air handler coils, ac condenser unit, evaporator

An air conditioning system is widely considered to be an essential appliance in the entire country of Singapore. From household residences to different industry offices, this dependable cooling machine is needed by many to survive the warm weather and increase total productivity. While it may be a simple piece of cooling machinery on the outside, the internal parts that make up an aircon are all sorts of complicated.

Enter the condenser coil, a device that transfers heat from one medium to another. The condenser coil is just one of the many components that allow an aircon to remove warmth from the outside and vent it inside. Not to be confused with the evaporator coils responsible for indoor air, which are usually located indoors compared to the condenser coils’ outdoor unit setting.

How Does An Air Conditioner Condenser Coil Work?

For you to understand how an aircon condenser coil works, it is important to point out its main function first: a place where all the warm air gets removed. The aircon condenser coil is responsible for the heat transfer process. This is where much of the absorbed heat is transferred from your house and into the open outdoors.

An AC condenser coil is made up of different tubes that are filled with refrigerant liquid. In order for it to fully function, a chiller inside the coil cools the fluid and moves through the condenser tubing. Once this process is done, it’s further converted into gas. Afterwards, the converted gas is distributed through the entire cooling system.

After this conversion process is done, the refrigerant then releases the heat and returns to a liquid state. From here, the cycle will continue in a closed system.

Looking into a condenser coil closely throughout this process will also show you the process of the refrigerant vapor. This vapor is usually processed through a cycle of warm trading loop, allowing it to be turned into a fluid and making the heat from the cold indoor zone get dismissed in the process.

From this condenser coil process, the aircon is able to provide the quality breeze that every homeowners and office workers expect.

Caring For Your Air Conditioning Condenser

It shouldn’t take an air conditioning expert to know that AC machines deserve  proper and regular check-up and maintenance. Whether you’re having problems with your overall AC system, condenser unit or evaporator coil, knowing when to call for help is very important. For your machine to continue performing at its absolute best, you need to schedule frequent appointments with an aircon technician. If done regularly, this allows you to save a lot of money by preventing any bigger performance issues down the line.

Heat Exchangers (Coils)

CONDENSER COIL

Heat Exchanger (Coils) for Condensers

Condenser coil or heat exchanger in HVAC/R system cools up the substances (i.e. refrigerants) and in turn let out latent heat from the system.

In a typical A/C system, the condenser coil is the one located outdoor letting out heat, while the other coil–the evaporator coil–is located indoor chilling the space.

Our condenser coils can be customized and designed to match any system requirements–air conditioning, refrigeration, or industrial processes. Circuiting can be matched to heat transfer volume requirements and coil face area can be split to your particular requirements.

Available Tube Material

  • Copper
  • Aluminum
  • Copper nickel

Additional tube material available upon request

Available Fin Material

  • Copper
  • Precoated aluminum
  • Copper nickel

Condenser (heat transfer)

In systems involving heat transfer, a condenser is a heat exchanger used to condense a gaseous substance into a liquid state through cooling. In so doing, the latent heat is released by the substance and transferred to the surrounding environment. Condensers are used for efficient heat rejection in many industrial systems. Condensers can be made according to numerous designs, and come in many sizes ranging from rather small (hand-held) to very large (industrial-scale units used in plant processes). For example, a refrigerator uses a condenser to get rid of heat extracted from the interior of the unit to the outside air.

Condensers are used in air conditioning, industrial chemical processes such as distillation, steam power plants and other heat-exchange systems. Use of cooling water or surrounding air as the coolant is common in many condensers.

History

The earliest laboratory condenser, a “Gegenstromkühler” (counter-flow condenser), was invented in 1771 by the Swedish-German chemist Christian Weigel.[2] By the mid-19th century, German chemist Justus von Liebig would provide his own improvements on the preceding designs of Weigel and Johann Friedrich August Göttling, with the device becoming known as the Liebig condenser.

Principle of operation

A condenser is designed to transfer heat from a working fluid (e.g. water in a steam power plant) to a secondary fluid or the surrounding air. The condenser relies on the efficient heat transfer that occurs during phase changes, in this case during the condensation of a vapor into a liquid. The vapor typically enters the condenser at a temperature above that of the secondary fluid. As the vapor cools, it reaches the saturation temperature, condenses into liquid and releases large quantities of latent heat. As this process occurs along the condenser, the quantity of vapor decreases and the quantity of liquid increases; at the outlet of the condenser, only liquid remains. Some condenser designs contain an additional length to sub cool this condensed liquid below the saturation temperature.

