June 21, 2023

Commercial HVAC in St. Louis, MO

How HVAC Systems Operate in Commercial Buildings

Regardless of the type of building you own or manage, not having the right HVAC system installed in your facility could lead to a loss of clientele and income. It can also make things difficult for your workforce as extreme temperatures occur, making the work environment less than ideal. While there are several types of commercial HVAC systems available to you, each unit is more complex than standard residential HVAC systems. Before you buy a commercial HVAC unit for your building, you should know how they work.

Understanding Commercial HVAC Systems

Commercial HVAC systems are designed to perform the same function as residential systems, which is to keep anyone inside the building comfortable while delivering high-quality air. These systems can be powered by gas or electricity. Ventilation systems are equipped with fans that bring in outside air and send it through a filtration component. The contaminated air in your building will then be expelled, which helps keep CO2 levels down.

Effective ventilation systems dilute gases, keep respiratory conditions at bay, and reduce odors. If you didn’t have this system in your building, there would be unwanted particles in the air, which would make it stale and increase the chances of mildew and mold growth.

How Commercial HVAC Works

There are three aspects of maintaining the temperature in your building with a commercial HVAC unit.

Air Distribution

Air is circulated through a ventilation system, which ensures that warm air rises while cool air falls. The air is thermally altered once it enters the unit.

Cooling or Heating

When you turn on the heating in a commercial HVAC system, the burners will produce combustion gas that’s sent to a heat exchanger. The exchanger will then warm the air before circulating it through the building. An air conditioner works in a similar fashion but in reverse. Certain commercial buildings are equipped with boiler systems that provide warmth by heating water. This water is then carried into pipes that are located along the ceilings, walls, and floors.


In order to control the heating and cooling functions, a commercial building uses programmable thermostats that send different heating and cooling signals during the day, which means that it works just like a residential HVAC unit. However, these HVAC systems can also come with direct digital controls (DDC) that are much more complex. These advanced controls allow you to benefit from improved reliability and energy efficiency in your building.

A computer uses sensors to keep track of temperature schedules and automate them. Staff members are capable of responding to the HVAC settings from a central workstation, which makes it possible for users to troubleshoot problems, perform light maintenance, and obtain performance updates. Whether your system comes with DDC functionality or basic controls, you can place temperature setbacks in the thermostat to save money. These setbacks occur when you don’t need either cooling or heating.

How Different Units Work

There are four basic types of HVAC units that you can install in your commercial building. They all work somewhat differently.

Packaged Units

A packaged unit comes with a condenser, evaporator, fan coil, and compressor. A thermostat is also provided. These systems are designed to give you everything you need in a commercial unit. Packaged air conditioners are typically window-mounted in hospitals, hotels, and condominiums. As for packaged heat pumps, they heat and cool the air by transferring heat energy to either increase or decrease the indoor air temperature.

Rooftop Unit

Rooftop units are placed on the roof to more effectively save space. The use of weather-resistant casing helps to protect the main components housed in a rooftop HVAC unit. These systems are relatively compact and come with an evaporator, blower, compressor, and condenser.

You have several options available to you when selecting a rooftop unit, the first of which involves the type of unit you’d like to purchase. You can obtain systems that either heat or cool indoor air or a unit that performs both of these functions.

The rectangular casing of a rooftop unit has an air hood that helps pull outside air in. This air will then pass through rotating metal sheets that assist with regulating the flow. Eventually, the air moves through a filter and into the coils to produce cool or hot air.

Split System

Split systems are ones that are attached to the building’s ductwork, which is similar to how a residential unit works. Since these systems are mainly designed for single-family homes, they are best used with smaller commercial buildings. This can include everything from a small office or boutique store to a cafe. Every area in the building can be controlled with DDC or a thermostat.

The main issue with a split system is that an additional HVAC unit might be required if you want every space in the structure to be controlled. Depending on the size of your building, this could lead to clutter and less available floor space. While it’s possible for zoning to be added to a split system for better control of each space, this functionality is costly.

VRF System

A VRF system is among the newest types of HVAC units that can be used in a commercial building. It was first invented in Japan during the early 1980s. They are highly advanced commercial HVAC systems that are made to be ductless. Instead of using ducts to assist with heating and cooling a home, they rely on heat recovery systems or heat pumps to move refrigerant from an outdoor unit that contains the necessary condensers and compressors. How quickly the refrigerant is sent to the building determines how cold or hot every zone becomes.

VRF systems are relatively quiet and shouldn’t take up much space in your building. The installation process is also relatively simple as long as you request installation from an HVAC technician. The majority of indoor VRF units can fit in an elevator and don’t require ductwork. VRF systems are around 30% more efficient when compared to ducted HVAC systems. The compressor can move at variable speeds to deliver more precise temperature changes, which means that energy won’t be lost in ductwork.

Contact Us

If you need to have a commercial HVAC system installed in your building, our team of technicians is standing by to provide you with quick installation services. We’ll look through your building beforehand to determine how much work needs to be done and provide you with an accurate estimate. If you have yet to purchase a commercial system, we can help you choose a long-lasting and efficient unit that will properly heat or cool your entire building. Here at Scott-Lee Heating Company, we also offer air quality solutions, new construction work, and HVAC repair and maintenance services to St. Louis residents and business owners. Additionally, we do quality metalwork. Our qualified technicians are available 365 days a year in case of emergencies. Contact Scott-Lee Heating Company today for more details about the work we do!