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Things To Know About Commercial HVAC Systems

Having a building that stays cool in the summer and warms in the winter – keeping your employees and clients comfortable year-round, is something you may take for granted. 

Both residential and commercial HVAC systems serve the same purpose: to cool, heat, and ventilate. However, as you would expect, commercial or corporate HVAC does it on a much grander scale. They also vary in terms of mechanisms and parts.

Understanding your commercial building’s HVAC system is an essential detail for many reasons, not the least of which is keeping the system humming along, so you aren’t stuck baking in the summer when something goes wrong, costing time and money. Today, we’ll explain some details about commercial building HVAC systems, how they work, what to expect for maintenance and more. 

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What is an HVAC system supposed to do?

All HVAC systems strive to keep temperatures comfortable, which is generally around 72 degrees Fahrenheit. Additionally, they aim to keep indoor humidity consistent at 40-60 per cent and air quality high, with CO2 less than 1,000PPM (Parts Per Million). That means that of one million gas molecules, 1,000 would be carbon dioxide, and the other would be other gases.

Although there are different types of commercial HVAC systems, they all operate similarly:

  • Air conditioner units lower temperatures by expelling hot air through HVAC refrigeration or water-cooled systems.
  • Heating systems do the opposite, using water, radiator coils, or gas to heat the air.
  • Ventilation systems use fans to circulate the air and pass it through filtration systems to clean it.

How do commercial HVAC systems differ from residential systems?

Residential systems are less complicated than commercial systems and differ significantly:

  • Size: As you would expect, commercial systems are much larger than residential systems. They also have different thermostats, condenser fans, compressors, evaporators, blowers, and dampers.
  • Location: A residential HVAC system is usually placed outside the house or on the roof, in some locales. On the other hand, a commercial scheme may be located in a building’s swamp cooler or on the roof. The latter is a great space saver, making for better noise control and easier access for maintenance.
  • Drainage: An individual AC unit may just have one drain or drain tray, but a commercial system has many pipes and drains to collect condensation.
  • Mechanism: This depends on both the structure and location. A residential HVAC system is usually a standalone unit, but commercial systems are generally modular. The parts in a commercial system are located in one spot, making it easier to upgrade or replace them.
  • Equipment: A commercial system is often massive and customized for the most efficiency and heating for the size of the building and its use.
  • Costs and maintenance: Commercial HVAC systems are much more expensive because of their complexity, and they should be installed, serviced, and maintained only by experienced commercial HVAC contractors and technicians.

The most significant difference between commercial and residential HVAC systems is their size and power. Residential units usually are smaller with less power. However, commercial properties range from small shops like coffee shops to large office buildings, warehouses, and public spaces. As a result, HVAC systems have different heating and cooling setups, layouts, and capacities to meet these diverse applications. In this article, we will consider the main types of commercial HVAC equipment options available. Check out HVAC Design and Installation Services page which has everything you might need near you.

Types of Commercial HVAC Systems

Commercial structures can benefit from a number of interconnected systems that provide heating and cooling to individual floors or other areas.

Split HVAC System

The split HVAC system gets its name from the way it’s set up and its components. The system comprises the following parts:

  • An indoor unit, such as an air handler
  • An outdoor unit, which is the condenser 
  • A programmable or non-programmable thermostat
  • A humidity control or filtration system
  • Ductwork, which moves conditioned air from the system to the building

Single-Split System

The single-split is an affordable commercial air conditioning system that is suitable for small spaces such as cafes, server rooms, shops, and offices. The compact design is easy to install, and this is why it’s preferred for new buildings or renovated commercial spaces. This is the most popular and affordable type of HVAC system, found most commonly in smaller commercial structures. These systems allow individual control of the heating and cooling for each space, making it ideal for offices with server rooms or restaurants.

This system is widespread and affordable in smaller commercial buildings and allows for each space’s heating and cooling control. This will be ideal if it’s an office building with a server room for computer equipment or a restaurant. This system features a combination air conditioner/furnace that passes air through refrigerant lines and circulates it via air ducts. However, each space you want to control, it requires a separate outdoor unit.

Domestic Air Conditioning
Domestic Air Conditioning

These systems typically include air conditioners that pass air by refrigerant lines and furnaces in one system that circulates air throughout the space via air ducts. The drawback of single split systems is that for each space you wish to control separately, you’ll need an outdoor unit – taking up precious space.


  • Cheaper to install and, therefore, ideal for small commercial spaces
  • Each of the units is self-contained. Therefore, if one breaks down, the others will still be working.
  • Energy-efficient. Each indoor unit can be used to deliver air conditioning only to the room that needs it.
  • The best solution for a single room that requires an additional HVAC system


  • It occupies a lot of space as it has an outdoor unit for each internal unit

Single split systems are the most affordable type of HVAC system and are suitable for small commercial building use. The heat and cool individual rooms — making them ideal for shops, server rooms, cafés, and small offices.

You can also use them in combinations to serve larger areas or multiple rooms. The only negative is that there needs to be enough external space to install a corresponding outdoor unit for each indoor unit.

Even though this is a less expensive system, it is very versatile, effective, and energy-efficient.

Multi-Split System

With multi-split systems, you can connect several indoor units to one external unit. These systems are usually installed in larger spaces like retail shops, doctors’ teams, and restaurants.

