Facility Conversion: Green Building Possibilities, and Reinvestment Conservatism - Case Study Example

 Facility Conversion: Green Building Possibilities, and Reinvestment Conservatism This study takes up facility conversion of a simple warehouse structure to commercial use. Warehouse—1 sits front portion of an Industrial Terminal situated along a hectic highway that winds an end at the conurbation toll gates. The terminal block consists of five warehouses made up of bare storage vault space which serves as depot in the retail chain, holding items for movement from the interior regions into the metropolis. Conversion of the Industrial Terminal facilities, presumes the application of radical thought: an old, simple structure can be put to use. The development intent aimed at enterprise creation for people within adjacent communities, a densely populated depressed area. The front most of five warehouses which stretches 200 meters corresponding to the highway was split in half to create roadway and traffic flow into the industrial block. Roadwork and open space completes 55% of the 22,365 square meter original warehouse footprint. One of the halves of the original warehouse, which has a floor area of 5, 804.5 square meters, is fit out as a bazaar of smaller stalls. Several corridors cut from road level through entrances 3 meters wide and 3 meters high. Along the perimeter there are a total of 19 direct exit points with a total linear opening of 54.3 meters, but this includes the number of back portion fire exits. The overall effect is practically a covered open space. Ventilation: The critical system under study (Describe the critical system and explain why it is selected) Common in a number of historic facilities is the practice of natural ventilation systems, which over several alterations of the facility use, these built in systems are compromised. By contentious views on energy usage and environmental issues, natural ventilation resurfaced as a method increasingly attractive for reduced energy consumption and acceptable ecological print (Walker, 2010). In the conversion of Warehouse—1, the ventilation system was reviewed of less importance since there were no recorded technical complications of difficulty in this category for the past 25—year warehouse operation. While this review provoked green build possibilities, the idea of facility conversion insofar also compromised capital expenditure constraint or reinvestment conservatism. The design approach is an application of the displacement ventilation theory by exhaust suction treatment, which relies heavily on the natural air movement in the vicinity. It occurs that the industrial block has a constant cool breeze from tree hedges that outline each warehouse zone. That is, a natural ventilation system depends on pressure differences to induce fresh air through a structure. Its dynamics can be caused by wind or buoyancy resulting temperature and humidity variations. To optimize these natural effects, the volume of ventilation shall depend on the configuration of openings. In effect, a natural ventilation system is appraised as a circuit, with even points given to supply and exhaust. Configuring openings between secondary partitions is a technique applied on the airflow circuit moving through a structure. If it must be noted, recent code requirements regarding smoke and fire transfer of a natural ventilation system are a designer difficulty. Assuming a stairway as the exhaust stack is a technique prevented under certain codes (Walker, 2010). The Warehouse—1 ventilation system devises a mechanical ducting layout which combines a main duct installed on the axis with low level duct droppers and transom type natural ridge ventilation installed at the roof ridges. Duct droppers are to suction in fresh air into the alleys and corridors, coming from road level entrances 3 meters wide and 3 meters in height (Magallona et al, 2008). Design of the ventilation system also considered the roof elevation which in it self presents natural air flow. Typical sections have a ground clearance of 6.2 meters at the eaves and 9.2 meters at its high points. And to minimize heat absorption, double bubble insulation R15 rating and 100% aluminium sheet covering were tucked underneath new replacements of steel roofing. The roof is mounted on a steel truss structure made sturdy by steel purloins and struts (Magallona et al, 2008). Facility Ingress: System Parameters of Occupancy (Identify the possible failure modes during the life stages, namely defect liability Period, stable operation and ageing) Getting facility occupants ready to operate concerns with the fit outs made on the cluster stall space. Adaptation of the natural ventilation system and requirement is mandated through the construction guidelines, which clearly states: no provision for exhaust air grills or flexible duct connection for occupant usage. Together with the construction of secondary partitions, electric circuitry and display space, the occupant is to provide for supplemental exhaust apparatus and devices to protect from heat accumulation and fire hazard. The Fit-out Guide is discussed with stall designers as a safeguard and to ensure the measures in place are carried out. A standard facilities management procedure is to send an inspection team for fit-out works appraisal before an operation commences. Risk assessment and rectification markings are conducted. In all, the guideline puts forward stern requirements for food based establishments but has left out details for ventilating within and around the cluster stall boutiques or food kiosks along lobbies and pathways. In facility operation: Ventilation defects At the start of the facility operation which fell during the cooler months of the year, the natural ventilation system proved adequate. However, when summer set in, consumer complaints relevant to ventilation inconveniences noticeably increased, and the count of prolonged consumer visits started to drop. It was also noticed that the tang of hot air and