[Figure: Floor plan of medical laboratory supply and return air arrangement. Colored line drawing plan, including laundry, washing room, clean air cabinet, reserved room, preparation room, culture room 3, culture room 2, quality control room, second changing room, shoe change, general zone corridor, power distribution room, consumables storage, testing 1, preparation room, cell separation room, culture room 1, and clean corridor, waste corridor, etc.; the lower-left corner contains the air outlet and damper legend table, and the right side contains notes.]

No. Legend Material Name
5 [symbol] Manual air volume damper
4 [symbol] Motorized air volume damper
3 [symbol] HEPA supply outlet GKF-15
2 [symbol] HEPA supply outlet GKF-10
1 [symbol] HEPA supply outlet GKF-5

Note: Each HEPA supply outlet is provided with an air volume damper of the corresponding duct size; each return air branch is provided with an air volume damper of the corresponding duct size.

Fig. 6-34 Supply and Return Air Arrangement

[Figure: Floor plan of medical laboratory exhaust air arrangement. Colored line drawing plan with a room composition similar to the figure above, including laundry, washing room, clean air cabinet, reserved room, preparation room, culture room 3, culture room 2, quality control room, second changing room, shoe change, plant room, general zone corridor, power distribution room, storage room, culture room 1, cell separation room 2, cell separation room 1, preparation room, testing 1, testing 2, and clean corridor, waste corridor, etc.; the lower-left corner contains the legend table.]

No. Legend Material Name
5 [symbol] Manual air volume damper
4 [symbol] Motorized air volume damper
2 [symbol] Check valve

Fig. 6-35 Exhaust Air Arrangement

Section 4 Medical Laboratory Power Supply System

A laboratory building contains various types of laboratories and instruments and equipment. In addition to maintaining the electricity for the laboratory's specific environment, the power supply system must also meet the special power requirements of existing and future instruments. For instruments with compressors such as centrifuges, refrigerated cabinets, and low-temperature freezers, the current required for motor start-up is often several times the operating current, and the moment of start-up often causes voltage fluctuation on that line; if many high-power instruments are connected to the same line, the instruments may work abnormally. Microelectronic instruments such as microbial electrical testers, biochemical analyzers, blood analyzers, and computers have relatively high requirements for power quality; the frequent start-up of high-power instruments generates voltage pulses, which can easily damage components or cause reading fluctuations, data loss, and other faults. Therefore, the design of a laboratory building's power supply system must not only reserve sufficient surplus capacity to meet future development needs, but must also provide an uninterruptible, regulated power supply. Because of the laboratory's distinctive nature, the power supply system of a laboratory building is unique in terms of power sources, wiring, lighting, and safety. The power consumption of a laboratory building is usually more than twice the existing power consumption.

I. Laboratory Power Sources

An uninterruptible, regulated laboratory power supply is an important part of ensuring stable instrument operation. To avoid unstable utility voltage or sudden power outages affecting normal laboratory operation, backup power sources and voltage regulators are usually installed. UPS power supplies are most commonly used in laboratories and fall into two categories: one is the ordinary UPS, which only provides uninterruptible power but cannot regulate voltage; the other is the online UPS, which both provides uninterruptible power and regulates voltage. Different UPS power supplies can be selected according to actual conditions and instrument requirements.

II. Laboratory Power Supply Wiring

  1. To prevent high-power instruments from interfering with one another during operation, a dedicated circuit is generally provided for each high-power instrument; microelectronic instruments and high-power appliances must not share the same circuit.

  2. Precision instruments that require uninterruptible power shall be equipped with a regulated UPS; laboratories that require uninterruptible power, such as culture rooms and biosafety laboratories, must use dual-protection dedicated power supplies.

  3. Each laboratory shall have three-phase and single-phase power, with a main power control switch near the laboratory door, facilitating wiring from the corridor, maintenance, and switching the room's power on or off. Equipment that must remain on standby after experiments stop shall be connected to a dedicated power supply circuit, so that work is not affected when the laboratory's main power is switched off.

