When it comes to refrigeration & HVAC, there are always questions about the condenser. What is a condenser? How does it work? How many types of condensers are there? Enough already! Don’t worry; we got you covered. Let’s kick a few basics out of the way, shall we?
What is a Condenser?
In simple terms, a condenser is a cooling device. The device liquefies gas by cooling it. Every refrigeration system uses condensers to condense steam or vapor to bring about a cooling effect. For instance, an HVAC system has a condenser responsible for cooling its environment (in this case, it could be your office, home, workshop, etc., etc.).
How Does a Condenser Work?
A condenser works in three phases, namely:
Usually, the vapor is super pressurized and superheated in the compressor and evaporator before it enters the condenser. The condenser then ejects the heat (desuperheats) from the vapor and liquefies it. More heat is lost in the condensation phase, and more of the vapor turns to liquid (about 90%). The sub-cooling state is there to ensure that no liquid refrigerant turns into vapor even with temperatures rises.
Types of Condensers
Condensers are available in different constructions and types. Their designs mainly vary depending on the refrigerant tubing and the condenser's working principle to cool the refrigerant.
There are different types of tubing, such as:
- Finned tubes – Provide increased surface area
- Plain tubes – the generic type
- Parallel and series-pass tubes – complicated but efficient
- Plate types
With that said, however, condensers are mainly characterized by their cooling method. Here are the different types of condensers.
1. Air-Cooled Condensers
These condensers follow a simple design and use the standard airflow in managing their cooling. The air-cooled condensers are mainly found in small units such as water coolers, household refrigerators, window air-conditioners, deep freezers, small packaged air-conditioners, split air-conditioners, etc.
The cooling load in these units is relatively small, and the refrigerant quantity used is small. Some refer to the air-cooled condensers as coiled condensers since they are made of aluminum or copper coil.
Air-cooled condensers are further subdivided into two categories: the forced convection types and the natural convection types. The forced convection condensers use a motor-operated fan to blow air in the condenser coil. In contrast, the natural convection types rely on the natural airflow depending on the condenser coil’s temperature.
2. Water-Cooled Condensers
I know you can guess this right, and yes, the water-cooled condensers use water as the fluid to remove heat from the refrigerant. They are the eco-friendly variation of the standard air-cooled condensers.
These condensers are mainly found in central air-conditioning, big packaged air-conditioners, large refrigerating plants, etc. They are applicable in areas where the cooling loads are very high, and large quantities of refrigerant flow via the condenser.
Like the air-cooled condensers, the water-cooled condensers come in different types, including double-type/tube-in-tube, Shell & tube type, and shell & coil type. The working mechanism is almost the same in all of them. One side of the piping flows the refrigerant, and water flows through the other piping, thus cooling and condensing the refrigerant.
3. Air-Water (Evaporative) Cooled Condensers
This condenser is a combination of both water and air condensers. Water sprays onto the coils; it evaporates, causing a temperature drop within the coils. The refrigerant within the coil condenses and cools down. In addition, cool air is also released from the condenser's bottom, blowing across the coils.
In this type of condenser, both air and water work in tandem to cool and liquefy the coil's refrigerant. These condensers are eco-friendly and are ideal for commercial HVAC systems. The air-water condensers are cheaper compared to the water-cooled condensers. They also offer an effective cooling solution in areas with a low water supply.