Medical Gases, Plumbing & Electrical Infrastructure for Healthcare

Medical gases, plumbing, and electrical infrastructure together constitute the services architecture of a healthcare building — the systems that deliver oxygen to a ventilator, hot water to a CSSD, UPS-backed power to an OT, and earthing to a microsurgical microscope. These systems are designed by specialist consultants but provisioned by the architect — service shafts, plant rooms, equipment yards, vertical risers, ceiling voids, structural penetrations, fire-rated separations, monitoring infrastructure. A hospital where the services architecture has been thoughtfully provisioned at concept stage operates reliably; one where services were "added later" suffers chronic operational issues that cost the institution years of frustration.

This guide is the eighth in the design-focused series and the second of the services pair. It assumes the reader has read the pillar regulatory reference, the regulatory deep-dives, the preceding design articles, and particularly the companion HVAC guide. Together those two guides cover the architect's services responsibilities in healthcare.

The guide is organised by service: medical gases first (oxygen, nitrous oxide, medical air, vacuum, AGSS, carbon dioxide, instrument air, nitrogen), then plumbing (water demand, hot water, drainage, special applications), then electrical (incoming HT, substation, DG, UPS, critical/non-critical loops, earthing). Each service is covered with the architectural-provisioning lens: where does the equipment go, how big should the room be, what shafts are needed, what loading does the structure see, how does the architecture support reliable operation.

"In a hospital, electrical reliability is patient survival reliability. Three minutes without UPS in an OT can be three minutes too many." — D.K. Sarin (b. 1948), former Director HSCC India, paraphrased

"Medical gas is invisible until it isn't. The day the oxygen pressure drops in an ICU is the day the architecture is judged on a decision made years earlier." — Anonymous senior healthcare engineer, paraphrased

1. Medical Gas Pipeline Architecture

Medical gases — oxygen, nitrous oxide, medical air, vacuum, carbon dioxide, AGSS (anaesthetic gas scavenging), and (in some hospitals) instrument air and nitrogen — are delivered through a piped network from central sources to outlets at every point of use. The architecture provisions the source yard, the manifold room, the riser shafts, and the outlet placement.

Gases — sources and central plant

Gas	Use	Central Source
Oxygen (O₂)	Patient breathing; resuscitation	LMO (Liquid Medical Oxygen) tank + cylinder backup; or PSA generator + cylinder backup
Nitrous Oxide (N₂O)	Anaesthesia (decreasing use)	Cylinder manifold
Medical Air (4 bar)	Anaesthesia, ventilator	Compressor + dryer + filter; redundant; cylinder backup
Surgical Air (7 bar)	Pneumatic surgical tools	Compressor; separate from medical air
Vacuum	Suction in OT, ICU, ward	Vacuum pump + receiver + filter; redundant
Carbon Dioxide (CO₂)	Laparoscopy insufflation	Cylinder manifold
AGSS (Anaesthetic Gas Scavenging)	Removes waste anaesthesia gases from OT	Vacuum-based scavenging line; vented to roof
Instrument Air (oil-free)	Some specialty applications	Oil-free compressor
Nitrogen (N₂)	Some surgical tools (orthopaedic)	Cylinder manifold

LMO yard — architectural provision

Element	Specification
Tank capacity	Sized for 7-day consumption + 50% buffer; typical 13 m³ for 100-bed; 25 m³ for 200-bed; 50 m³ for 500-bed
Yard area	60–90 m² for 100-bed; 100–140 m² for 200-bed; 200+ m² for 500-bed
Tank set-back from building	6 m minimum (PESO); 9 m preferred
Tank set-back from boundary	3 m minimum (PESO)
Yard surface	Concrete; bonded to earth
Fencing	Steel mesh, 2 m high, lockable gate
Vehicle access	Tanker turning circle 9 m radius; reverse-in possible
Vapouriser	Adjacent to tank; ambient or steam-heated
Pipe routing	From vapouriser to manifold room
Lightning protection	Earthed; surge protection on outgoing pipe
Fire protection	Hydrant within 30 m; manual call point at gate
Signage	"No smoking", "Oxygen", "Authorised personnel only"; bilingual

