What does HVAC really mean? 
HVAC Acronyms and Ratings Explained

When I go to people’s homes to provide HVAC quotes, I want the process to be valuable and informative. When describing our product offerings, often, each item has its own rating system. 

This can be confusing!!

AFUE, MERV…What does it all mean? 

Let’s take a quick look at some common ratings. 

What do the acronyms stand for and what do they mean for you?

Heating, Ventilation and Air Conditioning. 

This is what we do!  Our whole business revolves around HVAC. 

For a full description of an HVAC system and how it works in your home, please read our blog post, here.  

Filters are rated by MERV: Minimum Efficiency Reporting Value.  The higher the rating, the more efficient the filter is at capturing particles. 

Most standard 1” filters are rated at MERV 8. 

For more information, we have a detailed blog post describing MERV, here.  

Furnaces are rated by AFUE: Annual Fuel Utilization Efficiency. 
The higher the rating, the more efficient the furnace is.  It is the percentage of heat produced for every dollar of fuel consumed. 

What does this mean? 

To illustrate: How old is your furnace?  Older furnaces may only be 65% AFUE.  This means that 65% of fuel is turned into usable heat, whereas the rest is wasted!  It’s literally burning out your chimney!  AFUE rating is important to the environment, and your bottom-line! 

Do you like to save money? 

A higher AFUE rating can save you hundreds of dollars a year. 

Air conditioners are rated by SEER: Seasonal Energy Efficiency Rating. 

The higher the rating, the more efficient the AC is – that is: the less electricity the unit will use to cool your home. 

British Thermal Unit. 
One BTU is the amount of energy needed to raise the temperature of one pound of water one degree Fahrenheit. 

How does this work in your home?  

There are a number of factors to determine how many BTUs are required to warm your home.  These factors include: 

• The square footage of your home
• The climate
• Furnace efficiency 

Typically, the square footage is multiplied by a climate factor of 40.  This number is divided by the furnace efficiency.  This is how many BTUs are required to heat your home. 

In this example, a 2000 square foot home would require 80,000 BTUs in our climate.  However, this requirement is larger, depending on the efficiency of the furnace.  If you are looking at purchasing a 90% AFUE furnace, you would need 88,888 BTUs to heat your home. 

This isn't really an exhaustive list.  What did we miss? 

Are there any other Acronyms or Rating Systems that you would like to learn more about?  

Please let us know in the comments, below!