• SkillCat Team

Commercial vs Residential: HVAC Systems Complete Guide

Updated: Aug 12


Introduction to Commercial Systems: Chapter 2


Residential vs Commercial: Air Conditioning System


In this module, we will introduce you to components used for the commercial air conditioning system.

We will also compare components of commercial air conditioning systems with the residential system. Skip to quiz!


Air Conditioning Components

Recall that the refrigeration cycle runs the air conditioning system. The residential air conditioners are used to serve the needs of smaller areas, and we use them at home.The commercial air conditioners are used in large spaces such as office buildings.


Commercial systems differ from residential systems in terms of components used for air conditioning.


Recall that some components seen in residential air conditioning are:

  • Compressor,

  • Condenser,

  • Metering device,

  • Evaporator,

  • Blower fans,

  • Dampers, and

  • Ductwork.

Apart from these, the commercial system has additional components.


The additional components used in commercial air conditioning systems are:

  • Cooling towers,

  • Water Pumps,

  • Air handling units,

  • Solenoid switches, and

  • Economizers.

Recall that condenser is a type of heat exchanger that cools the refrigerant. In a commercial chiller system, we use a cooling tower as a heat exchanger in addition to the condenser. This equipment helps cool the condenser by supplying cold water.


We use water pumps to carry water from the condenser to the cooling tower in a commercial system. There are commercial systems that use the refrigeration cycle to provide cold water instead of cold air. Large water pumps are used in such systems to pump the water throughout the building.


An air handling unit (AHU) is a box-type structure that contains cooling coils, fans, and filters.


We use a single air handling unit to move the air throughout our home. In a commercial unit, we use more than one AHU. The image to the right shows AHU located on each floor of a commercial building.


Recall that a solenoid valve is used in residential air conditioners to turn the refrigerant flow on and off. In commercial systems, we use many solenoid valves to control the higher flow rate of refrigerant in the system. Multiple solenoid valves can help provide separate cooling for different office spaces.


Recall that one commercial system usually cools a complete building. However, the residents of different floors will have different temperature requirements. So the refrigerant flow is controlled by the solenoid valves to control temperatures.


In a commercial system, as the cooling or heating load is high, we use an economizer. It uses the wind blowing at the top of the building to cool the air inside. This reduces electricity consumption. We will learn about how this equipment is used in commercial systems in later courses.


Residential Vs Commercial Air Conditioner

Commercial and residential air conditioning systems both aim to provide human comfort. However, commercial air conditioning systems do it on a much larger scale.


Recall that the cooling capacity of air conditioners is expressed in tonnage. Residential air conditioners are available in 1.5 to 5-ton units. The average commercial AC size ranges from 2 tons for small buildings to more than 30 tons for large buildings.


The temperature for the residential system is maintained between 67°F and 82°F. The average temperature range for most commercial building spaces is 60°F to 76°F.


Recall that finned-tube evaporators are commonly used in most residential air conditioning systems. A commercial air conditioning system uses a spine fin type evaporator. Chilled water systems use shell and tube type of evaporators. We also use finned tube evaporators in some commercial HVAC systems.


We use a finned-tube type of condenser for residential air conditioning systems. Earlier, commercial systems were also equipped with fin and tube condensers. Microchannel types of condensers are replacing these condensers as they are more efficient and smaller in size.


Recall that in a commercial system, multi-stage compressors compress the refrigerant to high pressure and high temperature. We use a centrifugal or screw-type compressor for commercial air conditioners. Recall that a piston-type or scroll-type of compressor is often used in residential systems.


A commercial air conditioning system has additional components for providing cooling to large spaces. These additional components help provide large-scale cooling, efficient air conditioning, and better control over temperatures.



Residential vs Commercial: Heating System


In this module, we will compare commercial and residential heating systems.

We will also learn about the common components used in a commercial heating system. Skip to quiz!


Heating Components

Recall that heating systems raise the temperature of cold spaces to keep us warm and cozy!We burn different types of fuels like wood, natural gas, or propane to create heat.


The heat created by burning these fuels is distributed around the house or building. This principle of heating is the same in residential and commercial systems. However, we make use of different components for creating and distributing the heat.


Recall that the main components to create heat in a heating system are:

  • Combustion chamber,

  • Burner system,

  • Heat exchanger, and

  • Boiler.

We use heat distribution systems such as pumps and ductwork to distribute heat throughout the building. Along with these, control components such as control valves and control board is used in all heating systems.


Let us recall each component used in

heating system. The burner system is the section of the furnace where the fuel mixes with the air. The combustion chamber is the place in a system where the air-fuel mixture is burned.


The air-fuel mixture flows through the burner and is lit by the ignitor. The hot gases produced by burning the air-fuel mixture pass through a heat exchanger.


A blower fan blows the hot air from the burner system up and into the heat exchanger. The same principle is used to provide heating in commercial space. Although, the components are larger. We will go over each of them in later courses.


Component Difference

As residential heating systems provide heat to a much smaller area, the combustion chamber is much smaller in size. The combustion chamber of the commercial system is bigger. It is equipped with more control components to fulfill the requirements of a much larger space precisely.


