fbpx

BTU

BTU and Your HVAC System

Published on: April 1, 2020

What is a BTU and What Does It Mean For Your HVAC System?

If you’ve researched HVAC systems, you’ve probably noticed a phrase like ‘Capacity: 45,000 to 135,000 BTU/H’ under the specification details.  What is a BTU? What is a BTU/H? How do they affect your HVAC system? We will answer all these questions for you in this article.

What are BTU’s?

The acronym BTU stands for British Thermal Unit.  Specifically, 1 BTU is the amount of energy needed to heat or cool one pound of water by 1°F at sea level. With HVAC systems, the measurement is often expressed as BTU/H.  BTU/H is how many BTU’s per hour a system can add or remove heat from your home.

This may still not mean that much to you, but when it comes to your HVAC system, it should. 

What Does It Mean For My Air Conditioning Unit?

Your air conditioning unit doesn’t actually produce cold air.  Your air conditioning unit makes your home cooler by extracting the heat and humidity from it.  This HVAC rating tells you the amount of heat an AC unit can remove from the air per hour.  

Central air conditioning units typically list the cooling power as tons.  However, to convert tons to BTUs use 1 AC ton = 12,000 BTU/H.  For example, the typical cooling capacity of a Carrier or Bryant air conditioning unit is between 2 and 5 tons.  Measured in BTU/H, which equates to 24,000 to 60,000.  Note: An AC ton does not equal a metric ton of weight.

Several factors will determine how many BTUs your home needs to run efficiently.  Your geographical location, home size, window quality, and insulation type all have an impact.  Don’t merely assume that the more you have, the better.  In fact, having more than necessary for your home can lead to higher running costs and more repairs.

Heating Systems

Furnaces also use this calculation as a standard specification to refer to the heat output of a particular system. In this case, the higher the BTU, the more heat the unit can generate. Heating capacities for furnaces range from 40,000 to 200,000. However, most homes opt for capacity between 80,000 and 100,000 BTU/H. 

Like with air conditioning units, a higher BTU/H capacity rating isn’t always better.  If you have a system with more BTUs than needed for your space, your system won’t run efficiently. This could lead to higher costs.  If your capacity is too low, it won’t heat the space at all.

HVAC System Professionals

The best method for calculating the required amount for your home is to contact a local HVAC professional.  A trained technician can advise you of the most efficient rating for your HVAC system needs.  Let AC Southwest® help you find an HVAC professional in your area. Contact us for more information.