Concept report

Ibn SinaGeneral Teaching Hospital

MECHANICAL CONCEPT REPORT

OCTOBER 2012

TABLE OF CONTENTS

1.0 Introduction.................................................................................................................................... - 4 -

2.0 Regulations, Standards, & References............................................................................................- 5 -

2.1 HVAC Codes & Standards............................................................................................................- 5 -2.2 Plumbing Codes & Standards......................................................................................................- 5 -2.3 Fire Safety Codes & Standards....................................................................................................- 5 -2.4 Medical Gases Codes & Standards..............................................................................................- 5 -

3.0 Air Conditioning & Ventilation Systems..........................................................................................- 6 -

3.1 Design Parameters......................................................................................................................- 6 -3.1.1 Design Conditions...................................................................................................................- 6 -3.1.2 Ventilation Requirements.......................................................................................................- 9 -3.1.3 Noise Levels..........................................................................................................................- 11 -3.1.4 Pressure Philosophy..............................................................................................................- 12 -3.1.6 Air Filtration..........................................................................................................................- 12 -3.1.7 General.................................................................................................................................- 12 -

3.2 System Description...................................................................................................................- 13 -3.2.1 Chilled Water Generation.....................................................................................................- 13 -3.2.2 Air Side System.....................................................................................................................- 13 -3.2.4 Ventilation............................................................................................................................- 14 -3.2.5 Operating Theatres Ultra-Clean HVAC Design.......................................................................- 15 -

4.0 Plumbing (Water Supply & Drainage) Services...................................................................................- 18 -

4.1 Water Supply...................................................................................................................................- 18 -4.1.1 Design parameters...................................................................................................................- 18 -4.1.2 System Description...................................................................................................................- 19 -

4.2 Drainage Services............................................................................................................................- 22 -4.2.1 Design Parameters....................................................................................................................- 22 -4.2.1 System Description...................................................................................................................- 22 -

4.3 Rainwater Evacuation.....................................................................................................................- 23 -

Prepared by Type of doc Seq. # Rev. # Reference no Date PageSHZ REPORT 01 00 - OCT 2012 2 of 38

4.4 Plumbing Services Appendix...........................................................................................................- 24 -Appendix A: ASPE Data Book, Vol4, Chapter 10................................................................................- 24 -Appendix B: ASPE Data Book, Vol3, Table 2-2...................................................................................- 25 -Appendix C: Fixture Units Against Gallons Per Minute......................................................................- 26 -Appendix D: Hot water demand per fixture for various types of buildings.......................................- 27 -Appendix E: Fixture Units Per Fixture or Group.................................................................................- 28 -Appendix F: Building Drains and Sewers & Horizontal Fixture Stacks................................................- 29 -Appendix G: Horizontal Circuit and Loop Vent Sizing Table...............................................................- 30 -Appendix H: Size and Length of Vents...............................................................................................- 31 -

5.0 Fire Safety & Protection Services........................................................................................................- 32 -

5.1 System design.................................................................................................................................- 32 -

6.0 Medical Gases, Vacuum, & Anesthetic Gas Scavenging......................................................................- 33 -

6.1 General Description........................................................................................................................- 33 -

6.2 System Design.................................................................................................................................- 33 -6.2.1 Medical Plant............................................................................................................................- 33 -6.2.2 Medical Gas Distribution..........................................................................................................- 35 -


1.0 INTRODUCTION

The intent of this concept report is to establish key design criteria and guidelines, which are adopted for the preparation of the final mechanical design for the Ibn Sina 600-bed General Teaching Hospital project.

This report also describes the mechanical design analysis, elaborating design concepts, principles, and systems design that will serve as basis for development and further calculations during the next stage of detailed design.


