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Present: Nicole Benjamin-Ma, Susan Brauner, Taya Dixon, Matt Formicola, Jack Glassman, David Hart, Ben Haavik, John Hecker, Amy Cole Ives, Ken Johnson, Wendall Kalsow, David Kelman, Erin Knerr, Ellen Lipsey, Krista McFadden, Tom Maloney, Doug Manley, Pat Morrissey, Henry Moss, Pat Morrissey, Ivan Myjer, Bill Remsen, Brian Roche, Susan Schur, Malcolm Smiley, Jonathan Smith, Eric Ward, Sara Wermiel, Gary Wolf, Josh Wright, and Sally Zimmerman 1. Environmental Systems at Historic New England (HNE) Properties:We were pleased to welcome Ben Haavik, Historic New England's Team Leader for Property Care, and Erin Knerr, Kress Fellow for a grant to assess the performance of existing systems and recommend improvements to HVAC systems in HNE house museums. They are working on eight principal properties with the goals of upgrading environmental systems in them mainly for the collections but at the same time not harming the buildings. These changes will involve monitoring the environments in the buildings, eliminating moisture, and altering humidistatic controls. Under an NEH grant in the 1990's, these eight properties received new HVAC systems. Landmark Facilities Group was the design engineers, but some installations did not correspond to their designs and specifications. Installed HVAC approaches in the eight properties differed from one another, but they shared the basic idea of a "high-tech" humidistatic control system. There was an effort to identify sources of moisture in each house, but the properties were typically inspected then monitored for less than one month with hydrographs. Property improvements then focused on removing sources for water penetration. Performance goals were set with the NEH at relative humidity of 45% with 5% allowable variation. The control and monitoring systems depended upon DDC controllers for management from remote locations. Generally, air handling units (AHUs) were located in basements, with exhaust fans in attics. The design approach intended for basement volumes to be separated from upper floors. Early after 2000, problems became evident and were systemic. There were difficulties with the basics of the computerized communication links. Changes in software led to rapid obsolescence and abandonment of the DDC systems. Modems were DOS-based, and there was no budget to upgrade to Microsoft Windows. For some houses there was no data until 2001, then data soon stopped. Several equipment components were defective, in part because of the difficulty of maintenance but sometimes because initial quality was poor. A number of systems were never adequately balanced. Most intakes were oversized and sometimes the imbalance was reversed. Separation between basements and upper floors (collections) was seldom effective-often there were openings in ductwork that created links and spread moisture from below. Erin and Ben organized the Kress grant project around case studies, concentrating on the Codman House in Lincoln, Massachusetts (c1740) and Cogswell Grant House on the North Shore. They analyzed existing conditions and repaired roofs, chimneys (including caps), and rainwater disposal systems. They emphasized approaches that were relatively simple to understand and operate. They eliminated remote communication, installing local sensors and controls. At Codman, where the basement incorporates a 19th century dairy floor, they closed the basement windows, turned off a 24" fan connected to exterior air, and shut down the air handling unit. They added heat and dehumidification. Erin plotted "scatter charts" of RH values taken from monitors before and after the system alterations. The Codman basement was drier after the changes. As part of the earlier NEH HVAC installation, an internal elevator shaft was used as a chase for a duct connecting the basement to attic exhaust. The duct was not air-tight; and during the summer, moist air from below was released on upper floors. The Cogswell Grant House was a very wet house; it had no heat and the plumbing had been disconnected. It received treatment similar to that in the Codman House under the NEH grant. The house was equipped with new gutters and downspouts, a plastic covering was placed over the basement floor, an AHU was located in the basement, and an exhaust fan was installed in the attic. Humidistatic ventilation controls were installed. Again, Erin found openings in ductwork that linked basement to attic. The upper floors registered between 62% and 67% RH and mold in the upper floors was increasing. Erin shut down the NEH-vintage system but found no change in the data for temperature and humidity in the house. The attic fan was twice the capacity of the basement intake. Erin and Ben shut it down and added dehumidification to the basement. House managers and docents keep the front door open during the summer. HNE will add radiators to the basement. The houses are kept at about 55º F during the winter. During the summer, the houses have mechanical ventilation but almost no spaces are air-conditioned. HNE has revised their performance standards for interior temperature and humidity variations. In 2008, the organization accepts a spread between extremes of 30% and 60% RH while seeking to minimize the time spent at the extremes. Small spikes are