Mechanical Services Design Presentation.pptx

Presentation of Mechanical Services Design Proposals

1. Design philosophy 2.0 Introduction 2.1 General The proposed office complex is a 3-storey building with a ground floor parking located within an established neighborhood and is well connected to public transport and local amenities. This presentation outlines the main mechanical building services components that will be associated with the development, as well as providing details for the plant areas to be provided. The ultimate environmental design aim is to create a building that is comfortable, use little energy, less water, that produces less waste in operation or create waste in their construction. The following energy conservation initiatives are being considered for the proposed design:   Passive design principles will be employed to respond to environmental conditions of the building including orientation, solar access, prevailing winds, seasonal and temperatures changes during the day. High performance building envelope. A high-performance building envelope is proposed to maximize the performance of the passive building design and to minimize the energy use of the building mechanical cooling system throughout the lifetime of the building Mixed-mode ventilation - Mixed-mode ventilation is being considered for the perimeter washroom area. Mixed-mode ventilation combines both natural ventilation and mechanical ventilation systems therefore reducing energy consumption.

2. Design philosophy CONT.D Mixed-mode ventilation - Mixed-mode ventilation is being considered for the perimeter open plan offices. Mixed-mode ventilation combines both natural ventilation and mechanical ventilation systems therefore reducing energy consumption. Sewage Disposal/Treatment – A filtration bed would be installed after the septic tank to filter the effluent from the septic tank. The filtered effluent would then be pumped to irrigate the soft landscaping around the development. Water conservation – Building would be fitted with an Underground rainwater tank which would be treated and connected to all sanitary flushing systems. Across the development, rainwater shall be collected from approximately 680m 2 of roof area.   Borehole would be included as a third source of water for the development. For space saving and cost reduction, the rainwater would be channeled into the borehole to refill the aquifer. All taps to be installed should be of the infrared sensor type. All sanitary fixtures shall have the WELS rating stated below: Taps – 5 Stars Toilets – 4 Stars Showers – 3 Stars Solar Water Heating:– The feasibility of solar photovoltaics is currently under investigation. Solar thermal energy is proposed for providing hot water for the kitchens and canteen. Occupancy sensors for HVAC and lighting services – Occupancy sensors would be installed for the operation of HVAC and lighting services. This will be incorporated to avoid energy wastage.

3. 2.2 Scope of Works Mechanical services scope of works includes the following:   Design of cold and hot water storage and distribution system. Design of soil and wastewater system Design of firefighting system. Design of ventilation systems Design of lift system   3.2 Compliance with Codes and Standards The works have been designed in accordance with relevant British Standards current at the time and the recommendations/requirements of client’s preference and relevant consultant inputs. The mechanical systems will comply with Guidance notes, Technical memorandum and Standards provided by the following Institutions:   CIBSE Chartered Institution of Building Services Engineers (UK) American Society of Heating Refrigeration & Air-Conditioning (ASHRAE) Standards NFPA Standards ISO 9000 Standards British Standards (BS) and Codes of Practice. Ghana Building Codes. Ghana National Fire Service Code .  

4. Design Principles Location Accra - Ghana Summer 34.2 C DB, 28.3 C WB   Noise Ratings Offices, Meeting Room, Conference etc. NR 30 Eatery NR 40 Kitchen NR 45   Ventilation Requirements Per Person (fresh sir) 8 Liters per second Eatery (extract rate) 15 Air changes per hour Toilets (extract rate) 10 Air changes per hour Kitchen (extract rate) 25 Air changes per hour  

5. VENTILATION and AIR-CONDITIONING SYSTEM VRF System. (Air-conditioning) The VRF system would be designed to have multiple outdoor units serving each floor (zone), all the indoor units (FCU) on each floor (zone) shall be coupled to a VRF inverter-controlled Outdoor unit, thus ensuring that each zone shall be independently controlled as well as enhancing more flexibility. The outdoor units would be rated at 100% of their total load. Fan coil units providing conditioned air would adequately be designed and sized to offset heat gains and maintain the specified room temperature conditions as well as providing the required Air Quality. air allowances is always achieved The system would be designed to perform well under both full and part load conditions. The system selections will be further refined as the design progresses to ensure the following: Sustainable for external climate Availability of parts locally Shipment times to site Adequate redundancy is provided It is currently proposed that the VRF outdoor unit is located on the ground of the building. This is to ensure adequate maintenance access all round. The VRV system will consist of Outdoor Units and ceiling cassette Unit l to serve the various spaces (meeting room and the open offices). Control of the system will be via CO2 and Temperature sensors (Wireless or wired).

6. Hvac Equipment Indoor Unit . (Ceiling Cassette) Outdoor Unit . (VRF) The layout below , shows a ceiling cassette unit to be installed at the meeting room and open office space. All final positions to be coordinated onsite.