Manifold room — architectural provision

Element	Specification
Room area	12–18 m² for 100-bed; 25–40 m² for tertiary
Location	Adjacent to LMO yard or alternate gas source; near service shaft
Equipment	Manifolds for cylinder backup (O₂, N₂O, CO₂, N₂); pressure regulators; alarm panel
Ventilation	6 ACH; independent exhaust; alarm on low pressure
Fire-rated	2-hour separation from main building
Pipe entry	Sealed; through dedicated wall penetration
Cylinder storage	Strapped vertical; 5–10 cylinder capacity
Floor finish	Anti-static; sealed
Lighting	LED; emergency-backed
Door	Fire-rated; lockable; vision panel

Pipeline distribution architecture

Element	Specification (NBC Part 8 + IS 7902)
Pipe material	Medical-grade copper; certified seamless or DIN 1987; degreased
Pipe joints	Brazing with silver filler; pressure-tested
Pipe identification	Colour-coded per IS 7902; labelled at every metre
Vertical risers	Dedicated shaft; sealed at floor penetrations
Horizontal mains	Above ceiling; supported per piping standard
Branch lines	To zone shutoff valves
Zone shutoff valves	At each ward entry, OT entry, ICU entry; identifiable
Outlets at point of use	NIST or DIN; gas-specific; tested
Outlet density	Per OT: O₂×2, Air×2, N₂O×1, Vacuum×3; Per ICU bed: O₂×2, Air×1, Vacuum×3; Per ward bed: O₂×1, Vacuum×1
Pressure	4 bar at outlets (medical air, oxygen, N₂O); 7 bar (surgical air); 50 kPa (vacuum)
Alarm panels	At each shutoff zone; central master at manifold room; nurse station alarm
Pressure monitoring	Continuous; BMS-integrated
AGSS	Separate vacuum line; vented to roof; not connected to general vacuum

The architectural provision: dedicated medical gas riser shaft per zone, sized at minimum 600 × 600 mm; outlet placement schedule per room as part of GFC drawings; manifold and LMO yard sized at concept stage.

2. Plumbing — Water Demand and Hot Water

Water demand schedule for a 100-bed hospital (typical)

Use	Demand (litres/bed/day)	100-bed Total (KLD)
Drinking + cooking	5–10	0.5–1.0
Patient bathing	100–150	10–15
Family / attendant	50–80	5–8
Toilet flushing	30–50	3–5
Laundry	80–120	8–12
CSSD / OT cleaning	30–50	3–5
Kitchen	30–50	3–5
HVAC make-up (cooling tower, humidification)	Varies; 50–100	5–10
Cleaning / housekeeping	30–50	3–5
Landscape	Varies	2–5
Total	408–660	40–70 KLD

A 100-bed hospital therefore needs roughly 50 KLD water supply; 200-bed ~100 KLD; 500-bed ~250 KLD.

Architectural provision:

Element	Specification
Underground water tank — domestic	3-day demand + fire reserve = 200 m³ for 100-bed
Overhead water tank	1-day demand = 50 m³ for 100-bed; on roof or structural truss
RO / softener plant	If hard water (most Indian sites); ~ 8–15 m² plant room
Booster pumps	Plant room ~ 9–12 m²; redundant pumps
Main distribution shaft	Vertical riser 600 × 600 mm dedicated
Floor distribution	Above ceiling; manifold per ward
Hot water generation	Centralised boiler / heat-pump / solar-augmented; 60°C delivery; sized for peak demand
Hot water re-circulation	Continuous loop; insulated
Cold water	Insulated to prevent condensation
Fixture-level mixing	Thermostatic mixing valve at point of use; 38–42°C delivery
Backflow prevention	At every connection to public main
Water meter / leak detection	At main; at zone

Hot water demand and 60°C requirement

NABH and infection-control protocols require hot water ≥ 60°C at point of generation to control Legionella and other pathogens. Mixing valves at fixture deliver safe 38–42°C to prevent scalding.

