Central Air Conditioning How it Works

Central air outside units

Avoid the costly mistake of having the wrong air conditioning unit installed in your home. Knowing how different systems work will help you make informed decisions and save money when the time comes to install or replace your air conditioner.

elearning-training.com gathered information about central air conditioning components, how it works, types of air conditioners.

What Is a Central Air Conditioning Unit

An air conditioning system, more commonly referred to as a “split-system air conditioning system” or simply “central air,” is typically comprised of the following components:

  • An analog or digital thermostat that regulates the system’s operation
  • A fan, condenser coil, and compressor housed in an outdoor unit
  • An indoor unit located in the attic, basement, or centrally located space, housing a fan and the evaporator coil (this component circulates cooled air)
  • Insulated copper tubing guiding the refrigerant flow between the indoor and outdoor units
  • An expansion valve regulating refrigerant flow to the evaporator coil
  • Ductwork from the indoor unit, guiding or circulating cooled air throughout the space and back to the unit

The same components and principles comprising a residential air conditioning system are found, on a larger scale, in industrial/commercial units.

How a Central Air Conditioner Works

When you turn your thermostat down, machinery whirrs up and cools down the air. Right? Let’s better answer what happens when you turn your thermostat down:

  1. The thermostat is adjusted to regulate the amount of cool air to be distributed
  2. The compressor (outside) pumps refrigerant between the condenser coils (outside) and the evaporator cooling coils (inside) to cool indoor air
  3. Evaporator cooling coils remove heat and humidity from the air
  4. A fan or blower moves air over the cooling coils and disperses it through the ductwork
  5. A fan blows air over the condenser coils (outside) to release/dissipate the collected heat
  6. As ambient air is cycled back into the system, it passes through a filter(s) to remove particles and other impurities.

Note: The quality of air filter(s) used with your air conditioning system can significantly influence ambient air while keeping dust and impurities out of your system. Get an HVAC Inspection if you suspect a problem with air quality, impurities, or circulation.

Air Conditioner Types

Depending on your geographic location, how you prefer your air-conditioned, and the size or configuration of that space, there are three primary types of systems. Consider how the following air conditioning systems work:

Packaged Air Conditioner – This system, more common in the south and southwest of the country, contains the condensing coil, evaporator coil, blower fan, and compressor all in one unit. Packaged air conditioning units are ideal when there isn’t enough interior space for a split system or where rooftop installations are desired.

Like other systems, packaged air conditioning units remove warm air from the structure via return air ducts, forces it over evaporator coils, then returns that cooler air back to the structure through supply ducts. In the same manner as other systems, undesired heat is released outside by way of the condenser coil.

Split-System Air Conditioner – These systems are the most common air conditioning solutions. They contain an outdoor unit (compressor, condenser coil, and fan) and an indoor unit (evaporator coil, blower, and filter).

Split-systems can support varied (fan/cooling) speeds, allowing for single, two-stage, and multi-stage systems. Split-system air conditioning provides consistent, economical, and reliable temperature control throughout the entire structure.

Note: Two-stage and multi-stage air conditioning systems are more common in larger, renovated, and newer structures. They are often found in areas with severe cold or hot weather. These units will have a setting or switch presenting “low, medium, and/or high” options.

Ductless Air Conditioner – These systems are ideal for structures built without ductwork. Their installation is less invasive than other systems and can deliver chilled air to targeted areas within the structure. The indoor unit (blower fan and evaporator coil) connects to the outdoor unit (compressor, condenser coil, and fan) via copper tubing, which carries the unit’s refrigerant.

Central Air ductless unit

Installation of the indoor unit can occur on the ceiling, a wall, or the floor. With some systems, multiple indoor units can be connected to a single outdoor unit. Regardless of the number of indoor units, the operation of a ductless system is remarkably similar to that of a split-system.

Note: Today’s air conditioning systems operate on the same principles Willis Carrier applied when he invented the first modern air conditioner in 1902.

How Central AC Systems Work

In this article, you discovered essential information about air conditioning components and configurations, how these systems work, and types of air conditioning units.

Knowing how air conditioning systems work allows you to select the most efficient and economical system for your home or business.

Not knowing how AC units can be configured and installed can leave you with a structure riddled with uneven and uncomfortable air conditioning and costly utility bills, as your system will always have to overcompensate to meet your desired temperature.


