Types of central air conditioners

Types of central air conditioners you can choose from!

Modernization in technology has influenced even the domestic and commercial HVAC industry.

The influence has led to a demand for highly technological and energy-efficient central air conditioning systems.

Therefore, choosing the right type of central air conditioner is essential as it can maximize your initial and running costs and improve your comfort level. AC installation is a crucial step in your home or business owner’s journey.

So the critical point to focus on here is the different types of central air conditioners.

Well! here in this blog, we discuss this categorization in-depth.

First, we’ll discuss the four different central air conditioning system types.

And then, we’ll move toward the deeper categorization.

So, you need to accustom yourself to all these systems if you’re considering getting an air conditioning service for a new central system.

Four types of central air conditioning systems

Usually, there are four main types of cooling systems you can choose for your house.

All of these systems come with certain advantages and disadvantages.

Let’s have a look at them.

Types of central air conditioners #1: Split AC systems

Split AC systems are the most common air conditioners in homes with central air.

These systems can cool your home like no other if your property has a furnace.

The split AC system contains an evaporator coil separate from the compressor and the condenser.

The evaporator coil works by oozing out the hot air and moisture from your space, while the condenser and the compressor push the cool air in your house through the air ducts.

In most systems like these, the compressors and the coils are located in the outdoor unit. However, the evaporator coil is fitted inside your house, either in the crawl space, basement or cabinet area.

If you are looking for simpler ac repair in the future, then the split system is excellent.

Types of central air conditioners #2: Heat pumps

In the technical sense, heat pumps are not AC, but a heat pump can cool your house like an air conditioner.

However, when the temperature drops, you can also use it as a heating system.

Heat pumps use minimal energy, thereby lowering your cooling costs.

The system uses heat movement to condition your house. While heating, it pulls hot air from outside and pushes it inside while pushing the cold air outside.

On the other hand, the opposite process happens while cooling. During summer, the heat pump pushes the hot air outside.

All in all, heat pumps are one of the most cost-effective ways to condition your house. They will serve you for years without any problems if you do AC maintenance regularly.

Types of central air conditioners #3: Packaged units

Packaged central air conditioner units are generally found in commercial air conditioning systems.

In these systems, the evaporator, compressor and condenser are all fitted into a single unit rather than separating them between indoor and outdoor units.

The system is placed on a concrete slab near your house.

In the case of commercial buildings, the units are placed on your roof.

When the system is functioning, the packaged units pull hot air out of your house, cool it and then push it again towards the ductwork.

These systems also include heating coils, which reduces the need for a separate heating system.

Types of central air conditioners #4: Ductless mini splits

A ductless mini split can be your savior if your house lacks ductwork or some rooms are not connected to the central AC unit.

The reason is that Ductless mini splits consist of an outdoor compressor and indoor air-handling unit that work similarly to the traditional air conditioner.

However, the system runs through a small hole placed high on the wall and contains attached blowers so that they don’t run on the duct system.

Talking about the functionality of these systems, they pull the hot air from your house and circulate it in the refrigerant to cool it down.

The cooled air is then passed onto the house again.

Types of air conditioners based on functionality

The central air conditioners use air, water and sometimes both as a working fluid to provide the required heating and cooling levels.

So, based on these working fluids, the central air conditioning system can be categorized into three groups.

1. All-air systems: Use air as a working fluid for heating and cooling purposes.
2. All-water (hydronic) systems: Use water as a working fluid for heating and cooling purposes.
3. Air-water systems: Use both air and water as working fluids

These three systems have several systems with different configurations, and all of them come with certain advantages and disadvantages.

So let’s discuss all of these systems in detail.

All air systems

Only air is used as a working fluid to generate heating and cooling in these systems.

Also, the air controls the humidity levels and provides ventilation to your space.

Apart from that, these systems help remove odor from your house

These systems have several sub-systems which differ in functionality and configuration.

So let’s discuss them all.