taken in stride. Ivan Myjer noted that a rigid orthodoxy continues to bedevil the relationship between climate-control for historic collections and the management of moisture and temperature variations and vapor migration through building assemblies. Ben confirmed that while HNE accepts a humidity range from 30% to 60%, grant-making bodies and insurers for inter-museum loans do not. They typically require 45% with a variation of 3% - 5%. [This may be impossible to achieve, and if it were, it could cause building components to deteriorate because of condensation. Furthermore, these buildings once functioned without dependence on petroleum or coal for heating and cooling. The moral imperative of more sustainable approaches will necessarily require much better integration of engineering approaches for collections and building fabric, even when winter comfort is not a primary goal.] Pressurization, balancing and control remain difficult problems, but Ben and Erin are replacing dysfunctional fancy equipment with much simpler controls. In the past, the proprietary controls frequently broke down and a service call could easily cost $1,000. Today's strategy is to install controls that the house museum managers can learn to operate and that local HVAC contractors can easily replace. They are now studying off-the-shelf controls with Internet capability. HNE has simplified its approach to moisture in basements. Today's approach is focused on dehumidification and heating with no heroic attempts at air exchange. Ben is skeptical about the feasibility of installing effective vapor barriers in historic interiors, and this stance drew strong objections from Bill Remsen and John Hecker, who saw damp basement floor substrates as a constant, pernicious source of moisture that would affect each house. Pat Morrissey described water-proofing products that are injected through masonry to create positive-side membranes formed of gels that swell upon contact with moisture. Ben noted the integrity of historic finishes in many of the house museum basements as an impediment to vapor barriers under floors and behind stone retaining walls. Most systems are neither conservative nor reversible. Wendall Kalsow said that for the $120,000 HVAC system at Orchard House in Concord the design engineer remained responsible for monitoring and adjusting its operation for 24 months after it was installed. [Committee members will recall Wendall's colorful photographs of school children in down parkas wending their way through the Alcott interiors.] HNE has applied for an IMLS grant that will allow Ben and Erin to continue their monitoring and thoughtful system alterations through Codman, Cogswell Grant and other HNE properties. Ivan Myjer noted that typical AIC conferences and symposia have brought together experiences from drastically different climates and also had a strong collection management bias. Ivan suggested that we organize a conference focused on the Northeast region and bring together artifact conservators and with professionals chiefly involved with building conservation. Susan Schur mentioned several AIC conferences organized around the topic of HVAC in historic buildings. Tom Taylor of Historic Williamsburg was involved, so their subject matter was not restricted to artifact conservation. Susan also cited longitudinal studies of the effects of temperature and humidity variations in Italian churches that could offer lessons for our buildings in spite of the differences in climate. [The idea of a two-day long, intensive workshop on effective environmental management approaches to museum exhibit and collections storage areas in historic buildings in our region (both ocean-effect and drier, colder climatic zones) seems timely and worth further thought. Our BSA committee could sponsor and organize the event if issues of travel and accommodation stay simple. We will discuss possible approaches at our next meeting in October.] 2. Dueling Glass and Glazing Conferences: The committee noted the possibilities for confusion, undesirable redundancy or desirable complementarities between the APTI/Northeast and the Technology and Conservation glass and glazing conferences on March 20, 2009 and March 20, 2010. Jack Glassman and Pat Morrissey of APTI/Northeast said the lack of a common calendar had contributed to the coincidences of topic and dates. Organizers of the two conferences will confer to explore ways to manage press releases and content to improve the effect and appeal of both events. The specific conference topics seem to offer opportunities to minimize overlap and dilution and to draw participants on successive years. 3. Woburn Library: Jessica Pineo Lohnes remains in touch with our committee about ways to support her group that is affiliated with the Henry Hobson Richardson library. As they prepare the way for expansion, they are sponsoring lectures and tours about Richardson's architecture. The building is the first HHR library and the only one that has not yet incorporated any addition. 4. Advocacy Items:
8:00 a.m., Thursday, 9 October 2008 Featuring Bill Steelman, Essex National Heritage Area Heritage Development The Architects' Building, 52 Broad Street, Boston Henry Moss, Matthew Bronski, and Sara Wermiel co-leaders and scribes
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