dust had increased food spoilage among food kiosks located in the facility lobbies. Eventually this resulted in a drop in sales performance and increased overhead expenses. This difficult situation that has stressed the occupants and escalated occupant dissatisfaction, which in return, exerted on the facilities management for tenant retention schemes and alternatives to defer litigations or disputes on unpaid dues. On immediate, fire exits along the perimeter were kept open during operating hours, and security guard posts were readjusted. A thorough investigation of the ventilation system was tasked. The failure mode effect and analysis report applies the assigned ratings or values as explained in the table 1, the appraisal results found in table 2, identify task priority and justifies the course of action. Failure Mode Effect and Analysis (source: Treanor et al, 2005) Table—1: Assigned Values / ratings for columns 4—6 Rating / Valuation Frequency / Occurrence Severity for Customer Severity of Effect Probability of Detection 1 20 Very high. Failure is almost inevitable Loss of customer Extreme May endanger machine or operator. Hazardous without warning. None Table—2: Failure Mode Effect and Analysis (source: Hensen et at, 1996) Mode of Failure Cause of Failure Effect of Failure Frequency of Occurrence (1-10) Degree of Severity (1-10) Chance of Detection (1-10) Risk Priority FO x DS x CD Design Action Design Validation 1 2 3 4 5 6 7 8 9 Actual flow rate measurements of the exhaust fan indicates an underflow by as much as 40%. The data was gathered by measuring the fan discharge and exhaust grill velocities using an anemometer. When verified, underflow is confirmed. A plate is present at the discharge outlet of the exhaust fan. Ambient temperature and internal temperature are the same. 7 10 1 70 Refer to discussion Refer to discussion Roof ridge was enclosed by metal sheet to discourage ingress of rain. Noticeable increase in the number of consumer related complaints on ventilation inconveniences and a drop in the count of prolonged visits. The tang of hot air and dust had increased food spoilage 8 10 1 80 Refer to discussion Refer to discussion Severity x Occurrence x Detection= RPN RPN or Risk Priority Number Worksheet for Sub process step (source: Derosier et al, 2002) Hazard Analysis Identify Actions and Outcomes Failure Mode: First evaluate failure mode before determining potential causes Potential Causes Scoring Decision Tree Analysis Action Type (Control, Eliminate Accept,) Actions or Rationale Outcome Measure Person Responsible Management Concurrence Frequency of Occurrence Degree of Severity Chance of Detection Single Point Weakness Existing Control measure Can detect? Proceed? Findings/ Rectification Discussion (For major modes identified at each life stage, critically comment on the possible root causes, suggest corrective and preventive measures) The facility original use as storage vaults within an Industrial Terminal operated under rigid security control, with restrictive people and vehicle movement. Following the conversion of Warehouse—1 to commercial use has altered greatly the heat, dust and air movement on the perimeter. Inside the facility, the set of food stalls at the atrium aisles added inputs of steam generated by the heating devices and electrical equipment, human warmth and increased oxygen consumption, have in all contributed to the increased latent heat. The major inspection conducted on each components of the ventilation system: air handling units, fans, ductwork, dampers, filter units, terminals, fire dampers, and controls; reports the following: There is adequate access to fans, dampers, filters./ An air leakage test was completed./ Local isolation of motor and control circuits is provided and operational./ No grounded live components exist in the control panels. Panels and switchgear are clean and undamaged. Connections are tight on bus bars and wiring. Power and control wiring is complete and in accordance with circuit diagrams. Fuse ratings are correct./ Mechanical checks on fans complete, internal links on starters correct. Starter overloads are correctly set. Dashpots correctly charged, time adjustments and levels identical. Adjustable thermal cut-outs correctly set. All cover plates fitted. Declared voltage is available on each phase. Control circuit logic and starter operation is tested before motor is rotated. Operation of direct-on-line and simple control circuits is correct at the initial start up (Mver Associates, 2010). Findings in the mode of failure recognise the actual flow rate measurements of the exhaust fan indicate an underflow by as much as 40%. The data was gathered by measuring the fan discharge and exhaust grill velocities using an anemometer. When verified, underflow is confirmed (Mver Associates, 2010). During the visual inspection, it was found that a plate is present at the discharge outlet of the exhaust fan and vents along the roof ridge were enclosed by metal sheet to disallow storm rain seepage. It occurs that the Industrial Terminal stretches across an open plain where storm winds and rains are stubborn. The coverings installed were a remedy taken by the maintenance crew without approval of the facility ventilation designers (Mver Associates, 2010). Table 3 sets the regular system setting checklist to be carried out by the facility maintenance on a weekly basis accurate recording of variations is required. Table—3: System Setting Checklist (Source: Mver Associates, 2010/ Magallona et al, 2008). Air Distribution System –Setting Prior to Fan Start All branch regulating dampers open Fan main damper 50% open All fire dampers open Automatic control dampers set for full fresh air or full recirculation Grille louvers set square to face Ceiling diffuser cones set for full downward discharge Supply and extract fans running at same time Windows and doors in the building closed Installer ready to start system Initial Start Direction and rotation speed of motor shaft is correct Motor, fan and drive are free