HVAC COMPONENTS AND SYSTEMS - Ökohaus GER

1 V I T A L S I G N S C U R R I C U L U M M A T E R I A L S P R O J E C T 1 hvac COMPONENTS AND SYSTEMSTABLE OF CONTENTSHVAC COMPONENTS AND SYSTEMSWALTER GRONDZIKASSOCIATE PROFESSOR, FLORIDA A & M UNIVERSITYRICHARD FURSTUNDERGRADUATE RESEARCH ASSISTANTV I T A L S I G N S C U R R I C U L U M M A T E R I A L S P R O J E C THVAC COMPONENTS AND SYSTEMS 2 ACKNOWLEDGMENTSACKNOWLEDGMENTSThe hvac COMPONENTS and SYSTEMS module of the Vital Signs Project was developed at the School ofArchitecture, Florida A & M University (FAMU), Tallahassee, FL. The assistance of the Institute for BuildingSciences, School of Architecture, and Division of Sponsored Research at Florida A & M is Grondzik was Principal Investigator (and author) for the hvac COMPONENTS and SYSTEMS Furst, a FAMU undergraduate student, was responsible for materials review and final documentlayout and also assisted with all phases of module development.

2 Serge Rodrigue, a FAMU undergraduatestudent, prepared many of the original freehand sketches in the module. The case studies were researchedand assembled by Bob Rice, a FAMU graduate from the developers of other Vital Signs modules is gratefully acknowledged. The review commentsof Jack Kremers, Tang Lee, Russ Leslie, Ardeshir Mahdavi, and Werner Osterhaus (coordinated through theefforts of Charlie Brown) are appreciated. Special thanks go to Charlie Huizenga for his thorough review ofthe final draft. The cheerful and long-term assistance of Vital Signs graduate assistants Alison Kwok andRobert Marcial is especially noted; as is the perserverance of the Project Investigators -- Cris Benton, GailBrager and Bill information and opinions presented herein are solely the responsibility of the module authors, and donot necessarily reflect the position of the Project sponsors or managers.

3 Comments and suggestions fromthose who use this module are Vital Signs Curriculum MaterialsProject is administered by the Centerfor Environmental Design, Universityof California, Berkeley. Funding andsupport for the Project have beenprovided by the Energy Foundationand the PG&E Energy Center. CrisBenton is Principal Investigator forthe Vital Signs Project. Co-investigators include Gail Brager andBill I T A L S I G N S C U R R I C U L U M M A T E R I A L S P R O J E C T 3 hvac COMPONENTS AND SYSTEMSTABLE OF CONTENTSTABLE OF CONTENTSA cknowledgments ..Introduction .. hvac COMPONENTS ..Background ..Source COMPONENTS ..Distribution COMPONENTS ..Delivery COMPONENTS .. hvac SYSTEMS ..Local SYSTEMS ..Central SYSTEMS .. All-Air SYSTEMS .

4 All-Water SYSTEMS .. Air-Water SYSTEMS .. Water-Source Heat Pumps ..Application Examples ..Single-Family Residence ..Branch Bank ..Church ..Government Office Building ..Field Exercises ..Summary Listing ..Level One ..Level Two ..Level Three ..Glossary ..Bibliography ..24778192326262930323233343538424751535 459636470V I T A L S I G N S C U R R I C U L U M M A T E R I A L S P R O J E C TINTRODUCTION4 hvac COMPONENTS AND SYSTEMSHVAC COMPONENTS AND SYSTEMSINTRODUCTIONThis module of the Vital Signs curriculum package addresses hvac SYSTEMS . hvac (pronounced as fourseparate letters) is an acronym that stands for heating, ventilating and air-conditioning and generallyincludes a variety of active mechanical/electrical SYSTEMS employed to provide thermal control in of the thermal environment is a key objective for virtually all occupied buildings.

5 For thousands ofyears such control may have simply been an attempt to ensure survival during cold winters. In the modernarchitectural context, thermal control expectations go far beyond survival and involve fairly complexthermal comfort and air quality concerns that will influence occupant health, satisfaction and heating system ( H in hvac ) is designed to add thermal energy to a space or building in order tomaintain some selected air temperature that would otherwise not be achieved due to heat flows (heat loss)to the exterior environment. A ventilating system ( V ) is intended to introduce air to or remove air from aspace -- to move air without changing its temperature. Ventilating SYSTEMS may be used to improve indoorair quality or to improve thermal comfort. A cooling system ("C" is not explicitly included in the hvac acronym) is designed to remove thermal energy from a space or building to maintain some selected airtemperature that would otherwise not be achieved due to heat flows (heat gain) from interior heat sourcesand the exterior environment.