We sometimes use a power burner in high-end commercial systems. Power burners control the mixture of air and gas in the exact ratios required for generating precise temperatures. This type of control is not usually found in burners used for a residential system.


Recall that furnaces distribute the heat created using ductwork. When we use boilers in the heating system, hot water is distributed through pipes to heat up the commercial building. The length and number of pipe connections to distribute heat for commercial space is greater than the residential system.


Recall that the boilers in residential heating systems do not heat the water or steam to very high temperatures. This is why the boiler tank found in a residential heating system is much smaller. One tank is enough to provide heat for one average home.


The boiler and pumps used for commercial systems are of larger capacity. We can also find multiple boiler tanks and pumps that may be needed to heat up one building.


Commercial systems are designed for greater heating loads than residential systems. As commercial heating systems cater to heating requirements on a much larger scale, the components are also larger in size.



Residential vs Commercial: Ventilation System


In this module, we will introduce you to components used for the ventilation of a commercial system.

We will also compare ventilation components of commercial systems with residential systems. Skip to quiz!


Ventilation Components

Recall that a ventilation system keeps fresh air flowing through a home or building. This eliminates contaminants, moisture buildup, and odors inside the room. Ventilation is important to keep the house and its occupants healthy and comfortable.


Residential houses have windows that aid in proper ventilation. In addition to these, they have components such as fans, blowers, filters, ductwork, and dampers for ventilation. We use the same components for ventilation of commercial space.


Apart from the main components of the residential system, few more components are used for commercial ventilation, including:

  • Diffusers, and

  • Different types of the fan such as jet fan and exhaust fan.

Recall that the air is supplied from ductwork to a room through diffusers. Recall that a damper is a movable plate located in the ductwork that regulates airflow. The ventilation system uses an exhaust fan to move indoor air out of the building.


As the ventilation requirement of commercial space is more, the number of components required and their size are more. We will go over each component of the commercial ventilation system in later courses.


Component Difference

Recall that ductwork provides a closed pathway that directs the cool or hot air to definite spaces. The size and length of ductwork in commercial systems if much larger. The ductwork of commercial systems is also wrapped in different insulating materials that prevent heat transfer from the air inside the ducts.


A residential system can provide heating and cooling without using ductwork. Recall that a ductless mini-split systems does not require ductwork. It uses wall-mounted units to heat or cool the space. However, commercial systems cannot be made ductless.


Recall that fans and blowers are used in residential systems to draw air from the living room and pass it over the cooling coil. Then they force cool or hot air to enter the room. Comparatively, larger and high-power fans and blowers are used in commercial systems to force the cool or hot air through ductwork.


Jet fans are used for the ventilation of commercial spaces such as an enclosed cars in the basements of buildings. Jet fans remove carbon monoxide, and other smoke from car exhaust in basements and closed parking lots. This type of system is only used for commercial spaces.


High airflow is present inside the ductwork to provide proper ventilation to the commercial space. High airflow in the ductwork makes lots of noise. That is why ventilation of a commercial system is noisier than a residential system.


In a commercial system, ductwork is necessary to circulate cool or hot air to each room of a building. Jet fans are used for the ventilation of spaces such as enclosed car parks and basements of buildings. Ventilation components of the commercial system are noisier than residential systems.



Question #1: Which components are generally not found in residential air conditioning systems? (select all that apply)

  1. Evaporator

  2. Chilled water pumps

  3. Compressor guide vanes

  4. Ductwork

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Answer: Chilled water pumps, Compressor guide vanes

Recall that some components seen in residential air conditioning are:

  • Compressor,

  • Condenser,

  • Metering device,

  • Evaporator,

  • Blower fans,

  • Dampers, and

  • Ductwork.

Question #2: Economizers and air handling units are used in commercial air conditioning systems only.

  1. True

  2. False

Scroll down for the answer...








Answer: True

The components used in commercial air conditioning systems are:

  • Cooling tower

  • Water Pumps

  • Air handling units

  • Fan cycling unit

  • Solenoid switch

  • Economizers

Question #3: TWhich of the following components are used in a heating system? (Select all that apply)

  1. Compressor

  2. Burner

  3. Heat exchanger

  4. Condenser

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Answer: Burner, Heat exchanger

The main components of heating system are thermostat, combustion chamber, boiler, heat exchanger, and burner system.


Question #4: Power burners reduce the efficiency of the gas furnace or boiler due to inaccurate burning.

  1. False

  2. True

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Answer: False

Power burners control the mixture of air and gas in the exact ratios required for generating precise temperatures.


Question #5: Which component is used to distribute heat?

  1. Compressor

  2. Ductwork

  3. Heat exchanger

  4. Condenser

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Answer: Ductwork

Recall that furnaces distribute the heat created using ductwork. The boilers use pipes to carry hot water that is pumped to distribute heat in the space.


Question #6: What is the role of damper in ventilation system? (select all that apply)

  1. Control air flow

  2. Measure temperature

  3. Control fan power

  4. Filter air

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Answer: Control air flow

Recall that a damper is a movable plate located in the ductwork that regulates airflow. They decide how much heated or cooled air is required to feed into different areas of our ductwork.


Question #7: Exhaust fan is used to move outdoor air indoors.

  1. True

  2. False

Scroll down for the answer...