Medical air systems are a vital element of all hospitals and most other healthcare facilities. The engineer must consider expense, capacity, physical size and weight, space limitations, and mechanical and electrical utility availability in choosing a system for a particular project. It is important to coordinate the equipment selections with the owner as well as other engineering and architectural disciplines.
The first priority is life safety. Medical air is used for respiratory therapy and calibration of medical devices for respiratory application. Providing clean, oil-free air is mandatory. The medical air system should not be used to supply air for any other purpose (e.g., hospital laboratory use) because of the opportunities for contamination of the distribution system. If a patient inhales medical air contaminated by oil from a defunct compressor or nitrogen from a brazing purge, the consequences could be irreversible. In addition, a utility or pipeline shutdown must be coordinated with the hospital staff to prevent an accidental service termination while patients are connected to the system. Engineers should be aware of the requirements before designing any medical gas system.
Distribution Systems
Medical compressed air systems must be designed to prevent the introduction of contaminants or liquid into the pipeline. Medical air systems must:
• be supplied from cylinders, bulk containers, or medical air compressor sources; or reconstituted from oxygen USP and oil-free, dry nitrogen
• meet requirements of the medical air
• contain no detectable liquid hydrocarbons
• contain fewer than 25 ppm gaseous hydrocarbons
• contain 5 mg/m3 or less of permanent particulates sized 1 micron or larger at normal atmospheric pressure.
In a typical fully functioning healthcare facility, the medical air is supplied by a high-pressure cylinder manifold system or a medical air compressor system. Manifold distribution systems typically are used in facilities that have very little demand for medical air. Medical air compressor plants typically are for larger facilities.
Existing facilities may choose to upgrade their equipment and associated pipeline or add medical air plants as the facility expands. When selecting a piece of equipment for a new facility, the possibility of future expansion should be considered. To allow for future growth, it is good practice to be conservative in sizing a system.
Duplex Medical Air Compressor Source Systems
An engineer usually has more options available when designing for a new facility than for a renovation or replacement project. Electrical and mechanical utilities can be more easily calculated, and chilled water, ventilation, and electrical services can be sized and adequately located. The ideal schematic design contains a well-ventilated, easily accessible mechanical room dedicated to medical gas equipment.
In selecting a medical air compressor for an upgrade, the engineer may have some trouble due to mechanical utility inefficiencies (e.g., poor chilled water quality, a poorly ventilated mechanical space). The local electric utility may not support the pump arrangement, or poor equipment access may require breakdown of equipment parts at a significant cost increase. It is imperative to conduct thorough surveys of the surrounding mechanical space and utilities before determining the best type of compressor for the project.
It is a good idea to select more than one type of compressor at the schematic design phase. You should develop a master plan that shows existing demand and estimated spare capacity. The owner may want to obtain a cost estimate before making a final decision.
Types of Compressors
All medical air compressors must be able to deliver compressed air that does not contain oil. This article specifically deals with medical air systems for Level 1 hospitals.
There are three acceptable types:
• Oil-free compressors: These reciprocating compressors have no oil film on surfaces exposed to air being compressed. They do have oil in the machine and require separation of the oil-containing section from the compression chamber by at least two seals. The interconnecting shaft and seals must be visible without disassembling the compressor.
• Oilless compressors: These reciprocating or rotary-scroll compressors do not have oil in the machine. Lubrication is limited to seal bearings.
• Liquid ring pump: These rotary air compressor pumps have a water seal. It is recommended that a heat exchanger be utilized to conserve seal water.
Medical air compressor plants should be sized to serve peak calculated demand when the largest compressor is out of service. In an efficient design of a larger system (i.e., three pumps or more), each compressor is sized to handle an equal percentage of the peak demand and create redundancy. There never should be fewer than two compressors.