Hot water use	Temperature at use
Hand-wash	38–42°C
Patient bathing	42°C
Laundry	60°C (washing)
CSSD / dishwasher	65–82°C
OT scrub	38°C

Architectural plant: central hot-water generator (boiler / heat-pump / solar-thermal) at basement or rooftop; insulated re-circulating loop throughout; thermostatic mixing valves at fixtures.

Drainage architecture

Drainage Stream	Architectural Provision
Soil + waste (general)	100–150 mm vertical stack; vented at top
Patient toilets	Dedicated risers; trapped at every fixture
OT / ICU drains	Trapped; disinfection point; separate stack from general
Kitchen	Grease trap upstream; separate stack
Laundry	Separate stack; lint trap
Mortuary	Disinfection at source; separate stack
Pathology / lab	Separate stack; pre-treatment for chemicals
Imaging — film developer (legacy)	Silver recovery; separate handling
Dialysis effluent	Separate stack; chemical content monitored
Floor drain — wet areas	Sloped floor; trapped; UV / disinfection at high-risk
Roof / terrace rainwater	Dedicated stack; recharge / harvest
ETP / STP feed	Separate underground main to plant

The architect provides the drainage layout drawing with stack locations, vent terminations, and special-handling streams. Crossing of soil/waste with medical gas / electrical / data is avoided via separate shafts.

Sluice room architecture

Element	Specification
Area	4–6 m² per ward unit
Sink	Sluice / hopper for body fluid disposal; flush + spray
Bedpan washer	Wall-mounted; thermal disinfection 80°C+
Floor finish	Welded vinyl; coved skirting; floor drain
Walls	PVC panel or epoxy
Ventilation	10 ACH; negative pressure
Door	Self-closing; lockable

3. Electrical Infrastructure — Critical-Care Reliability

Hospital electrical reliability is patient-survival reliability. The architecture provisions a hierarchy of supply: HT (high-tension) incoming, LT (low-tension) distribution, DG (diesel generator) backup, UPS (uninterruptible power supply) for critical loads.

HT incoming and substation

Element	Specification
HT incoming voltage	11 kV typical (some 33 kV for tertiary)
HT load	100-bed: 500–800 kVA; 200-bed: 1000–1500 kVA; 500-bed: 2500–4000 kVA
Substation area	30–60 m² for 100-bed; 60–100 m² for 200-bed; 100–200 m² for 500-bed
Substation location	Ground floor; separate building or fire-rated within main
Transformer	11 kV/415 V; cooling-oil filled or dry-type
Transformer separation	6 m setback from building (oil-filled); fire-rated wall (dry)
HT/LT panels	In substation; segregated
DG synchronisation	Auto-transfer switch (ATS)
Earthing	Dedicated earth pit; separate from neutral and lightning
Lightning protection	Roof-level; earthing pit
Substation ventilation	Cross-ventilated; or AC for sealed substation
Substation access	External direct; service vehicle access

DG sizing

Hospital	DG Capacity	Notes
100-bed	500–625 kVA (1 unit) + redundancy optional	Auto-start within 10 sec
200-bed	750–1000 kVA (2 units in parallel)	N+1 redundancy
500-bed	1500–2500 kVA (2–3 units N+1)	Critical-loop dedicated
Tertiary 1000-bed	4000–6000 kVA	N+1 with separate critical loops

DG architectural provision:

Element	Specification
DG room area	~ 1 m² per kVA (for housing only); 30 m² minimum for 500 kVA
Acoustic enclosure	Mandatory for DG > 50 kVA outside DG room
Fire compartmentation	4-hour rated separation from main building
Ventilation	Forced; sized for combustion air + cooling
Exhaust	Stack height per CPCB (30 m for > 800 kW)
Fuel storage	Day tank (200–500 L) inside DG room; bulk tank external (1000–10,000 L)
Bulk tank set-back	6 m + from building (PESO); bunded
Auto-transfer switch	At substation
Synchronisation panel	If parallel DG

UPS and critical-load loop

UPS Application	Capacity	Backup Time
OT critical loads (lights, anaesthesia, monitor)	25–40 kVA per OT	60 min
ICU critical loads	20–30 kVA per 6-bed ICU	60 min
Server / data centre	Sized to load	30+ min
Fire alarm	Per panel	24+ hrs (battery)
Emergency lighting	Per circuit	2 hrs (battery)