from vibration and undue noise Motor running current is correct for sequence timing adjustments Motor running current is balanced between phases There is no sparking at the slip rings Motor and bearings are not overheating and water coolant is adequate There is no seepage of lubricant from the housing Reduced speed and motor running currents are correct on multi-speed motors Initial Run Fuses, switchgear and motor are not overstressed Motor current reaches design value or full load current, whichever is the lower Fan pressure developed does not exceed system design pressure Running—In Period Drive guard fitted Fan shaft and bearings aligned Ductwork Measurement points identified and test holes drilled Dampers installed and accessible Ductwork cleaned internally Terminal units cleaned Air filters fitted and cleaned Terminal filters fitted and cleaned Fan chamber/air handling unit clean Fire dampers open Air leakage tests completed Electrical - General Wiring complete Power available All electrical panels site check Motor insulation tests completed Fitted fuse rating OK Overload set Dashpot charged (where applicable) Starter operation OK Electrical - Fans Direction of rotation of fan/ motor shafts correct Fans and motors lubricated Fans rotates freely Drive guard fitted Fan shaft and bearings aligned Motor level and aligned Pulleys aligned Vee belts fitted, tension correct Anti-vibration mountings OK Static balance OK Building Doors and windows fitted Suspended ceiling fitted Recirculation and air transfer openings - correct size and position Structure not interfering with access to dampers and terminals Leakage test completed on builder’s work shaft and other structural air channels and plenums Keys available for all locked rooms - including plant room Implications and Recommendations (Discuss the implications to facilities management and recommend appropriate maintenance policies and State any limitations and assumptions made) The lack of proper facility ventilation has resulted in 1—consumer complaints relevant to ventilation inconveniences, 2—a drop in the count of prolonged consumer visits, 3—increased food spoilage, 4—drop in sales performance, 5—increased overhead expenses, 6—stressed angry occupants, escalating occupant dissatisfaction, 7—poor tenant retention schemes, 8—litigations on contract pre-termination, 9—more occupant disputes on unpaid dues. It can be said that the system defect has affected upon the poor facility performance and bad reputation after its conversion. The designed ventilation system does not account for these ventilation loads, especially what is attributed by the consumer volume. It is recommended that additional exhaust devices should be provided over the row of food stalls. The careful configuration of the internal space, size and placement of openings can still be adjusted. Each bazaar stall should incorporate separate supply and exhaust openings. Air vents within occupant stalls should be offset from each other for optimal air mixing. All obstructions to airflow are to be immediately dismantled; other measures to prevent water seepage during storm are to be studied. A design limitation is noted on the application of low level duct droppers should be located high above entrances to maximize stack effect. Re-computation by the designers team should be undertaken. Fan-assisted cooling strategies should be considered for cross ventilation and effective temperature drop at one tenth the consumption of electrical energy in comparison to air-conditioning systems. For prediction potential of air movement, the following are incorporated: cooling energy, fan electricity, whole body thermal comfort, local discomfort gradient, local discomfort turbulence intensity, ventilation efficiency and contaminant distribution, whole building integration and integration over time. Table—4: Activity, Persons responsible Ventilation System Rectification Procedures Activity All obstructions to airflow are to be immediately dismantled Realignment of low level duct droppers, locate high above entrances to maximize stack effect Installation if fan-assisted cooling strategies for cross ventilation and effective temperature drop Bazaar stall incorporate separate supply and exhaust openings, air vents offset from each other for optimal air mixing Target completion 3-7 days 14 days 7 days 30 days upon served notice Persons responsible Contractor Maintenance crew after design computation by designer Contractor / job out Individual occupant contractors under the supervision of maintenance crew and monitoring of the facilities leasing coordinator Conclusion Even when displacement ventilation is a demonstrated technology for various facilities, usually factories and workshops, the advantages over a mixing type of ventilation system are not so clear when facility applications are altered. Implications of facility alterations should be thoroughly studied such that the capability to improve indoor air quality while simultaneously reducing energy demand can be achieved. References Derosier, J. Stalhandske, E., Bagian, J., and Nudell, T. (2002), Using failure mode and effect analysis. USA: The VA National Center. Hensen, J., Hamelinck, J. and Loomans, M. (1996), Modelling approaches for displacement ventilation in offices. Yokohoma: 5th International Conference on Air Distribution. Crow, K. (2002), Failure modes and effects analysis. New York: DRM Associates. Mver Associates (2010), Inspection Report Ref: MV2803-020110. Manila: Baesa Industrial Terminal. Magallona and Aromin Designs (2008), Project Descriptive. Manila: Baesa Industrial Terminal. Treanor, K. and Ollerton, B. (2005), Process of failure modes and effect analysis. Mississippi: Northrop Grumman Corporation. Walker, A. (2010), Natural Ventilation. Washington: National Institute of Building Sciences Zhang, T., Lee, K., and Chen, Q. (2009), A simplified approach to describe complex diffusers in displacement ventilation for CFD simulations. China: School of Civil and Hydraulic Engineering. Read More