How Do I Choose the Right New Furnace?

Gas or Electric: Pick the Fuel Type First

Your first step is to decide whether you need a gas or electric furnace. If you live in a northern climate and natural gas is available, gas should usually be your first choice because it heats efficiently in cold weather. Electric furnaces tend to make more sense in milder regions or where a gas line is not available. Once you know the fuel type, you can focus on getting the size right.

Find Your Current Furnace's BTU Rating

To size a replacement, you need to know how much heating capacity your home requires. The easiest way to find this is to remove the service panel from your existing furnace and look for the BTU rating on the data label. You will usually see two numbers, an input rating and an output rating. Either figure gives you a solid starting point for matching a new unit, since a properly sized older furnace was already chosen for your home.

Match the Capacity, Rounding Up

Gas furnaces are sold in steps of roughly 20,000 to 25,000 BTU. You do not have to pin your heating requirement down to the last BTU. Just get as close as you can to your current rating, then select the furnace with the nearest capacity, rounding up rather than down. Rounding up gives you a little headroom on the coldest days without making the system badly oversized.

Quick Sizing Reference

Buying Your Furnace Online

AC Direct sells furnaces and complete HVAC systems online and ships them direct, but we do not perform installation or service. Once you know the fuel type and capacity you need, you can compare gas and electric furnace options and order the right match. Every order is backed by the AC Direct Price Promise, plus downloadable installation guides and free technical support.