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Air cooled chillers use the refrigeration cycle to produce chilled fluid, typically water or a mix of water and glycol. This chilled fluid is then capable of removing heat from machinery, food, or other equipment and continuously run back through the chiller.

Air Cooled vs. Water Cooled Chillers

Air cooled and water cooled chillers have many things in common. They both belong to the same vapor compression chilling family, and they both use an electronically driven mechanical compressor to force refrigerant around the system. In fact the majority of their components are the same. The main difference between the 2 is how unwanted heat is ejected from the system.  Water cooled chillers pump water through a sealed condenser and disperse it through a cooling tower. Air cooled chillers use fans to force cool air across the condenser.

A water cooled chiller’s cooling tower and pump take up more space than the fans in an air cooled chiller. Because of this main component difference, air cooled chillers have a more compact footprint. Cooling towers are also more expensive to maintain, making air cooled chillers the clear lower maintenance option. In general, air cooled chillers have significantly lower upfront costs as well.

Components of Air Cooled Chillers

Compressor

The compressor provides the driving force for moving the refrigerant around the system.  There are four main types of compressors. Three of them (screw, scroll, and reciprocating) use positive displacement to create pressure, and the fourth (centrifugal) creates pressure with centrifugal force.

Condenser

The condenser is a configuration of horizontal pipes through which hot refrigerant runs. Air is moved across the condenser to dissipate unwanted heat.

Condenser Fans

These fans represent the main difference between air cooled and water cooled chillers. As they move air across the condenser, unwanted heat is removed from the system so the cycle can start all over again.

Expansion Valve

The expansion valve expands the refrigerant from liquid form to gaseous form before it enters the evaporator.

Evaporator/Heat Exchanger

In the evaporator, chilled water is created when unwanted heat is drawn into the refrigerant before it is fed into the condenser.

Filter Drier

The filter drier protects your chiller by removing unwanted contaminants and moisture from the system. They do get clogged with repeated use and need to be replaced regularly.

Air Cooled Chilling From North Slope Chillers

Air cooled chillers house all of these components in a single space saving cabinet that is easily incorporated into any operation. Air cooled chillers from North Slope Chillers are portable and easy to use no matter the application. Our chillers excel at cooling lasers, welders, food storage containers, lab equipment, printers, EDM, hydroponic reservoirs, plastic injection molds, fermentation tanks, server rooms, oil extraction equipment…the list goes on and on! Contact North Slope Chillers to find the right air cooled chiller for your needs at (866) 826-2993 or [email protected].

Centrifugal chillers are typically the most economical chiller to use for cooling sizable buildings. They can efficiently produce a high flow rate and are ideal for larger applications. Centrifugal chillers usually have fewer moving parts than other varieties, and with less mechanical friction are more cost effective to maintain. Some cooling applications require greater portability and lower cooling temperatures than centrifugal compressors are built to produce. Their range of usefulness is limited by their large footprint and emphasis on volume instead of cooling power.

Types of Compressors

Positive Displacement Compressors

There are 4 main types of compressors found in vapor compression chillers: scroll, screw, reciprocating, and centrifugal.  Scroll, screw, and reciprocating compressors work through the process of positive displacement. Positive displacement compressors capture gases into a chamber, then reduce the volume of the chamber to cause compression.

Centrifugal (Kinetic) Compressors

These compressors use centrifugal force to turn kinetic energy into pressure. As gases enters the compressor, they are spun radially outward causing them to compress. Centrifugal force then throws the gases back out at a high velocity.

Centrifugal Force

Centrifugal force is an inertial force that acts on all objects rotating around an axis. It is the same compressing force you feel in many carnival rides or when you make a u-turn in your car, and is a very energy efficient method of compression.

A common centrifugal force experiment is to take a bucket of water and, with a straight arm, quickly rotate at the shoulder and swing the bucket upward and around a vertical loop. Centrifugal force compresses the water enough to counteract gravity so that even when the bucket it upside-down, the water stays in the bucket.

Centrifugal compressors take this force one step further with expelling the gases out at a specific point in the radial spin. This is best explained by imagining a ball at the end of a rope. If you were to swing the rope vertically around an axis (your hand) at a high velocity, centrifugal force will be pulling the ball outward. When that rope is released at the correct angle, the ball will exit the loop at a high speed and be hurled upward.

Parts of a Centrifugal Compressor

Basic centrifugal compressors are made from 4 main components: an inlet, impeller, diffuser, and collector.

Inlet

An inlet is a pipe in which the gases enter the compressor. Some inlets are open and simple, others contain valves or channels to direct flow in the direction needed inside the compressor.

Impeller

Impellers are the key component in generating centrifugal force. Rotors with carefully angled vanes or blades spin and raise the energy of the gases inside the compressor.

Diffuser

These high velocity fluids or gases are thrown outward and hit the diffuser which converts the kinetic energy into pressure by reducing the velocity.  Diffusers accomplish this in a variety of ways, such as channels or wedged vanes for the high velocity substance to compress against.

Collector

The collector is an empty chamber which gathers the flow coming out of the diffuser. The shape of a collector varies greatly but typically resembles a nautilus shell so it can collect around the entire radius of the impeller and diffuser. Collectors can also sometimes contain valves or other components.

Chilling Solutions

Industrial chillers and their components should be carefully selected so they are ideally situated for the application at hand. Understanding the function and benefits for different compressors can help you find a tailor made chilling solution for your needs.

Chilling Solutions From North Slope Chillers

North Slope Chillers offers easy to install, portable chillers that won’t disrupt your current setup. Contact us to find the chilling solution for your needs:

(866) 826-2993 [email protected]

What Are Cooling Chambers?

Cooling chambers are anodized aluminum storage racks that are specifically designed to store and transfer sensitive liquids. They have grids of wells that can safely house configurations of different sized test tubes and vials while they are being chilled. The anodized aluminum prevents corrosion and ensures cold temperatures are sustained in each lab sample.

What Are Cooling Chambers Used For?

Aluminum cooling chambers are used in many different laboratory applications as samples are put through a process called thermal cycling.

Thermal Cycling

Clinical laboratory research requires meeting exact temperatures for exact periods of time in order to produce accurate results. Thermal cycling exposes reactants to repeated cycles of heating and cooling to start, stop, suspend, or stabilize chemical reactions. One of the most common uses for thermal cycling cooling chambers is a method called PCR (Polymerase Chain Reaction).

PCR

PCR was developed in 1993 by Kary Mullis as a precise method for copying strands of DNA. DNA strands are suspended in tubes of liquid and housed in aluminum cooling chambers while they are thermally cycled. The DNA goes through anywhere from 20-40 different temperature stages causing it to melt, elongate, bind, and reform as needed. Thermal cycling for PCR has become critical to many different industries from medical research to forensic analysis.

How Are Cooling Chambers Thermally Cycled?

Cooling chambers can be housed in many different types of containers as they hit their required temperature targets. These containers range from large fridge-like chambers that are specially calibrated for thermal cycling to small foam ice-chest sized boxes with cooling blocks that can be stored on a counter top.

Total Temperature Control From North Slope Chillers

North Slope Chillers offers portable, easy to install chillers that won’t disrupt your current setup. For more about our temperature control products, contact us: (866) 826-2993 or [email protected].