Building Services, and Sustainable Engineering: Plant Maintenance - Essay Example

? Building Services and Sustainable Engineering: Plant and Maintenance Preface Due to the aim of the assignment, in the paper we should predict the behavior of items of plant operating in two phase processes, evaporation and condensation; with an assistance of mathematical model, we will simulate the items of plant, specifying maintenance for building services plant; ultimately, it must be provided commission of building services systems. Accordingly, our objectives as well as expected learning outcomes are: to create a plant mathematical model based on the prediction of the plant behavior running in two phase processes; further on, the heating and cooling loads will be calculated to estimate the energy consumption, operating coasts, and the life lengths of the system; finally, we will test the proposed plant due to the general procedure of CIBSE or ASHRAE guides. As for expected learning outcomes, we will be able to size heating and cooling plant; also, it will be possible to predict summertime temperature and design systems to reduce overheating risks; furthermore, it is needed to estimate the preheating period required and annual energy use and carbon emmission; finally, we would prepare effective preventive maintenance schedule, considering innovative systems. Building Renovation Case Study Initially, we need to represent client's requirements, task, and marking criteria. Accordingly, as for the client's reauirments, the amount of outdoor air is required to the first and second floors of the given building which needs renovation. (Temperature, relative humidity, wind speed, and wind direction are given properly in the Climate Record Data table.) Additionally, concerning the task, it is strongly recommended to review building regulation, suggesting some constructions which will meet building regulations for the room; then, it is needed to estimate the operative temperature which is likely to occur in each of the rooms, calculating the cooling and heating loads for the building to keep the room operative temperature at a comfortable level; moreover, we have to select a heating and cooling plant capacity based on the design loads, showing the processes on psychometric charts for the summer season and proposing a maintenance procedure with estimation of a life cycle cost for the building owner to keep the system running. Therefore, to solve Problems 1 and 2 as they were represented by Figures 1 and 2, we might firstly state the most relevant points of the assignment: we have a task to reconstruct one of the two-storey buildings, which has a flat roof; running four production lines and having the width and length of respectively 150 and 100 metres, this first floor is shown in Figure 1; from the other perspective, as for the second floor, it has 60% of walls facing toward the South and East, being triple glazed with 6.4 mm air space, along with each window dimension as being estimated like 1.5x1x0.15 (respectively, its width, height, and thick); hovewer, the annual electricity supply fee to run the building is $20 per kilowatt, and the energy price is expected to increase 10% per year. So, due to the very hot temperature in the apartments during the summertime, it was suggested by the management that the building needs renovation concerning walls, windows, and ceiling: certainly, it must have been done according to Building Regulations' requirements. To conclude with, we are asked to estimate the capacities of the heating and cooling (see Appendix 1), keeping in view the sustainability and CO2 emmision issues. Review Building Regulation and Suggest the Constructions Which Will Meet Building Regulations for the Room We will start this sub-chapter with room conditions, then, will be analyzing current building regulations, being finally able to answer why the management wishes to renovate the building by reconstructing the walls, windows, and ceilings accordingly to the current building regulations, keeping in view the sustainability and CO2 emission issues. As we know, task is to reconstruct one of the two-storey buildings, and the building has a flat roof. Specifically, width and length of the building, on its first floor, are 150 and 100 metres respectively, whereas on the second floor 60% of walls, facing toward the South and East, are triple glazed with 6.4 mm air space; moreover, each window dimension on the second floor has 1.5m.X1m.X0.15m (respectively, width, height, and thick). Furthermore, annual electricity supply fee to run the building is $20 per kilowatt, and the energy price is expected to escalate 10% per year, as it was stated by the ordinary conditions of the assignment. Then, due to the building regulations on glazing and electrical safety, “minimum requirments for the provision of safety glazing to protect against impact hazards, and for glazing manifestation (e.g. warning markings in large panes)”, along with “new rules for electrical safety in the home, the garden, and outbuildingds” which need to be taken into account. (Threlkeld, 1970) Based on some building regulations (ASHRAE Handbook, 1996), we could admit that some parametres are not allowed by the regulations, and these mistakes allow us to renovate walls, windows, and ceiling because of extreme summertime hot. In fact, there are three facts which might disturb a lot. Firstly, 60% of walls facing toward South and East are triple glazed with 6.4 mm air space; then, each window dimension is too large, as well as annual electricity supply fee to run the