Conventional systems

The conventional systems can be categorized into two groups:

1. Fixed supplied air volume flow rate.
2. Variable supplied air volume flow rate.

The airflow rate remains consistent in the Fixed supplied air volume flow rate; however, the supplied air temperature is changed to obtain the desired temperature.

The air temperature is fixed in the Variable supplied air volume flow rate. However, the desired temperature is obtained by changing the airflow volume.

Conventional systems offer many advantages like:

• Simple and easy to use as the components are of simple configuration.
• Inexpensive initial cost.
• Reasonable running costs, which provide energy-efficient performance.
• No noise as the air handling unit, including the fan, is placed in the plant room away from the zone.
• Centralized maintenance.

Variable air volume system

Variable air volume systems can affect the variation in the thermal loads.

The reason is- The volume of air supply from a VAV air handler differs according to the zone thermal load.

The fan that supplies air is controlled to maintain consistent static pressure in the ductwork.

While considering the static pressure sensor in the duct, you can maintain the sir-supply volume in one of the following ways:

• Bypass dampers.
• Variable speed drive (VSD) in the fan motor maintains the fan speed.
• Inlet vanes either within the supply fan casing or upstream.

Variable volume systems help with ventilation and cooling and usually rely on single duct systems. If it is necessary, the terminal heats the air.

The systems are suitable for retail stores, schools, houses, hotels, office buildings, hospitals etc.

One advantage of these units is that the initial and operating costs are low because the air volume needs simple controls within 20% of the air outlets.

Multi-zone system

In multi-zone systems, the cooling and the heating coils are fitted parallel to each other, where the amount of air supplied and the temperature is constant and maintained.

The unique thing about the system is that hot and cold air are mixed in the required ratios, and the air mixed with fixed temperature and volume is pushed back into the conditioned zones.

Multi-zone systems are suitable for the following set-ups:

• Buildings and structures containing many small and large zones require separate temperature ranges and controls. For instance, schools and offices.
• Structures with different directions and internal loads. Example- Banks.
• Buildings with interior zones of various sizes like television and radio studios.

Here are some of the advantages of multi-zone unit systems:

• The system allows you to control the temperature of different zones and spaces separately for the zones that are considered separate areas.
• The smaller size of these units is pretty simple to operate. You can assemble it in a plant area or factory setup as it meets the needed requirements.
• There is an easy switch in the cooling system to produce warm air and vice-versa. You can do it manually by changing some settings in the air handling unit in the plant room.
• It allows smooth and easy distribution of air. The reason is- The system uses only one air duct and several outlets and exits, so the balancing process is easy.
• The air handling unit uses centralized refrigeration equipment.
• It is effortless to maintain the system as all air handling units are located in the plant room.
• Quiet operation.
• The system is quite affordable with low costs.

Reheat system

Reheat systems are considered an excellent choice in the application of variable loads.

The system works by cooling the air to the zone’s lowest temperature.

The cooled air is circulated to all the zones, and the desired temperature is attained by reconditioning the supplied air.

Electric heaters or hot water can be used as reheaters located in the terminal units of the conditioned zones.

Reheat systems help reduce humidity levels in cold zones by increasing the supplied air temperature.

Dual duct system

As the name suggests, a dual duct system allows you to separately control the temperature in conditioned zones and places.

Temperature control is attained by supplying the air from the hot air to the cold air duct.

Both the hot and the cold air is mixed in proper proportions, and the air is supplied to the zone to maintain the temperature.

These systems are preferable for multiroom buildings like hotels, apartments, offices, hospitals, large laboratories, schools etc.

