System Sizing Guide

Running the Test

Follow the steps in the video and fill out the information in the form below. Once you submit the required information, you will receive an email with the results of the test. This estimate will help us determine which size system is right for you.

Calculating Run Time

The run time of the furnace is the measurement of how long the flame is actually on. This is usually 3-15 minutes depending on current temperatures. Taking multiple samples can help ensure an accurate size estimate.


Calculating the heating needs of your home will require the temperatures inside and outside your home. The better insulated your home is, the slower it will lose heat in the winter, which means that you do not need to replace the lost heat as quickly.

What is a BTU?

A BTU is a measurement of energy and is commonly used in the United States when referring to heat output. It is defined as the amount of energy needed to heat or cool one pound of water by one degree Farenheit (1055 joules). By understanding how hard you current furnace needs to work to keep your house warm in the winter, we can tell which size goethermal system is appropriate for you!