ASHRAE HVAC APPLICATIONS IP CH 8-2015 Health Care Facilities.pdf

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1、8.1CHAPTER 8HEALTH CARE FACILITIESREGULATORY AND RESOURCE OVERVIEW 8.1Air Conditioning in Disease Prevention and Treatment 8.2HOSPITAL FACILITIES 8.2Air Quality . 8.3Specific Design Criteria. 8.5Facility Design and Operation. 8.12Sustainability . 8.13OUTPATIENT HEALTH CARE FACILITIES. 8.14Diagnostic

2、 and Treatment Clinics 8.14Dental Care Facilities 8.14Continuity of Service and Energy Concepts. 8.14RESIDENTIAL HEALTH, CARE, AND SUPPORT FACILITIES 8.15Design Concepts and Criteria 8.15ONTINUAL advances in medicine and technology necessitateCconstant reevaluation of the air-conditioning needs of h

3、ospitalsand medical facilities. Medical evidence shows that proper air con-ditioning is helpful in preventing and treating many conditions, andventilation requirements exist to protect against harmful occupa-tional exposures. Although the need for clean and conditioned air inhealth care facilities i

4、s high, the relatively high cost of air condition-ing demands efficient design and operation to ensure economicalenergy management.Health care occupancy classification, based on the latest occu-pancy guidelines from the National Fire Protection Associations(NFPA) Life Safety Codeand applicable build

5、ing codes, should beconsidered early in project design. Health care facilities are uniquein that there may be multiple, differing authorities having jurisdic-tion (AHJs) overseeing the design, construction, and operation of thefacility. These different AHJs may use different standards or differ-ent

6、versions of the same standards. Health care occupancy classifi-cation is important to determine for fire protection (smoke zones,smoke control) and for future adaptability of the HVAC system for amore restrictive occupancy.Health care facilities are increasingly diversifying in response toa trend to

7、ward outpatient services. The term clinic may refer to anybuilding from a residential doctors office to a specialized cancertreatment center. Integrated regional health care organizations arebecoming the model for medical care delivery as outpatient facilitiestake on more advanced care and increasin

8、gly serve as the entry-way to the acute care hospital. These organizations, as well as long-established hospitals, are sometimes constructing buildings that lookless like hospitals and more like luxury hotels and office buildings.However, when specific health care treatments in these facilities arem

9、edically consistent with hospital-based treatment activity, then theenvironmental design guidance applicable to the hospital-basedtreatment should also apply to the clinics treatment environment.For the purpose of this chapter, health care facilities are dividedinto the following categories:Hospital

10、 facilitiesOutpatient health care facilitiesResidential health care and support facilitiesThe general hospital provides a variety of services; its environ-mental conditions and design criteria apply to comparable areas inother health care facilities. The general acute care hospital has a coreof pati

11、ent care spaces, including rooms for operations, emergencytreatment, delivery, patients, and a nursery. Usually, the functions ofradiology, laboratory, central sterile, and pharmacy are located closeto the critical care space. Inpatient nursing, including intensive carenursing, is also within the co

12、mplex. The facility also incorporates akitchen, dining and food service, morgue, and central housekeepingsupport.Outpatient surgery is performed with the anticipation that thepatient will not stay overnight. An outpatient facility may be part ofan acute care facility, a freestanding unit, or part of

13、 another medicalfacility such as a medical office building.Nursing facilities are addressed separately, because their funda-mental requirements differ greatly from those of other medical facil-ities in regards to odor control and the average stay of patients.Dental facilities are briefly discussed.

14、Requirements for thesefacilities differ from those of other health care facilities becausemany procedures generate aerosols, dusts, and particulates.1. REGULATORY AND RESOURCE OVERVIEWThe specific environmental conditions required by a particularmedical facility may vary from those in this chapter,

15、depending on theagency responsible for the environmental standard. ANSI/ASHRAE/ASHE Standard 170 represents the minimum design standard forthese facilities, and gives specific minimum requirements for spacedesign temperatures and humidities as well as ventilation recommen-dations for comfort, asepsi

16、s, and odor control in spaces that directlyaffect patient care.Standard 170 is in continuous maintenance by ASHRAE, withproposed addenda available for public review/comment and pub-lished addenda available for free download from https:/www.ashraorg. It is republished in whole approximately every fou

