HVAC (Heating, Ventilation, and Air Conditioning) systems facilitate achieving an occupants’ thermal requirements. Such systems are used in different buildings, such as institutional, commercial, residential, and industrial buildings. Today we dive into the various types of HVAC systems.
HVAC units come in different types, each having its pros and cons. You can select the one that best suits your personal and constructional requirements.
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What is a Residential HVAC System?
A residential HVAC system is used for heating and cooling the home. Such a system may include air conditioners, furnaces, and heat pumps. These systems are accompanied by comfort controlling devices such as thermostats, ductwork, and other smart controls.
The heating process is achieved with a boiler or a furnace in residential buildings. You can also connect your water system with the same heating system to get warm water.
For cooling purposes, air conditioners lower the inside temperature compared to the outside atmosphere. You can combine both the heating and cooling functions by using a heat pump. Heat pumps are capable of performing both functions efficiently.
1. Standard Heating and Cooling Split Systems
Standard heating and cooling split systems are the most popular and common types of residential HVAC systems. They have separate units for heating and cooling purposes. One of them is an indoor unit, and the other is an outdoor unit.
The cooling unit of such HVAC systems is installed outside. The outdoor unit consists of compressors, refrigerant, and coils for cooling purposes. Moreover, there is a fan to blow out hot air.
The heating unit or indoor unit is placed somewhere in a storage area. This unit is typically a gas furnace. The temperature is controlled using a thermostat, and the hot air is distributed in the house via a fan through ductwork.
You can easily control this HVAC system with a simple thermostat to maintain the temperature inside the house. These are the simplest units in terms of installation.
- The heating and cooling split systems are cheaper compared to other HVAC systems.
- They have lower operating costs as gas furnaces are more affordable as compared to oil furnaces or boilers.
- Their efficiency ranges from 80% to 99%. Low-efficiency furnaces are more budget-friendly.
- Installation of a standard split system requires ductwork.
- There is a risk of carbon monoxide leaks or explosions because of the gas furnace.
2. Heat Pump System
Heat Pump systems are becoming popular these days, and the industry is growing. They are also known as air source heat pumps.
Heat pumps perform both heating and cooling operations. They use refrigerant (circulating it with a compressor’s help) to achieve high and low-temperature requirements.
For cooling purposes, the refrigerant absorbs heat from the air. The refrigerant turns into a high-pressure liquid from low-pressure gas. The compressor then sends the refrigerant to the outdoor unit, where the fan blows the heat out of the refrigerant, leaving a low-pressure gas behind.
In heating, the process is reversed as refrigerant absorbs heat from the outdoor unit and releases it to the indoor coils.
The indoor unit is like an air handler that spreads the hot/cool air through the system with a blower’s help.
- They have relatively lower equipment costs as compared to geothermal heat pumps.
- The air source heat pumps have lower operating costs.
- They are less efficient when it comes to heating in extreme cold. Moreover, the heat pump system requires a secondary heating system to meet the requirements.
- They require ductwork for installation.
- As the refrigerant absorbs and releases the air into the atmosphere, it can spread odor and dust.
3. Hybrid Split / Dual-Fuel System
The Hybrid Split HVAC system is more like a Standard Heating and Cooling system with add on features. As the name implies, the dual-fuel system, the hybrid split runs with two different heat sources depending on the weather conditions.
When the temperature outside is freezing, the hybrid split system uses furnace heat for heating the home. As the temperature outside rises above the freezing point, the hybrid system switches to a traditional electric heat pump mechanism.
The ability to switch between gas and electric power distinguishes the hybrid split system from other HVAC systems. These systems can be controlled using thermostats and are compatible with traditional ductwork.
Hybrid Split systems are energy efficient and are a great way to reduce energy costs in mild climate areas.
- The Dual-Fuel system is energy efficient, reducing annual energy costs.
- You can control the system using simple thermostats.
- They are compatible with traditional ductwork.
- They perform efficiently in colder regions.
- They are costly compared to the traditional split or dedicated heat pump systems.
- They require ductwork for installation.
4. Mini-Split System
Mini-Split systems come either as an air conditioner or as a heat pump which performs both heating and cooling. They have an indoor and outdoor unit and can support multiple indoor units. The indoor unit disperses the air through the fan.
Multiple indoor units allow independent control of temperature in each room. You can either use a single indoor and outdoor unit or go for multiple indoor units accompanied by a single outdoor unit having large BTU values.
They function just like a standard heat pump using inverter technology. These systems are ductless.
Installing a mini-split system can be more expensive. But these initial costs can save you money in the long run. You can easily conserve energy by only using the units in the occupied rooms hence saving the cost of heating or cooling an empty room.
- The annual energy costs of mini-split systems is less.
- Ductwork is not needed for installation
- You can heat up or cool down individual zones.
- These are high-performance HVAC systems.
- The setup cost is high.
- The system can require regular maintenance.
5. Packaged System
The packaged system has all its heating and cooling components in one large unit and is best suited for small houses. These systems can be placed in outdoor or even indoor storage areas.
The packaged system has a blower for dispersing the hot/cool air throughout the house and withdrawing the atmosphere’s untreated air.