2.0 REGULATIONS , STANDARDS , & REFERENCES

The mechanical works within the project shall be designed to comply with the following codes and standards:

2.1 HVAC CODES & STANDARDS

2.1.1 ASHRAE HVAC Design Manual for Hospitals & Clinics

2.1.2 AIA/AHA Draft Interim Sound and Vibration Design Guidelines for Hospital and Healthcare Facilities

2.1.3 ASHRAE Handbook: HVAC Systems and Equipment

2.1.4 ASHRAE Handbook: HVAC Applications

2.2 PLUMBING CODES & STANDARDS

2.2.1 National Plumbing Code (U.S.)

2.2.2 ASPE Plumbing Engineering Design Handbook

2.2.3 ASPE Plumbing Systems Data Book

2.3 FIRE SAFETY CODES & STANDARDS

2.3.1 National Fire Protection Association (NFPA)

2.4 MEDICAL GASES CODES & STANDARDS

2.4.1 HTM 02-01 Health Technical Memorandum 02-01: Medical Gas Pipeline Systems

2.4.2 HTM 2022 Health Technical Memorandum 2022: Medical Gas Pipeline Systems - Design, Installation, Validation and Verification

2.2.3 ASPE Special Plumbing Systems Data Book


3.0 AIR CONDITIONING & VENTILATION SYSTEMS

3.1 DESIGN PARAMETERS

3.1.1 DESIGN CONDITIONS

Outdoor Conditions:

Outdoor Conditions in Iraq for the HVAC load calculations are as follows:

Summer Conditions: Dry Bulb Temperature: 48.0 deg.C

Wet Bulb Temperature: 25.8 deg.C

Daily Range: 18.9 deg.C

Winter Conditions: Dry Bulb Temperature: 0 deg.C

Wet Bulb Temperature: -2.8 deg.C

Indoor Conditions:

For typical spaces, the indoor conditions are:

- Design Temperature: [20 – 23.9] deg.C- Relative Humidity: 50 % (±10%)

For hospital spaces, ASHRAE HVAC Design Manual for Hospitals and Clinics, Table 4-1 provides the design temperatures, relative humidity, pressurization requirements, fresh air requirements, and all indoor conditions necessary for design:




3.1.2 VENTILATION REQUIREMENTS

Healthcare facilities require large amounts of fresh, clean, outside air for breathing, and for control of hazards and odors through “dilution ventilation” and exhaust makeup. Under normal circumstances, outside air contains much lower concentrations of aerosols than indoor air. When filtered by high-efficiency filtration, such as is mandated by various codes and standards, outside air can be regarded as virtually free of micro-organisms and particulates. When outside air is not at an acceptable quality level, as may occur in industrialized areas, further process filtration is required.

In addition to a good source of outside air, adequate ventilation requires the careful location of intakes to avoid contamination, exhaust of contaminants, an adequate and controlled quantity of makeup air, and good distribution and mixing of the clean air throughout the spaces served.

As stated under section 2.0, “ASHRAE Standard 62-2001, Ventilation for Acceptable Indoor Air Quality” is the reference for the minimum design requirements.

Quantity of Ventilation Air

The ventilation rates shall cover ventilation for comfort, as well as for asepsis and odor control in areas of acute care that directly affect the patients.

The ventilation requirements for hospital space are available above in ASHRAE HVAC Design Manual for Hospitals and Clinics, Table 4-1. For each space, the minimum air changes of outdoor (fresh) air and the minimum total air changes per hour are listed. Ventilation rates in accordance with ASHRAE Standard 62, Ventilation for Acceptable Indoor Air Quality, are used for areas for which specific ventilation rates are not given.

Location of Outside Air Intakes

Air intakes shall be located at an adequate distance away from potential contamination sources. Typically, minimum separation shall be 25 feet (7.6m) as established by the AIA Guidelines, and 30 feet (9.1m) as established by ASHRAE Handbook. For safety, the design shall proceed according to the more conservative specification. However, even the “safer” ASHRAE separation distance is only preliminary, and greater separation may be required depending several factors, including but not limited to:

- Nature of contaminant

- Direction of prevailing winds

- Relative locations and placements of the intake and the contamination sources


The design shall also follow the guidelines listed herein:

- Intakes shall be at an adequate distance away from stack vents, equipments vents, and cooling towers.

- Adequate vertical distance from ground level shall be insured to avoid contamination (0.9m to 1.2m FFL).

