providing a superior acoustic environment:

  • Reduce sound reverberation time (echo factor)
  • Limit airborne noise (sound transmission from space to space)
  • Reduce impact noise
  • Minimize background noise

The reduction of sound reverberation time is accomplished by employing sound-absorbing surfaces, such as fabrics, carpeting and acoustical ceilings. The best plan is to configure those spaces to reduce, rather than amplify the sound energy.

When limiting airborne noise, one important consideration is to design high sound transmission class (STC) assemblies. STC is a laboratory measurement used to study the resistance of a wall, ceiling, or floor to the passage of sound. The higher the STC number, the more the sound is deadened. Also, try to enclose or separate spaces with group activities that may create chatter from common areas, using acoustically efficient walls.

To reduce the transmission of impact noise, you can design high-impact insulation class (IIC) assemblies. Isolate finished floors and ceilings by installing resilient underlayments, by using sound-absorptive floor coverings and by using resilient ceiling suspension systems that include sound-absorbing cavity insulation.

Design your HVAC systems to absorb energy and reduce background noise so airborne noise isn’t transmitted through the ductwork. Mechanical equipment should be isolated using vibration dampening techniques and high sound transmission reduction enclosures.

Creating a quiet environment makes for happier homes and offices.

Stan Gatland is Manager of Building Science Technology for CertainTeed Corporation

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Reshaping the Built Environment Passively

Posted December 3, 2010 By Stan Gatland and has 1 comment.

Stan Gatland

The Passive House concept gained a great deal of traction over the past year and the 2010 Passive House Conference, which was held in Portland, Oregon in November, was proof of the growth and interest.  The attendance grew from 250 last year to 350 this year.

It is clear from the growth of the conference that building professionals in the U.S. and Canada are beginning to gravitate to the Passive House Standard. The primary goal of Passive House technology is to reduce your heating and cooling load so that very little energy is needed to maintain comfort.

The people who came by the CertainTeed booth were much more knowledgeable about passive house technologies and had practical experience with regard to designing and constructing passive homes in all parts of the U.S.  That was a significant change from previous years.

CertainTeed remains the only large building materials manufacturer sponsoring the Passive House Conference. The Passive House Institute has created a Passive House Alliance which will work closely with the Institute to promote Passive House building energy efficiency standards and construction in the U.S.  A grassroots effort like this could have significant impact on adopting standards that truly support energy efficient building.

Attendees were very interested in Saint-Gobain’s Isover Multi-Comfort House strategy. This passive house concept has been very successful in Europe. There were several colleges and universities at the conference and we took this opportunity to talk with them about the Multi Comfort House Student Competition which invites teams of architecture and engineering students from around the world to compete in a passive design competition.  Philadelphia University has participated in the past and the hope is that  other U.S. colleges and universities will consider participating in the 2011 competition.  

It was good to talk with designers who are using CertainTeed Optima® insulation with our Membrain™  smart vapor retarder in very deep cavities using TJI joists to achieve the insulation levels needed to meet Passive House standards. We have conducted hygrothermal analysis to assist designers who are using this system.

One of the notable speakers this year was Dr. Robert Hastings, architect and energy consultant from Austria who gave his perspective on this trend.  Dr. Hastings has been involved internationally in sustainable building and solar energy since the 1970’s when the first wave of concern regarding energy consumption hit the mainstream. Unfortunately, the progress that was made in the 70’s was quickly abandoned once oil became readily available again. 

Let’s hope that this groundswell will not be abandoned as in the past. As a nation, we need to continue to move toward energy independence.

Stan Gatland is Manager, Building Science Technology for CertainTeed Corporation

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New Design Paradigm Unleashed at BEST 2 Conference

Posted June 8, 2010 By Stan Gatland and has 1 comment.

Portland, Oregon

The second Building Enclosure Science and Technology Conference (BEST 2 2010) was held in Portland, Oregon in April and hosted by the Building Enclosure Council and the Portland chapter.  For a new conference in a difficult economy, I was amazed at the level of participation. The conference presented leading research from the United States, Europe and Canada and combined academic as well as real world applications and examples of successful projects. 

It is no secret that buildings account for 48 percent of all Green House Gas emissions annually and consume 40 percent of all energy.  There is an ever present push to develop new sustainable solutions to existing systems.  With the adoption of reductions in green house gas emissions by governments, building professionals and manufacturers are in need of identifying and implementing new ways to solve issues relating to energy efficiency, moisture management, acoustics and hygrothermal performance.

The three day Conference was divided into three tracks: Energy Efficiency in Buildings, Whole Building Performance and Fenestration Solutions all focusing on what is being called the New Design Paradigm for Energy Efficient Buildings. The message was that it is not enough to address the efficient use of energy.  It’s the durability of buildings, indoor air quality and livability that also must be addressed.

