ASHRAE Technical Committee 1.12 - Moisture Management in Buildings

NEWS

(January 16, 2008) ASHRAE Publishes Book on Hot, Humid Climate Building Design Guidance
Building operators and designers around the world face common issues related to thermal comfort, ventilation and energy. But these measures take on greater concern for buildings in hot and humid climates. In addition, areas with these climates, such as South Asia, are experiencing rapid construction growth.

Design guidance on critical issues for achieving excellence and long-term sustainability in these climates is contained in a new book from ASHRAE. The ASHRAE Guide for Buildings in Hot and Humid Climates identifies and explains key issues for owners, architects, HVAC designers, contractors and building owners as they plan, build and operate air-conditioned buildings – in a sustainable way – in hot and humid climates. “All countries want to achieve high standards of energy efficiency,” author Lew Harriman said. “But recent history warns that mold and mildew problems in hot and humid climates can overshadow any gains made through energy reduction. On the other hand, the practical experience of ASHRAE’s members shows that by focusing on several critical building enclosure design details and by keeping the indoor air dry, owners and designers can avoid mold problems and have high indoor air quality, while their buildings use much less energy than outdated designs."

Topics covered in the book include improving thermal comfort, managing ventilation air, reducing energy consumption and avoiding bugs, mold and rot. The book explains ASHRAE’s standards in these areas. It also highlights common problems seen in hot and humid climates, along with practical alternatives for avoiding such problems.

“The guide was created in part because of requests from designers and owners in North America, but also because of requests from government agencies in developing countries that are working to establish robust building codes to guide energy use and indoor environmental quality,” Harriman said. “When balancing the equally important concerns of low energy consumption, high thermal comfort and healthy indoor air, ASHRAE’s experience and internally-informed consensus standards can be very helpful.”

A second edition is planned for January 2009 that will add more information arranged into sections aimed at each different member of the construction and delivery team.

The cost of The ASHRAE Guide for Buildings in Hot and Humid Climates is $59 ($49 to ASHRAE members). To order, visit the online bookstore at www.ashrae.org.

(October 9, 2007) ASHRAE Provides Guidance on Achieving Good IAQ
Providing design guidance on how to achieve good indoor air quality is the aim of a proposed guideline from ASHRAE now open for public comment. Guideline 24P, Ventilation and Indoor Air Quality in Low-Rise Residential Buildings, is the companion guideline to ASHRAE Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings. The guideline is open for public comment until Oct. 29, 2007.

The proposed guideline would provide information on envelope and system design, material selection, commissioning and installation, and operation and maintenance. The guideline goes beyond the requirements contained in Standard 62.2 by providing explanatory and educational material that would be inappropriate in the code-intended standard. Topics addressed in the guideline but not covered in the standard include carbon monoxide alarms, air distribution, better air filtration and unvented combustion appliances.

“While both Standard 62.2 and Guideline 24P seek to provide acceptable indoor air quality, the guideline goes beyond by providing additional information for achieving good indoor air quality,” Steve Emmerich, chair of the committee writing the guideline, said. “The guideline also provides information on topics such as verification of ventilation equipment performance and operations and maintenance, which, though important, are not easily addressed in a code-intended standard.”

(June 7, 2007) ASHRAE Publishes 2007 Residential IAQ Standard
The 2007 version of the ASHRAE residential indoor air quality standard is now available. ANSI/ASHRAE Standard 62.2-2007, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings, is the only nationally recognized indoor air quality standard developed solely for residences.  It defines the roles of and minimum requirements for mechanical and natural ventilation systems and the building envelope intended to provide acceptable indoor air quality in low-rise residential buildings.

Changes to the standard from the 2004 version include application of exceptions based on climate map zones vs. degree-day based, making it easier to apply the standard; inclusion of a new technology of condensing dryers that do not have an exhaust flow like traditional dryers; and a change in requirements for testing and rating ventilation fans.

The cost of Standard 62.2-2007 is $39 ($32 to ASHRAE members). To order, visit the online bookstore at www.ashrae.org.