UPS architectural provision:

UPS room 12–18 m² near substation
Battery room separate (acid fumes); ventilated
Cabling segregated — UPS feeds direct to critical circuits without crossing non-UPS

Earthing and lightning protection

System	Earthing Provision
Body earth (electrical equipment)	< 1 Ω; separate pit
Neutral earth	< 1 Ω; separate pit
Lightning earth	< 10 Ω; separate pit
Equipotential bonding	OT, ICU, MRI room
MRI cage earthing	RF cage continuous earth
Patient bedside earth	OT, ICU isolated earth (low-impedance)
BMS / data earth	Star-point earth

Architectural provision: dedicated earthing pits at perimeter; vertical earth conductors in shafts; equipotential bonding ring at OT/ICU floor level.

Critical-loop circuit segregation

Load Type	Power Source
Critical (OT, ICU, fire alarm)	Mains + DG + UPS
Essential (general lighting, lifts, water pumps)	Mains + DG
Non-essential (HVAC, kitchen, laundry, admin)	Mains only (DG optional)

The architect's electrical drawings distinguish these three circuits — colour-coded — and the building's distribution panels are physically separated to prevent cross-contamination.

4. Special Applications — Dialysis Water, MRI Power, Imaging UPS

Dialysis water treatment (haemodialysis)

Stage	Specification
Pre-filter	20 μm sediment
Carbon filter	Dechlorination
Water softener	Sodium ion exchange
Reverse osmosis	Two-stage; AAMI / ISO 13959 quality
Storage tank	Stainless steel; UV-sterilised
Distribution loop	Continuous re-circulating; PEX or PVC sanitary
Dialysis chair tap	Quick-disconnect
Water testing	Endotoxin, bacteria, hardness — daily / weekly

Water plant area for a 12-chair dialysis centre: 18–25 m².

MRI room electrical / RF

Element	Specification
RF Faraday cage	Continuous copper / steel; door RF-tight; viewing window RF-screened
Magnetic field exclusion	5-gauss line marked; equipment / personnel restrictions inside
Quench vent	From cryostat to roof; minimum 10 cm diameter
Magnet delivery route	Removable wall panel or roof access
Power	Dedicated transformer; clean ground
RF filters at penetration	All cables, pipes filtered through cage

Imaging UPS

CT, cathlab, mammography, and other imaging equipment require dedicated UPS (typically vendor-supplied) plus building UPS for monitor and display. The architect coordinates room electrical with vendor specification.

5. The Architect's Services Toolkit

#	Step	Output
1	Programme review — outlets per room, gas, plumbing	Services brief
2	Medical gas — LMO yard sizing, manifold location	LMO + manifold plan
3	Medical gas — outlet schedule per room	Outlet schedule
4	Medical gas — riser shafts and zone valves	Riser layout
5	Plumbing — water demand calculation	Water demand schedule
6	Plumbing — UG / overhead tank sizing	Tank schedule
7	Plumbing — hot water plant + re-circulation	Hot water scheme
8	Plumbing — drainage stack layout	Drainage scheme
9	Plumbing — special applications (dialysis, mortuary, kitchen)	Special drainage
10	Electrical — HT load and substation sizing	Substation scheme
11	Electrical — DG sizing and room	DG scheme
12	Electrical — UPS critical loop	UPS scheme
13	Electrical — earthing and lightning	Earthing scheme
14	Critical / essential / non-essential circuit segregation	Distribution scheme
15	BMS integration for gas, plumbing, electrical	BMS scope
16	Fire-rated separations for plant rooms	Compartmentation drawing
17	Acoustic isolation for DG, plant	Vibration / sound scheme
18	Service shaft sizing and sealing	Shaft schedule
19	Maintenance access — every plant	Access provision
20	Commissioning brief — gas, water, power	Commissioning schedule

