Balancing of a Water and Air System (PDF

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104 Record test data on the NTT test data summary sheet (Appendix 13.1). Upon completion of the test, the sheet is signed by the NTT TAB engineer and any representatives of the manufacturer, purchaser, or owner who are present. Give one copy of each authenticated test form to each person signing the test form. Instrumentation Temperature measurements shall be made with calibrated mercury-in-glass or resistance thermometers. These thermometers must be accurate to ±O.1"F with indicators or recorders graduated in increments of not more than 0.2ºF (0.lºC). All air temperature measurements shall be made with mechanically aspirated psychrometer using the type of thermometers described above. The temperaturesensitive element shall be shielded from direct sunlight or other significant sources of radiant heat. When measuring wet bulb temperature, cover the temperature-sensitive element with a wick continuously wetted with distilled water of a temperature approximately equal to the wet bulb temperature being measured. The wick shall fit snugly over, and extend at least 3/4 inches (19 mm) past, the temperature-sensitive element. The air velocity over the element shall be at least 950 (4.8 m/s) and no greater than 1050 (5.3 m/s) feet per minute. Any of the following calibrated devices may be used to measure water flow rate: • Venturi or flow nozzle 104
105 • Orifice plate • Turbine meter (traverse) • Pitot tube (traverse) • Other mutually agreed upon flow measuring devices For these devices, ensure that the proper upstream and downstream flow conditions exist. Report of Results The report of test results must include: • A description of the cooling tower, including the name of the manufacturer, the model number, serial number, orientation, and principal dimensions. • A sketch of the installation showing the location of instrumentation for measuring water flow, water temperatures, air temperatures, etc. Note any buildings, walls, obstructions, or other equipment in the immediate vicinity of the tower being tested. Give particular attention to any equipment or facilities discharging heat or vapor near the tower. • A copy of all test data sheets, plus a single summary sheet tabulating all test data averages used in calculating results and comparing them to the associated design values for the same parameter (Appendix 13.1). • A copy of all calculations made in determining the result. • A brief summary stating the test result and mentioning any areas in which the test deviated from the test parameters. • The distribution of the report shood be limited to the parties directly involved in the test. Evaluating the Test Since a cooling tower test can seldom, if ever, be conducted at both design heat load and design entering wet bulb temperature, the test procedure and method for calculating results must address several issues, including: • Establishing the maximum deviations between the design conditions and actual test conditions that can be allowed while still yielding a valid test result. • Specifying the instrumentation and procedures that must be used in order to obtain an accurate measurement of the actual cooling tower thermal performance. • Establishing a consistent procedure for comparing the measured performance to the required performance. The degree to which the test conditions may deviate from design and still yield a valid test, as set forth in the test parameters, has been accepted practice in the cooling tower 105
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Balancing of a water and air system
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3 8 TBA (Testing, Balancing and Adj
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5 Air Balancing Multiple Hood syste
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7 87 Series Loop 88 One pipe main 9
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9 Testing and Balancing HVAC A syst
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11 13. Filter frame properly instal
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13 13. Measure and record all requi
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15 15 Example 3: Find the nearest s
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17 For traverses taken in round duc
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19 Flat Oval Duct Traverses For fie
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21 Balancing Devices Volume Dampers
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23 Turning Vanes Turning vanes (Fig
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25 Balancing the VAV System The gen
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27 maximum out-side air damper for
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29 determines how much energy is in
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31 the water removing capacity of a
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33 Table 8A Dry Bulb on left, Wet B
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35 60 58 56 54 52 50 48 46 44 42 40
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37 Foot³ per 1lb Altitude 0 Feet A
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39 Table 9 C Air Density at 29.29
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41 41 Wet-Bulb (F) .0 .1 .2 .3 .4 .
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43 Table 11A Enthalpy at saturation
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45 Table 11 C Enthalpy at saturatio
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47 Wet bulb temperature____________
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49 and replacement should be shut o
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51 duct may be great; the balancing
Page 53 and 54: 53 Design below the 250°F limit (A
Page 55 and 56: 55 Differential Pressure Gauges The
Page 57 and 58: 57 Venturi The venturi is a device
Page 59 and 60: 59 Pressure Total pressure Velocity
Page 61 and 62: 61 Table 1 shows that if the coil i
Page 63 and 64: 63 adjustment of these devices is n
Page 65 and 66: 65 Grouting Motor and lubrication N
Page 67 and 68: 67 For every outside temperature ot
Page 69 and 70: 69 4. Identify the riser with the h
Page 71 and 72: 71 2. Turn the pump off 3. Close th
Page 73 and 74: 73 Net positive suction head availa
Page 75 and 76: 75 All automatic control valves mus
Page 77 and 78: 77 77
Page 79 and 80: 79 4. Read and record the actual pu
Page 81 and 82: 81 13. Record the coils design and
Page 83 and 84: 83 Air Control Air is always presen
Page 85 and 86: 85 • allow draining of all or par
Page 87 and 88: 87 Valves have linear throttling ch
Page 89 and 90: 89 to all the terminals down the li
Page 91 and 92: 91 Pump Circuits Primary-Secondary
Page 93 and 94: 93 • Evaporator: • the design a
Page 95 and 96: 95 95
Page 97 and 98: 97 Condenser • the design and act
Page 99 and 100: 99 • Each reading of liquid tempe
Page 101 and 102: 101 • Design and actual entering
Page 103: 103 differs from the average by mor
Page 107 and 108: 107 BTUH = GPM X 60 X 8.337 X ∆T
Page 109 and 110: 109 Lam = lbs. of air per minute th
Page 111 and 112: 111 When dry bulb temperature measu
Page 113 and 114: 113 GPM = FPM X Gallons per foot FP
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