Pumped Systems - Building Services and Equipment - Past Exam Paper, Exams of Materials science

Download Pumped Systems - Building Services and Equipment - Past Exam Paper and more Exams Materials science in PDF only on Docsity! Cork Institute of Technology Bachelor of Engineering in Building Services Engineering – Stage 2 (EBSEN_7_Y2) Summer 2008 Building Services and Equipment II (Time: 3 Hours) Instructions Answer FIVE questions, All questions carry equal marks. Examiners: Mr. Will Bateman Dr. Mervyn Smyth Mr. Declan Leonard Reference Material to be provided. Question Location 1. Table 1, 2, 3and 4 – Hot and Cold Water Pipe Work Design Q1 (attached) 2. CIBSE Table 4.18 Page 4-40 – Water 100C in Copper Pipe Q1 (attached) 3. Hot and Cold Water Design Spreadsheet Q1 (attached) 4. CIBSE Table C4.11, Page 4-15 – Water 750C Med Grade Steel Q3 (attached) 5. Table 4.36. –Velocity press loss factors for pipe fittings. Q3 (attached) 6. Ductwork Design Sheet Q5 (attached) 7. CIBSE Fig C4.2 – Pressure Drop for air in galvanised circ ducts Q5 (attached) 8. CIBSE Table 4.42 – Velocity pressure of air. Q5 (attached) 9 Table 4.35. –Velocity press loss factors for duct fittings. 2pages Q6 (attached) Q1 (a) You have been asked to design the water storage and distribution for a new primary school. The school will consist of 4 identical 2 storey blocks each catering for 100 pupils. Using the table below calculate the volume of cold water which should be stored on site. [4 marks] 2 (b) The hot and cold water distribution pipe work within this school building could be designed as a gravity system or a pumped system. Different target water flow velocities can be applied to gravity or pumped systems. List one suggested target water flow velocity for each type of system. [2 marks] (c) Life cycle cost is becoming more important in the design of all building services systems. Explain the term life cycle cost. Describe how particular design choices can effect life cycle cost when sizing a pumped hot or cold water systems. [4 marks] (d) Fig 1.1 shows the cold water pipe work layout for a changing room area within the new school. Determine the most economical diameters of the copper distribution pipes labelled AB, BC, etc. Assume a continuous demand due to peak usage. Reference - Tables 1, 2, 3 and 4 – Hot and Cold water pipe work design. Reference –Table C4.19 Page C4-40 – Flow of Water at 100C in Copper Pipe. Fill in the relevant data on the Hot and Cold Water design spreadsheet supplied. Put your name on the sheet and attach the sheet to your answer book. [10 marks] 13/15mm Bib taps 4 x Wash Basin 13/15mm LP Ball 15mm Isol v/v 4 x W.C 19 00 75 0 FD 2500 2500 3000 GEC A B DIMENSIONS SHOWN ARE IN MM. PLEASE SHOW ALL CALCULATIONS PLEASE WRITE YOUR NAME ON ALL SHEETS. FIG 1.1 COLD WATER PIPEWORKSTORAGE TANK VALVE STOP H 15mm Isol v/v 60 00 4 x Shower (Gravity Feed) Float v/v 5 Q3 (a) A two pipe LPHW central heating system is shown in Fig 3.1. Radiator 1 is associated with pipe section 1, Rad 2 with pipe section 2, etc. Assume that the heat output listed already allows for a fixed percentage for heat loss from the exposed pipe work, i.e. no need to add on an additional 5% for heat loss from the insulated pipe work. Under the design conditions shown, find the following for pipe sections 1, 2, 3 and 4. (i) Pipe diameter, (ii) Pressure drop per meter - dPl, (iii) Length equivalent factor - le. NB: it is not necessary to compare the actual heat loss from the pipe work with the theoretical value estimated. Table C4.11 Page 4-15 attached for reference. [12 marks] Table C3.14 – heat emission from horizontal steel pipe – Not required. (b) For the same LPHW circuit the actual pressure drop through pipe sections 1, 2 and 3 has already been calculated as follows. Pipe section 1 – 32760 Pa, Pipe section 2 – 49450 Pa, pipe section 3 – 17110 Pa. For pipe section 4, find the effective pipe length of the straight pipe plus fittings. From this find the total pressure drop for pipe section 4. Use this to derive a pump duty for the circulation pump in this circuit. Bends are welded mild steel elbows and isolation valves are gate valves. Table C4.36 attached for reference. [8 marks] 6 Q4 (a) Domestic heating controls are used to achieve and maintain the desired room air temperatures and to minimise the amount of fuel needed to achieve those room air temperatures. Describe what equipment you would recommend and how you would go about using that equipment to achieve these objectives for the two storey domestic dwelling shown below. NB: reproduction of this sketch is not necessary, written description sufficient. [8 marks] LIVING GROUND FLOOR PLAN UP HALL ROOM SITTING UTILITY ROOM DINING KITCHEN STUDY / BED 5 TOILET BLR BOX ESB METER ROOM ROOM W AR DR O BE 90 0 TR AY 12 00 X EN.S TAB LE EN.S H.P BATH MASTER BED 1 BEDROOM BED 4 W AR DR O BE DOWN TA BL E OPEN TO BELOW LANDING FIRST FLOOR PLAN BED 2 GUEST BEDROOM BED 3 TA BL E WARDROBE WARDROBE Figure 4 (b) Building Management Systems ( BMS ) are used to control heating and cooling in large commercial and industrial buildings. The BMS is used extensively to control 3 port valves. With the aid of a neat sketch, show a cut away view of a 3 port valve showing how the valve plug is positioned relative to the 3 ports. [6 marks] (c) The three port valve can be used in two different arrangements when controlling the temperature of a heat emitter. Draw a neat sketch of both arrangements / modes and briefly explain how each mode differs in the way it controls the room temperature. [6 marks] 7 Q5 (a) Computer Lab – Room A285 is to be refurbished in CIT. There may be up to 40 people using the room at any one time. Using a fresh air supply criteria of 8 lit / sec / person establish the required fresh air supply into this room. [2 marks] (b) Using the overall room dimensions 12m x 6m x 2.4m shown on the sketch in Fig 5.1 below, establish the air change rate for this room.i.e.12m, 6m, 2.4m. [4 marks] (c) List an acceptable range of air flow velocities which may be used in ventilation duct work. Suggest a target air flow velocity in any ventilation ducting that may be installed to bring fresh air into this room. Explain why you have chosen that velocity target. [4 marks] (d) Using the proposed ductwork layout shown in Fig 5.1 below, size the extract air ductwork using the constant pressure drop method, use a target pressure drop of 0.6Pa/m. Use the ductwork design sheet attached to establish the most economical circular duct size for the layout shown. Ensure you put your name on the sheet and attach the sheet to your answer book. Fig C4.2, Table C4.42 and Table C4.35 Page 1&2 attached as ref. [10 marks]