System Installation
NOTE: All installation and maintenance are to be performed only by qualified personnel who are familiar with local codes and regulations, and experienced with this type of equipment. CAUTION: Sharp edges and coil surfaces are a potential injury hazard. Avoid contact with them.
General
1.Structure supporting unit must be designed to support both the unit and the fluid. Table 2 provides weight of fluid per gallon. Tables 3 and 4 provide unit weight and volume data. Provide suitable flashing of the roof, if this is a roof installation. For ground level mounting, a concrete pad is recommended. Mounting holes permit the unit to be bolted down to withstand wind pressures. Provide adequate clear- ance for unobstructed air flow to coils. See page 2 for Space and Location requirements.
2.Level mounting is necessary to assure proper fluid distr-
Table 2. Fluid Weight Per Gallon
Percent Glycol | Pounds Per Gallon |
0 (Water) | 8.345 |
10 | 8.395 |
20 | 8.495 |
30 | 8.604 |
40 | 8.712 |
50 | 8.804 |
bution through the coil as well as flooded suction for the pump.
3.Water piping must comply with local codes. Correct pipe sizing will help reduce pumping power and operating costs.
4.In case of doubt, consult the manufacturer for the dry cooler fluid pressure drop at the specific conditions on your job.
5.Provide sufficient valves and unions to permit easy ac- cess to parts subject to wear and possible repair or re- placement.
6.After fluid piping is completed, all joints should be leak tested.
7.Where city water makeup is required, follow local codes, making certain that disconnecting provisions are provided.
8.Select wire in accordance with nameplate data and local codes.
Piping Installation
The piping system should provide maximum leak pre- vention. Weld or sweat joints should be used where possible or tightly drawn Teflon tape threaded pipe joints should be made if needed. The fact that glycol solutions or other heat transfer fluids will leak where water will not, must be taken into ac- count.
The glycol system should not employ a pressure reduc- ing valve. This is because a slight leak would lead to dilution
of the mixture. Any refill should be controlled so as to main-
tain the proper
Table 3 shows pressure drops for various pipe sizes at flow rates commonly used with a typical dry cooler. These pipe sizes are not necessarily always correct for the run from the condenser to the dry cooler. Proper pipe size will depend on available pump head. This can be determined by subtract- ing from the total available pump head at design flow, the con- denser pressure drop and the dry cooler pressure drop. Allow some safety factor for last minute pipe fittings added to the system and for eventual fouling of the system.
a.Glycol piping requires no insulation except when fluid tem- perature will be below ambient dewpoint temperatures. Dry coolers normally produce about 70° or higher fluid temperatures.
b.Vents are required at all high points in the piping to bleed air when filling the system. If fluid coolers are at high points, vent valves should be installed at each fluid cooler. c. It is recommended that gate valves be installed on both sides of the pump to prevent loss of fluid in the event the pump should require repair or replacement.
Table 3. Pressure Loss in Feet of Water
| Pipe | Type "L" | Schedule 40 Steel | Copper Tube Head | ||
Flow | Size | O.D. | Head Ft./100 Ft. | Head Ft./100 Ft. | ||
GPM | Steel | Copper | Equiv. Length | Equiv. Length | ||
15 |
| 1 | 1 | 1/8 | 17.6 | 15.0 |
20 |
| 1 | 1 | 1/8 | 30.2 | 23.1 |
25 |
| 1 | 1 | 1/8 | — | 34.6 |
25 | 1 1/4 | 1 3/8 | 11.5 | 12.6 | ||
30 | 1 1/4 | 1 3/8 | 16.3 | 17.4 | ||
35 | 1 1/4 | 1 3/8 | 21.8 | 23.0 | ||
40 |
| — | 1 | 3/8 | — | 26.3 |
40 | 1 | 1/2 | 1 | 5/8 | 13.0 | 12.9 |
45 | 1 | 1/2 | 1 5/8 | 16.5 | 15.7 | |
60 |
| — | 1 5/8 | — | 26.3 | |
60 |
| 2 | 2 1/8 | 7.9 | 7.0 | |
80 |
| 2 | 2 1/8 | 13.7 | 12.0 | |
100 | 2 1/2 | 2 5/8 | 8.5 | 6.1 | ||
150 | 2 1/2 | 2 5/8 | 18.6 | 12.9 | ||
200 |
| 3 | 3 1/8 | 10.7 | 9.1 | |
250 |
| 3 | 3 1/8 | 16.5 | 13.7 | |
300 | 3 1/2 | 3 5/8 | 11.1 | 9.2 | ||
300 |
| 4 | 4 1/8 | 5.9 | 4.9 | |
350 |
| 4 | 4 1/8 | 7.9 | 6.5 | |
400 |
| 4 | 4 1/8 | 10.2 | 8.2 | |
Glycol Charge
The amount of ethylene glycol required depends upon the following:
a.The holding volume of the system which includes the hold- ing capacity of the condenser, the holding capacity of the interconnecting piping (Table 3) and the holding capacity of the dry cooler (see Table 3).
b.Percentage of glycol required by volume to provide pro- tection at the design minimum outside temperature (see Table 2).
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