- Adequate access to outside air intake plenums shall be insured in the design process. Also, measures to minimize the possibility of access by unauthorized personnel shall be taken into considerations for security purposes.

Exhaust of Contaminants and Odors

The design shall provide exhaust systems for the removal of contaminants and odors, preferably as close to the source of generation as practically possible (Refer to AGS system section 6.0). Some major source exhaust in a hospital facility include:

- Chemical fume hoods and biological safety cabinets (typically used in laboratories)

- Trunk ducts in surgical applications (removes anesthetic gases and aerosols)

- “Wet” X-Ray film development machines (chemical fumes)

- Cough inducement booths or hoods (as used in contagious respiratory disease therapy)

When contaminants and odors cannot be practically captured at the source, the space of generation shall be exhausted (eg. Laboratories, soiled laundry, waste storage, dirty process, anesthesia storage, and disease isolation spaces).


3.1.3 NOISE LEVELS

Maximum permissible background noise levels for most spaces are established using room criteria (RC) or noise criteria (NC) curves. The HVAC design takes into consideration the following issues:

- Equipment Noise: From fans, FCUs, and AHUs- Air Transfer Noise: Ductwork, dampers, louvers, grills, & diffusers.

All equipment included in the design shall take into consideration room noise limitations and manufacturers’ proper installation data. Excessive noise generation in ductwork will be avoided by limiting the flow velocities as per ASHRAE Handbook, HVAC Applications. Also, supply, return, exhaust, and fresh air terminals, including all grills, diffusers, and louvers shall be designed in-parallel with noise-limiting criteria.

Table 1.4-1 of the 2006 AIA/AHA Draft Interim Sound and Vibration Design Guidelines for Hospital and Healthcare Facilities lists maximum allowable levels of noise generated by health care facilities:

The World Health Organization (WHO) recommends a limit of 40 dBA (comparable to a residential area at night) for maximum nighttime noise levels in hospitals and 30 dBA in patient rooms. The design of mechanical systems shall ensure that mechanical background sound levels do not exceed the recommended design criteria for room noise levels listed in Table 3.3-1 of the 2006 AIA/AHA Draft Interim Sound and Vibration Guidelines for Hospital and Healthcare Facilities:



3.1.4 PRESSURE PHILOSOPHY

Pressure gradients among rooms and spaces rule the direction of air infiltration, and thus all aerosols that are carried by the air of the spaces.

Positive pressurization of a space prevents the air from neighboring spaces to infiltrate, and advocates evacuation of aerosols. De-pressurization (negative spaces) prevents the air of the space from escaping or “contaminating” neighboring spaces.

The table (ASHRAE HVAC Design Manual for Hospitals and Clinics, Table 4-1 – APPENDIX A) lists the pressure relationship to adjacent areas of all hospital spaces.

Boundaries between functional areas (wards & departments) shall have directional control by providing air movement, which is generally from clean to less clean. Where continuous directional control is not required, variations should be minimized, and in no case should a lack of directional control allow the spread of infection from one area to another.

3.1.6 A IR F ILTRATION

Minimum levels of air filtration efficiency are available in AIA 2001 “Guidelines for the Design and Construction of Hospitals and Healthcare Facilities”. The air filtration must be read in lieu of the space air changes per hour ventilation requirements, provided in ASHRAE HVAC Design Manual for Hospitals and Clinics, Table 4-1 listed in section 3.1.2.

Medical facilities HVAC systems require two filter beds, one upstream of the coil, and a final filter bank downstream of the coil.

In orthopedic, bone marrow transplant, and organ transplant suits and recovery rooms, an additional stage of HEPA filtration is recommended at the air outlets.

ASHRAE Standard 52.1- 1992 provides dust spot efficiency rating for filter testing. Minimum efficiency rating value MERV 7 is required before the coil, and MERV 14 as the final or secondary filter.

Refer to section 3.2.5 for the design of operating theatres, that require a special ultra-clean space HVAC design.

3.1.7 GENERAL

The HVAC design procedure takes into consideration other design parameters including the following:

- Envelope U-Values: Including walls, partitions, windows, doors, floors, ceilingsData to be extracted from Architectural & Structural details.