6 Cooling SYSTEMS are normally considered as part of the AC in hvac ; ACstands for air-conditioning system, by ASHRAE (American Society of Heating, Refrigerating and Air-ConditioningEngineers) definition, is a system that must accomplish four objectives simultaneously. These objectivesare to: control air temperature; control air humidity; control air circulation; and control air the word control is often loosely construed, encompassing anything from pin-point control forcentral computer facilities to ballpark control for residences, the requirement that an air-conditioningsystem simultaneously modify four properties of air demands reasonably sophisticated SYSTEMS . Thismodule will focus on air-conditioning SYSTEMS , as owner and occupant expectations for many commonbuilding types tend to require the use of this broad family of SYSTEMS . Heating SYSTEMS (such as portableelectric heaters or fireplaces), ventilating SYSTEMS (such as whole-house fans or make-up air units), andsensible-cooling-only SYSTEMS are also used in buildings and will be discussed in this module.

7 Theemphasis, however, will be on multi-function air-conditioning SYSTEMS are of great importance to architectural design efforts for four main reasons. First, thesesystems often require substantial floor space and/or building volume for equipment and distributionelements that must be accommodated during the design process. Table 1 suggests the extent of theserequirements for a variety of building types. Second, hvac SYSTEMS constitute a major budget item fornumerous common building types. Figure 1 summarizes hvac cost percentages for selected buildingtypes. Third, the success or failure of thermal comfort efforts is usually directly related to the success orfailure of a building s hvac SYSTEMS (when passive SYSTEMS are not used) -- even though the hvac SYSTEMS should be viewed as part of the larger architectural system. Table 2 summarizes causes foroccupant complaints in existing commercial buildings and emphasizes the importance of hvac SYSTEMS tothe satisfaction of occupants.

8 Last, but not least, maintaining appropriate thermal conditions throughHVAC system operation is a major driver of building energy consumption. Figure 2 provides a breakdown ofenergy uses for typical residences and commercial buildings in both hot and cold I T A L S I G N S C U R R I C U L U M M A T E R I A L S P R O J E C T5 hvac COMPONENTS AND SYSTEMSINTRODUCTIONF igure 1. hvac system cost as apercentage of total buildingconstruction cost for selectedbuilding types. (From varioussources)If an architect is to maintain any semblance of control over the total building design process, he or shemust understand hvac SYSTEMS . hvac SYSTEMS consume an important part of the building constructionbudget, account for a major portion of a typical building s annual energy consumption, often requiresubstantial space allocations (that may drive building organization schemes in larger buildings), andcontribute to interior environments that are critically evaluated by building occupants on a day-by-daybasis.

9 Successful hvac SYSTEMS are often the key to successful buildings. Although it is unlikely that anarchitect will fully design an hvac system, even for residential projects, it is critical that the architectmanage the system design and component selection processes to retain control of the final buildingproduct. Such management requires an understanding of system objectives, the role of key systemcomponents, the types of SYSTEMS that are available, and what such SYSTEMS can and can not hvac system development from a broad building-wide perspective, the architect can (andusually will) leave the specifics of system design to consulting organization of this module is based on a flow of concerns from basic principles, to COMPONENTS , toassemblies of COMPONENTS (termed SYSTEMS ), to applied examples of SYSTEMS . Field studies to strengthenunderstanding of terminologies, concepts, and SYSTEMS are provided following the case study examples.

10 Aglossary is included to provide easy access to the many technical terms encountered in this module. Anannotated bibliography provides recommendations for other sources of information on building module is not intended to be used as a stand-alone document. The design of hvac SYSTEMS isintimately related to other building concerns, including but certainly not limited to: lighting system design,building envelope design, thermal comfort, and indoor air quality. Cross references to other Vital Signsmodules are indicated where System Space Requirements as a Percentage of Gross Building Floor AreaGross FloorDomicile-related Institutional Assembly-based LaboratoryArea (ft2) Occupancies Occupancies Occupancies Occupancies10,000 6 % 8 % 9 % 11 %50,000-100,000 4 % 6 %7 % 10 %500,000 3 % 4 % 5 % 8 %Approximate values that include floor space for central equipment (chillers, boilers, pumps) and air circulationequipment (fans).