(May 31, 2007) International Code Council Adopts 62.1 Ventilation Rate Procedure
Approval of ASHRAE’s Standard 62.1 ventilation rate calculation procedure for the International Mechanical Code (IMC) marks a milestone for the high-profile mandatory-language standard after years of development aimed at code adoption. This week, the International Code Council approved an ASHRAE proposal to incorporate the prescriptive ventilation rate procedure from ANSI/ASHRAE Standard 62.1-2004, Ventilation for Acceptable Indoor Air Quality, in the IMC. The code establishes minimum regulations adopted and implemented by federal, state and local government agencies for mechanical systems in new buildings.

“With adoption of the new ventilation rates into building codes, we can expect to see reduced air intake flow  in many previously over-ventilated buildings,” Dennis Stanke, chair of the 62.1 committee. “With adoption of the new calculation procedures, we can expect to see improved indoor air quality in many previously under-ventilated multiple-zone systems. Ventilation systems with lower outdoor rates compared to the current code reduce both first costs and energy costs, while system designs that account properly for air distribution within buildings result in better indoor air quality than designs based on over-simplified air distribution assumptions.”

The current ventilation criteria in the IMC are based on ASHRAE Standard 62-1989. Based on 20 years of IAQ research and experience with ventilation system design, ASHRAE introduced an improved version of the standard in 2004 to include the new rates and calculation procedures. This code change makes both the IMC and the 2006 Uniform Mechanical Code consistent with the ASHRAE standard.

“The new ventilation rate procedure requires designers to account for pollutant sources from both the building and its occupants, and to account for the efficiency of different ventilation systems when delivering outdoor air to the breathing zone,” Stanke said.

The new requirements will be included in the 2007 IMC Supplement.

(May 30, 2007) Organizations Collaborate to Provide IAQ Guidance

Six organizations related to the built environment are collaborating to provide advanced indoor air quality (IAQ) design guidance for the industry. The collaboration will develop a book and professional development course that will describe an integrated process for achieving improved IAQ in all elements of a building.

Participating organizations are the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), the American Institute of Architects (AIA), the Building Owners and Managers Association (BOMA), the U.S. Environmental Protection Agency (EPA), the Sheet Metal and Air Conditioning Contractors’ National Association (SMACNA), and the U.S. Green Building Council (USGBC). The groups recently formalized the collaboration through a memorandum of understanding.

“The book and course will give guidance to designers and builders so that buildings may be constructed, operated and maintained to improve IAQ without constraining the building function or the comfort and productivity of the occupants,” said Andrew Persily, chair of the steering committee overseeing the project.

Last year, ASHRAE was awarded a $510,000 three-year cooperative agreement with the EPA to develop the Advanced Indoor Air Quality (IAQ) Design Guide for Non-Residential Buildings. The book will assist building professionals in implementing high-performance designs and improving building IAQ performance in a broad range of buildings. The book is expected to be published in April 2009 and followed later in the year by the course.

(May 22, 2007) ASHRAE Publishes New Standard 62.1
ASHRAE’s new 2007 ventilation standard contains key changes impacting ventilation system designers and their designs. ANSI/ASHRAE Standard 62.1-2007, Ventilation for Acceptable Indoor Air Quality, sets minimum ventilation rates and other requirements for commercial and institutional buildings.

The new standard includes requirements for the separation of areas with environmental tobacco smoke (ETS) from areas without ETS in the same building. Although some local building and health codes prohibit smoking indoors in many buildings and locations, other codes allow smoking in designated areas. In buildings that allow smoking in designated areas, effective separation of ETS areas ensures “ETS-free” areas contain little or no ETS-related contaminants. The new separation requirements help designers ensure effective separation, according to Dennis Stanke, committee chair.

Another change clarifies of how designers must analyze mechanical cooling systems to help limit space relative humidity. Many buildings suffer from air quality problems related to dampness, including mold and other microbial growth. In the past, the standard required a design analysis at specified load conditions, in an effort to demonstrate that a given design approach in a given climate could successfully limit space RH to 65 percent or less.

“Those load conditions could be confusing and difficult to establish,” Stanke said. “The new requirements include a specific easy-to-establish load condition. Each system must be analyzed to check its dehumidification performance at this challenging condition to help designers make system configuration and control choices that reduce the likelihood of high-humidity problems in buildings.”

