The Pain-Free Guide to Buying a New Gas Furnace

January 30, 2014

Do you need to replace your gas furnace soon? I know all the jargon can cause your eyes to glaze over. But don’t worry; we’ll make it so the average joe (and jane) can understand.

In this article, we’ll give you a brief overview of what you need to look for when shopping for a furnace while explaining all the jargon along the way.

Ready?

Start with energy efficiency: AFUE

You want to look at energy efficiency first because it affects how high or low your heating bills will be. And living in the Kansas City area, that’s obviously a big deal.

To understand how efficient a furnace is, look at it’s Annual Fuel Utilization Efficiency (AFUE) rating. This percentage tells you how much gas the furnace uses to heat your home. The higher the AFUE percentage, the lower your heating bills will be.

There are two general levels of gas furnace efficiency:

  • Mid efficiency (80%-83%) 
  • High efficiency (90%-98%)

So what do these percentages mean to you? Think about it like this: A furnace with an 80% AFUE rating means for every dollar you spend on heating, 80 cents goes towards heating your home and 20 cents is wasted as it goes up the flue pipe.

Make cents? Good. 
 
You may hear another contractor mention conventional furnaces and condensing furnaces. But don’t get too caught up in that jargon.

These two types of furnaces are just different ways of achieving the energy efficiency levels we just mentioned.

Just remember this:
conventional furnaces=mid efficiency furnaces
condensing furnaces=high efficiency furnaces 

How to choose the right furnace energy efficiency level

It’s all about your budget.

It should be no surprise that a higher efficiency furnace costs more. So if you can’t afford a high efficiency furnace, then you’ll get a mid efficiency furnace.

But if you can afford a high efficiency furnace, the long-term savings means the furnace pays for itself, especially with our climate.

To see if a high-efficiency furnace makes sense for your family use this Life Cycle Cost Estimate tool from ENERGY STAR.  Basically, it shows you how many years it takes for a higher efficiency furnace to pay itself back through lower energy bills.

Keep in mind a furnace lives about 18-20 years.

You’ll need to get at least two installation estimates from a contractor for two different furnace efficiencies before you can use this tool.

If you want the long-term money savings of a high energy efficiency furnace, remember that we have financing available, with approved credit. 

Select the furnace burner and blower type

Regardless of the efficiency level you get, you’ll also need to decide the burner and blower motor options for the furnace.

For burners, there are different “stage” types. This option will affect how comfortable you are and how efficiently the furnace will run.

There are three different stage types:

  • Single-stage
  • Two-stage
  • Modulating

single-stage furnace burner can only run at full blast or not at all—there’s no inbetween. That means you’ll have more peaks and valleys of temperature in your home, translating to more discomfort and higher energy bills.

two-stage (or dual-stage) furnace burner has two settings when they’re on: high and low. The addition of the low option allows the furnace to keep the heat from dropping too low beyond your thermostat setting while not having to run at full blast.

modulating furnace (most efficient) can adjust its burner at any point between off and high. It’s constantly adjusting its flame to try to keep your home’s temperature constant. This provides better comfort and lower energy bills.

Similarly to the different burner types, there are 3 different types of blower motors that affect how comfortable you’ll be:

  • Single speed: Just like the single stage furnace, the blower either runs full blast or is off.
  • Multi-speed: Similar to the two-stage , it has a few different speeds (low, medium, high). It can ramp up or down to depending on what you need. Think of it as like having different gears on a car.
  • Variable speed (most efficient): Like the modulating burner, the variable speed blower can incrementally adjust how much air it blows based on your heating needs.

What you need to let a professional handle

You’ll also need to know what size/heat capacity your furnace will be.

But don’t worry about that. A contractor will have to perform a Manual J heat load calculation on your home to find the right size furnace.

Got questions? We have answers!

I hope this brief overview helped de-jargon the different types of furnaces. Feel free to ask us any questions you have. We’re always ready to help.

Santa Fe Air Conditioning and Heating serves the Kansas City area. For more information, contact us online


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