- Equipment Loads: The heat dissipation from mechanical and medical equipment- Lighting Loads The heat dissipation from lighting- Occupancy Loads The heat dissipation from people (sensible & latent)


Despite the fact that the ventilation requirements are more likely to exceed the thermal loads in most spaces, the HAP load calculation will account for the aforementioned parameters at later stages of the design procedure.

3.2 SYSTEM DESCRIPTION

3.2.1 CHILLED WATER GENERATION

A central chilled water plant, located in the plant building adjacent to the hospital, follows the Primary/Secondary Variable Flow Design, which has become the standard approach for large central chilled water plants using multiple chillers with multiple cooling loads, and their respective cooling towers.

The primary loop is hydraulically independent (de-coupled) from the secondary loop for the loads, and therefore the primary circulating pumps are constant-speed, relatively low-head, and intended to provide constant flow through the chiller’s evaporator.

The secondary pumps deliver the chilled water from the plant to the AHUs and FCUs of the site buildings. An independent secondary circulation loop will be designed for each zone/building.

Note: Guard Shacks shall have mini-split heat pump units.

3.2.2 A IR S IDE SYSTEM

The hospital - once properly zoned - shall be climatized with fan-coil units and air handling units, fed with a 4-pipe system: Chilled Water Supply & Chilled Water Return for the cooling mode, Heating Water Supply & Heating Water Return for the heating mode.

Air handling units will be selected, arranged, and distributed to serve defined areas of similar functions and operations and according to orientation.

Air handling units (double skin with thermal and acoustical insulation) will be located in plant rooms in each department, to ease the access for maintenance.

Also, the fan-coil units and air handlers shall have proper fresh air supply to meet the ventilation standards discussed above. Fresh air intake will be mainly from the nearest façade available in the department. Air is returned from the space to the air handling unit for recirculation or exhaust. Mixing of return air among zones shall not be allowed.

AHUs will be provided with sound attenuators to reduce noise transmission to the spaces they serve. Ducting for air distribution shall follow SMACNA standards, and sized to provide the required air flow and acceptable velocities that shall limit the noise to the acceptable values listed in section 3.1.3.


In the operating rooms, the Air handling unit will be located directly above the operating room and the access to it for maintenance will be from outside the O.R. They will be 100% fresh air units and counter flow heat recovery section is required.


3.2.4 VENTILATION

Clean exhaust fans, dirty exhaust fans and special exhaust fans will mainly be located on roof taking into consideration the wind direction and the minimum distance allowable between all of these different fans.

Re-circulation of air in ventilation systems will be employed only in areas where the conditions are clean and the air is suitable for re-circulation.

The air might be contaminated and is unsuitable for re-circulation.

The dirty exhaust system will provide mechanical ventilation for the removal of unpleasant odors and contaminated air, dirty utility rooms, cleaner’s rooms, bathrooms, showers and disposal rooms irrespective of their location. These rooms will always be maintained at a negative pressure.

Dirty and special extract fans

Dirty and special extract fans will be located externally on the roof close to the areas to be ventilated. The secondary vertical shafts between patient bedrooms will be used mainly for the exhaust duct.

Discharge from dirty and special exhausts will be kept as far away possible from the supply air inlets to avoid contamination. Intake louvers and exhaust fan outlets will be sited to take account of wind directions and surrounding buildings.

Dirty exhaust will have 100% standby fans with automatic change over controls.

Ventilation of special areas

Ventilation of special areas such as operating rooms, isolation rooms, will be designed to maintain positive or negative pressure within the space.

Operating rooms will be maintained under positive pressure by an excess of supply air with a low flow rate extracted at low level to clear anesthetic gases.

The surplus of supply air will exhaust via pressure stabilizers (relief flaps) with extract provided outside the theatre.

The pollution rooms in ICU will be provided with positive pressure and negative pressure as specifies.

The positive pressure rooms will be achieved by means of supply derived from the general ICU supply system. This branch will be fitted with a HEPA filter and dedicated boosts fan with variable speed drive. A dedicated extract fan will be provided operating at a lower duty than the supply air system.