Countless variations exist in condenser design, with design variables including the working fluid, the secondary fluid, the geometry and the material. Common secondary fluids include water, air, refrigerants, or phase-change materials.

Condensers have two significant design advantages over other cooling technologies:

  • Heat transfer by latent heat is much more efficient than heat transfer by sensible heatonly
  • The temperature of the working fluid stays relatively constant during condensation, which maximizes the temperature difference between the working and secondary fluid.

Examples of condensers

Surface condenser

surface condenser is one in which condensing medium and vapors are physically separated and used when direct contact is not desired. It is a shell and tube heat exchanger installed at the outlet of every steam turbine in thermal power stations. Commonly, the cooling water flows through the tube side and the steam enters the shell side where the condensation occurs on the outside of the heat transfer tubes. The condensate drips down and collects at the bottom, often in a built-in pan called a hotwell. The shell side often operates at a vacuum or partial vacuum, produced by the difference in specific volume between the steam and condensate. Conversely, the vapor can be fed through the tubes with the coolant water or air flowing around the outside.

Chemistry

In chemistry, a condenser is the apparatus which cools hot vapors, causing them to condense into a liquid. Examples include the Liebig condenserGraham condenser, and Allihn condenser. This is not to be confused with a condensation reaction which links two fragments into a single molecule by an addition reaction and an elimination reaction.

In laboratory distillationreflux, and rotary evaporators, several types of condensers are commonly used. The Liebig condenser is simply a straight tube within a cooling water jacket, and is the simplest (and relatively least expensive) form of condenser. The Graham condenser is a spiral tube within a water jacket, and the Allihn condenser has a series of large and small constrictions on the inside tube, each increasing the surface area upon which the vapor constituents may condense. Being more complex shapes to manufacture, these latter types are also more expensive to purchase. These three types of condensers are laboratory glassware items since they are typically made of glass. Commercially available condensers usually are fitted with ground glass joints and come in standard lengths of 100, 200, and 400 mm. Air-cooled condensers are unjacketed, while water-cooled condensers contain a jacket for the water.

Industrial distillation

Larger condensers are also used in industrial-scale distillation processes to cool distilled vapor into liquid distillate. Commonly, the coolant flows through the tube side and distilled vapor through the shell side with distillate collecting at or flowing out the bottom.

Air conditioning

Condenser unit for central air conditioning for a typical house

condenser unit used in central air conditioning systems typically has a heat exchanger section to cool down and condense incoming refrigerant vapor into liquid, a compressor to raise the pressure of the refrigerant and move it along, and a fan for blowing outside air through the heat exchanger section to cool the refrigerant inside. A typical configuration of such a condenser unit is as follows: The heat exchanger section wraps around the sides of the unit with the compressor inside. In this heat exchanger section, the refrigerant goes through multiple tube passes, which are surrounded by heat transfer fins through which cooling air can circulate from outside to inside the unit. There is a motorized fan inside the condenser unit near the top, which is covered by some grating to keep any objects from accidentally falling inside on the fan. The fan is used to pull outside cooling air in through the heat exchanger section at the sides and blow it out the top through the grating. These condenser units are located on the outside of the building they are trying to cool, with tubing between the unit and building, one for vapor refrigerant entering and another for liquid refrigerant leaving the unit. Of course, an electric power supply is needed for the compressor and fan inside the unit.

Direct-contact

In a direct-contact condenser, hot vapor and cool liquid are introduced into a vessel and allowed to mix directly, rather than being separated by a barrier such as the wall of a heat exchanger tube. The vapor gives up its latent heat and condenses to a liquid, while the liquid absorbs this heat and undergoes a temperature rise. The entering vapor and liquid typically contain a single condensable substance, such as a water spray being used to cool air and adjust its humidity.