7. Toilet Extract Washroom extract fans consisting of an inline ceiling mounted extract fan, ductwork and grilles is proposed. From the shaft the ductwork will branch off to serve the washroom on each floor as required. Make up air for the toilets will be taken from the adjacent corridor spaces, door undercuts or transfer grilles will be required to ensure an adequate airpath is provided. Access panels would be provided in the ceiling to provide easy access for maintenance and installation. All circular air valves would be installed with a back-draft damper to prevent back flow of exhaust air back into washrooms that are not being used.   The layout below shows, the washroom extract layout all final positions to be coordinated onsite. In-line ceiling mounted fan Extractor fans shall be installed in all kitchen areas, washrooms and storerooms

8. Cold Water Supply   Cold water will be run from the various water supply to the underground water storage. From the underground water storage water will be pumped to the roof water tanks. Roof water tanks would feed all sanitary fixtures in the building by gravity.   Proposed sources of water are as follows: Ghana Water Company Mains Rainwater harvesting Borehole as Alternative Cold Water Storage: The water storage capacity of 30,000 liters is based on occupancy and number of sanitary fixtures and should be adequate for minimum 72-hour interruption of water supply. Plumbing SYSTEM Underground c oncrete water tank shall be located underneath the carpark on the ground floor. Automatic booster pump set shall lift water from the concrete water tanks to the roof water tanks. Rainwater Harvesting: Another alternative source shall be rainwater harvesting. Rainwater shall be collected from the roof of the building and channeled through class ‘B’ uPVC downpipes to be installed on the service ducts provided and finally discharged to the underground tanks. Rainwater shall be treated and fed back into the building services and part would be used for the firefighting system .

9. Borehole System To fulfill or satisfy conservation of portable water usage and also due to acute water shortage in the country, which is likely to worsen in the near future, alternative source of water supply in the form of borehole system shall be provided. The actual location and water quality of the borehole shall be determined from geotechnical site investigation & water testing. Hot Water( Solar water heaters)   Hot water will be provided by solar thermal water heating system located on the roof. The exact size and storage capacity of each of the above options will be reviewed in detail at the next stage.   Plumbing SYSTEM cont’d Sewage & Waste water drainage     All Soil Vent Pipes are located within the service shafts as provided. Any washbasins located within any washroom will be provided with a stub stack as required.   All sewage and wastewater pipes would be run under the floor slab and within the ceiling space of the washrooms below.   Sewage collection shall be of the combined system for both the soil and waste with drainage pipes in class ‘B’ uPVC pipes. Inspection chambers / manholes shall be located at all points of direction changes and at not more than 20m intervals.   Sewage from water closets shall be discharged into the septic tank and filtration bed system for treatment and final disposal respectively

10. construction waste management Waste Reduction: The following initiatives are to be considered to minimize waste during construction and operation phases: Construction waste management - During the construction phase, a project-specific construction waste management plan (WMP) will be developed and implemented by the head contractor. This is to ensure that recycling of waste from demolition and construction is maximized, and that the volume of demolition and construction waste ending up in landfill minimized. The sub-contractors will be instructed to send the recyclable resources recovered from demolition and construction back to their manufacturers and suppliers for recycling / reuse where possible. Operational waste management - To ensure recycling of operational waste, a dedicated storage space will be provided for locating recycling bins.

11. Water booster pump and treatment system Fully equipped booster set pump shall be design to maintaining a minimum pressure of 3 bar regardless of flow changes and fluctuation with 1duty and 1standby as a redundancy, high efficiency and the best performance for energy conservation. Multi-Cartridge / Reverse Osmosis water filter systems with Ultraviolet water purifiers shall be design to purify the Bulk water from GWCL before stored in the overhead tanks

12.   Three F ire-fighting systems have been proposed for the project. These are project. Portable Fire Extinguishers Fire Hosereel System External Pedestal Fire Hydrants   External Fire Hydrant There shall be 2-no. pedestal type fire hydrant to BS 750 served by a 100mm dia HDPE pipe ring main connected to the Ghana Water Company (GWC) mains but outside the water meter. The fire hydrant pipeline shall be anchored at all points of direction change as well as take-off tees and bends for the hydrants. FIRE FIGHTING SYSTEM Portable Extinguisher The building shall be equipped with potable extinguishers i.e., 4no fire extinguisher 9L foam or 10kg carbon dioxide or 9kg dry chemical powder on each floor. Fire cabinets and hose reels Fire hose reels with cabinets shall be designed for each floors. All fire hose-reels shall be 25 mm x 30m non-swinging types with drum rotates on a fixed spindle. Fire fighting Pumps Fully equipped electric fire water pump with 45 meters pressure head delivery at 7 l/s , shall be connected to the firehose reel system.

13. Fire pump and hose reel cabinet 25mm x 30mm swing hose reel and stop with 6kg or 12kg ABC powder extinguisher. door and hose reel swing out a full 180° with red epoxy powder coated standard finish surfaced or recessed mounting. Centrifugal fire pumps have excellent quality, optimized design, high efficiency and the best performance for energy conservation. ABC dry powder is multipurpose for all a, b, c and electrical fire risks. Its ideal for residential, commercial and industrial applications.

14. The vertical transport provision comprising 2No. 8-passenger. The lift shall be design to be functional, reliable, and safe. Priority will be given to accessibility, with wide opening doors to enable easy entry and exit. This will increase comfort and convenience for people with limited mobility. The following energy efficiency measures shall be implemented where possible without adversely affecting performance; Use of passenger sensors to disable car services when not in use High efficiency drives Regenerative power back into the electrical system ELEVATOR OR LIFT