The negative pressure rooms will be achieved by means of a dedicated extract fan discharging to atmosphere. The extract will not be filtered as it is not anticipated that seriously infection disease requiring this will be located in this unit.


Supply air will be provided to control temperatures and satisfy fresh air requirements.

The isolation rooms will be provided with reheat batteries to control temperatures as required by in room set point adjustment.

3.2.5 OPERATING THEATRES ULTRA-CLEAN HVAC DESIGN

Continual advances in medicine and technology necessitate constant revaluation of the air conditioning needs of hospitals and medical facilities. Conditioning in the operating theatres stands out for its complexities and stringent demands on:

- Air-quality- Airflow pattern- Temperature Control- Humidity control- Bacterial control- Cross-contamination control- Special air-filtration- Exhaust system.

The Laminar Air-flow System

The Laminar Air-flow System provides aseptic condition and has been found effective in the treatment of patients who are highly susceptible to infections, like those undergoing organ transplant, open heart surgery or any major or minor operation.

In laminar flow, air conditioned air enters the room through filters covering ceiling area over the Operation Table (O.T.), is exhausted through the four return air ducts near the floor, with air flowing in parallel lines and at uniform velocity of 0.45 m/s. Thus any air makes only one pass through the room and any contamination created in the room is carried out. This type of design is therefore also called “displacement flow”.

Velocities in laminar flow range are necessary to prevent setting out of dust particles. With this type of direct flow areas of different velocities are minimized, reducing turbulence.


The ceiling above O.T. table is entirely taken up with filters, and return air ducts are used to exhaust the air. The air shower created above the O.T. helps sweep contamination to the floor and out, thus avoiding any contamination build up. Particles generated at one workstation are removed without affecting others:

Air Quality & Cleaning

Various types of filters are installed at air intakes, double skin air handling units to maintain indoor air quality levels and also at exhaust outlets to prevent the release of inborn pollutants outdoors .

Three-level filtration can be used instead of two-level filtration where necessary:

Pre Filters: Efficiency of 90% down to 10 micron, used in addition to above filters.

Fine Filters: Efficiency of 99% down to 5 micron, used for balance areas & exhaust points.

HEPA filters: With efficiency of 99.97% down to 0.3 micron used for Operating rooms & I.C.U’s. These are special high flow types with more media to handle higher air quality.

Three-stage filtration ensures longer life of high cost filters and easy maintenance. HEPA filters retain all type of bacteria & viruses, as their size is greater than 0.3 micron.

The Air Handling units used are of double skin type having thermal break profile with direct driven “German plug fan” so that no belt carbon is being transmitted in the air.


Further, the AHU is being operated through variable frequency drive which helps in maintaining constant air flow velocity throughout the filter life.

Also continuous supply of fresh air is recommended to remove the anesthetic gases and to maintain air quality.

Higher recirculation ensures continuous filtration of bacteria and particulate generated inside O.T., while positive pressure inside the O.T. ensures that no outside air leaks in during door opening and through cracks.

Low-level extraction ensures minimization of turbulent air pockets, which are regarded as contaminating:


4.0 PLUMBING (WATER SUPPLY & DRAINAGE) SERVICES

4.1 WATER SUPPLY

4.1.1 DESIGN PARAMETERS

The domestic water consumption for the hospital is based on 225gal/bed/day as per ASPE plumbing fixtures volume 4 (refer to appendix A).

The domestic water consumption for the residential building is based on 60gal/day/person (227.4 l/day/person but we will consider that the daily water consumption is 250 l/day/person) as per ASPE plumbing fixtures volume 4 (refer to appendix A).

The daily soft water consumption for the project is based on the number of meals per day and on the consumption of soft water by the laundry machines and the medical equipment.

The estimated soft water consumption for kitchen is based on the rate: 10gal/meal and the hot water demand is 4gal/day as per “National Plumbing Code”.

The consumption of the laundry machines and the medical equipment is based on the “EDIM manuals” per the medical consultant's specifications.

R.O water estimation is based on the flow rate required and on the consumption per cycle for each type of medical equipment as per “EDIM manuals”.

