April 19, 2022

The science behind commercial HVAC is often misunderstood by business owners and facilities managers alike. However, understanding how these two elements work together to maintain a functional, high-performing commercial HVAC system is important to ensuring maximum productivity for your corporate building. 

This blog gives a detailed overview of these concepts to facilitate designing more efficient and environmentally friendly buildings that have minimal impact on indoor air quality, create an overall comfortable atmosphere with regards to temperature and humidity, and lower the overall energy consumption. 

Commercial HVAC 101

Commercial HVAC systems are the backbone technologies that keep commercial buildings comfortable. Typically, standard commercial HVAC systems have four primary components:

Heating: The heating part of your commercial HVAC system can work in a variety of ways. Some buildings use furnaces, boilers, or direct-fired heaters to warm the air before it’s circulated. Others use heat pumps for more efficient heating.

Ventilation: Ventilation brings fresh air into a space, while expelling stale air. Ventilation can be accomplished with fans, but in many commercial buildings ventilation is done via an air handler that pushes stale air out while bringing in fresh air in.

Air conditioning: This is the most “visible” aspect of HVAC, since most people are familiar with window units and central air conditioners. Air conditioning uses refrigeration to cool down the inside of a building on hot days.

Controlling components: All of these systems need controls to make sure they’re working properly and efficiently. While large commercial HVAC systems typically have complex computerized controls, smaller systems may use simple on/off switches or thermostats to control temperature levels in a building.

Now, let’s dive into the basics of air and energy for commercial buildings.

Commercial HVAC Airflow Basics

The rate at which air moves through a building is an important factor when maintaining maximum occupant comfort. Airflow is measured as the volume of air that passes through an opening; cubic feet per minute (cfm) in imperial units, or cubic meters per second (m3/s) in metric. The airflow rate depends on several factors, including the size of the opening, the density of the air, and the difference in pressure across the opening.

Air enters a building through openings like doors, windows, and vents before it circulates around the building and leaves again. This could be through the same openings it entered by, or through purpose-designed outlets like air conditioning units.

There are two types of airflow: natural and mechanical. Natural airflow is caused by differences in air pressure between two locations – air flows from areas of high pressure to areas of low pressure. Mechanical airflow is forced by an external source, such as an electric fan or HVAC system.

Commercial HVAC Energy Efficiency

Energy Efficiency (EE) is the use of technology that requires less energy to perform the same function. In commercial HVAC systems, it means improving performance while reducing energy consumption and cost.

There are two main approaches to EE in commercial buildings:

Components – making the equipment more efficient by installing more efficient components and optimizing the design based on real-world operating conditions. This approach can be applied to new construction or retrofits.

Systems – taking a holistic view of a building’s energy usage and applying combinations of equipment, controls, and practices to improve overall efficiency. This is most often used for retrofits due to the cost of integrating multiple systems together during new construction.

Commercial HVAC Service and Solutions by Donnelly Mechanical

With ever-changing building codes and environmental policies, adopting a comprehensive approach to commercial HVAC design, installation, and maintenance is necessary for keeping up with the latest developments and ensuring an optimal building environment for all. To learn more about the commercial HVAC services and solutions that are right for your systems, contact the Donnelly team today

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