Installation and Start Up

INSTALLATIONS

Just as important as selecting the right equipment for your application, providing the correct installation will ensure your cooling equipment does the job and will operate maintenance free.

Installations can be broken out into several sections.

A.   Mechanical Room and Plant Layout

Good planning will ensure your installation will go as planned and will keep costs down and on budget. It will also reduce issues relating to maintenance access and future growth.

You will need the equipment dimensions, shipping and operating weight, moving and support requirements, maintenance access points, electrical requirements (MCA, Voltage, Connection Points and necessary disconnects), city water and sanitary sewer requirements, and pipe connection sizes and locations.

B.   Setting the cooling equipment in the desired location.

Depending n the size of the equipment and the location of where it is to be placed, you may need properly sized lifts, cranes and other equipment to move it into location.

You should plan your route to ensure there are no obstructions or obstacles in moving your cooling equipment. Also ensure what are the limiting factors in the size of the cooling equipment, like doorways, loading docks, ceiling heights and the method of shipping to your facility (width and height).

C.   Locate the facility services and ensure they are adequate for the cooling equipment needs.

Find out what your power needs are and locate them in the plant relative to the cooling equipment location. Also locate both city water line size and location and make sure it is also adequate. Any draining, bleed-off of process cooling water must go into a sanitary sewer. Plan your route and your needs for sanitary sewer. 

D.  Mezzanines and Support Structures

Any equipment that needs to be located on a mezzanine or support structure requires a proper engineered analysis of the load on the support members. Placing a Cooling Tower on the roof will require an analysis of the roof structure to determine if it can support the weight.

Any support structure must be designed for operating weight, start-up torques and wind and snow loads.  

E.   Pipe Installations

The most important aspect on pipe installation is to ensure that the pipe is large enough to minimize pressure losses through the system and provide the proper flow to all processes.

A common guideline is to use the lesser of either a maximum velocity of 10 fps or a pressure loss of 10 ft per 100 feet of pipe. In longer pipe runs, you may want to adapt a lower guideline. For gravity return pipe, a slope of 1” per 10 feet is recommended and a velocity less than 4 fps.

Plan your route to avoid obstructions like cranes and support columns. Ensure that the pipe is not obstructing forklift routes or are in danger of being hit.

Calculate the weight of the pipe filled with water and make sure your roof/columns can support the weight (see structural engineer).

Common pipe material used are sch40 steel, sch80 PVC, copper, and stainless steel.

The limiting factor on using sch80 PVC is the water temperature. If your water temperature can climb to 110ºF or warmer, the pipe becomes soft and can start to sag creating weak points at the joints. Sch80 PVC has the advantage of being low cost and not rusting. However, making any repairs or changes will require at least 8 hours for the glue to set. It is recommended that isolation valves be placed on sections that can be isolated for repairs or changes without affecting the flow to the rest of the plant. If you are using plastic valves, these valves must be periodically used or they can stick eliminating their usefulness when needed. Steel ball valves or butterfly valves are an ideal replacement for plastic valves.

Sch 40 Steel can be susceptible to rust. The cooling water must have rust inhibitors and stay filled with water to reduce the impact of corrosion.

Copper pipe in small sizes ( ½” to 1 ¼” ) is an ideal replacement for small plastic pipe. PVC pipe in these sizes are not rigid enough and require additional support. Also if the process has a high return water temperature (like air compressors), you would want to avoid using plastic pipe for the return drops.

Thin wall stainless steel pipe can also be an alternative if you do not want to use steel pipe or require something more durable than PVC pipe. Thin wall stainless steel is only nominally more expensive than steel piping and can handle more corrosive water.

F.   Refrigeration Piping

Some cooling equipment requires field refrigeration piping between components. Most common is the refrigeration piping required between the outdoor condenser and the chiller.

Refrigeration piping, like water piping, must be sized to ensure minimal losses while keeping velocity high enough to ensure refrigeration oil flow. (See proper refrigeration pipe sizing charts.) Only proper refrigeration copper pipe must be used. Once completed, a vacumn is applied to evacuate any contaminants and to ensure no leaks. Traps are also a consideration in proper refrigeration piping. A qualified refrigeration mechanic is recommended for refrigeration piping.

G.   Other Considerations

Check the quality of the power being supplied. You may want to include phase protection.

Depending on the pipe installation, water hammer may be an issue. Slow actuating valves, soft starters or a water hammer arrestor are all solutions.

Check the quality of your make-up water. If your make-up water is too hard, you may want to install a water softener. Check with your local water experts.

START-UP OF COOLING EQUIPMENT

Whenever possible, the use of a factory approved start-up technician is recommended. Before start-up, make sure you have a copy of the Installation, Operation and Start-up Manual. Review that the installation is completed before start-up and a cooling load is recommended to allow the equipment controls to be adjusted for the applications. If available, a copy of the factory test sheet is also recommended.

Some things that are part of the start-up:

• Power on. For chillers, power is required for at least 8 hours before start-up.

• Rotation. For pumps and fans, power connected incorrectly will cause the pump or fan to turn backwards.

• Amp Draw. By measuring the amp draw, you can determine if a motor may be faulty or the wiring is faulty.

• Control wiring. Make sure that all sensors are wired back to the controller and that the sensors are properly installed.

• Pressures and flows. Too much or not enough flow and pressure through a chiller evaporator, a chiller water-cooled condenser, a dry fluid cooler, or a Cooling Tower can cause the unit not to operate properly.

• Refrigeration Pressures. Reviewing the refrigeration and oil pressures and comparing them to the factory test sheet will ensure the equipment is operating properly.

• Controllers timers and set points. These must be tuned for the system and should ideally be done when the process is running. A second visit may be recommended.

• Training. Authorized plant personnel and a local contractor should be part of the training. Training should include start-up, servicing, maintenance and upkeep.

SPARE PARTS

Get a list of recommended spare parts based on the maintenance upkeep. Also, get a list of how long it would take to get the major components in case of a major failure. This way, you can plan your alternatives.

Example of a Mechanical Room Layout