Multi-split systems work the same way as single-split systems, but you can connect additional indoor units to one outdoor unit. This system is often used in restaurants, shops, and offices. The fewer outdoor units you need, the less space they will take up and the more aesthetically pleasing they are to the eyes.

Multi-split systems operate similarly to the single split system but offer much higher energy efficiency and a much smaller outdoor footprint. Multi-split systems allow you to connect up to 9 indoor units to one outdoor unit. These systems also include sensors that detect temperature changes and can adjust as needed, consuming far less energy. 

Heat pumps in this type of system are also designed to move air to work with the natural flow of warm air into cool areas, saving money and energy. However, these systems do require more installation time, so the cost of installation can be higher.

A multi-split system has a lot of pipework and needs to be properly installed. Get a professional to do the job, as installation mistakes can reduce your HVAC efficiency by 30%.


  • Takes up less space. One outdoor unit can be used with several indoor units.
  • It preserves the external appearance of your building
  • The installation doesn’t require your building to have ductwork


  • The installation cost is higher
  • The installation can take longer as there is more pipework to be done

VRV or VRF System

The Variable Refrigerant Volume (VRV) or Variable Refrigerant Flow (VRF) system uses a refrigerant as its heating and cooling element. This is the best system for use in medium or large commercial spaces since it has a single condenser that can be used for more than one evaporator. Our exclusive range of services for HVAC Breakdown and Repair Melbourne will help you in many services, including Installation, or Maintenance, or Service & Repair.

Variable refrigerant flow (VRF) and variable refrigerant volume (VRV) refer to the same type of commercial HVAC system. Therefore, the two terms are used interchangeably.

This is a great HVAC solution for medium to large applications such as hotels, larger offices, or retail spaces.

These systems are best for more significant mixed-use type buildings, such as larger office buildings or hotels. 

Heat Recovery VRF systems can provide heating and cooling to different spaces at once, using warm air “waste heat” from areas of the building and delivering it to where heat is required, especially great for buildings with lots of smaller rooms. Heat pump VRF systems provide either heat or cooling and are best for larger open areas. 

VRF and VRV systems use heat pumps and heat recovery. Heat pump systems provide heating or cooling to a building at any time, which is ideal for open-plan spaces. Heat recovery systems can provide simultaneous heating and cooling to a number of areas simultaneously, making it a suitable solution for a building with different rooms. Efficient commercial HVAC systems recover waste heat from around the installation and use it to heat water and other spaces. The heat recovery system is flexible as you can cool one room while heating another.

Each of the system’s internal units uses an Electronic Expansion Valve (EEV) to control the refrigerant supply, ensuring it is in line with the demand from the building space.

There are two types of VRV systems:

  • Heat pump systems, which are used for either cooling or heat pumping. These are large multi-splits units that are more efficient for open spaces.
  • Heat recovery systems, which can cool and heat buildings simultaneously. The systems save energy and are ideal for use in commercial spaces comprising of several rooms.


  • Ideal for medium and large commercial spaces
  • Easy to install in buildings under expansion
  • Quick installation without inconveniencing occupants of the building


  • Expensive to install
  • If the unit breaks down, the whole HVAC system will be affected

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CAV System

The CAV system uses a compressor, such as Danfoss or Copeland, that operates at total capacity until the temperature required in the building is achieved.

The system is ideal for commercial spaces where temperatures remain constant for a long time, for example, manufacturing and warehouse facilities.


  • Suitable for spaces that have constant ventilation requirements


  • Produces fixed air volume, which results in high energy costs in spaces that don’t require the most increased airflow
  • Are poor at controlling humidity

VAV System

The Variable Air Volume system is suitable for spaces with varying heating and cooling needs. The system compressor or fan speed varies depending on the temperature of the room. The compressor also regulates the refrigerant flow to maintain consistent temperatures. This makes the system energy-efficient.


  • Saves energy costs
  • Suitable for buildings with variable ventilation loads
  • Superior control of humidity and temperature


  • Expensive to set up
  • The system takes up a lot of space since a fan room must be located in the building

The ideal HVAC system for your building will depend on the air conditioning needs. The right commercial air conditioner will provide value for your money.

How Long Do HVAC Systems Last?

In a world of constantly changing technology, as well as changing environmental conditions both indoors and out, HVAC systems require different kinds of care – and you may be tempted to upgrade more frequently. The current commercial HVAC units should last 10-15 years. Some of the factors that impact the longevity of your HVAC include:

  • Usage demand over the years; climate of your area
  • Quality and efficiency of the system
  • Proper installation and maintenance

Key Questions to Define Your HVAC System

Every HVAC system has essential components in common, although there are many ways to implement and optimize them. When evaluating an HVAC system, keep in mind these elements that contribute to performance:

  • What fuel is used for heating – electricity? Oil? Gas?
  • What’s the coolant – chiller? Gas air conditioner? An electric heat pump or air conditioner? Check out our range of Melbourne home paintings to help with your problem. 
  • How is the heat or cooling delivered through space? Ducted air? Water system?
  • What kind of ventilation approach is used? Is there a dedicated ventilation system?

While many large HVAC systems mix and match various components, it’s a good idea to go through this checklist before any work is done on the system. This way, you know what you’re dealing with and can recognize common points of fault.

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