Other changes include:

  • Additions to Table 6-1 of minimum outdoor air requirements for dwelling units in high-rise residential buildings. These requirements apply to residences in buildings over three stories. Low-rise residential buildings are covered by ASHRAE Standard 62.2, Ventilation and Acceptable Indoor Air Quality in Low-Rise Residential Buildings.
  • New or previously overlooked occupancy categories. In response to proposed changes from users of the standard, ASHRAE added several occupancy categories to Table 6-1 with associated minimum outdoor air rates. These include, for example, daycare sickrooms, university/college laboratories, break rooms and coffee stations, and laundry rooms.
The cost of ASHRAE Standard 62.1-2007 is $65 ($52 for ASHRAE members). To order, visit the online bookstore at www.ashrae.org.

 

(January 16, 2007) Indoor Environmental Design Focus of ASHRAE Satellite Broadcast
Specific solutions to the everyday challenges of achieving indoor environmental quality within real-world budget constraints will be presented by ASHRAE in an upcoming satellite broadcast/Webcast.

Indoor Environmental Design: Practical Solutions to Everyday Problems, sponsored by ASHRAE’s Chapter Technology Transfer Committee, will take place from 1-4 p.m. EDT, April 18, 2007.

"This program will benefit designers, building owners, architects, contractors and facility managers who are faced with the daily engineering challenge of specifying systems that maximize IAQ, thermal comfort and noise control," said Bill Williams, chair of the broadcast committee. "Viewers will be given guidance on how to provide ventilation air that helps protect buildings instead of increasing mold risk, how to avoid the three most common mistakes in ventilation system design and operation, and how to provide comprehensive filtration without breaking their budget."

Bill Coad, PE, president of Coad Engineering Enterprises, St. Louis, Mo., and past ASHRAE president, will present an overview perspective on indoor environmental quality and introduce the following panel of experts:

Hoy Bohanon Jr., PE, owner and consultant, Bohanon Engineering Winston-Salem, N.C., "Ventilation System Design: Avoiding Three Common Mistakes"

Lew Harriman, director of research, Mason-Grant, Portsmouth, N.H., "Ventilation Air: First, Do No Harm"

Dan Int-Hout, chief engineer, Krueger-HVAC, Richardson, Texas, "Noise, IAQ and Thermal Comfort – Can You Have It All?"

Chris Muller, technical director, Purafil, Doraville, Ga., "Behind the Access Door – Advances in Affordable Filtration for IAQ"

There is no fee for registration. For more information, email ashrae-satellitebroadcast@ashrae.org or call 678-539-1139.

 

(September 22, 2006) 1st Public Review of ASHRAE Standard 160P, Design Criteria for Moisture Control in Buildings
This is the first public review of proposed new Standard 160P. It specifies performance-based design criteria for predicting, mitigating, or reducing moisture damage to buildings depending upon climate, construction type, and HVAC system operation. It applies to all types of buildings, building components and materials.

The 45-day public review period runs from September 22, 2006 to November 6, 2006. This public review draft can be downloaded from http://www.ashrae.org/technology/page/331.

 

(May 18, 2005) ASHRAE Position Document on Mold
Due to the proliferation of mold in buildings, sound moisture management should take precedence over energy cost savings, according to a new position document from the ASHRAE.

Energy conservation goals may conflict with moisture management goals. In fact, traditional methods of dehumidification, such as reheat systems, may increase energy use, Ron Vallort, ASHRAE president, said. “Considering energy conservation and moisture management goals in the design, construction, operation and maintenance of HVAC systems can minimize energy use and cost,” he said. “However, the impact of mold proliferation suggests that energy cost savings should not be achieved at the expense of sound moisture management.”

Minimizing Indoor Mold Through Management of Moisture in Building Systems outlines ASHRAE’s position on the management of moisture in buildings by describing issues related to the topic and highlighting resources available through the Society regarding the management of moisture and mold in buildings. The document recommends that for proper moisture management include:
Building envelopes, penetrations and building systems be designed and built to protect the indoor environment and the building materials from water infiltration or accumulation.
Building and system design consider internal or exterior moisture that could cause condensation on surfaces or within materials.
Building and system design, operation and maintenance provide for drying of surfaces and materials prone to moisture accumulation under normal operating conditions.
Building and system design, operation and maintenance provide for water management of surfaces and materials that are expected to have moisture present.
Mechanical system design should properly address ventilation air.
Building and system design, construction and operation take into account occupant uses.
Each building have an operation and maintenance plan.
The sequence of operation for the HVAC system contain appropriate provisions to manage humidity, control pressurization and monitor critical conditions.
Moisture accumulation be investigated in a timely manner and steps be taken to identify and control the course of water.