17、r years withall published addenda incorporated. Standard 170 is also included inits entirety in the Facility Guidelines Institutes Guidelines forDesign and Construction of Hospitals and Outpatient Facilities andGuidelines for Design and Construction of Residential Health, Care,and Support Facilities

18、 (FGI 2014a, 2014b). The FGI Guidelines areadopted in more than 42 U.S. states by AHJs overseeing the plan-ning, construction, and operation of health care facilities in thosestates.Agencies that may have standards and guidelines applicable tomedical facilities include state and local health agencie

19、s, the U.S.Department of Health and Human Services including the Centersfor Disease Control and Prevention (CDC), Indian Health Service,Food and Drug Administration (FDA), U.S. Public Health Service,and Medicare/Medicaid, U.S. Department of Defense, U.S. Depart-ment of Veterans Affairs, and The Join

20、t Commissions HospitalAccreditation Program.ASHRAE Guidelines 10 and 29 may be especially applicable tothe design of health care facilities. ASHRAE Proposed Standard188 addresses practices to help prevent the elderly and immune-suppressed populations common in health care facilities fromacquiring Le

21、gionnaires disease. The HVAC Design Manual forHospitals and Clinics (ASHRAE 2013) presents enhanced designThe preparation of this chapter is assigned to TC 9.6, Healthcare Facilities.8.2 2015 ASHRAE HandbookHVAC Applicationspractice approaches to health care facility design and greatly sup-plements

22、the information in this chapter.NFPA Standard 99, which has been adopted by many jurisdic-tions, provides requirements for ventilation of medical gas storageand transfilling spaces. It also has requirements for heating, cooling,and ventilating the emergency power system room.American Society for Hea

23、lthcare Engineerings (ASHE) mono-graphs and interpretation tools are an important resource to helpintegrate facility management considerations into the built envi-ronment. The American Conference of Governmental IndustrialHygienists (ACGIH 2013) Industrial Ventilation: A Manual ofRecommended Practic

24、e for Design includes guidance on sourcecontrol of contaminants.International standards for health care ventilation include theCanadian Standards Associations CSA Standard Z317.2, and guide-lines by the Australasian Health Facility (available at .au). The Health AuthorityAbu Dhabi(HAAD) released the

25、ir Health Facility Design Standards in January2011 (http:/.au/haad.hfg/). ASHRAE inter-national associate societies (e.g., Indias ISHRAE) may have healthcare resources specific to the local culture and climate; see http:/www.ashraeasa.org/members.html for a list of associate organiza-tions.Other med

26、ically related organizations with design and/or opera-tional standards and guidelines that may be applicable to health carefacility design include the United States Pharmacopeia (USP), Amer-ican Association of Operating Room Nurses (AAORN), and Associ-ation for the Advancement of Medical Instrumenta

27、tion (AAMI).Along with HVAC requirements for normal operation, manyhealth care facilities are considered essential facilities with pro-grammatic requirements to remain operational after earthquakes orother naturally occurring events. Building code importance factordesignation and application can req

28、uire structural and restraint fea-tures not normally included in other types of facilities. Many healthcare facilities have on-site diesel engine generated electric power,which can necessitate EPA fuel storage permitting, security require-ments, and potentially air permitting issues.FGI (2014a, 2014

29、b) requires the owner to provide an infectioncontrol risk assessment (ICRA) and prepare infection control riskmitigation recommendations (ICRMR) that are intended to pre-identify and control infection risks arising from facility constructionactivities. The ICRMR and ICRA are then to be incorporated

30、in thecontract documents by the design professional. Therefore, it isessential to discuss infection control objectives with the hospitalsinfection control committee.1.1 AIR CONDITIONING IN DISEASE PREVENTION AND TREATMENTHospital air conditioning plays a more important role than just thepromotion of

31、 comfort. In many cases, proper air conditioning is afactor in patient therapy; in some instances, it is the major treatment.Studies show that patients in controlled environments generallyhave more rapid physical improvement than do those in uncon-trolled environments. Examples include the following

32、:Patients exhibiting thyrotoxicosis (related to hyperthyroidism) donot tolerate hot, humid conditions or heat waves very well. Acool, dry environment favors the loss of heat by radiation andevaporation from the skin and may save the patients life.Cardiac patients may be unable to maintain the circul

33、ation neces-sary to ensure normal heat loss. Air conditioning cardiac wardsand rooms of cardiac patients, particularly those with congestiveheart failure, is necessary and considered therapeutic (Burch andPasquale 1962).Individuals with head injuries, those subjected to brain operations,and those wi

