September 2, 2021

How Many BTU Furnace Do I Need?


Right Amount of BTU On Furnaces

When choosing an appropriate furnace for your home heating needs, size is crucial since it highly affects your heating system’s general efficiency and functionality. Suppose one manages to settle on the right furnace size during a purchase. In that case, they’re certainly going to have an easy time maintaining the furnace’s energy costs. How many BTU furnace do I needLet’s find out.

Unfortunately, some homeowners seemingly purchase the wrong furnace sizes for their space, thus leading to unavoidable energy bills or low levels of efficiency.

When selecting a furnace size, professionals use the BTU (British Thermal Unit) to measure and conclude the energy output created by your furnace during the heating process.

How many BTU furnaces do I need? Home-heating furnaces generate approximately 40-45 BTUs when heating one square foot of your home space. Using the right calculation software, you can determine the furnace size appropriate for your home. Or contact an HVAC technician to help you estimate the proper furnace size.

Furnace BTU/Square Foot

To identify the most appropriate heating furnace for your house, you’ll not only have to know the BTU size estimation.

If you live in a mild climate, the furnace should generate around 40 to 45 British Thermal Units per square foot, i.e., a 100- 112K BTU heating furnace to heat a 2500 ft² home space.

Therefore, you’ll have to consider the BTU rating of your furnace and its efficiency levels to decide on the right furnace size for your home. The ‘Rule of Thumb’ states that you should purchase a furnace producing 40-45 BTU/ft² heat load for your home.

For instance, if you have a 2700ft² house, you’ll require a 100,000-130,000 BTU furnace to efficiently heat your home during the cold winter days and nights.

The Manual-J load procedure is a popular method in estimating how many BTU furnaces you’ll require to heat your home. Professionals consider it as one of the best and most accurate size calculation methods.

The Manual-J load is an equation determining the furnace size considering your house’s insulation, construction, ventilation, and even the size of your home space. However, this procedure should be used by experienced HVAC technicians since they’ve probably mastered the approach better than anyone else.

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Furnace Sizing Considerations

Apart from calculating the BTU rating of the furnace, there are other factors to consider. They include the efficiency level, surrounding climate, and even construction structure of the home you want to heat.

This section of our guideline will take us through the few considerations a homeowner should make to estimate the proper furnace size. Let’s go!

Furnace Efficiency Levels

The furnace’s efficiency also factors in calculating the BTU you’ll need to heat your home space.

We recommend you take your time choosing from the wide range of efficiency levels attained by different furnaces. High BTU furnaces heat more efficiently compared to lower BTU furnaces.

As stated before, you can determine the efficiency level of a particular home furnace by checking out their respective AFUE rating. High efficiency will be expensive during the purchase, but the usage energy costs will be favorably cheaper.

Low-efficiency furnaces are usually cheaper upfront but with high operating costs. We recommend you choose a high-efficiency heating mechanism if you live in a cold climate like Calgary.

Construction Structure

Your home’s construction design and structure are vital when choosing an appropriate furnace size. For example, more floors in a home will insulate the house better than a single-floor home.

The enhanced insulation of more floors improves your home’s heating efficiency. In such cases, a smaller furnace may meet your needs. Secondly, poorly sealed doors and leaky windows increase energy costs; thus, you will require a higher BTU heating system to compensate for the heat leakage.

How Many BTU Furnace Do I Need – Conclusion

There are many factors to consider when determining the size of your furnace. The above factors are guidelines in choosing the right size of furnace for your home. To ensure that you purchase the right BTU furnace, we recommend that you consult an HVAC professional.