How Do I Know How Big of Furnace I Need? – Whether you are replacing an old furnace or adding a furnace to a home with an existing alternative heat source, you may be wondering, “How do I know what size furnace I need?”

Here are some tips to help you find a furnace that’s enough to heat your home without being over the top.

Don’t just assume replacing a furnace with the same size unit is the best fit. If the furnace is too small, it will have to run too long and too frequently to maintain a comfortable temperature. If it is too large, it will cycle on and off too often to run at peak efficiency.

How Do I Know How Big of Furnace I Need?

Life span of a furnace

First off, if you aren’t sure about the age of your furnace and are contemplating the need to replace it, it’s helpful to know most furnaces last 15-20 years. Some furnaces that have fewer hours of usage and have been maintained well can last longer but it’s good to plan for a replacement around the 15-year mark.

Understanding BTUs

The acronym BTU stands for British Thermal Unit, which is the industry standard used in measuring the heating efficiency of furnaces. Furnaces range from 40,000 to 200,000 BTUs which makes the average consumer question what the difference in rating is and how to make an educated decision on the size that will meet their needs.

Fortunately, there is a calculation professionals use to determine BTU needs.

In milder climates, you can calculate the square footage of your home and multiply it by 30. For colder climates that go below freezing regularly, multiply the square footage of your home by 60.

Here’s a quick guide:

1,000 square feet: 30,000 to 60,000 BTUs

How Do I Know How Big of Furnace I Need?

1,200 square feet: 32,000 to 64,000 BTUs

1,500 square feet: 45,000 to 90,000 BTUs

1,800 square feet: 54,000 to 108,000 BTUs

2,000 square feet: 60,000 to 120,000 BTUs

Finding a furnace with the correct BTUs for your heating needs is one of the most important decisions you will make.

Other factors besides square footage can include the layout and ductwork in your home. For a professional analysis of how these factors impact your home’s heating needs, get a free quote.

Fuel types

If you are replacing a furnace, it is usually most cost-effective to purchase a furnace that uses the same fuel source as your previous one. However, if you are adding a furnace and are contemplating fuel options, the most common fuels are natural gas, propane, oil and electricity. Depending on where you live, one of these fuel sources may be easier to come by than others. The current market price of these fuels can also be considered to ensure you aren’t purchasing a furnace that will require a fuel source that is more expensive than other options.

Programmable thermostat

When you replace your furnace, it’s a good time to look at your thermostat and make sure it is meeting your needs. If you do not currently have a programmable thermostat, this small addition can help save you big money. Home temperatures can be adjusted to keep you warm during the day, but the temperature can be automatically lowered while you are sleeping at night. Making this adjustment on a thermostat will ensure these changes are made daily and even lowering the temperature a few degrees can add up to big savings when it is done consistently. If you are taking a vacation, this is another good time to lower your temperature and save on your heating costs.

While installing and replacing a new furnace is a big expense, it can also be considered an investment. Newer furnaces have higher efficiency which will save you money in the long run.

For diagnostics, service and repair, you can contact us to set up your appointment with Three Rivers Heating.

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