34、th barbiturate poisoning may have hyperthermia,especially in a hot environment, caused by a disturbance in the heatregulatory center of the brain. An important factor in recovery is anenvironment in which the patient can lose heat by radiation andevaporation: that is, a cool room with dehumidified a

35、ir.Patients with rheumatoid arthritis have been successfully treatedin a hot, dry environment of 90F db and 35% rh.Dry conditions may be hazardous to the ill and debilitated by con-tributing to secondary infection or infection totally unrelated tothe clinical condition causing hospitalization.Clinic

36、al areas devoted to upper respiratory disease treatment andacute care are often maintained at a minimum of 30% rh. Thefoundation and associated clinical benefit of this practice haverecently come under question, so the designer is encouraged toclosely consult the latest design guidance and the facil

37、ity ownerwhen establishing this design criterion.Patients with chronic pulmonary disease often have viscous respi-ratory tract secretions. As these secretions accumulate andincrease in viscosity, the patients exchange of heat and waterdwindles. Under these circumstances, the inspiration of warm,humi

38、dified air is essential to prevent dehydration (Walker andWells 1961).Patients needing oxygen therapy and those with tracheotomiesrequire special attention to ensure warm, humidified supplies ofinspired air. Cold, dry oxygen or bypassing the nasopharyngealmucosa presents an extreme situation. Rebrea

39、thing techniques foranesthesia and enclosure in an incubator are special means ofaddressing impaired heat loss in therapeutic environments.Wound intensive care (burn) patients need a hot environment andhigh relative humidity. A ward for severe burn victims shouldhave temperature controls (and compat

40、ible architectural designand construction) that allow room temperatures up to 90F db andrelative humidity up to 95%.Reducing hospital-acquired infections (HAIs; also called nos-ocomial infections) has become a focus of the health care industry.Environmental factors influenced by the HVAC system are

41、typicallyidentified as directly contributing to only a small portion of the over-all HAIs. However, HVAC engineering controls directly contributeto maintaining asepsis, such as required differential pressure relation-ships between spaces, directional airflow, methods of air delivery,air filtration,

42、overall building pressurization, etc. A well-designedHVAC system also affects indoor environmental quality and asep-sis integrity through specifically HVAC-related factors (e.g., ther-mal comfort, acoustics, odor control). Therefore, HVAC systemeffectiveness can also lead to an improved healing envi

43、ronment forthe patient, contributing to shorter patient stays and thereby mini-mizing the patient exposure to HAIs. ASHE (2011) provides anengineering perspective on the topic with many additional refer-ences.2. HOSPITAL FACILITIESAlthough proper air conditioning is helpful in preventing andtreating

44、 disease, application of air conditioning to health care facil-ities presents many problems not encountered in usual comfort con-ditioning design.The basic differences between air conditioning for hospitals (andrelated health care facilities) and that for other building types stemfrom the (1) need t

45、o restrict air movement in and between depart-ments; (2) specific requirements for ventilation and filtration todilute and remove contamination (odor, airborne microorganismsand viruses, hazardous chemicals, and radioactive substances); (3)different temperature and humidity requirements for various

46、areas;and (4) design sophistication needed for accurate control of environ-mental conditions.Health Care Facilities 8.3Infection SourcesBacterial Infection. Examples of bacteria that are highlyinfectious and transported in air or air and water mixtures areMycobacterium tuberculosis and Legionella pn

47、eumophila (Legion-naires disease). Wells (1934) showed that droplets or infectiousagents of 5 m or less in size can remain airborne indefinitely.Viral Infection. Examples of viruses that are transported by andvirulent within air are Varicella (chicken pox/shingles), Rubella(German measles), and Rube

48、ola (regular measles). Research indi-cates that many airborne viruses that transmit infection are origi-nally submicron in size, though in air they are often attached tolarger aerosol and/or as conglomerates of multiple viruses, whichmay be more easily filtered from the airstream.Molds. Evidence ind

49、icates that some molds such as Aspergilliscan be fatal to advanced leukemia, bone marrow transplant, andother immunocompromised patients.Chemicals. Hospitals use various chemicals as disinfectants,which may require control measures for worker or patient safety.Many pharmaceuticals are powerful chemical agents.Control MeasuresOutdoor Air Ventilation. If outdoor air intakes are properlylocated and areas adjacent to the intakes are properly maintained,outdoor air is virtually free of infectious bacteria and viruses co