The position document, Minimizing Indoor Mold Through Management of Moisture in Building Systems, can be viewed at http://www.ashrae.org/template/AssetDetail/assetid/43903.

 

(February 14, 2005) Register For ASHRAE Satellite Broadcast or Webcast on Mold

Concerns about mold in the building environment are no longer limited to just humid environments or North America. Mold is now a global concern for designers, contractors, building owners/operators and building occupants. Information on how to properly control moisture and humidity conditions in order to minimize mold will be presented in an April 13, 2005 (1:00 to 4:00 PM EDT), satellite broadcast and Webcast, Mold in Our Building Environment, sponsored by ASHRAE’s Chapter Technology Transfer Committee (CTTC).

If you have any questions, e-mail CTTC-SatelliteBroadcast@ashrae.org or call 678-539-1139.

(December 8, 2004) ASHRAE 2005 Public Session: Battling Humidity in Southern Climates
“Beat the heat” takes on special meaning in Florida as the HVAC&R industry fights the battle between energy costs and hot and humid climates. “Florida has a tropical climate that affects all aspects of life in the area - at home, at work and at leisure,” Fred Betz said. “As a result, a significant problem and concern in Florida is energy usage and humidity control.” Guidance on energy and humidity control techniques in building design and construction, types of equipment that can be used, and how to commission and maintain these systems will be provided by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) at its 2005 Winter Meeting, Feb. 5-9, Orlando, Fla.

ASHRAE’s public session, Energy and Humidity Reduction Practices in Southern Climates, will take place from 3-5 PM on Monday, February 7, at the Orange County Convention Center. Admission is free, and registration is not required. The session features five speakers from the central Florida engineering and research community who will focus on HVAC challenges in Florida, according to Betz, chair of the session. Speakers and topics are:

"Florida’s New Energy Code: What’s Changing in July 2005," by Muthusamy Swami, Florida Solar Energy Center, Cocoa, Fla. The new state code is slated to go into effect July 1, 2005. Swami will discuss the current status and upcoming changes to the energy code for commercial buildings. Impact of changes, compliance pathways and relationship to national codes and standards will be discussed as well as tools and resources available to compliance users.

"Whole Buildings: Why Everything Interacts," by Neil Moyer, Florida Solar Energy Center.

"Shell & Lighting Systems: Reducing Sensible Gains," by Wayne Dunn, SunBelt Engineering, Jacksonville, Fla.

"HVAC: Strategies for Ventilation and High Humidity Control," by Don Shirey, Florida Solar Energy Center.

"Commissioning: Cradle to Grave Building Design," by J. David Odom, Liberty Building Diagnostics Group, (location). A few buildings begin life as catastrophic problems, often requiring massive amounts of money and attention to correct their defects. A much larger number of buildings begin life with nuisance problems that require significant corrective attention soon after they are occupied. Both of these problematic building types, and even the pool of well performing buildings, often gradually degrade into poor performance as they age. Odom will focus on risk factors that buildings face from infancy to old age and what can be done to improve their performance.

Click here for the full ASHRAE press release

(October 7, 2004) ASHRAE Sponsors Education Courses at 2005 Winter Meeting

Fourteen education courses, including a professional development seminar on preventing moisture problems, will be offered by the ASHRAE Winter Meeting, February 5-9 in Orlando, Florida.