Like most technical conferences there was too much information to cover. I focused my attention on design strategies to improve energy efficiency and hygrothermal performance of different types of building envelope systems.  Many speakers highlighted the ramifications of poorly integrated new technologies, the need for greater insulation levels and building air tightness while maintaining building durability.

Design professionals must keep up with the latest research in building envelope technology in order to accelerate the drive towards net-zero energy buildings.  The BEST 2 Conference, like the ASHRAE forums, is an excellent opportunity to exchange knowledge and best practices.

I would be interested in hearing your thoughts and experiences.

Stan Gatland is Manager, Building Science Technology for CertainTeed Corporation

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A Glimpse at the Future of Architecture

Posted May 24, 2010 By Stan Gatland and has 3 comments.

Purity of Division - winning project from Philadelphia University

I recently judged the international ISOVER Multi-Comfort House Competition for architecture and engineering students from Philadelphia University.  CertainTeed Insulation sponsors this program and takes the winning team to compete with university students from 16 other countries. There were five teams vying for the opportunity to present their projects at the Multi- Comfort House Competition from May 19- 22, 2010 in Innsbruck, Austria.

The competition project was to renovate an existing commercial building that sits on a canal along the Seine River in France.  The teams were to retrofit the existing building to create a sustainable structure.  While the teams were given carte blanche in creating their projects, all were surprisingly viable. 

In general, projects that were offered by engineering students focused more on function and form while architectural students initially approached the project from a design and visual beauty perspective.  The winning project “Purity of Division” balanced the design between a community library overlooking the canal and several living machines that cleaned the canal water, converted CO2 gas into oxygen with a bioreactor and produced algae for sale to the pharmaceutical industry.  

Superior building envelope thermal performance was achieved through high levels of insulation, whole building air tightness, triple-glazed spectrally selective windows and the isolation of thermal bridging.

A comprehensive whole building energy analysis was performed using Energy10 simulation software.  The results predicted 50 to 65 percent energy savings due to the passive house design techniques alone. The buildings HVAC system, a geothermal heat pump, used the canal water in a unique heat exchanger array along the canal wall to reduce electricity needs by an additional 20 to 25 percent.  The winning Team also incorporated roof top photovoltaics and a thermal hot water system.

It was very interesting to judge these projects and each project had different strengths of design or engineering but in the end “Purity of Division” won the day.

There were three major categories for judging which included several components but basically it was:

  • Design and function
  • Multi-Comfort House Criteria
  • Sustainability

All of the projects were creative and comprised very forward thinking concepts. As a Building Scientist, I was very happy at the depth of knowledge illustrated by these projects and based on what I experienced, the future of design and architecture especially with regard to Passive House and sustainability is in very good hands.

Stan Gatland is Manager, Building Science Technology for CertainTeed Corporation

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The Durability Challenge of Energy Retrofits

Posted February 17, 2010 By Stan Gatland and has 6 comments.
Stan Gatland

Stan Gatland

As a member of the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE),  I participate in technical committees that deal with building performance from a heat, air, and moisture perspective. One committee explores best practices for building envelope design. The committee focuses on how to manage heat, air, and moisture flow through assemblies. 

At a recent forum, members discussed concern that in the rush to create air-tight building envelopes with high levels of energy efficiency, the long-term impact on durability due to these changes may be overlooked.  Energy efficient, air-tight buildings have a greater potential to accumulate moisture and have less energy to dry out.

The Department of Energy is poised to support the energy efficiency retrofit of existing homes by improving air tightness and adding thermal insulation.  This time, hopefully, the history of the 1980s and 1990s does will not repeat itself regarding the durability issues related to energy efficiency retrofits.  Moisture related damage typically takes seven to 10 years after the retrofit of an existing home or construction of a new energy efficient home if measures are not taken to address moisture.

DOE recognizes the need to control interior humidity levels, as well as address combustion safety.  If adjustments are not made to control humidity levels and circulate fresh air it could cause other problems like excess moisture which could result in mold.

Another concern is combustion safety. By making an assembly more air-tight, you have less air available for combustion events. For example, hot water heaters and furnaces that once relied on a building’s air leakage to supply enough air to the combustion process may backdraft if enough air is not available in a well sealed home.   Direct ventilation may now be required to compensate for the retrofit.   

DOE is recommending that energy retrofit contractors address moisture management issues and combustion safety by following guidelines outlined in ASHRAE Standard 62.2 as a way to insure proper indoor air quality for residential buildings and increase the durability of assemblies.