The demand for hot and cold water supply is calculated according to the fixture-unit method as defined in the National Plumbing Code (NPC).

The demand for hot and cold water supply for hospital plumbing fixtures is calculated according to the fixture-unit method or the flow method as defined in the ASPE Data Book-Volume 4, where the hospital’s plumbing fixtures and their Fixture-Unit requirement are provided in Table2-2: Hospital Plumbing Fixtures – APPENDIX C.

Knowing the number of FU for every fixture, APPENDIX D gives the gallons per minute against fixture units.


4.1.2 SYSTEM DESCRIPTION

4.1.2.1 Cold Water System

The cold water supply to the site is obtained from the municipality network and shall be stored in a concrete water tank (untreated water tank located in the plant room. This tank will be sized for one day reserve.

Untreated water is conveyed by means of a booster pump to a treatment plant. Filtered water (domestic water) shall be stored in a treated water tank sized for one day reserve.

The domestic filtered cold water will be distributed from plant room to each building (residential building, hospital, morgue and guard shacks...).

Booster sets for filtered water are dedicated for each building:

One booster set for the residential building One booster set for the hospital and guard houses One booster set for the morgue One booster set for the plant room building

Water Treatment Plant for Soft Water

After testing the city water, a proper treatment should be adopted to afford soft water in several points in the hospital building and in the morgue; therefore a softener will be installed for this purpose. One booster set is dedicated to feed these buildings with soft water such as the main kitchen and laundry. Also, medical equipments require soft water for their good running. A concrete Soft water tank sized for 2 days reserve of soft water demand required to feed the hospital and shall be located in the plant room.

Water Treatment Plant for Reverse Osmosis Water (R.O)

Medical equipments require R.O water for their good running, so another water treatment set (R.O package) shall be installed for this purpose.

A concrete R.O water tank is required in the plant room and one booster set is dedicated to feed the hospital with R.O water.

UV sterilizers are used after the R.O for potable water to feed the and the residential building. A potable stainless steel tank shall be located in the plant room.


Emergency PE Water Storage Tanks

Emergency PE water storage tanks located on roof are required, and are connected to the domestic water system in order to afford water to the building in case of failure of domestic water pressure booster set or in case of failure of electric power.

Irrigation & Cooling Towers

Concrete tanks and pumping sets will be provided for:

- concrete irrigation water tanks- concrete cooling towers water tanks

4.1.2.2 Hot water system

The domestic hot water and hot water return will be distributed from hot water storage tanks (central hot water storage heaters) installed in the plant room and heated by boilers to each building via the site trench (residential building, hospital, morgue and guard shacks) and they run in the false ceiling of the buildings to the bathrooms or to others utilities.

Hot water storage heaters are dedicated for each building and are heated by the fuel oil burner and have electrical resistance as back up:

Hot water storage heaters for the residential building. Hot water storage heaters for the hospital and the morgue.

Soft hot water and soft hot water return pipes will be distributed too from the plant room to the buildings.

Hot water systems shall be central, pressurized by the cold water system. The (60°C) water system should serve the residential building, hospital toilets and employee toilets. The (80°C) water system should serve all kitchen and laundry fixtures where (80°C) hot soft water is required for dishwasher equipment and laundry machines.

The hot water system should be mechanically circulated, and all high points automatically vented by means of float operated vent valves piped to drain. Hot water is distributed to all point of use under adequate pressure.


Domestic hot water supply and return pipes shall be galvanized steel inside pump room, technical areas and shafts.

Domestic hot water storage heaters will be sized based on the ASHRAE HANDBOOK 1999, as mentioned in Table 1: Hot Water Demand in Fixture Units (listed below) and in Table 9: Hot water demand per fixture for various types of buildings.


4.2 DRAINAGE SERVICES

4.2.1 DESIGN PARAMETERS

The gravity evacuation design is divided into two separate systems:

The soil water system: gathers soil water from building water closets and kitchens. (black water)

The wastewater system: gathers waste water from lavatories, showers, bathtubs, laundries, and other grey-water drains.

The wastewater and soil water gravity evacuation systems and their venting system are sized according to the National Plumbing Code. The tables below extracted from the code show the fixture unit sizing parameters.

