1. The unit shall have an Aluminum tubing system with Aluminum intermediate supports.
2. The floor of the unit shall be of Aluminum checker plate and insulated with a minimum of 2” insulation.
3. The walls of the unit shall be constructed of 2” thick polystyrene insulation with 26 gauge galvanized construction. The Color shall be white.
4. Units that are shipped in several sections shall be bolted together with neoprene gasket in between creating an air tight seal.
5. The cooling coil drain pans shall be insulated with Arm-Flex and made of 304L stainless steel double sloped allowing the condensate to fully drain out. The drain connection shall be a minimum 1 ¼”.
6. Stacked cooling coils shall have a 304L stainless steel intermediate drain pan draining to the lower drain pan with a minimum 1” drain.
7. All coil connections shall be outside the unit casing.
8. The coils shall be individually removable. Cooling coils shall be mounted on stainless steel track and heating coils mounted on mild steel angle painted with rust inhibitor paint. The coils will need to be supported when removed from the air handler.
9. Indirect cooling coils shall have cleanable return bends and seat connections.
10. Air Blenders shall be constructed of galvanized steel painted with rust inhibitor paint.
11. Pre and Final Filters shall be face load in galvanized steel frames. Suitable for AAF of Farr filters.
12. The mixing section shall have low leak parallel blade dampers constructed of Aluminum.
13. Access doors shall be hinged and lockable with Arosio style hinges, 210 Ventlok handles, locking hasp bulb gasket and round viewing window.
14. Each access section shall have a Vapor tight marine light with one common backlit toggle light switch at the filter section. The wire for the marine lights shall be run in rigid conduit.
15. The filter section shall have a Magnehelic filter gauge, Dwyer, Series 2000, Model #: 2003, range 0 to 3”wc.
16. Fan and motors shall be solidly mounted on a frame.
17. Motors shall be inverter duty motors.
18. Ahu-1 Unit shall have direct evaporative cooling. The media shall be Glas-Dek. The evaporative cooling section shall have a 304L stainless steel with a 12” deep tank and enclosure, water pump, float valve, make-up water connection, drain connection, overflow connection and quick fill connection. Sump pump shall have a disconnect.
TEST REPORT:
AHU-1 Fan Section On Dec. 5, 1998 a series of sound power measurements were performed to determine the insertion loss of the Coolbreeze inlet and discharge silencer system installed in the AHU-1 built for the Humanities and Woodbury, Arts and Sciences building.
The air handler consists of five sections housing a mixing plenum, filters, heat and cooling coils, an evaporative cooling section, and a supply air fan. For the test all sections upstream of the fan were removed. This permitted direct measurement of the sound power radiated from the inlet and discharge silencer.
The sound power was measured using the procedure outlined in ISO 10494. A total of 30 measurement stations were surveyed: 18 for the inlet, 12 for the discharge. The general arrangement is shown in figure 1. Sound pressure levels were measured with a calibrated B&K 2230 sound level meter with a 1625 1/3 octave filter set.
Sound power levels were computed in accordance with ISO 10494. The insertion losses are computed by subtracting the measured sound power from the sound power levels generated by the AXIAD II Vaneaxial FTFA-2-125-10-1770-75 supply air fan. The fan sound data was provided by Twin City. The results are summarized below.
| |
63 |
125 |
250 |
500 |
1000 |
2000 |
4000 |
8000 |
Hz |
| |
|
|
|
|
|
|
|
|
|
| Lw Fan |
97
|
106
|
108
|
110
|
108
|
101
|
97
|
90
|
dB
|
| Discharge |
|
|
|
|
|
|
|
|
|
| Lw Discharge |
80
|
84
|
89
|
84
|
78
|
73
|
70
|
68
|
dB
|
| IL |
17
|
22
|
19
|
26
|
30
|
28
|
27
|
22
|
dB
|
| Inlet |
|
|
|
|
|
|
|
|
|
| Lw Inlet |
85
|
82
|
83
|
78
|
70
|
69
|
68
|
67
|
dB
|
| IL |
12
|
24
|
25
|
32
|
38
|
32
|
29
|
23
|
dB
|
Fan Analysis:
Supply Air Flow : 70,000 cfm
External Static Pressure : 1.80” wc
Internal Static Pressure
Silencers : 0.50” wc
Direct Cooling : 0.22” wc
Cooling Coils : 0.49” wc
Indirect Cooling : 0.45” wc
Heating Coil : 0.07” wc Air Filters : 1.50” wc
Air Blender : 0.25” wc Mix Box : 0.10” wc
Total Static Pressure : 5.10” wc
Fan Selection : Axiad II Vaneaxial FTFA-2-125-5-10-1770-75 Fan Efficiency : 80 %
Fan BHP : 65.56 Bhp
Motor Size : 75 Hp per fan Premium Efficiency, 1770 RPM
Fan Analysis:
Supply Air Flow : 11,000 cfm
External Static Pressure : 1.35” wc
Internal Static Pressure
Silencers : 0.25” wc
Cooling Coils : 0.57” wc
Indirect Cooling : 0.51” wc
Heating Coil : 0.06” wc
Air Filters : 2.20” wc
Air Blender : 0.25” wc
Mix Box : 0.10” wc
Total Static Pressure : 4.59” wc
Fan Selection : Twin City Vaneaxial TCVA-24B6
Fan Efficiency : 71 %
Fan BHP : 12.64 Bhp
Motor Size : 15 Hp Premium Efficiency, 1750 RPM
|
Fan Sound Data:
|
|
Hz
|
63
|
125
|
250
|
500
|
1000
|
2000
|
4000
|
8000
|
|
Duct Lw
|
74
|
69
|
61
|
59
|
54
|
49
|
53
|
59
|
