What is an AC Condenser?

Your AC unit is responsible for keeping your home cool and comfortable throughout the year. And it does this well – unless something goes wrong with the condenser.  The AC condenser unit is responsible for helping your system manage both humidity and temperature. This is what keeps you warm in the freezing winter months and cool in the hot summer days. As such, it sees a lot of action throughout the year. Which means it requires regular maintenance to work properly.  But what is it exactly? 

What is the Condenser Unit? 

Do you know that box sitting outside your home? You may refer to it as your AC unit, but more specifically, that’s your condenser.  During the hot months, the condenser collects heat and expels it from your home. In Winter, on the other hand, a heat pump condenser will do quite the opposite. It’ll collect heat and eject that back into your home.
Simply put, your condenser transfers heat to where it needs to go. 

How do AC Condensers work? 

To understand how the condenser works, you need to understand the role it plays in your entire system.  In an HVAC system, the low-pressure refrigerant passes through evaporator coils, absorbing the heat from the air. Coolant, in turn, passes to the compressor inside your condenser and is converted to liquid. Heat is then dissipated from the coolant fan in the condenser. And this process repeats itself.  Your average AC-only condenser has only a handful of controls – on and off. However, many AC units today include optional controls such as brownout time delay, hard start kits, low ambiance control, and crankcase heaters. Each improves the system in its own way. For example, brownout time delay controls protect the compressor when voltage drops or rises outside of a safe range.  The condenser itself is a set of coils located inside the outdoor unit. A fan blows across these coils and dissipates heat from the refrigerant inside them, allowing it to convert into a liquid. Without this, the refrigerant in your HVAC system would retain heat, failing to cool or warm your home.  Let’s take a look at those parts in more detail now. 

What are the Parts of an AC Condenser? 

Although condensers vary in design, they have the same basic parts. These include the condenser cabinet that includes the condenser coil, compressor, fan, and various controls.  The condenser coil itself typically consists of copper tubing with aluminum fins. However, some systems use all-aluminum tubing to transfer heat faster. For the sake of maintenance, these tubs should be cleaned regularly to allow heat to transfer efficiently.  The condenser fan is what circulates air across the coils in your typical condenser. (There are some exceptions, and we’ll cover those in a moment.) This part depends on airflow. As such, should it ever be blocked by debris, your condenser will operate at a suboptimal level.  As for the compressor, that’s the core of your condenser system. It’s what compresses the refrigerant and pumps into the coils to be cooled in the first place. In AC units, this refrigerant is cooled at the condenser and passes that through to the evaporator coil to cool further. Contrast this with heat pump compressors where hot gas is pumped directly to the evaporator to provide heat rather than cool it. 

Signs Something is Wrong with Your Condenser 

A lot can go wrong with a condenser, especially if you haven’t had it maintained in some time. Fans can break, coils can leak, and motors can wear out. The point is, if your condenser fails, your AC unit fails.

Common signs there’s something wrong with your condenser include: 

  • Refrigerant leaks from the unit 
  • The fan isn’t running 
  • Your AC is blowing warm air into your home 

Should your AC unit experience any of these problems, it’s time to call an HVAC professional to diagnose and repair your system. 

The Types of Condensers 

Condensers come in three primary types, and they all depend on how they remove excessive heat. 

  • Water-cooled – Less common than the air-cooled condenser, the water-cooled condenser works by pouring water over the condenser coil
  • Evaporative – The odd duck of the group, evaporative condensers typically don’t use refrigerant or coils. Rather, they remove heat by allowing water to, as the name implies, evaporate directly into the air.
  • Air-cooled – This is possibly the most traditional or recognized form of condenser. The system works by blowing air over the condenser coil. These are what we typically see in residential buildings. 

Regardless of the type of condenser in your HVAC system, they require regular maintenance to ensure optimal efficiency.