Preventing Moisture and Mold Problems: Design and Construction Guidelines (instructors: David MacPhaul, P.E., CH2M Hill, and J. David Odom, Liberty Building Diagnostics Group Inc.) will be held from 8 AM to 3 PM on Saturday, February 5 at the Wyndham Palace Resort.The cost of this professional development seminar is $460 ($360 for ASHRAE members), and attendees will earn continuing education credits. To register, visit www.ashrae.org./orlando or call ASHRAE’s Customer Service Department at 1-800-527-4723. After December 10, attendees must register at the meeting.
Click here for the full ASHRAE press release

(October 7, 2004) Controlling Mold Strong Focus of ASHRAE 2005 Winter Meeting

The warm and sunny weather that draws millions of tourists to Florida, site of ASHRAE’s 2005 Winter Meeting, translates into a hot and humid climate that can lead to problems with mold and mildew. Several sessions related to hot and humid climates, including  Florida, will be presented at the American Society of Heating, Refrigerating and Air-Conditioning Engineers’ meeting, Feb. 5-9, Orlando, Fla., at the Wyndham Palace Resort. Ninety-five sessions will be presented as part of the technical program.

“Designing, constructing and operating buildings in locations such as Florida is difficult due to the hot and humid climate,” Kelley Cramm, chair of the Society Program Committee, said. “Our goal is to make engineering in these climates easier by providing guidance on humidity control issues, techniques and equipment.”

A seminar addresses design and construction in hot and humid climates, focusing on design of walls, roofs, mechanical systems and interior finishes as they relate to moisture control, durability and indoor air quality. Another seminar focuses on mold and mildew case studies in Florida, including a presentation on the effects of operation and control of mechanical systems on mold growth in hotels.

Dehumidification considerations are required in most applications today. A seminar addresses the relationship of moisture and mold dehumidification, and methods and solutions to improve dehumidifier efficiencies. Using air-to-air energy recovery to meet new humidity control requirements in ASHRAE’s ventilation standard is addressed in a seminar. Up-sizing of air-conditioning equipment usually does not improve humidity control in hot and humid climates, but appropriate application of air-to-air energy recovery systems and related technologies can help designers meet the requirements.

The technical program is comprised of 55 seminars (presentations on a central or related topic with no published papers), 17 symposia (presentations with papers on a central subject), 19 open-discussion forums, two technical sessions (paper presentations), a poster session and a public session. A total of 105 papers will be presented.
Click here for the full ASHRAE press release

(September 17, 2004) ASHRAE to Host Satellite Broadcast on Mold

Concerns about mold in the building environment are no longer limited to just humid environments or North America. Mold is now a global concern for designers, contractors, building owners/operators and building occupants. Information on how to properly control moisture and humidity conditions in order to minimize mold will be presented in an April 13, 2005, satellite broadcast and Webcast, Mold in Our Building Environment, sponsored by ASHRAE’s Chapter Technology Transfer Committee (CTTC).

“Moisture management and humidity control require a team effort during the design, construction, start-up and operation phases of a facility,” Wilfred Laman, chair of CTTC, P.E. said. “If any part of the team fails to perform their tasks in proven and prescribed methods, the facility may promote mold formation and growth. This broadcast will be beneficial to all team members by describing how each should perform their tasks properly.” The level of interest in mold has also expanded to the legal profession due to the claim that “mold is gold” based upon recent jury awards in mold-related cases, according to Laman. For situations where mold is present, various proven assessment and remediation processes will be addressed for different types of facilities.

Speakers will include biological, chemical, investigative and health experts, design architects, engineers and contractors who specialize in mitigation.The broadcast will be similar to the 2004 ASHRAE broadcast on homeland security, which as viewed by more than 20,000 viewers at more than 1,500 locations earlier this year.Program and site registration details will be announced soon. Questions and requests for site registration materials may be emailed to CTTC-SatelliteBroadcast@ashrae.org
Click here for the full ASHRAE press release

(September 2, 2004) Humidity Control I and II Professional Development Seminar Offered Online
ASHRAE will present its fall professional development seminars online. The professional development seminars traditionally are held in cities across the nation. Following the success of an online pilot course held earlier this year, ASHRAE decided to host the seminars online.

Humidity Control I and II will take place from 1-4 p.m. (EDT) Oct. 4-5. The course, based on ASHRAE’s Humidity Control Design Guide for Commercial and Institutional Buildings, will help designers achieve true control of humidity rather than just its moderation. The first day of the humidity course will focus on basic principles, loads and equipment. The second day will focus on applications, control levels and mold avoidance. The instructor is Lew Harriman, author of the design guide and director of research and consulting at Mason-Grant in Portsmouth, N.H.