Here are some of the advantages of dual-duct systems:

• Separate temperature control in each zone as cold and hot air is present.
• The system even comes in smaller sizes as the central system’s serving zones are reduced.
• Easy swap from the hot to cold modes and vice-versa. It is done by the place or zone thermostat, which is adjusted annually.
• The boilers and the refrigeration equipment are located all in one place; therefore, electricity, sewage services, and water are also located in the same plant room. It helps achieve centralized maintenance.
• High filter efficiencies.
• Centralized outdoor air inlets. With this, no rainwater or dust particles from the outdoor environment can enter your unit.
• Low-cost operation.
• Quite functioning as the fans and refrigeration machines are placed away from the conditioned zones.
• Flexible air duct system designs. Medium and high air speeds are possible if the building requires it.

Some of the disadvantages of the dual-duct systems are:

• Using separate ducts raises your initial costs when compared to the other systems.
• Precise and separate control requires a large handling unit, so the system’s total cost goes up.
• Dual duct systems are considered inefficient energy and, therefore, not recommended much.

All water system

All water system uses water as a working fluid for conditioning your home.

The water is transferred and pumped to the fan coil unit in the zone that needs conditioning.

The fan coil unit then uses the zone air or outdoor air for cooling or heating your house.

If the fan coil unit uses outdoor air, you might need a separate duct system for your house or building.

Fan coil units

Fan coil unit systems are used in all-water central air conditioning systems.

Cold/hot water flows through the unit coils from the central chillers and boilers.

Controlling the water’s flow rate helps in maintaining the air temperature.

On the other hand, the control valves maintain the flow rate.

Fan coil units are cost-friendly and are generally suitable for hotels, hospitals, pathology and offices.

Some advantages of fan coil units are:

• Cost-effective.
• The system doesn’t need ducts.
• Doesn’t take much space
• Easy installation.

However, there are some disadvantages of these units as well, like:

• Does not control room air humidity properly.
• Needs regular maintenance within the air-conditioned places.
• Risk of bacterial growth in water pipes.

Air-water system

As the name suggests, the air-water system uses air to water as a working fluid to generate cold and hot air.

These systems usually have two units:

1. Induction units.
2. Fan coil units.

Let’s understand both of them in detail.

Induction units

Induction units in the air-water central air conditioners are suitable for apartments, hospitals, hotels, patient rooms, skyscrapers and places with limited space.

These systems are generally suitable for zones with higher thermal loads.

Also, the induction units are great for buildings where some rooms require cooling while others require heating.

Fan coil units

The fan coil units are similar to induction units in terms of functionality.

The difference, however, lies in the use of the fan.

The fan coil systems are suitable for multi-room places like hospitals, hotels, and apartments where you can alter the operating mode during the cold season.

Some advantages of these units as compared to the induction units are that these systems are quiet, and you can control the fan speed.

However, the fan coil unit has a higher initial cost than the induction units, which makes the latter more preferable.

Final thoughts

With the numerous options and factors to consider, you need an experienced professional to assist you with the decision-making.

At RLD services, we are a team of experienced professionals who will guide you in selecting a suitable unit.

Call us now to request a free home estimate!

FAQs

Here are some of the questions people usually ask:

What are the three types of central air conditioning systems?

The types of central air conditioning systems are:

• Ducted air conditioning system.
• Split system air conditioning.
• Multi-split air conditioning system.
• Controls.

What are the four main types of HVAC systems?

The HVAC systems are categorized into four types. These systems come in different specifications and sizes that fit right into your home and business.

These categories are:

• Heating and cooling split systems.
• Hybrid split system.
• Duct-free (Mini-split).
• Packaged heating and air conditioning system.

What is the best type of central air conditioner to use?

Central air conditioners are one of the best and most effective ways to keep your house cool and comfortable.

Apart from the comfortable cooling, you also get:

• Lower energy bills.
• Reduced humidity.
• Cooler temperatures.

What is the difference between AC and central AC?

Window AC units cool individual rooms and are less potent than central air conditioners.

On the contrary, central ACs cool your entire house.

It helps regulate the hot and cold air throughout your space.

When combined with furnaces, air conditioners can give you the results of a complete HVAC system.

The Central air conditioner will take care of the cooling, and the furnace will do the heating.