6. Common Services Failure Modes

#	Failure	Prevention
1	LMO yard set-back inadequate	6 m PESO from concept
2	Manifold room without independent ventilation	6 ACH; alarm on low pressure
3	Medical gas outlet density inadequate	NABH-aligned schedule
4	Zone shutoff valves absent	Per ward/OT/ICU
5	Hot water below 60°C at generation	Boiler / heat-pump sized for 60°C
6	RO water plant absent for hard-water site	18–25 m² plant room
7	Drainage stacks merged across streams	Separate stacks per stream
8	OT/ICU drains via general stack	Dedicated stack + disinfection
9	Mortuary effluent without disinfection	Disinfection at source
10	DG sizing under-spec	100% essential + 50% non-essential margin
11	UPS sizing under-spec for OT/ICU	Per-OT 25–40 kVA
12	Earthing combined (body + neutral + lightning)	Separate pits
13	Battery room without ventilation	Acid fumes vented
14	Acoustic — DG noise > 75 dB at boundary	Acoustic enclosure
15	DG fuel storage insufficient	3-day diesel reserve minimum
16	Substation in fire-prone location	Fire-rated separation; clearance
17	MRI quench vent incorrectly routed	Vent to roof, all-weather
18	Dialysis water plant under-spec	AAMI quality + 1.5x capacity

References

ANSI/AAMI (2014) AAMI RD 52: Dialysate for Hemodialysis. Arlington: AAMI.
ASHRAE (2019) ASHRAE Handbook — HVAC Applications: Health-Care Facilities. Atlanta: ASHRAE.
Bureau of Indian Standards (2016) National Building Code of India 2016, Part 8 — Building Services. New Delhi: BIS.
Bureau of Indian Standards (2003) IS 7902: Pipeline Distribution System for Medical Gases — Code of Practice. New Delhi: BIS.
Bureau of Indian Standards (2007) IS 14665: Electric Traction Lifts — Code of Practice. New Delhi: BIS.
Bureau of Indian Standards (1991) IS 3043: Code of Practice for Earthing. New Delhi: BIS.
Bureau of Indian Standards (2003) IS 15301: Hydraulic Design of Fixed Fire Protection Systems. New Delhi: BIS.
Central Pollution Control Board (2018) DG Set Emission Standards. New Delhi: CPCB.
Facility Guidelines Institute (2022) Guidelines for Design and Construction of Hospitals. St. Louis: FGI.
IEC (2017) IEC 60364-7-710: Low-Voltage Electrical Installations — Medical Locations. Geneva: International Electrotechnical Commission.
ISO (2017) ISO 13959: Water for Haemodialysis and Related Therapies. Geneva: ISO.
Joint Commission International (2020) International Standards for Hospitals. 7th edn. Oakbrook Terrace: JCI.
Joshi, D.C. and Joshi, M. (2018) Hospital Administration. 2nd edn. New Delhi: Jaypee Brothers.
NABH (2020) Standards for Hospitals, 5th Edition. New Delhi: NABH.
Petroleum and Explosives Safety Organisation (2016) Static and Mobile Pressure Vessels (Unfired) Rules 2016. Nagpur: PESO.
US Environmental Protection Agency (2010) Drinking Water and Health. Washington: EPA.
World Health Organization (2008) Essential Environmental Health Standards in Health Care. Geneva: WHO.
World Health Organization (2017) Guidelines for Drinking Water Quality. 4th edn (with first addendum). Geneva: WHO.

Author's Note: Services architecture is the half of healthcare design that the architect provisions but does not personally engineer. The architect's discipline is to engage MEP consultants from the brief stage and ensure that building decisions support the services strategy. Indian projects routinely mis-provision services — undersized substations, wrong-located LMO yards, mixed drainage stacks, inadequate UPS — because the architect treated services as a downstream MEP problem. This guide establishes the provisioning method that produces hospitals that operate reliably from day one. The remaining four guides in this design-focused series cover specialty typologies, sustainability, and the business of healthcare commissions.

Disclaimer: This article is for informational and educational purposes only and does not constitute professional architectural or engineering advice. Services design depends on specific project parameters and must be done by qualified MEP / electrical / mechanical engineers in coordination with the architect. Studio Matrx, its authors, and contributors accept no liability for decisions made on the basis of the information in this guide.