The tables (from the National Plumbing Code) attached in the Appendices are as follows:

Table 11.4.2 : Fixture Units per Fixture or Group

Table 11.5.2 : Building Drainage and Sewers

Table 11.5.3 : Horizontal Fixture Branches and Stacks

Table A : Horizontal Circuit and Loop Vent Sizing Table

Table 12.21.5 : Size and Length of Vents

4.2.1 SYSTEM DESCRIPTION

The drainage services will comprise waste water (grey water) and soil water (black water) drainage which are separated inside buildings and independent rain water drainage from the roof of the building.

Access caps will be provided for rodding and cleaning purposes for all parts of the drainage services.

No floor drains are allowed except in the dirty utilities.

All drainage piping will be apparent and suspended under ceiling.

The horizontal drainage network (internally and externally) will be oversized to minimize the probability of blockage due to misuse of users.

Special acid-resistant drainage pipes will be used for laboratories. Wastewater from laboratories shall be treated in a neutralizing pit prior to discharge to the soil network.

Waste water from kitchens has drainage to grease interceptor prior to connection to soil network.


Plant room has drainage to oil separator prior to connection to soil manhole.

The morgue will also be provided with a treatment system for organic materials in the drainage waste.

The design concept provides 2 options:

Option 1

In case there is no municipality sewer connection:

Two independent gravity sewer networks serve the site, waste water network and soil water network. The waste water is conveyed to a treatment plant to be used for cooling towers make up water. The soil water is conveyed to a treatment plant to be used for irrigation make up water.

Option 2

In case there is a connection to municipality sewer network:

The two separate drainage systems (soil & waste) inside the buildings are joined together outside the buildings in a gully-trapped manhole. The site sewer network is then connected to the existing municipal network at a convenient location or to a lifting station than to municipality sewer.

4.3 RAINWATER EVACUATION

Rain Water drainage shall be collected from roof, and discharged by gravity into an outdoor manhole. From the outdoor manhole water shall be led into the Municipality network or to a lifting station.

Non return valve shall be installed between the buildings network and the Municipality network.

If there is no municipal rainwater evacuation network, the rainwater discharge destination shall be determined by the contractor after on-site investigation, and the design will follow accordingly.


4.4 PLUMBING SERVICES APPENDIX

APPENDIX A: ASPE DATA BOOK , VOL4, CHAPTER 10


APPENDIX B: ASPE DATA BOOK , VOL3, TABLE 2-2


APPENDIX C: F IXTURE UNITS AGAINST GALLONS PER M INUTE


APPENDIX D: HOT WATER DEMAND PER FIXTURE FOR VARIOUS TYPES OF BUILDINGS


APPENDIX E: F IXTURE UNITS PER F IXTURE OR GROUP


APPENDIX F: BUILDING DRAINS AND SEWERS & HORIZONTAL F IXTURE STACKS


APPENDIX G: HORIZONTAL C IRCUIT AND LOOP VENT S IZING TABLE


APPENDIX H: S IZE AND LENGTH OF VENTS


5.0 FIRE SAFETY & PROTECTION SERVICES

5.1 SYSTEM DESIGN

While most occupancies rely mainly on evacuating occupants as part of their fire protection strategy, hospitals must rely on the building and the building systems to protect its occupants while they remain in place. This is called “defend-in-place” strategy.

The fire safety design, following the NFPA codes and regulations, and shall be per the Fire Consultant's guides, strictly followed per their instructions.

The principles are described below:

Full-coverage sprinklers with wet risers and independent zone valves for each floor and as needed, with landing valves in all staircases with dry risers, and Siamese connection for fire brigade located as convenient.

Fire hose reel cabinets arranged and positioned in the building near staircases, escape routes, and entrances as well as where necessary. Each cabinet will house a manual fire extinguisher – dry powder. The reel shall be complete with automatic valve (jet spray).

Internal pipe work will run in the ceiling void in shafts with air release valves at all high points.

An automatic dry powder extinguisher will be used for the control equipment and switchgear rooms.

