A circulating cooling system (also known as a chilled water system) is a closed-loop, temperature-controlled water system that uses water as a heat transfer medium to transport heat away from a regulated space or process. These systems use standard compressed refrigerants or evaporative cooling in pipes or coils to cool water. The cooling water is pumped through the system piping to the final heat exchanger/cooling coil. The surface of the heat exchange coil is cooled by chilled water.

In air-to-air heat exchange, fans move air through coils, removing heat from the air and providing cooling air for building Spaces or processes that are being cooled. In the direct exchange chilled water cooling process, heat is removed from the process through direct contact between the heat exchanger and the product being cooled, whether liquid or solid material.

Isolating these systems is important for satisfactory operation. Fiberglass insulation has a long and successful history as the most commonly chosen insulation material for chilled water systems. The areas that typically need insulation in a chilled water cooling system are the barrel body and head of the cooler, the pump, the pipe and the piping specialty. Insulating these components can achieve: energy saving equals reduced operating costs, reduced machine usage and wear equals reduced operating costs, improved system efficiency, happier occupants, condensation control equals reduced problems caused by moisture, and so on

1, the science of condensation formation in mechanical systems

Water vapor molecules that are always present in the atmosphere are attracted to any cooler surface, where they condense to form liquid water. Warmer water vapor molecules transfer energy to the cooler surface. These water molecules gather on a cold surface in sufficient quantities to form a liquid that sits on the surface of any structure that does not allow water vapor to pass through.

2. Basic knowledge of condensation control

Two key parameters in the installation must be met to control condensation formation on mechanical systems, including pipes, pipes and equipment.

First, the total amount of insulating material used must have sufficient resistance to the flow of thermal energy to keep the surface temperature of the insulating system above the atmospheric dew point, regardless of the atmospheric temperature, relative humidity, and dew point (i.e. condensation formation).

Second, the adiabatic system must include a material classified as a vapor retarder, either a separate system used only as a vapor retarder, or an adiabatic material with vapor retarder properties. A steam retarder is a material that resists the penetration of all or a large number of water molecules in the form of steam. If the insulation system does not provide sufficiently low thermal conductivity and low water vapor permeability, condensation can still form.

3, pipe and pipe control condensation options

Different combinations of two key insulation system components (insulation and finishing systems) can be used to achieve the goal of preventing condensation from forming on the surface of the insulated mechanical system.

Fiberglass insulation materials have different heat flow rates, depending on the density and thickness of the product. Denser, thinner fiberglass insulation can provide just as much insulation value as thicker, less dense fiberglass insulation. The finishing systems used for mechanical insulation have different levels of emissivity, which changes the energy flow rate of the system. High reflective finishes require thicker glass fibers than non-reflective finishes for the system to work properly. This is an important consideration when selecting system components, combined with field conditions that may limit choice.

4, the shortcomings of frozen water insulation installation effect is not good

Poor installation of chilled water insulation systems can lead to negative effects, such as:

1) Damage to assets, including damage to building finishes and moisture in building components, requiring corrective costs;

2) Lead to excessive energy consumption, increase operating costs;

3) Lead to excessive wear of the machine and increase maintenance costs;

4) It may lead to mold growth in the facility and require repair costs;

5) Premature removal and replacement of insulation devices will result in repeated costs;

5, the key to effective installation

Some key details need to be taken care of in the thermal insulation installation of chilled water systems: the correct thickness for the worst expected temperature, relative humidity and air flow combination. Many times, the wrong thickness is chosen for a variety of reasons. Longitudinal joints/joints, butt joints/joints, fitting insulation, hanger insulation and steam sealing are the most common features of thermal insulation systems that require special attention. Getting each of these details right is just as important as the others.

6, the importance of steam retarder and correct installation

Water vapor finds its smallest entry point through damaged vapor retarding materials or systems. The steam retarder system on the insulation unit is the key to successful installation. As mentioned earlier, the right insulation thickness combined with a well-executed steam retarder makes the use of fiberglass insulation in chilled water the preferred option.

Now available in Utsen Fiberglass pipe insulation products offering 0.01 perm water vapor permeability, this product is a multi-layer flexible laminated composite, usually composed of foil, paper, film and reinforcement material, to seal the joints between the pipe insulation layers, completing the sheathing system.

Appropriate steam DAMS or steam seals must be installed, including all terminals. As part of or prior to coating the protective finish, the accessory insulation material must be treated with a vapor blocker. Seal the throat joints and circumferential edges of the PVC fitting covers to all joints using PVC steam seals or adhesives/solvents. Any damage or gaps in the vapor retarder material must be repaired.

7, applicable to the principle and practice of industrial products and process cooling

When thinking of chilled water devices, most people think of HVAC comfort cooling systems in commercial buildings. Many industrial processes also use chilled water to cool products or maintain process temperatures. These same principles of fiberglass insulation apply to industrial chilled water systems as well as HVAC chilled water systems.

Fiberglass insulation forms the basis of an efficient and economical system for insulating a wide range of chilled water cooling systems. Following good installation practices, especially those related to the steam retarder function, is key to success, and properly specified and installed fiberglass systems have been used in chilled water systems for many years.