building, being evaluated around $20 per kilowatt. So, according to the current building regulations and requirments for the hot reduction from the management, such relevant steps must be proposed: initially, average percentage of walls facing toward South and East must be actually below 60% rate, and, definitely, not being triple glazed with 6.4 mm air space: so, average percentage of walls being triple glazed needs to be reduced, as well as single parameters of each window which can be regarded as disproportionally large ones. Ultimately, electricity should flow more economically in order to increase fire defence of the building and to decrease costs for supplying with it. In the forth-coming chapters we will propose our own variants of salvation of these overall design and engineering construction problems concerning hot reduction within the building totally. Estimate the Operative Temperature Likely to Occur in Each of the Rooms Accordingly, to find a simple measure for the heat loss from a person and a simple measure for the thermal indoor climate, the operative temperature could be calculated (Mcquiston, Parker, and Spitler, 2000), with the estimations based on formula: To = A x Ta + (1 – A) x Tr, where To is the operative temperature [C]; Ta is the air temperature [C]; Tr is the mean radiant temperature [C]; A is a factor accordance to the relative air velocity (A=0.5 for var=0.2 m/s, A=0.6 for var= 0.2-0.6 m/s, A=0.7 for var= 0.6-1.0 m/s) (Holman, 2002). Therefore, To = 3.5 x 40 + (1 – 3.5) x Tr, and Tr = F(P—1) xT1+F(P—2) xT2+........+F(P—n)xTn, where Tr is the mean radiant temperature for a person [?C]; Ti is the temperature of surface i [?C]; and F(P-i) is the angular factor between a person and surface i [–] (Ozisik, 2000). So, as it was stated by researcher, “the angular factor between a person and a rectanglr on the wall, floor or ceiling is far more complicated calculating,” since there is is no exact formula for “calculation of the angular factor between a person and a surface.” (Threlkeld, 1970) Calculate the Cooling and Heating Loads for the Building to Keep the Room Operative Temperature at a Comfortable Level … . Select a Heating and Cooling Plant Capacity Based on the Design Loads, Showing the Processes on Psychometric Charts for the Summer Season … . Propose a Maintenance Procedure and Estimate a Life Cycle Cost for the Building Owner to Keep the System Running … . Estimation of Behavior of BSE Plants To calculate the transfer units as defined in the following equations, we need firstly to provide the very conditions, that is: water is to be cooled from 37.78°C (100°F) to 29.44°C (85°F) in a counter flow cooling tower when the outside air has a 23.98°C (75°F) wet bulb temperature, and the water to air flow ratio is 1.0. Definitely, using the formula N = UAmV/?wcw = ? (hsa - ha) -1 dt, where U is the overall mass-transfer coefficient between the water and air (kg/s-m 2 ); Am is mass-transfer surface area per volume associated with U (m 2 /m 3 ); then, Mw is mass flow rate of water through the tower (kg/s); Cw is the specific heat of water (kJ/kg-°C); hsa is enthalpy of moist air at temperature t (kJ/kg); ha is enthalpy of moist air at temperature t (kJ/kg); t is water temperature at a particular location in the tower (°C); L is a design length of the cooling water. Therefore, … . Conclusions To conclude with, we need to put an emphasis that we estimated the operative temperature that was likely to occur in each of the rooms; also, we calculated the cooling and heating loads for the building to keep the room operative temperature at a comfortable level; then, we selected a heating and cooling plant capacity based on the design loads, showing the processes on psychometric charts for the summer season; ultimately, we proposed a maintenance procedure, estimating a life cycle cost for the building owner to keep the system running. Also, we have provided some theoretical calculations concerning estimation of behavior of BSE Plants in order to estimate the behaviors of the Building Services Plant. From the other perspective, as for the calculation of heating and cooling loads, psycometric charts for the summer season, and a maintenance procedure with estimation of the life cycle costs, etcetera, it is vital to use the appropriate data constantly from the client's requirments (especially the amount of outdoor air) along with data from the climate record data (especially relative humidity, wind speed, and wind direction) and Appendix 1: HVAC System Data, obtaining to show all available HVAC systems for air-conditioned rooms when the operation, maintenance, and repair costs are annually raised at the rate of 12%. However, the exact estimations of behavior of BSE plants, as well as cooling and heating loads for the building, heating and cooling plant capacity based on the design loads, and a maintenance procedure with estimation of life cycle costs appear to become rather uncertain due to our unability to provide the inavitable calculations of relatively high rate of complexity. References ASHRAE Handbook, HVAC Systems and Equipment Volume. American Society of Heating, Refrigerating, and Air-Conditioning Engineers, Inc. Atlanta: GA, 1996. Holman, J.P., 2002. Heat Transfer, New York: McGraw-Hill. Mcquiston F.C., Parker J.D., and Spitler J.D., 2000. Heating, Ventilating, and Air Conditioning – Analysis and Design, London: Wiley. Ozisik, M. N., 2000. Heat Transfer: a basic approach, New York: McGraw-Hill. Threlkeld, J.L., 1970. Thermal Environmental Engineering, London: Prentice-Hall & Englewood Cliffs. Read More