Portable fire extinguishers will be provided where necessary for areas such as electrical room, mechanical room and lifts rooms, and where needed, per the Fire Consultant's requirements.

Wet fire pipes are distributed inside the site trench from the plant room building to the residential building, hospital and morgue (refer to fire fighting schematic diagram and fire fighting dry & wet riser diagram). Siamese connections for dry risers are installed for all buildings (refer to fire fighting schematic diagram).

The fire fighting design shall be in full compliance with all relevant NFPA codes and regulations.

All stairwells shall be pressurized by at least 25 Pa. The pressure difference shall not, in any case, be more than that which permits the doors to begin to be opened by a force of 41 Joules (which is the case when the pressure difference exceeds 62 Pa).


6.0 MEDICAL GASES , VACUUM , & ANESTHETIC GAS SCAVENGING

6.1 GENERAL DESCRIPTION

The Medical Gases Design aims to provide a safe and effective method of delivering medical gases, medical air and surgical air from the source of supply to the appropriate terminal unit by means of a pipeline distribution system.

Medical vacuum is also provided by means of a pipeline system.

Anesthetic gas scavenging disposal systems are provided to control occupational exposure to waste anesthetic gases and agents.

The medical gases systems include the following:

- Oxygen- Nitrous Oxide- Nitrous Oxide / Oxygen Mixture- Surgical Compressed Air (CA7)- Medical Compressed Air (CA4)- Vacuum- Anesthetic Gas Scavenging (AGS)

6.2 SYSTEM DESIGN

6.2.1 MEDICAL PLANT

The medical gas plant is located at the morgue building. The design follows the regulations specified in HTM 2022 (Medical Gas Pipeline Systems - Design, Installation, Validation and Verification, Health Technical Memorandum 2022). It comprises the installation of all equipment needed for the plant of each system:

6.2.1.1 Oxygen System:

The system comprises a 2-bank manifold of J-sized oxygen cylinders, with automatic change-over actuator, and a twin-branch pressure regulating station. Provisions for bulk oxygen storage are integrated into the design of the plant to allow for future connection.


Refer to drawing #1140 for system schematic.


6.2.1.2 Nitrous Oxide:

The system comprises a 2-bank manifold of G-sized nitrous oxide cylinders, with automatic change-over actuator, and a twin-branch pressure regulating station.


6.2.1.3 Nitrous Oxide:

The system comprises a 2-bankmanifold of G-sized O2/NO2mixture cylinders, with automatic change-over actuator, and a 2-cylinder emergency reserve bank.

Refer to drawing #1150 for system schematic

6.2.1.4 Surgical Compressed Air:

The system comprises a 2-compressor + after cooler installation, one main and one stand-by, a compressed air receiver reservoir, filtration station, and pressure regulation station.


6.2.1.5 Medical Compressed Air:

The system comprises a multiple compressor + after cooler installation, a compressed air receiver reservoir, filtration station, and pressure regulation station.

Refer to drawing #1160 for systemschematic

6.2.1.6 Vacuum:

The system comprises a multiple vacuum pump installation, a vacuum receiver reservoir, filtration station, and control unit.

Refer to drawing #1170

6.2.1.7 Anesthetic Gas Scavenging:

The design allocates de-centralized dedicated AGS stations within the hospital building, in plant rooms for each ward that utilizes anesthetic gas.


6.2.2 MEDICAL GAS D ISTRIBUTION

Piping from the medical gas plant at the morgue building will reach the hospital building in the site trench. Refer to drawing# 1180 “Medical Gas Distribution Diagram” for sitelayout.

In the hospital building, Area valve service units (valves in valve boxes) will be provided to all medical gas and vacuum system in accordance with HTM2022A.

AVSUs will be located at all departmental entrances with further AVSUs as follows to provide secondary isolation.

Operating Theatres: AVSUs to each operating theatre suite to recovery beds

PCVICU, & CVICU: 2 sets of AVSUs each serving half the beds in each area

The following table shows the required medical gas flows at the terminal units:

Source: Health Technical Memorandum 02-01: Medical Gas Pipeline Systems


Date post:	20-May-2015
Category:	Design
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