  4. Fully consider the electricity and the number of outlets required by all laboratory instruments; laboratory benches shall be provided with a certain number of three-phase and single-phase power outlets; outlet circuits shall have leakage protection devices; outlets shall be located away from sinks.

  5. The designed power supply shall fully consider a rational layout and safe, convenient use; in addition to meeting current needs, future laboratory development shall be considered, with sufficient expansion capacity to meet the laboratory's needs.

  6. In damp locations, locations with corrosive gases or vapors, and locations with fire or explosion hazards, power distribution equipment with corresponding protective performance shall be selected.

  7. Because chemical laboratories contain corrosive gases, power distribution conductors shall use copper-core wire. Physics laboratories may use aluminum-core conductors.

  8. The laboratory grounding system ensures personal safety and the normal operation of instruments. Common types of grounding include safety protective grounding, anti-static grounding, DC grounding, and lightning-protection grounding.

  9. Where a scientific laboratory building (room) is supplied with power of two or more different voltages or frequencies, separate distribution protection devices should preferably be provided, with clear distinction or marking. Where supplied by the same distribution protection device, good physical isolation shall be provided. Lines of different voltages or frequencies shall be run separately and shall not be laid in the same conduit. Power lines of the same equipment or laboratory production line and control circuits without anti-interference requirements may be laid in the same conduit.

  10. For high-rise or multi-story scientific laboratory buildings with many circuits, vertical runs should preferably be laid in pipe shafts. Power and low-voltage (ELV) cabling should preferably have separate pipe shafts. Where laid in the same pipe shaft, they shall be laid on opposite sides of the shaft. See Figures 6-36, 6-37, and 6-38.

[Figure: Design drawing of laboratory floor outlet power distribution (CAD plan, including the layout of laboratory/auxiliary rooms, distribution feeders and outlet circuits, pipe shafts, and dimension/axis annotations)]

Fig. 6-36 Design Drawing of Laboratory Outlet Power Distribution

[Figure: Design drawing of laboratory UPS outlet power distribution; whole-floor laboratory layout, including laboratory areas, auxiliary rooms, changing rooms/toilets/stairs and elevators, and red UPS outlet distribution lines, with dimensions and room labels.]

Fig. 6-37 Design Drawing of Laboratory UPS Outlet Power Distribution

[Figure: Design drawing of laboratory low-voltage (ELV) systems — including bacterial culture room, inoculation room, reagent preparation, specimen preparation, gene amplification, washing room, HIV laboratory area/buffer/preparation area, blood bank, luminescence, immunology, biochemistry, stool and urine routine, clinical testing, specimen reception, body fluid reception room, blood collection area, duty room, pre-treatment area, doctors' office, reagent storage, storage room, cleaning room, meeting room, director's office, men's/women's changing rooms, stairs, waste lift, and the curved curtain wall at the bottom; ELV information/telephone points (e.g., 2T, T+F, 2T+2F, 4T+F) and 200×100 cable trays are marked in the figure.]

Fig. 6-38 Design Drawing of Laboratory Low-Voltage (ELV) Systems

III. Laboratory Lighting

1. Quantity of Laboratory Lighting Equipment

The quantity of lighting equipment required in a laboratory is determined by the following factors: the type of work, the color of the workbenches, the colors of the ceiling and walls of the workroom, the distance between fixed lighting and the work surfaces, and the size of the space to be illuminated.

Once the above factors and the required illuminance standards have been determined, a certain number of lighting fixtures that meet the illuminance standards can be selected, as shown in Table 6-8.

Table 6-8 Laboratory Illuminance Standards

Room Name Average Illuminance (lx) Work Surface and Height (mm) Remarks
Class I laboratory 100-150-200 Bench surface 750~850 General lighting
Class II laboratory 150-200-300 Bench surface 750~850 Local lighting advisable
Changing room 100-150-200 Floor General lighting
Clean zone (office, meeting room, archive room) 150-200-300 Desk surface 750 Local lighting advisable

2. Installation Positions of Laboratory Lighting Equipment

Lighting equipment should be installed perpendicular or diagonal to the work surfaces; this both unifies the layout and eliminates shadows cast by objects. Lighting installed parallel to work surfaces usually produces shadows from the staff working at the bench and from the cabinets above the bench. Where there are no cabinets above the work surface, lighting equipment may be installed parallel to the work surface or directly above the working side of the surface.

