Introduction to Commercial Systems: Chapter 2
Residential vs Commercial: Air Conditioning System
In this module, we will introduce you to components used for a commercial air conditioning system. We’ll also compare components of commercial air conditioning systems with that of residential systems. Skip to quiz!
Air Conditioning Components
Recall that the refrigeration cycle runs an air conditioning system. Residential air conditioners are used to serve the needs of smaller areas, so we use them at home. Commercial air conditioners are used in larger spaces, like 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.
Aside from these, a commercial system has additional components.
Additional components used in commercial air conditioning systems are:
Cooling towers,
Water Pumps,
Air handling units,
Solenoid switches, and
Economizers.
Recall that condensers are a type of heat exchanger that cools 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 a 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 water throughout a 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 air throughout our home. In a commercial unit, we use more than one AHU. The image to the right shows AHUs 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 a 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. Because of this, refrigerant flow is controlled by solenoid valves to control temperatures.
In a commercial system, when the cooling or heating load is high, we use an economizer. It uses wind blowing at the top of a building to cool the air inside. This reduces electricity consumption. We’ll learn about how this equipment is used in commercial systems in later courses.
Residential Vs. Commercial Air Conditioners
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 a 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 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 refrigerant to both high pressure and temperature. We use a centrifugal or screw-type compressor for commercial air conditioners. Recall that a piston-type or scroll-type compressor is often used in residential systems.
A commercial air conditioning system has additional components to provide cooling to larger 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’ll 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 a 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 heat.
Recall that the main components needed to create heat in a heating system are:
Combustion chamber,
Burner system,
Heat exchanger, and
Boiler.
We use heat distribution systems like pumps and ductwork to distribute heat throughout a building. Along with these, control components like control valves and control boards are used in all heating systems.
Let’s recall each component used in heating systems. A burner system is the section of a furnace where fuel mixes with air. A combustion chamber is the place in a system where the air-fuel mixture is burned.
The air-fuel mixture flows through a burner and is lit by an 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 a heat exchanger. This same principle is used to provide heating in a commercial space. Although, the components are larger. We will go over each of them in later courses.
Component Differences
As residential heating systems provide heat to a much smaller area, the combustion chamber is much smaller in size. The combustion chamber of a commercial system is bigger. It’s 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 a heating system, hot water is distributed through pipes to heat up a commercial building. The length and number of pipe connections to distribute heat for commercial space is greater than that of a residential system.
Recall that the boilers in residential heating systems do not heat 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’ll 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 rooms. Ventilation is important to keep a house and its occupants healthy and comfortable.
Residential homes have windows that aid in proper ventilation. In addition to these, they have components like fans, blowers, filters, ductwork, and dampers for ventilation. We use the same components for ventilation in commercial spaces.
Apart from the main components of a residential system, few more components are used for commercial ventilation, including:
Diffusers, and
Different types of the fans like jet fans and exhaust fans.
Recall that air is supplied from ductwork to a room through diffusers. Recall that a damper is a movable plate located in ductwork that regulates airflow. A ventilation system uses an exhaust fan to move indoor air out of a building.
As the ventilation requirement of commercial space is more strict, the number of components required is higher. They’re also larger. We will go over each component of a commercial ventilation system in later courses.
Component Difference
Recall that ductwork provides a closed pathway that directs 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 a space. However, commercial systems cannot be made ductless.
Recall that fans and blowers are used in residential systems to draw air from living rooms and pass it over cooling coils. Then they force cool or hot air to enter a room. Comparatively, larger and higher-power fans and blowers are used in commercial systems to force cool or hot air through ductwork.
Jet fans are used for the ventilation of commercial spaces, like enclosed car parks and 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 ductwork to provide proper ventilation to a commercial space. High airflow in ductwork makes a lot of noise. That’s 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 like enclosed car parks and basements of buildings. Ventilation components of a commercial system are noisier than residential systems.
Question #1: Which components are generally not found in residential air conditioning systems? (select all that apply)
Evaporator
Chilled water pumps
Compressor guide vanes
Ductwork
Scroll down for the answer...
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.
True
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: Which of the following components are used in a heating system? (Select all that apply)
Compressor
Burner
Heat exchanger
Condenser
Scroll down for the answer...
Answer: Burner
Heat exchanger
The main components of heating systems are thermostats, combustion chambers, boilers, heat exchangers, and burner systems.
Question #4: Power burners reduce the efficiency of a gas furnace or boiler due to inaccurate burning.
False
True
Scroll down for the answer...
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?
Compressor
Ductwork
Heat exchanger
Condenser
Scroll down for the answer...
Answer: Ductwork
Recall that furnaces distribute the heat created using ductwork. Boilers use pipes to carry hot water that is pumped to distribute heat in a space.
Question #6: What is the role of a damper in a ventilation system? (select all that apply)
Control air flow
Measure temperature
Control fan power
Filter air
Scroll down for the answer...
Answer: Control air flow
Recall that a damper is a movable plate located in 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 fans are used to move outdoor air indoors.
True
False
Scroll down for the answer...
Answer: False
Ventilation systems use an exhaust fan to move indoor air out of a building.
Question #8: Which ventilation component is not required for both commercial and residential system? (select all that apply)
Air filter
Fan
Blower
Ductwork
Scroll down for the answer...
Answer: Ductwork
In commercial system we use ductwork to circulate cool or hot air to the each room of a building. A residential ventilation we may or may not use ductwork.
Question #9: Separate ventilation fans are not used for ventilating enclosed car parks.
True
False
Scroll down for the answer...
Answer: False
Jet fans are used for the ventilation of enclosed car parks such as basements of building.