UNDER FLOOR AIR DISTRIBUTION (UFAD) SOLUTIONS OVERHEAD SYSTEM UFAD SYSTEM
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- A product of AirFixture USA I DON T CARE ZONE B R E A T H I N G Z O N E W E L L M I X E D CONSTANT VOLUME DIFFUSER WITH PERSONAL CONTROL 4 WAY DEFLECTION CONSTANT VOLUME DIFFUSER VAV TIME MODULATED DIFFUSER WITH ROUND GRILL VAV TIME MODULATED DIFFUSER WITH SQUARE GRILL
0% FLOW FIG 1 100% FLOW FIG 2 Process of Time Modulation 50% Flow really means 100% flow to 50% of the area FIG 3 50% Flow with Time Modulation = 50% flow to 100% of the area FIG 4 50% SMART FIG 5 50% Flow really means 100% flow to 50% of the area FIG 6 25% SMART FIG 7 25% SMART FIG 8 25% SMART FIG 9 25% SMART FIG 10 25% SMART FIG 11
The conditioned air is supplied by the zone AHU to the under floor plenum but the return spent air shall be drawn back to the AHU through the false ceiling or the space above the access floor. The whole under floor void shall be used as a supply air plenum to distribute the conditioned air thus enhancing thermal mass storage. The Zone air handling unit must operate in a Variable Volume mode to avoid over pressurization of the floor void The Terminal Units (AET-TU) operation shall automatically determine the air flow needed from the quantity of terminal units dampers which are open or closed. This shall automatically and simply guarantee constant under floor pressure within the specified limits. The air flow change will be caused by a variation in voltage input to the fans approx between 110-120V(0%) and 230V(100%) through communication between the Controller of the AET-TUs (open-close dampers) and the Controller of the AHU (namely the Hiromatic) operating the change by means of a well proven algorithm. The AET-V could be allocated into a technical room with grilles for air return. The fresh air could be directly introduced into the room and it will be mixed with recycling air. A FANTILE UNIT
Under floor supply and return channels are created by means of baffles (underfloor air partitioning) placed in the access floor void. Return air grilles are positioned in the floor over return Plenum to permit the return of spent air to the AHU unit for re-conditioning. Set into the floor over supply Plenum are individually controlled Fan terminals of either recessed or floor standing configuration. These terminals, AET-TUs., introduce air into the space above in accordance with the dictates of their own on board control system. AET-C Conditioned Air Modules are suitably located throughout the office space to suit thermal demand and supply conditioned air locally to serve the needs of the space. A FANTILE UNIT The low underfloor pressure in the two sections, supply and return, is kept at the desired level by means of a suitably sized under floor by pass in the underfloor air partitioning, this can be easily changed and baffle can also be repositioned or modified, if necessary as space reconfiguration demands.
Flexibility Because the rate of business growth and the rate of change in office equipment technology places flexibility of systems much higher on the list of priorities. In speculative developments the need to meet unknown requirements of unknown user s effectively must be the aim. The Flexiblespace system permits major swings in usage in the space and the incorporation of such a system virtually future-proofs the building s ability to service change for the expected life of the building. Conventionally, designs are carried out against a set of assumed design criteria and systems are installed to meet them. In some cases the incoming user s requirements are for less than the initial design provided and this is wasteful. In other cases the system provided falls seriously short of the user s requirements and the whole system requires changing. This too is wasteful. With the Flexiblespace systems approach the demands of each incoming user can be met quickly and effectively and during the occupancy can be easily adapted and upgraded to meet the increasing or decreasing needs in each area of the space occupied. With simple facility management, redundant equipment from one area can be re-utilized elsewhere. Partitioning changes to meet new working arrangements are easily catered for and simple relocation or provision of additional diffuser and / or fan air terminal in the floor quickly adapts the air conditioning. This flexibility permits a higher efficiency of space usage and maximizes business activity to the advantage of the owner and user. Longer occupancies can be achieved because the building can continue to meet the user s needs. Ease of Installation Because with the Flexiblespace systems heat loads in area s can change without the need to re-design ductwork and pipework thus reducing engineering and drafting inputs. For example, to double the cooling demand in a cellular office, an additional diffuser and / or fan air terminal would be brought to the room, a floor tile lifted and the diffuser and / or fan terminal inserted in its place and plugged into the below-floor power supply. This operation takes minutes rather than days as with conventional systems. Avoidance of Co-ordination problems Because with conventional systems the major co-ordination problems occur attempting to route ductwork, pipework and other services in false ceiling areas along with lighting, power and the false ceiling support structure itself. Pressure-testing of pipework and ductwork and final fixing of grilles and diffuser s into the finished false ceiling cause major problems and damage. The Flexiblespace system does away almost entirely with the need for horizontal air conditioning ductwork and pipework and thus reduces co-ordination problems dramatically. With correct programming it is possible to eliminate the need for multiple trade activity in areas, resulting in reduced damage to finished work and a faster overall installation programme. Operation Costs Because the Flexiblespace space system operates with very low air pressure within the floor void ( in the order of 20 pascals ).As a result, installed fan power is approximately 50 % of that required for a conventional system. The central plant operation costs are similar to those of a fan coil system with the advantage of reduced fan power on the ventilation system as a result of the reduction of horizontal ductwork and the associated resistance Maintenance Aspects Because the floor void being easily accessible and highly reduced or no duct work, the system can be far more easily cleaned. Trained maintenance staff can simply lift the floor tiles and vacuum if the need arises, but in tests the system has been shown to be generally far cleaner in operation than conventional systems. Safety Because the provision of all essential services below an easily accessible raised floor does away with the need for erection towers and high level working. Accuracy of electrical work can be much improved and many of techniques employed in the Flexible Space approach permit factory assembly of modular units further improving quality control and accuracy of installation. The removal of high level piping and the effects of flooding during commissioning are avoided not only improving safety, but also reducing possible damage to second fix trades, carpets and other finishes. Re-configurations of office spaces later in the life of the building are much more easily and safely carried out. Fit Out Contractor Work Because the Flexible Space system incorporates a raised access floor, the need for leveling screeds is totally eliminated with the tolerances being taken up by the adjustable pedestals of the raised floor. It avoids entirely the early jumble of trades fighting for space during the first fix crevassing exercise, permitting a more easily managed, faster constructed, and much tidier and safer site generally. It is an ideal system for the shell and core approach to building as no decisions on heating and cooling loads, duct layouts or power data and telecom provisions have to be made until the user requirements are defined. Potential LEED Points with Flexible Space Concept Energy & Atmosphere Optimized energy performance reduce building energy use below levels specified in ASHRAE Standard 90.1 (1-10 pts) Indoor Environmental Quality Improved ventilation effectiveness performance of UFAD system results in ventilation effectiveness greater than 0.9 (average for overhead mixing systems), as measured according to ASHRAE Standard 129-1997 (1 pt) Controllability of systems provide individual control of thermal, ventilation, and lighting systems to support improved occupant comfort, health, and productivity (1-2 pts) UFAD LEED CREDIT Points Optimize Energy Performance 3 to 4 pts Measurement & Verification 1 pt Increased Ventilation Effectiveness 1 pt Construction IAQ Management plan 1 pt Controllability of Systems 1 pt Thermal Comfort 1 pt Total Point Opportunity 8 to 9 Points LEED CREDIT RAISED ACCESS FLOOR Recycled Content Local/Regional Materials Low-Emitting Materials Total Additional Points Points 1 to 2 pts 1 to 2 pts 1 to 3 pts 3 to 7 Points
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