Black or non-white matte workbench surfaces effectively reduce reflected light and glare, thereby relieving eye fatigue.

There are many ways to install luminaires, including recessed (concealed), semi-recessed, suspended, wall-mounted, desk-top, and corridor types. Different installation types produce different light distributions. Combining fixed luminaires with accent lighting, spot lighting, high-intensity lighting, and special-purpose lighting can make an ordinary workroom comfortable, attractive, and visually pleasing.

3. Selection of Laboratory Lighting Equipment Types

Fluorescent lamps are generally advisable for laboratory lighting: they have a long service life, a large luminous area, high luminous efficacy, and low heat output. In analytical chemistry laboratories, when judging the color-change endpoint of volumetric titration indicators visually, a fluorescent lamp can be installed at the operating position. In laboratories with strict electromagnetic interference requirements, gas discharge lamps should not be used. In radioactive laboratories, sterile rooms, infectious microorganism laboratories, and laboratories handling carcinogens or toxic substances, recessed clean luminaires shall be used, wiring shall be concealed wherever possible, and light switches shall be installed in the corridor outside. Laboratory areas used for microorganism separation and molecular biology experiments must effectively protect staff and specimens from contamination; ultraviolet (UV) lamps are the most commonly used disinfection equipment. Fixed UV lamps mounted on a smooth ceiling shall be no more than 2.1 m from the floor, and the number of UV lamps shall be determined according to the laboratory space. When using UV lighting equipment, it must be confirmed that object surfaces (e.g., wall surface coatings, work surfaces) can withstand the bleaching effect of UV light. The control switch shall be located outside the door and separated from the control switches of general lighting; the laboratory

entrance shall have a text-based illuminated signal indicating the laboratory's working status; in damp locations, locations with corrosive gases and vapors, and locations with fire or explosion hazards, luminaires with corresponding protective performance shall be selected; evacuation indicator lights shall be installed at safety exits and along evacuation routes so that evacuating personnel can evacuate quickly in an emergency; lighting shall be provided in pipe service spaces and supplied by a separate branch circuit or a dedicated distribution box (panel). See Figures 6-39, 6-40, 6-41, and 6-42.

[Figure: Design drawing of laboratory lighting power distribution]

Fig. 6-39 Design Drawing of Laboratory Lighting Power Distribution

[Figure: Single-line diagram of laboratory power distribution system and circuit schedule; the left side shows the incoming supply, dual-power transfer, metering, and lightning protection of distribution box 2AL2; the right side is the outgoing circuit schedule 1WL1–1WL26]

Fig. 6-40 Laboratory Power Distribution System Diagram 1

Distribution box: 2AL2, 56.0 kW

Annotations on the left single-line diagram:

  • Incoming line (standby): WDZBYJ-4×50+E25 → NSX160N-3P/125A+MX
  • Incoming line: WDZBYJ-4×50+E25 → NSX160N-3P/125A+MX; C65H-4P/50A
  • Dual-power transfer switch: WTS-A-160A/4P
  • Measurement/metering: V, A, Wh; PD800H-H14; BH-0.66 150/5; WEFPT-125ZR; EFP
  • Surge protection: PRD-4P, In = 40 kA
  • Breaker side note: with shunt trip, disconnects in case of fire
  • Note below diagram: Equipment power supply to be designed separately in the second stage by the distribution box and power outlets.

