What Is The Difference Between Commercial And Residential HVAC System?

hvac systems

What Is The Difference Between Commercial And Residential HVAC System?

Regardless of whether summer is heating up your space or chilly weather has come around again, your comfort depends upon your HVAC system. It is important to understand the differences between commercial and residential HVAC systems in order to know what you should expect from each one. Here are seven main differences comparing the two.


Because commercial spaces tend to include a great deal more square footage as well as serving a greater number of people, their HVAC systems require more power than do residential systems. Sizing both systems is similar, making use of such variables as square footage, the number of occupants, efficiency, and peak usage hours. All of these variables tend to have higher values in commercial spaces, requiring a higher tonnage output for adequate cooling and heating. Generally speaking, power output for commercial units is larger, but a little less precise. In contrast, residential HVAC systems focus on more precise sizing for greater cost efficiency.


Rooftops are a common location for commercial heating and cooling systems. Though not always the case, a major reason for placing HVAC units in this area has to do with the space that they take up. Placing smaller, residential HVAC system components beside or behind a home tends to be more practical due to both dimensional space and structural features that make rooftop installation less desirable. There is a variety of reasons associated with rooftop placement of HVAC systems for commercial applications, including:

  • Saving Space. In most commercial settings, space comes at a premium and owners prefer to make use of unused rooftop space.
  • Greater Security. In addition to dimensional size, commercial HVAC systems often need a greater amount of security against vandalism or tampering. Rooftop installation allows for greater controlled access to commercial systems.
  • Noise Disruption. Operational noise from heavier systems can be disruptive. Rooftop placement allow for noise isolation.
  • Maintenance Access. A final rooftop placement consideration includes the capacity to conduct system maintenance without interrupting normal business operations.


The structure and components of a commercial HVAC system compared to a residential system varies considerably, especially in complexity. Residential systems are relatively simple in their design and the components used. They commonly include eight straightforward, standard components in every installation, which include less complex usage of the occupants. However, commercial systems must be more adaptable to the type of building or level of service they are providing. Along with the basic components necessary for controlling and dispersing heating and cooling, commercial HVAC systems often require additional components to limit or restrict treated air in various zones of the building. The reason for this relates to the use of various zone occupancy and activities that take place during different times of the day or night. Commercial units also tend to require advanced systems for exhaust alleviation, which are not necessary in most residential installations.


Residential HVAC systems are split systems. This means that certain components are present in the indoor portion of the system while others are present in the outdoor portion of the system. Modification and expansion of these components is not possible. In contrast, a commercial HVAC system is much more flexible, allowing owners to accommodate changing needs as their operations increase or decrease. Commercial systems are modular, which means that adding or taking away various components of the system can take place increasing or reducing heating capacity. The various parts of a commercial system are housed together, making upgrading and maintenance easier.


The drainage system included with a residential HVAC system is compact and contained in a much smaller area, which is often a single pan placed outside the home. The size and power of most commercial systems makes drainage much more complicated. It is common for commercial HVAC systems to include multiple pipes and pans to accommodate drainage, ensure complete evaporation and prevent overflowing. Consequently, these components add to the necessary dimensional space required to accommodate them.


A residential unit handles heating, cooling and humidity control using two components: an outdoor compressor and an indoor evaporator (split unit). Additional components are not common, because overall variations in a residential installation do not include a wide range of extremes. This is not true with a commercial HVAC system, which make use of thermostats, dampers, blowers and other systems to effect different zones of the building during different hours of the day and night. The reason these additional pieces of equipment are necessary relates to the fact that all HVAC functions are contained in a single unit rather than in a split unit.


Residential HVAC systems are relatively simple to maintain. In most cases, limited maintenance is necessary at the beginning of each seasonal phase for either the air conditioning system or the furnace and costs are minimal. Maintenance on a commercial HVAC system requires a great deal more dedication and effort due to the complexity of the various systems, the size of the unit itself and the various components of its mechanics. Commercial systems need additional monitoring, which is not a common requirement of a residential unit. This additional attention, sizing and complexity adds a lot of costs to maintaining a commercial HVAC system, making it much more expensive to operate.


Besides being more expensive to maintain, the initial investment cost of a commercial HVAC unit is typically higher. Just to help establish a baseline, the estimated cost of a basic, commercial rooftop HVAC system will start close to $4,000. However, there are a number of variables, which effect the initial cost of a commercial system, including:

  • Capacity of the Unit
  • SEER (Seasonal Energy Efficiency Rating)
  • Quality and Brand
  • Optional System Features
  • Climate and Location

Keep in mind that higher quality, more efficient HVAC systems tend to offset their initial costs through longer warranty periods, lower maintenance costs, and lower operating costs.

What is necessary to heat and cool a residence varies from what is necessary to heat and cool a commercial building. Though they produce the same objective, because of these different requirements, the HVAC systems used in each application are different. It is important to know the differences, what to expect from each type of application, and the difference in costs.

While LEGACY primarily installs and maintains residential HVAC systems, we do it better than the rest. Contact us to learn more about our services and the products we provide for all applications.

Share this post