Commercial HVAC System Types

Commercial hvac system external units

Avoid losing money with an inadequate HVAC system serving your commercial building. By knowing which commercial HVAC system best serves your commercial building, you can easily keep your entire building comfortable without straining your budget.

elearning-training.com gathered information about the different types of HVAC systems and how they keep your building’s climate controlled.

What Are the Types of Commercial HVAC Systems?

Purchasing a heating and cooling HVAC (Heating, Ventilating, and Air-Conditioning) system for a commercial building, whether a new building or replacing the system in an existing property, can be overwhelming without knowing what types of HVAC systems are appropriate for your property.

The following are three categories under which you can classify most HVAC systems:

• Single Split Systems
• Multi-Zone (Multi Split) Systems
• VRF (Variable Refrigerant Flow) or VRV (Variable Refrigerant Volume) Systems

Single Split Systems – This affordable and very popular type of HVAC system is an excellent option for most small commercial buildings. Since this system allows individual heating and cooling, it is a popular choice for apartment buildings, hotels, schools, and multi-use buildings, housing restaurants, shops, offices, etc.

A single split system is comprised of one indoor installation and one corresponding outdoor installation connected by a refrigerant line and communication/electrical cables. The indoor installation houses a fan, a cooling coil, a heating section, and air filtration. The outdoor section consists of a compressor and a condenser.

Since each indoor unit of a single split system requires a dedicated outdoor unit, location and space may become problematic depending on the number of units needed. If the outdoor units are to be located on the building’s roof, the roof’s load capacity should be considered to avoid surpassing the roof’s dead load capacity.

Multi-Zone Systems – A multi-zone HVAC system uses a single compressor to power multiple air outlets. Unlike a single split system that works off one thermostat for temperature control, a multi-zone system provides individual control for each room’s temperatures.

Multi zone commercial hvac unit

Multi-zone systems are great solutions for new and existing constructions with non-ducted systems. They are an exceptional choice for room or office additions where extending or installing ductwork is not feasible. Multi-zone systems are a popular choice for small and medium-sized commercial buildings.

A multi-zone system is comprised of multiple indoor installations connected to one outdoor installation and connected by refrigerant lines and communication/electrical cables. Like single split systems, the indoor installation houses a fan, a cooling coil, a heating section, and air filtration, while the outdoor section consists of a compressor and condenser.

VRF or VRV Systems – A VRF or VRV system is a multi-zone type of system. With a single outside unit that may contain multiple compressors. This is connected to several inside units (up to 60 for some models) by refrigerant piping, electrical, and communication wiring.

Like single and multi-split systems, VRF or VRV systems use a refrigerant to heat and cool the air in the system. This refrigerant can be conditioned by a single unit or multiple outdoor units as it is circulated throughout the property to multiple indoor units. Unlike other types of systems, energy consumption can be reduced by allowing varying degrees of cooling in specific areas.

VRF or VRV systems can offer an excellent heating and cooling solution for larger commercial buildings due to its precise control over the refrigerant flow. Thanks to the system’s electronic expansion valves, each internal unit receives the exact amount of refrigerant needed to adjust or maintain the room it is in.

HVAC Interconnected Systems

Commercial buildings can benefit from various interconnected systems providing heating and cooling to individual floors, rooms, or spaces. You may see the following in a large-scale commercial HVAC system:

Heat Pumps – Uses heat extracted from air or water for heating. In a heat pump with a water source, water is piped through the structure to supply the heat pump.

Roof Top Units – These units can be found on the roof or ground, and duct conditioned air into the building. These units are very common in commercial HVAC applications.

Chillers – These units produce cool water distributed to cooling coils through piping systems.

Heaters – These come in two types:

• Hot air furnaces that burn fuel to heat the air
• Radiant heaters that use infrared radiation to heat objects directly.

The size and configuration of a commercial building’s HVAC system will be determined mainly by the amount of space contained in the building and its construction.

Tip: Keep your HVAC system operating at peak performance by having it serviced bi-annually, once in the spring and again in the fall.

Commercial hvav maintenance and repair

Types of Commercial HVAC Systems

In this article, you discovered the different types of HVAC systems, how they control your building’s climate and interconnected systems that aid in that process.

By installing an HVAC system that adequately controls the heating and cooling of your commercial building, you can absorb initial installation expenses and save money over time.

When an inadequate HVAC system is installed in a commercial building, expenses will increase dramatically from over-use and eventual upgrades or replacement of the system.