Circuit schedule on the right:

Breaker Model Contactor/Switch Model Circuit No. Phase Conductor Model/Spec Use (Installed Power)
DPNa-16A LC1-D18 1WL1 L1,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A LC1-D18 1WL2 L2,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A+vigi30mA — 1WL3 L3,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A — 1WL4 L1,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A — 1WL5 L2,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A — 1WL6 L3,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A — 1WL7 L1,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A — 1WL8 L2,N ZRBV-2×2.5-PVC16-WC~ACC/CT Lighting power (1.0 kW)
DPNa-16A+vigi30mA — 1WL9 L3,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL10 L1,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL11 L2,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL12 L3,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL13 L1,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL14 L2,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL15 L3,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
C65N-3P/D20A — 1WL16 L123,N ZRBV-5×4-PVC25-WC~ACC/CT Power/outlet power (3.0 kW)
DPNa-16A+vigi30mA — 1WL17 L2,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL18 L3,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL19 L1,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL20 L2,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
DPNa-16A+vigi30mA — 1WL21 L3,N ZRBV-3×2.5-PVC20-WC~CT/FC Outlet/laboratory power (2.0 kW)
C65N-3P/D20A — 1WL22 L123,N ZRBV-5×4-PVC25-WC~ACC/CT Power/outlet power (3.0 kW)
C65N-3P/D50A — 1WL23 L123,N ZRBV-5×10-PVC40-WC~ACC/CT UPS power (18 kW)
DPNa-16A+vigi30mA — 1WL24 — — Spare
DPNa-16A+vigi30mA — 1WL25 — — Spare
DPNa-16A+vigi30mA — 1WL26 — — Spare

[Figure: Single-line diagram of laboratory low-voltage power distribution system, captioned "Fig. 6-41 Laboratory Power Distribution System Diagram 2"]

[Figure: Single-line diagram of laboratory low-voltage power distribution system, captioned "Fig. 6-42 Laboratory Power Distribution System Diagram 3"]

IV. Laboratory UPS Power Supply

The normal operation of hospital medical equipment must be guaranteed by a stable, reliable power supply; the quality of the power supply directly affects the normal use of medical equipment, and large, high-end, precision medical equipment in particular has higher requirements for power supply quality.

A UPS (Uninterruptible Power System/Uninterruptible Power Supply) is a constant-voltage, constant-frequency uninterruptible power supply containing an energy storage device, with an inverter as its main component. The simple principle of this UPS is: after utility power enters the UPS, it is rectified into direct current; one path feeds the charger to charge the battery, and the other path provides DC voltage for the inverter to operate; the inverter converts the direct current into stabilized-voltage, stabilized-frequency, clean 50 Hz alternating current to supply the load. When utility power is abnormal or interrupted, the inverter is powered by the battery and continues to operate, so the inverter is always working and power is supplied to the equipment without interruption. UPSs were initially mostly used to power computer systems; today hospitals also use UPSs as the power source for relatively important medical equipment.

A large amount of precision equipment is used in the medical industry, and the utility grid is prone to many problems during peak electricity consumption, such as voltage surges, voltage spikes, voltage transients, overvoltage or undervoltage, and power interruptions. These problems are very serious and greatly interfere with electrical equipment such as computer systems, medical equipment, communications equipment, and electronic devices, easily causing equipment damage and data loss and bringing serious economic losses and work inconvenience to users. The normal operation of medical and biological research equipment must be guaranteed by a stable and reliable power supply, because power supply quality directly affects the performance of medical equipment; large, high-end, precision, cutting-edge medical and biological research equipment in particular has higher requirements for power supply quality. Therefore, a stable and reliable UPS power system, as a high-performance power source, is especially important for protecting medical and biomedical equipment. See Fig. 6-43.

[Figure: Design drawing of laboratory UPS outlet power distribution — colored architectural floor plan divided into bacterial culture room, inoculation room, reagent preparation, specimen preparation, gene amplification, washing room, HIV laboratory area/buffer area/preparation area, water treatment plant room, cold storage, blood collection area, body fluid reception room, luminescence, immunology, biochemistry, clinical testing, meeting room, director's office, men's changing, women's changing, pre-treatment area, doctors' office, duty room, specimen reception, reagent storage, storage room, cleaning room, men's/women's toilets, waste lift, and other areas; distribution lines are shown in red, UPS equipment/outlet positions are marked at many locations, and dimensions are marked around the perimeter.]

Fig. 6-43 Design Drawing of Laboratory UPS Outlet Power Distribution