Accessory Equipment
Several pieces of mechanical equipment accompany the medical air compressor system:
• Intake: The compressor’s air intake must be located outdoors, above roof level, and at least 10 ft from any door, window, other intake, or other opening. Intakes must be turned down, screened, and equipped with intake filter mufflers. These filters remove large amounts of particulates (microscopic particles of solid or liquid matter suspended in the air) and contaminants at the compressor inlet.
• Air receiver: The role of the air receiver is to store air and balance pressure variations. It must have a full-size bypass as well as a manual and automatic drain to remove any collected condensate. It must meet American Society of Mechanical Engineers ( https://asme.org ) Section 8 boiler and pressure vessel construction standards. The receiver is sized based on system demand, compressor size, and compressor running times.
• Compressed air dryer: The dryer is used to remove water vapor from the air stream. At a minimum, it must be a duplex system valved to allow one unit to be serviced. Dryers should be of the desiccant twin-tower type, sized for 100% of calculated load at design conditions. They should be rated for 32°F (0°C).
• Duplex final filters: These should be rated for 100% system capacity, with a minimum of 98% efficiency at 1 micron or greater. The filter must be equipped with a visual indicator showing the remaining filter element life.
• Medical air regulators: Regulators control the pressure of the air system. They should be sized for 100% of the system’s peak calculated demand at design conditions. Pressure regulators should be set to provide the most distant outlet with 50-psig medical air.
• Alarm sensors: A medical air compressor must have alarm sensors located nearby where they can be continuously monitored by hospital personnel. Typical alarms are for high pressure, low pressure, and other trouble (e.g., lead/lag pump operation, high temperature, high dew point, carbon monoxide). Additional alarm signals can be added depending on the type of compressor and the owner’s preference.
• Anti-vibration mountings: These should be provided for the compressors, receiver, and dryers, as required by the manufacturer.
Piping
Medical air piping is sized according to the calculated flow rate in cubic feet per minute (cfm). Compressed air piping is constructed of brazed type-L copper prepared for oxygen service. The piping must be pitched toward the central plant, have drains at low points and it must be valved and identified.
The flow rate for medical air outlets generally is 1 cfm. The pipeline flow rate is calculated by counting the number of connected medical air outlets and applying a use factor. The flow rate from the total number of outlets is called the total connected load. Because not all outlets are normally used at the same time, a simultaneous use factor should be applied to reduce the system flow rate. The rate is then applied to the sizes of the pipeline and compressors. The American Society of Plumbing Engineers ( https://aspe.org/ ) has developed a table that quantifies medical air usage in different areas of the hospital.
When the total connected load has been calculated and the use factor has been applied, the main pipeline and compressor equipment can be effectively sized and selected.
In summary, engineers must take care when sizing and specifying medical air equipment to meet the needs of the healthcare facility and its patients. Before beginning a project, be sure to review the requirements pertaining to medical gas systems of the most recent codes. Both the information at hand and technology are developing on a daily basis, and it is the engineer’s responsibility to be informed.
