How Does an HVAC System Work?

August 29, 2024

What Does HVAC Stand For?

HVAC stands for heating, ventilation, and air conditioning. These systems are responsible for controlling and moving heated or cooled air throughout buildings, whether it’s a home, office, or large indoor space. While there are various types of HVAC systems, they all operate in a similar way: bringing in fresh air and using mechanical ventilation to adjust the temperature to the desired level.

HVAC units can also regulate humidity levels and enhance air quality by using air cleaners that trap bacteria, spores, and virus-sized particles. When our HVAC technician visits your home for a pre-installation assessment, they will help you choose the system and options that are most suitable for your home and needs.

What Does an HVAC System Do?

At its core, an HVAC system works by taking in air, then cooling or heating it before distributing it into an indoor space, according to the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE). This space could be anything from a single room to an entire building, like a house, office, or school. Some components of an HVAC system can serve multiple functions. For instance, your home might have separate units for air conditioning and heating, or a heat pump that handles both cooling and heating.

Beyond just circulating air and maintaining indoor comfort, HVAC systems can enhance air quality by filtering out dust, particles, spores, bacteria, and viruses. Additionally, whole-home humidifiers and dehumidifiers can adjust humidity levels, helping to maintain the ideal dew point in your home. This can make your home feel cooler without needing to rely as much on a cooling system.

All of these components connect to either a traditional or internet-connected (smart) thermostat. With a more advanced control system, you can use an app to fine-tune your HVAC equipment, ensuring each part operates efficiently. Programmable and smart thermostats can also lower your heating and cooling costs by keeping the temperature within a specified range.

Let’s talk about some HVAC terminology

HVAC systems come in many different forms, which can be overwhelming on its own, but there’s also a lot of technical jargon to understand when you’re shopping for one. Many of these terms are related to energy-efficiency standards set by the U.S. Department of Energy (DOE), with minimum efficiency requirements that can vary depending on where you live. Here are some of the key terms you should know:

AFUE: Energy consumption by heating sources, including furnaces and boilers, is measured in terms of Annual Fuel Utilization Efficiency, or AFUE. A system’s AFUE rating is a percentage reflecting the ratio between energy used and the system’s output. Higher percentage numbers indicate higher energy efficiency.

Btu: Standing for British thermal units, Btu is the specific amount of heat it takes to increase the temperature of 1 pound of water by 1 degree Fahrenheit. A Btu rating indicates the amount of energy an air conditioner uses in an hour. The higher the Btu rating, the more powerful the AC unit is.
dB vs. dBA: Decibels (dB) measure sound. The difference between these two is that dB measures all sound waves, while dBA (A-weighted sound measure) refers to sounds that a human can perceive.

EER vs. EER2: An EER rating is an air conditioner’s energy-efficiency rating as it relates to the amount of Btu it uses. EER2 is the newer version of EER that uses updated testing procedures mandated by the U.S. DOE. High EER/EER2 ratings indicate a high level of efficiency.

HSPF vs. HSPF2: Heating Seasonal Performance Factor, or HSPF, is the total heating output of a heat pump for an entire season. A high HSPF indicates a high output level. HSPF2 is the newest version of the measurement that better reflects real-world conditions.
SEER vs. SEER2: Seasonal Energy Efficiency Ratio, or SEER, measures the energy efficiency of air conditioners and heat pumps across an entire season. SEER2 is the updated version that better represents real-world conditions. A higher SEER rating means a more efficient system. SEER2 rating numbers are lower than SEER ratings because of added testing metrics.