Summers in the Midwest are both hot and humid—a combination of factors that makes a reliable air conditioner a downright necessity. Of course, having an air conditioner is only half the battle. The other half involves keeping it properly maintained by a reputable HVAC company, to avoid the additional expenses associated with poor performance and mechanical breakdowns.
Many people struggle to keep their air conditioning system properly maintained simply because they fail to understand the various parts that go to make it up. If you would like to learn more about what it takes to keep your air conditioner ticking, read on. This article will introduce you to one important—and often overlooked—component: the capillary tube.
A capillary tube is a thin coiled piece of copper piping. The chief characteristic of a capillary tube is the extremely narrow nature of the tube, which can have a diameter as small as 0.5mm. The reason for this is that, by restricting the flow of refrigerant, a capillary tube affects important changes in both its pressure and its temperature.
The capillary tube in most air conditioning systems resides inside the condenser unit—i.e., that large square box sitting in your backyard. This component is located on the supply side of the system. In other words, it is used to treat the refrigerant as it is on its way back to the indoor evaporator unit.
To fully appreciate the role played by the capillary tube, it is important to have a thorough understanding of the movement of refrigerant throughout your system. The actual act of cooling takes place inside of your home, in the evaporator coil. As the refrigerant absorbs heat from home, it changes from a liquid to a gaseous state.
It is the state in which the refrigerant arrives back to the outdoor condenser unit. There it passes first into the compressor, which raises its pressure. Then it flows to the condenser, which is responsible for turning the refrigerant back into its liquid state. Once this has been accomplished, the refrigerant flows through the capillary tube en route back to the evaporator.
The restrictive nature of the capillary tube helps to prime the refrigerant for the absorption of more heat. It does this by lowering its temperature, while also increasing the pressure. Both of these changes are brought about by the restricted size of the tube.
Here it is important to acknowledge that a capillary tube belongs to a broader category of refrigeration components known as throttling devices. A capillary tube is what is not as a non-adjustable throttling device. It is the simplest type and one which is distinguished by the fact that the flow rate of the refrigerant cannot be altered or changed in any way.
It is a perfectly acceptable limitation for a residential air conditioning system. Commercial systems, on the other hand, often require more sophisticated types of throttling devices. These allow the flow rate of the refrigerant to be altered to meet changes in the service demands being placed on the unit.
Capillary Tube Problems
Capillary tubes are subject to two main types of problem: leaks and clogs. Leaks occur thanks to the relatively fragile nature of this component. Should internal vibrations cause the capillary tube to start rubbing up against the walls of the condenser unit, holes will soon form in the wall of the tube. Such leaks will greatly reduce the effectiveness of the system as more and more refrigerant escapes.
Clogs are equally problematic. These are caused by debris, contaminants, or build up occurring within the refrigerant lines. Such things can limit or even obstruct the flow of refrigerant through the very narrow capillary tube. This, in turn, will make it harder for your air conditioning system to achieve a given cooling task.
Regular maintenance visits are the key to ensuring proper functioning not only of the capillary tube but of all the components inside of an air conditioner. Be sure to contact a reliable HVAC technician in your area to perform check-ups on a regular basis.