Equation

For an ideal single-pass condenser whose coolant has constant density, constant heat capacity, linear enthalpy over the temperature range, perfect cross-sectional heat transfer, and zero longitudinal heat transfer, and whose tubing has constant perimeter, constant thickness, and constant heat conductivity, and whose condensible fluid is perfectly mixed and at constant temperature, the coolant temperature varies along its tube according to:

{\displaystyle \Theta (x)={\frac {T_{H}-T(x)}{T_{H}-T(0)}}=e^{-NTU}=e^{-{\frac {hPx}{{\dot {m}}c}}}=e^{-{\frac {Gx}{{\dot {m}}cL}}}}

where:

  • is the distance from the coolant inlet
  • is the coolant temperature, and T(0) the coolant temperature at its inlet
  • is the hot fluid’s temperature
  • is the number of transfer units
  • is the coolant’s mass (or other) flow rate
  • is the coolant’s heat capacity at constant pressure per unit mass (or other)
  • is the heat transfer coefficient of the coolant tube
  • is the perimeter of the coolant tube
  • is the heat conductance of the coolant tube (often denoted)
  • is the length of the coolant tube

An Introduction to Coil Heat Exchangers

Coil heat exchangers in their simplest form, use one or more tubes that run back and forth a number of times. The tube separates the two fluids. One fluid flows inside the tube and another flows on the outside. Let us have a look at a heating example. Heat is transferred from the hot inner fluid to the tube wall via convection, it then conducts through the pipe wall to the other side and the outer fluid carries this away also through convection.

The Coil Type Heat Exchanger produced by metal industries are suitable to transfer heat in a wide variety of operating conditions and to refuse to accept decay for the longest period of time possible under the harshest operating circumstances. Coil-type exchangers are more efficient than shell and tube exchangers for low flow rates. Due to their simple construction, they are low in price and easy to clean on the shell side. Thermal efficiency approximates that of a true countercurrent flow type exchanger.

Condensers are used for condensation vapors cooling liquids. Condensers are made by fusing a number of parallel coils in a glass shell. Coil Type Heat Exchangers are artificial to special requirements as to dimensional tolerances, finish and tempers for use in condensers and heat exchangers.

Copper heat exchanger tubes are normally supplied in straight length in annealed half-hard temper. Coil Type Heat Exchangers shaped by are metal industries not only have stiff tolerances the most dependable dimensions throughout the tube length. The tube surface is clean both inside. Coils are made in different diameters using tubes different bores.

How Does a Coil Heat Exchanger Work?

The Applications of Coil Heat Exchangers

When it comes to heat exchangers, coil heat exchangers specifically are ideal for applications including boiler air preheating, pulp dryers, unit heaters, condensing and cooling as well as high-pressure, air tempering, and dryer applications. Depending on the application, there are many types and styles of coil heat exchangers to choose from.

Some of these include stainless tube bundles, double-pip heat exchangers, stainless steel tube immersion coil, bare tube immersion cooler, gas to water cooler, copper coil heat exchangers, combination ambient air/chiller water cooler, or coil tube-in-shell design to name a few. Each of these may also come in a variety of sizes and each has specific advantages. However, coil heat exchangers, in general, can be expected to have many advantages overall as well.

The Advantages of Coil Heat Exchanger?

Some advantages of coil heat exchangers include high efficiency, flexibility, low-pressure drop, they require little maintenance, are compact and lightweight, and are also easy and inexpensive to install. Coil heat exchangers tend to have higher efficiency than other types because of the large number of closely aligned tubes. This design aspect enlarges the heat transfer area, which results in a higher heat transfer co-efficient overall.

This efficiency equates to higher production while using less energy and that means big savings both upfront and in the long run. The coil-type heat exchanger is also known for being compact and lightweight due again to the closely packed tubes. The exchangers’ compact, lightweight design as well as their unique vertical orientation also means that they will take up less space and will be easier and less expensive to install. Their lightweight and compactness also lend to the flexibility mentioned earlier.

Another advantage of these heat exchangers is that there are many options when it comes to model types and configurations, which means they can be used with a wide variety of temperatures, flows, and pressures.

This flexibility equates to greater value overall. In addition to the benefits I just mentioned, coil heat exchangers also have low-pressure drops and require little maintenance as the structure of the tubes allows for turbulent fluid flow, which minimizes fouling and scales build-up. They can also be easily removed from the piping system to be flushed if that is necessary. Saving time and money both on installation and maintenance can go a long way for your business, and allows for overall smoother operations and less hassle and frustration.

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