Participants will earn .6 continuing education units, six professional development hours, or six American Institute of Architects learning units.The cost is $690 ($590 for ASHRAE members). For more information or to register, visit www.ashrae.org/onlinepds.
Click here for the full ASHRAE press release

(May 25, 2004) Study Links Mold to Some Ailments
Scientific evidence links mold and other factors related to damp conditions in homes and other buildings to asthma symptoms in some asthmatics as well as to coughing, wheezing and other upper respiratory tract symptoms in otherwise healthy people, says a new report by the Institute of Medicine of the National Academies. The available evidence does not support an association between either interior dampness or mold and the wide range of other health complaints that have been ascribed to them, but the possibility of a link cannot be ruled out.
Click here for the full ASHRAE press release

(May 25, 2004) Mold, Other Environmental Concerns Addressed in ASHRAE Seminar
Environmental Health Issues: Mold and Other Indoor Environment Concerns will take place from 10:15 a.m.-12:15 p.m. Monday, June 28. It is sponsored by ASHRAE’s Environmental Health Committee. It will feature presentations on health effects associated with exposure to indoor air. Indoor air chemistry and the topical issues related to mold and ventilation systems including mold prevention in new construction are presented, according to chair Sidney Parsons, P.E., Council of Scientific and Industrial Research, South Africa.
Click here for the full ASHRAE press release

(April 23, 2004) Indoor Environments Highlighted in ASHRAE Technical Program
To help designers, engineers, contractors and others meet those expectations, indoor air quality and comfort will be a strong focus of the ASHRAE 2004 Annual Meeting technical program. Ninety-three technical program sessions will be presented at the meeting, which takes place June 26-30, at the Gaylord Opryland Resort and Convention Center, Nashville, Tenn. Some 25 sessions will focus on indoor air quality and comfort as well as ventilation and air distribution.

A seminar focuses on new means of controlling humidity through HVAC equipment and energy recovery systems. The potential for fungal growth is exacerbated by improper sizing of equipment. Another seminar examines current engineering and legal issues that must be considered in designing, constructing and operating buildings. Some estimate that mold litigation and insurance claims may exceed asbestos and Superfund claims combined.
Click here for a complete list of technical program sessions

 

(December 12, 2003) ASHRAE Offers Information on Control of Mold, Moisture
A new online technical resource, Mold and Moisture Management in Buildings, contains 22 ASHRAE Journal articles and papers presented at ASHRAE IAQ conferences and semi-annual meetings. "This collection provides extensive technical background along with specific suggestions for avoiding mold- and moisture-related problems," Lew Harriman, a member of ASHRAE's technical committee on moisture management in buildings, said. The papers and articles address mold fundamentals, moisture movement in building assemblies, dehumidification and HVAC systems, and also discussions of typical problems and solutions for both commercial and residential buildings.

"Problems associated with mold and moisture seldom fall neatly into any single professional responsibility," according to Harriman. "Biology, medicine, engineering, architecture, construction and building operation all contribute to understanding and managing moisture in buildings. When difficulties occur, they usually expose gaps between these disciplines and often expose shortcomings of our overall understanding of the behavior of moisture and its consequences."
Click here for the full ASHRAE press release

The collection can help the professional community as well as the general public understand the technical issues surrounding mold and mildew, according to Harriman. The cost of Mold and Moisture Management in Buildings is $49 ($35 ASHRAE members).
Click here for more information

 

(March 7, 2003) Advice Dispensed at ASHRAE Public Session: Proper Equipment Sizing, Good Maintenance Solves Mold Problems
How do you prevent mold in small commercial and residential buildings? By removing the water, according to a speaker at the American Society of Heating, Refrigerating and Air-Conditioning Engineers' (ASHRAE) recent public session. Simple steps to remove mold in small commercial and residential buildings by decreasing humidity were presented at the public session held in Chicago, IL during ASHRAE's 2003 Winter Meeting, January 25-29.
Click here for the full ASHRAE press release

 

(December 27, 2001) ASHRAE Book Advises Cost-Effective Humidity Control
As concern grows over moisture damage in commercial buildings, members of building teams need practical advice to minimize the costs and maximize the benefits of controlling humidity. The Humidity Control Design Guide for Commercial and Institutional Buildings, published by the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE), provides such guidance.
Click here for the full ASHRAE press release