Before you buy a furnace, you'll need to know what size it should be. To do this, you'll need to know the BTU output of your home's heating system. Is it a ductless (infrared) heating system? Or maybe a heat pump?

What's the square footage of your home and how many people live in it? These are all questions that will help determine what size furnace will work best for your needs.


Furnaces are rated by the amount of BTUs they generate. The higher the number, the more heat you'll get from your furnace.

The BTU rating for a furnace is based on three factors:

  • The size of your home

  • The size of each room in your home

  • How cold it gets outside


The burner is the part of the furnace that heats the air, which is then distributed to your home by ductwork. The BTU rating will be listed on the package and should be available in your furnace's manual if you have misplaced or lost yours.

Most furnaces have one burner, but there are some that have multiple burners installed together. For example, a condensing gas furnace may have two burners: one for heating and one for cooling purposes.

If this is the case with your furnace, it's important to know how many BTUs each individual burner produces so you can determine its total output before purchasing equipment or accessories that require additional BTUs throughout their life span (such as humidifiers or pumps).

Heat exchanger

Heat pump

Heat pumps are more efficient than furnaces in terms of how they convert energy and can be used in both hot and cold climates.

Heat pumps are also considered a greener option since they use electricity to produce heat instead of burning fossil fuels.

However, heat pumps can be quite expensive and require maintenance that can add up over time.

If you're looking for a heating or cooling solution for your home, it's important to consider all your options carefully before making any decisions.

Duct system design

Duct system design is the process of determining what type of ducts will be needed and how they should be laid out in your home.

The most important thing to remember when designing your duct system is that it should be designed to avoid under-sizing or overloading, which can lead to extra energy costs because you’re either not cooling/heating properly or using more energy than necessary.

For example, if you have too few registers (or indoor units), then all the air will go into the rooms where there are registers instead of being evenly distributed throughout your house making it harder for everyone in their rooms at once to achieve comfortable temperatures.

Or if there aren’t enough air returns in each room with a register, then there isn’t enough airflow through those spaces meaning no matter how much energy you put into heating/cooling them, they still might feel cold in winter or stuffy year-round due to poor ventilation.

The Infrared Exception

The type of infrared heater you choose will depend on your needs and the size of your space. For example, if you want to dry clothes in an outdoor shed or garage, a portable infrared heater might be a good choice.

However, if you want to heat an entire room or home, then a ceiling-mounted unit is best.

If you're shopping for infrared heaters online and have no idea which one will work best for your needs, try looking at our guide on how much energy they use (in watts) as well as their BTU rating (in British thermal units per hour).

Then compare these results with those provided by other websites that sell similar products before making a final decision!

Avoid BTU Extremes

It's important to consider the size of your home, room, and temperature range when choosing a furnishing. For example, if you live in a large three-bedroom apartment with vaulted ceilings and hardwood floors throughout, it would be advisable to purchase a furnace that is rated for a home up to 2,000 square feet.

A smaller unit would not provide adequate heating throughout the space and may cause uneven temperatures within your home.

On the other hand, if you have an oversized living room with an open-concept kitchen on one side of it that measures 600 square feet then choosing an oversized furnace will cause poor air circulation, as well as increased energy costs due to excessive BTUs being used which would make using such equipment overkill for most homeowners who live in smaller spaces or homes where rooms are separated by walls instead of having open concept layouts like yours, does now

To choose the proper BTU output for your heating system, you need to take several factors into consideration.

To choose the proper BTU output for your heating system, you need to take several factors into consideration.

  • The size of your home. A larger home requires a higher Btu output than a smaller one because the larger space will be unable to maintain a comfortable temperature without more heat.

  • The climate where you live. If you live in a colder location, such as Alaska or Montana, you will need more heat than someone who lives in Florida or Hawaii would require because it gets colder there!

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Ruthe Bosco
Ruthe Bosco
Hi! I'm Ruthe Bosco, and I'm an editor at I love cooking and trying new recipes, but I also love spending time in the kitchen with my family and friends and that's why I love the idea of having a website that focuses on sharing recipes with others who are just starting out in the kitchen. Because we all have to start somewhere, right? I'm a big fan of cooking for my friends and family, because I think it's important to be able to do something with your hands while you're spending time with people you care about. It helps everyone feel more connected and relaxed when they're sitting down together over a meal. I'm also passionate about being able to balance my work life with my personal life and because The Disney Chef is such an interesting place to work, it makes it easy for me to find the right balance between my two worlds!