1.0 EXECUTIVE SUMMARY:

Transcription

1 1.0 EXECUTIVE SUMMARY: ASHRAE Standard was used to evaluate the required outdoor air requirement for The Jack S. Blanton Museum of Art in. This report outlines that the museum does meet ASRAE Standard To evaluate the standard some assumptions had to be made for space criteria that were not designated in ASHRAE Standard 62.89, these assumption are outline in Section 3.0. Using the multiple space equation outlined in Section 4.0, the critical fraction of outdoor air for the building was found to be for a conference room space. The required amount of outdoor air calculated for the building is approximately 83, 840 CFM. The amount of fresh air being brought into the building is approximately 90, 000 CFM. This indicates that the museum does meet the ventilation standard for acceptable air quality. ASHRAE Standard 62: Report Page 1 of 7 11/13/2002

2 2.0 BUILDING DATA: 2.1 Building Base Information The Jack S. Blanton Museum of Art is a 135, 000 sq. ft. facility mostly consisting of art gallery space. The museum also includes educational space, office space, preparation space for exhibits and conservation laboratory. The building has been divided into sections that best represent the type and use of spaces within the building. The divisions are defined in Figure 2.1. For example, all of the art galleries are grouped under the section Gallery Space. The supporting calculations for the assignment are done with respect to the sections. The sections also represent differences in air flow and space conditions within the building. The building sections with respect to area are represented in Figure 2.2. Space Divisions Division Definition A Public Area Public spaces in the building B Gallery Space Art display areas in the building C Prints & Drawings Gallery Space Art space specifically for prints D Education Classroom spaces in the building E Prints & Drawings Area Storage and prep areas, museum curators and curators offices F Preparation Area Preparation and shops for building of exhibits in the museum G Collection Area Collection Storage H Conservation Area Space for restoration and conservation of art work I Support Services Support for the building Building Area Distribution 3,998 2,107 2, ,772 1, ,738 Public Area Gallery Space Prints & Draw ings Gallery Space Education Prints & Draw ing Area Preparation Area Collection Area Conservation Area 36,709 Support Services Figure 2.2 Building Area Distribution according to section ASHRAE Standard 62: Report Page 2 of 7 11/13/2002

3 2.2 Building Air System The mechanical system for the museum features one large air handling unit which feeds all spaces. The air is fed to each space through a dual duct system. Zone humidification is also present in the air system. All calculations are done with respect to the one large air handling unit. ASHRAE Standard 62: Report Page 3 of 7 11/13/2002

4 3.0 ANALYSIS The following section discusses the analysis used to evaluate the building for ASHRAE Standard All supporting calculations and spreadsheets are located in Appendix A. 3.1 Assumptions ASHRAE does not offer occupancy values and outdoor air requirements specific for art museums. As a result, an assumption had to perform design calculations. The assumptions made are based on past experience with art museums at a previous summer internship. The assumptions made for the assignment are outlined below Occupancy Assumptions The following occupancy assumptions were made for calculation purposes: Gallery spaces: 50 sq.ft./person Lobby spaces 50 sq.ft./person Collection Storage: 200 sq.ft/person Prep and Shop area: 100 sq.ft./person Conservation area: 100 sq.ft./person Fresh Air Requirement Assumptions The following ventilation rate assumptions were made for calculation purposes: Gallery spaces: 15 CFM/person Lobby spaces: 15 CFM/person Collection Storage: 20 CFM/person Prep and Shop area: 15 CFM/person Conservation area: 15 CFM/person Classroom: 50 CFM/person Note: the classroom is designed in the format of a conference room and could be used as a conference room, so the value of the conference room was used for calculations 3.2 Calculation of Outdoor Air Requirement The outdoor air requirement for the building was calculated using a series of spreadsheets to perform the analysis. The space characteristics are defined in Table 1, Appendix A. The table is organized by division within the museum to represent what activities occur in each section. The space characteristics define a space within the building, the use of the space, the space area and the design occupancy for each space. Next, the amount of outdoor air required for the space was calculated using the recommendations given in ASHRAE Standard The supply air for each space was ASHRAE Standard 62: Report Page 4 of 7 11/13/2002

5 also calculated. The fraction of outdoor air required to supply air can now be calculated as Z (Eq. 1). Z = V oc /V sc (Eq. 1) V oc = the outdoor flow rate required V sc = supply flow rate in the critical space When the value of Z has been caculated, the highest Z defines the critical space or Z c. Table 2, Appendix A summarizes supply air flow, required outdoor air flow, and Z for each space. Table 3, Appendix A lists a summary of the airflow required for each space within the building. The resulting Z c for the building was calculated as for Study Room in the building. The study room is a small conference room where the museum curators can meet to discuss information about specific pieces of art work. Knowing Z c the corrected outdoor air flow rate can be calculated using the multiple spaces equation (Eq 2) found in ASHRAE Standard Y = X/{1 + X Z] (Eq. 2) X = uncorrected fraction of outdoor air in the system supply Z = the fraction of outdoor air in the critical space The supporting calculations for the multiple spaces equation can be found in Table 4, Appendix A. The resulting value for the corrected outdoor air flow rate was 83,840 CFM. The outdoor flow rate for the building is 90, 000 CFM. The building does meet ASHRAE Standard because the outdoor air brought into the building (90, 000 CFM) is greater than the required amount of outdoor air for the building, (83,840 CFM). ASHRAE Standard 62: Report Page 5 of 7 11/13/2002

6 4.0 DISCUSSION: The Ventilation Rate Procedure was used to determine the amount of fresh air required for the museum. The Ventilation Rate Procedure is driven by calculating the required the adjusted fraction of outdoor air required for the building. The Ventilation Rate procedure was used for the design of the museum by the MEP engineer. Another method than can be used to determine interior space conditions is the Indoor Air Quality Procedure. The indoor air quality procedure is based on measuring the indoor air quality in the space through sensors. The sensors communicate through a controls sequence to the air handling system. The sensor signal indicates when more fresh air is needed for a particular space. The use of the Indoor Air Quality Procedure can also have a higher first cost. The additional sensors required are expensive and also require an elaborate controls sequence. With an elaborate controls sequence, it will also require a knowledgeable facilities team to operate the system. The Indoor Air Quality Procedure will not work correctly if the facilities team does not understand how to properly operate and maintain the system. Due to the strict tolerances needed for gallery spaces, the Indoor Air Quality Procedure would not be likely to be used. The air system in a museum needs to operate smoothly as to not have large fluctuations in the space conditions. The low tolerances guarantee that the gallery controls are tighter. Therefore, the use of the ventilation rate procedure produces a more accurate result for the case of an art museum. ASHRAE Standard 62: Report Page 6 of 7 11/13/2002

7 5.0 REFERENCES: 1. ASHRAE Standard 62.89, Ventilation for Acceptable Indoor Air Quality 2. Ove, Arup & Partners, Project design documents and assumptions for calculation of gallery spaces ASHRAE Standard 62: Report Page 7 of 7 11/13/2002