Sizing a Commercial HVAC System

commercial hvac sizing

How do you size a commercial HVAC system?

A commercial HVAC system provides space heating and cooling. The system is found in larger spaces like companies, large factories, restaurants, etc. 

Commercial HVAC size is rated in tons, and the available sizes increase by increments of 1/2 tons. The typical commercial A / C for small buildings varies from 2 to 30 tonnes for big buildings. 

Here is a simple step by step ways to calculate the commercial HVAC size that you will need:

  • Calculate the square footage of the area you would like to cool down (building or room group). Notice that the equation below is focused on 8-foot ceilings, so a wider ceiling area would need a wider system. 
  • Use a volume of 500 to divide the square footage. 
  • Multiply Step 2 and 12,000. 
  • For every person who works in the building all day, attach 380 Btu. If the number varies, do take an average.
  • Add 1,000 Btu for each window within the space. Add 1200 Btu each for each kitchen
  • Finally, to determine the size of the HVAC system, divide the amount of Btu you need by 12,000

How does a commercial HVAC system work?

HVAC system facilitates three processes, which are heating, ventilation, and air conditioning. Each cycle requires a specific module that creates your commercial HVAC sizing system together—and operated by your central thermostat. 

Firstly, the thermostat will launch the heating cycle for HVAC systems with furnaces by signalling the furnace. Throughout the furnace, a gas valve must open to fire the gas flame. Then, the heat produced by the burner is used to heat the heat exchanger. As it flows through the exchanger, the heat is then transformed into the air. Once the heat is converted into air, it is distributed to the furnace using an internal motor and fan. The heat is distributed through the ductwork installed in the whole building.

Secondly, the ventilation works by releasing harmful contaminants created through flues and vent pipes during the heating and cooling process while allowing for controlled entry of new air.

Finally, refrigerants or substances used to absorb the heat, begin in the form of gas. The gas is squeezed by a pump, which increases the temperature. After the gas has adequately been pressurized, it is moved to a condensation coil. It releases the heat and transforms the gas into a more cooling liquid. A blower finally takes in the warm air and releases it over an evaporator. The liquid transforms again into a colder substance, removes the heat from the air, and efficiently cools it.

commercial hvac system

What are the types of commercial HVAC system?

The significant forms of a commercial HVAC system are:

  • Split System Air Conditioning system

Single splits are the cheapest form of air conditioning devices and are ideal for use in small commercial buildings. They provide individual rooms with heating and cooling, making them perfect solutions for small offices, stores, cafés, and server rooms. 

  • Multi-split Air Conditioning system

Multi-split controls several indoor units with one outdoor unit. They can be used to keep a large floor as well as many rooms comfortable. They are often used in places such as restaurants, offices, doctor’s operations, and shops.

  • VRF or VRV Air Conditioning.

VRF calls for Variable Refrigerant Flow, while VRV calls for Variable Refrigerant Volume. 

It is the best solution for medium to large applications, including hotels, retail spaces, bigger offices, and mixed-use buildings. The systems are powerful, robust, and simple to operate, capable of fulfilling the maximum heating and cooling requirements of larger buildings. 

What are the components of a commercial HVAC system?

There are several differences in the components that make the commercial HVAC systems operate. This fundamental component comprises: 

  • Air conditioner  
  • Condenser 
  • Air Cleaner 
  • Terminal Units
  • Chiller
What's the difference between residential and commercial HVAC?

HVAC systems have two distinct types: residential and industrial. The differences between them mainly include: 

  • Size

A commercial HVAC system is considerably larger than a residential HVAC. Bigger buildings need more significant structures. And this carries with it more complexities of how the system works.

  • Location

 A residential HVAC system is installed on the side of the home, in a garage, crawl room, or even while a commercial HVAC system is usually mounted on the building. 

  • Complexity 

A residential HVAC system is developed as a single and separated device while the commercial HVAC is built as a composite device for a commercial network. With all the parts installed together on the rooftop.

How do you calculate HVAC tonnage?

Two terms are generally used by heating and cooling professionals typically: British Thermal Unit (BTU) and Tonnage. One BTU reflects how much power is required to lift one pound of water from 58.5 degrees Fahrenheit to 59.5 degrees Fahrenheit at sea level. And a ton of air conditioning determines how much power the device will use to remove 2,000 pounds of ice over a 24-hour cycle or one ton of ice. The following step is used to estimate HVAC Tonnage:

  • Determine the area to be cooled as square footage. Measure each room’s length and width, multiply those measurements to get the square footage, and add each room’s square footage. 
  • To achieve the base value of Btu Multiply the square footage by 25. Add 400 Btu for each occupant, and 1000 Btu for each window or door outside. 
  • The projected tonnage is calculated by dividing the overall Btu by 12,000.
How many tons of AC are needed per square foot?

The rule of thumb, as illustrated below, is used in calculating tons of AC needed per square foot. 

  • Calculate the cooling load of your home and sum up all the heat sources.
  • Subtract everything to be cooled by the amount of 500 square foot areas.
  • Apply 380 BTUs for any worker employed inside a building to the estimate because commercial buildings are expected to see higher foot traffic. 
  • Add 1,000 BTUs to the calculations for each window meeting sunlight
  • Add 1200 additional BTUs to the calculations for each new kitchen in your building
  • Divide the square footage of the house by 500 to determine how much air conditioning you’ll require. 
  • Multiply this figure by 12,000 BTUs and apply the additional heat produced by walls, staff, or areas such as kitchens to that amount. 

The final value will give you a clear indication of the tons of AC needed per square foot.