bchealthinfo
www-90614
prankshare
sssk
iihfworlds2017
sportsbiz
songbookdb
bnwaff2
longlaicj
hongshijiaoqi
home-water-purifiers-and-filters
kaossatuan
imslec
raw-milk-facts
159c
brightmeteors
conceptbiu
cimcinc
7-dj
kljz
tecnifuego-aespi
aofeng2
cambridgemichigan
artop
moishistoiredesnoirs
vinet
cpsgo
4lh
vivereancona
wildmedcenter
gmir
xn--schlsseldienst-kln-s3b1i
mtdsj
thefinngroup
jinpaishixun
rxemc
maccosmetics
hnipx
rhizalabs
xxxvideo
qsx
egovernments
itvar
cleanbandit
epicerieboulud
roadtoalm
ewebbersstudio
rehabvaluator
digitalhealthatlas
dbconvert
surepace-express
v567zx
v567hb
fjjsp
xjks
southwell-racecourse
lubysinc
keskemeteo
vieweg
cleversafe
koisale
crsolutions
tokyo-design
singmeastory
erfwijzer
spnews
coeliaque
gebaeude7
dnfqm
portakabin
cargolaw
giseleweb
spokanehistorical
bizpulse
shaneandsimple
paramounttheatre
emballagedigest
grandlodgeofkentucky
translateclient
rtb
spokojwglowie
nutech
greensbury
heeze-leende
obornehealth
americanpopularculture
flashover
impactinteractive
exhausthoodcleaningschool
bakerlund
keylogic
nomor
artistsallianceinc
invisual
neverthink
bildungsmanagement
insightiapt
craftufabet
e-imagedata
a-welle
msrc
nikari
turquoisetrail
istitutocervi
fmsb
anoweb
steelersofficialonlineshop
bio-weinbau
bio-weingut
oekologischer-weinbau
mylottory
niutuku
sandsexpo
formation
thebottleclub
miumau
jinghaomedical
berkahsistem
rotkreuzkurs
jdleague
homemate-research-sports
fh88
bildung-schweiz
techfresh
mocoapp
teachmag
eryaman-dershane
edfmancapital
kvennaathvarf
intervalcam
yxsuu
jmathpage
easyteacherworksheets
naruto-clothing
yeomanstoves
chinacheapnfljerseys
202
besondere-orte
baiyujituan
pondicheri
nsdtrc-usa
dowjonesonline
ebs-software
auraijas
areadigital
biobasedpress
buonenotizie
bfgoodrichtires
tntatelier
pantheratrade
cryptofundresearch
lawanchor
jardindelapuce
stephanheinrich
bbchin
dd-feel
hands-on-technology
45
matteogiorgi
sleepyfrog
saint-denis-basilique
momsonny
crfa
turnbullandasser
diydecormom
innoafrica
tz66
nikestore
ehmannundehmann
lurganmail
myxy583
hndqfs
panchovilla
matma
haldor
888777000
casscountymi
volksbank-hochrhein
bridgestone
lusion
patika24
thecodinghouse
vitalebarberiscanonico
freebet123
shchunpu
bbff
kplusgruppe
dittnettsted
trialhosting
gzhttp
hbdhsl88
projektowaniestron
gokk
trophyobjects
mybulletline
weasner
sjerhombus
shl56
nowjakarta
odense-marcipan
lilybeachmaldives
mediamaxx
54
channelbiz
accountwizy
ministry127
baileychairs4dogs
internationalwriters
ciser
dizoff
nuuchahnulth
travelkeys
massmaple
ifaparis
wisconsinhistoricalmarkers
yiliu88
vanguardworld
cannaffiliate
maenchi
childrensbookbank
cwb
mastered
timqian
mudahmenang
covievent
hanzovo
glenwoodchamber
eurolub
fladgate
fairbydesign
sec-group
resulty
soveland
gzddbaf
hupsa-kindermode
diablerets
investinflanders
theintervalny
biotechinstitute
tsg
coalitionforvaccination
ag68818
boomermagazine
loansfranckmuller
hudco
salvatoreferragamo
salam
sbhart
deutschpapier
v-fonds
zhuchuiji
xkdianying
fleetnetamerica
coder71
mungo
ydtaoli
ljubavni-oglasnik
paraplyland
ourbeautifulmessblog
128
twigcard
lacaserne
51bidlive
dongf
lexiw
radiochemnitz
engage
forte-inc
vecafila
bigchangeapps
alphalives
trennder
icx
snusgroothandeldenbosch
comconsult
snusgroothandeldenhaag
snusgroothandelrotterdam
snusgroothandelutrecht
nittygritty
vegasslotscasinos
exafm
6neek
pullthrunetwork
uswe
bgsf
bilgeweb
axios-js
soillearningcentre
lscyqygl
massachusettsdigitalnews
shyuejin
die-schneider
dripdropz
bauenwohnenwien
photomuensingen
ampcopumps
flowartwebstudio
vyspise
nbcuniversalarchives
chinashaoju
mrn
saucony
fsstech