September 19, 2020

Decoding Common HVAC Terminology

If you need air conditioning, heating, and other household comfort systems, then you’ll probably end up doing some online research. A quick search may give you a lot of unfamiliar terms. These will range from confusing phrases to very cryptic abbreviations. To conduct a successful search for HVAC systems, it’s good to understand the various terms, phrases, and abbreviations. This will help you understand everything there is to the system that you purchase. To help you decode these terms, the following is a list of the most popular terminologies and their meaning.


This term is an abbreviation of the Energy Efficiency Ratio. You will mostly find this terminology used for geothermal heat pumps and also air conditioners for windows. When used, the rating provides an idea of how efficient your heat pump or air conditioner is. Using this ratio, you have a way of differentiating between and comparing various products. To calculate this ratio, EER assumes that the indoor temperatures are at 80 degrees, outdoor temperatures are at 95 degrees, and the humidity is 50%.


When looking for technicians to help you with HVAC solutions, understanding what ACCA means could be handy. This term is an abbreviation of Air Conditioning Contractors of America. The non-profit organization has a membership of more than 60,000 experts. The organization also has more than 4,000 businesses run and operated by some of the members. The ACCA provides the installation, maintenance, testing, and performance standards of cooling, heating, and other indoor systems. To find ACCA accredited contractors, you can search their website. The ACCA website also provides information on companies and institutions certified to provide you with approved systems.


Just like EER ratings, SEER is an energy efficiency ratio used to compare central air conditioners. SEER is an abbreviation of the Seasonal Energy Efficiency Ratio. The calculation of SEER involves the division of BTU per hour of the cooling by the electrical input. Once you get this figure, you can then calculate the average for any given season. In a nutshell, SEER ratings give you an idea of how much cooling you can get from your system for a given season. Systems with higher SEER ratings offer more efficiency.


This is a rating schedule for heat pumps. You could say that it is the heat pump for SEER ratings. The rating will give you the ratio of the seasonal heat output to the system’s power. BTU is the unit in which you calculate the power output. Watts are units for measuring power. Most heat pumps in the air source categories have HSPF ranging between 7 and 9. Heat pumps using geothermal heat sources have a rating of 10 and above.


Do you want to understand how efficient the ductwork in your home is? CFM will tell you just that. CFM (Cubic Feet per Minute) is a calculation that measures the amount of air that goes through your ductwork in a minute. Apart from giving you information on ductwork efficiency, CFM will help you upgrade and improve your air conditioning system.


MERV stands for the Minimum Efficiency Reporting Value rating. This systems tells you how strong filter is. If the value is high, it means that your air conditioner or furnace will more particles from the air. If your filter has a rating of 4 and below, then your filter offers minimal filtration. Filters rated between 5 and 8 can stop tiny particles. These particles can be as small as 3.0 pm. Ratings that stand between 9 and 12 mean that your filter can stop auto emissions and dust from humidifiers. If your filter has a rating of more than 13, it can prevent smoke and other airborne pollutants.

Relative Humidity

If you want to buy a humidifier or dehumidifier for your home, it would be essential to understand its relative humidity. It is a percentage that compares the actual water vapor already in the air and the capability of air to hold water vapor. For homes, you should go for systems that give you relative humidity of between 40% and 60%.

Contact the Pros

If you require services such as HVAC maintenance, repair, or installation service, call us at Scott-Lee Heating Company. We can help you find products with the best ratings for your home. Residents throughout Greater St. Louis rely on our crew.