Americans have traditionally had access to inexpensive energy but that is changing. We do need to address retrofitting older buildings, but it is crucial to not create other problems while doing so.

Stan Gatland is Manager, Building Science Technologies for CertainTeed Corporation

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Embracing the Passive House

Posted December 3, 2009 By Stan Gatland and has 5 comments.
Stan Gatland

Stan Gatland

If there is any reliable source to confirm that the building community in the United States is beginning to embrace the passive house concept, it was the 4th Annual North American Passive House Conference held in October at the University of Illinois at Urbana-Champaign.  In 2008, there were only 15 certified passive house consultants in the United States but by the end of this year there will be over 200.  More than 300 architects and building professionals attended the conference this year.

 The passive house concept has been incorporated into building design practice for over 10 years throughout the world.  While many countries, including the U.S, have increased energy efficiency requirements for building through regulation, a relatively small percentage of industry partners have embraced the passive house concept on a large scale. 

The primary goal of passive house technology is to reduce your heating and cooling load so that very little energy is needed to maintain comfort.  It is critical that we control energy consumption and identify ways to improve our structures to improve their efficiency. It is understood that it will take time but programs like passive house build the awareness necessary to drive lasting change in energy conservation.

The ways to achieve passive house energy levels include increasing insulation in the walls and roof, providing pre-heated and pre-cooled air by coupling it with the ground through ducts buried into the earth (more practical on new construction), orientation of the building for maximum use of sunlight along with passive shading techniques, and installing high performance windows. But with the heightened focus on air tightness in passive house construction, more attention needs to be paid to indoor air quality and ventilation.

The other critical need to achieve any of these goals is the education of building occupants.  People need to maintain the systems in order to attain the maximum benefit.

Saint-Gobain, the parent company of CertainTeed, collaborated with the Passive House Institute in Germany and developed an educational marketing program called the ISOVER Multi-Comfort House.  

At the conference, I introduced CertainTeed’s Multi-Comfort House Educational Program which is a program CertainTeed will launch in 2010 to help train architects, building professionals and design students in passive house technologies.  The key components of the CertainTeed program are comfort (thermal, indoor air quality, acoustical and visual), safety and environmental protection benefits with design recommendations for all climate zones.

Understanding how products work together in the building envelope, especially in different climate zones, is critical to achieving passive house efficiencies.  Some valuable resources regarding passive house and net-zero building include the US Passive House Institute, the US Department of Energy – Net-Zero Building Technologies Program, the National Renewable Energy Laboratory, and the US Department of Energy Building America Program.

Stan Gatland is Manager, Building Science Technologies for CertainTeed Corporation.

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Blogging from Building Science Summer Camp

Posted August 24, 2009 By Stan Gatland and has no comments yet.

Stan Gatland photo_1I am Stan Gatland, Manager, Building Science Technology at CertainTeed Corporation.  I am joining my colleague, Lucas Hamilton, in the Blogosphere.

Every year, I have the opportunity to attend training for Building Science professionals affectionately known as Summer Camp. Ok, we call it camp, but really, there are no tents or campfires songs, or even horseback riding.  Actually, it’s officially called the Thirteenth Annual Westford Symposium on Building Science, sponsored by Building Science Corporation.) Not only is it a great opportunity to learn about the latest and greatest  Building Science trends but for me, the most beneficial part of  ‘Camp’ is the informal meeting of the minds to share current challenges and generate new ideas, solutions and debate about best practices. The attendees include architects, engineers, physicists, designers, builders, material scientists, manufacturers and other building professionals.

 There has been significant growth in the attendance at “Camp” over the years due to increased focus on the building envelope, energy efficiency, moisture management and sustainability.

I was particularly interested in the information presented by Andreas Holm and Hartwig Kuenzel from the Fraunhofer Institute in Germany.  The interest in building science actually began with the introduction of insulation into buildings in Europe in the early 20th century and led to the establishment of the Institute for Building Physics at the Fraunhofer Institute. Historically, Europe and Canada are well ahead of the US with regard to Building Science.

 Among their topics was the discussion of how whole building performance changes with respect to moisture when adding thermal insulation. Adding insulation reduces the amount of heat that flows through an assembly. While this improves energy efficiency and thermal comfort, it also reduces the amount of energy available to dry assemblies and can cause colder surfaces to accumulate more moisture over time. The Institute is looking at ways to improve the moisture management performance of buildings that have become very energy efficient.

They also talked about indoor climate control and energy concepts for schools. Making buildings more air tight may require indoor humidity control through fresh air ventilation.

If you have participated in one of these, or have some thoughts on building science topics of interest, let me know.  I’m glad to be one of CertainTeed’s “Blog-gurus” and look forward to talking with you on occasion.

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