The packaged system performs heating and cooling, depending on the type of unit installed. The most popular units are:
An air conditioner and a gas/electric furnace
- Heat Pump
both heating and cooling performed by a single unit
A heat pump and a gas furnace as a secondary heating device
This system is very efficient and budget-friendly. The maintenance costs are also lower. But such systems are not best suited for excellent heating performance in extreme cold.
- The equipment cost is less compared to other HVAC systems.
- They have a small physical footprint.
- The maintenance costs are lower.
- They offer fewer options compared to other standard HVAC systems.
- They are not as efficient when it comes to heating.
6. Water Based Boiler System with AC
Water-based boiler systems are efficient but costly. Such HVAC systems use hot water that is distributed throughout the house in pipes to generate heat.
They are the norm in most of Europe and growing in popularity in the US.
The boiler system sets up zonal control allowing different temperature settings in each room. They can be installed without ducts, but this is only for heating purposes. If you need central air conditioning, you have to install vents.
Boilers come in different sizes and types. You can use gas, oil, or electricity to heat the boiler’s water, mostly a sealed vessel. The hot water is finally sent to the radiator or a fan coil that heats the atmosphere.
You can also install the hot water pipes in the subfloor to radiate heat through the floor. This provides a comfortable and cozy environment during winters.
- It is an efficient heating system.
- You can get hot water for domestic needs like laundry and bathing using combi boilers.
- It is expensive to install boilers and radiant floor pipes.
- You need to install radiant floor pipes.
- Such heating systems take time to reach the desired temperature and operate slowly.
7. Ground Source / Geothermal Heat Pump Systems
Geothermal heat pumps are favored as they use renewable energy. Geothermal systems achieve heating and cooling requirements by circulating hot and cold water in the pipes underground.
The water in the pipes has refrigerant that helps in absorbing heat from the ground in winters. It is easier to absorb heat underground as the temperature is 50 to 60 degrees below ground.
In summers, the refrigerant absorbs heat from the house and dumps it into a relatively calm ground. It is an eco-friendly mechanism for heating and cooling the home.
Geothermal heat pumps are very efficient and great for delivering desired temperatures. The annual energy costs are far lower than other HVAC systems. But setting up a geothermal system is quite expensive.
- Geothermal heat pumps are very efficient and eco-friendly.
- They are energy and cost-efficient to run
- They are very expensive to install
- Maintenance and repair are costly and challenging at the same time.
8. Electric Furnace / Electric Resistance Heaters & AC System
Electric Resistance Heaters and standalone AC Systems are affordable but consume the most energy. They are best suited for homes that require the least amount of heating. Such systems convert electricity into heat. Electric resistance heat is achieved through either of them:
- Baseboard heaters
- Radiant heaters
- Space heaters
- Wall heaters
For heating, the air is blown through a heating element, which moves to resistance coils through blowers. The heated air then disperses throughout the home through supply ducts.
For cooling, the air is cooled using AC’s cooling coil, connected to the furnace fan that blows the hot air over the cooling coil and then distributes the cool air throughout the home using the same air ducts.
These HVAC systems are the most effective as the electrical energy is dedicated to heating and cooling only. They are also eco-friendly as carbon monoxide is not produced.
- It is the most effective heating and cooling system.
- This HVAC system is budget-friendly and is relatively inexpensive.
- It consumes the most energy resulting in higher utility costs.
- They are best for occasional heating requirements.
Questions relating to types of HVAC systems
What are the most common types of HVAC systems?
The most common type of HVAC system is the standard heating and cooling split system. This system comes with two units, namely an indoor and an outdoor unit. The indoor unit is mainly for heating purposes, and the outdoor unit is used to achieve cooling requirements.
The cooling component uses refrigerant to cool the warm air and disperse it throughout the house via ducts, and a fan is used to blow out the warm air from the outdoor unit.
While heating, the indoor unit is powered by a gas furnace. The hot air is then distributed in the house via ductwork.
What are the two types of recovery systems HVAC?
The two most used methods of recovery are:
- Vapor Recovery
- Liquid Recovery
In the vapor recovery process, the refrigerant gets collected in a vapor state from the HVAC system. In the recovery unit, these vapors turn into the liquid through condensation. The liquid is then transferred to the recovery cylinder.
In the liquid recovery method, the refrigerant gets collected in the liquid form from the HVAC system. This method is ideal for recovering a considerable amount of refrigerants.
The selection of the recovery method depends on the HVAC system type.
What is the difference between forced air and radiant heat systems?
A gas furnace produces forced air heat. The air gets heated in the furnace and then blown into the ducts system to get distributed in the entire house.
The forced air heating technique is used in most common HVAC systems, including standard heating and cooling split systems, heat pump systems, and hybrid systems.
Radiant heat is more efficient as it is distributed through subfloor pipes. The heat is distributed evenly in this method. Radiant heat is used in water-based boiler systems and geothermal heat pump systems where hot water is radiated through pipes in the house to in-room radiators.
So there you have it! The standard split system is the most commonly used HVAC system. The Hybrid Split is a cost-effective choice. The mini-split is best suited for demanding occupants.
The packaged system is best for small spaces. Geothermal is expensive but pays off in the long run. Hence, you can compare and decide on the one that is most suitable for you. Leave a comment and let us know what option you think is best!