Why Is Furnace Sizing So Important?

image of tape measure depicting furnace size and hvac installation

Large furnaces are impressive but aren’t always the best option for your home. Highly powerful machines may only offer sub-optimal results if installed in incompatible spaces. It is recommended that you match your home’s needs instead of aiming to get the largest available size. Selecting a furnace can be complex as it requires the consideration of several factors. Have an experienced HVAC technician to help you as they know how to scientifically calculate the best furnace size that’s compatible with your home. Keep reading to learn the importance of furnace sizing.

Explore Our HVAC Services Call To Schedule An Appointment

Why Is Furnace Sizing So Important?

Many people get furnace sizing wrong. They often choose furnaces using dubious criteria. They usually undershoot or overshoot the mark because they don’t have the proper guidance in selecting the right furnace, resulting in adverse effects. They will suffer negative consequences, especially if the selected furnace is far from the ideal size. It may cause physical and financial stress rather than help your family. Even the smallest gap may cause problems. Therefore, getting it right at the onset is essential so you can enjoy years of stress-free ownership. Here are several disadvantages of incorrect furnace sizing and valuable tips on how you can choose the most suitable furnace size for your home.

Call Today: (732) 349-5059

What’s Wrong with Oversized or Undersized Furnaces?

Here are several negative impacts you will experience with undersized or oversized furnaces:

Related Article: Seek A Second Opinion Before Replacing Your HVAC System


feeling chilly due to improper furnace size

An undersized furnace doesn’t have sufficient power to warm your entire home. This will become especially obvious during the coldest days of the year. The furnace may be running on full blast, but you still require layers of clothes and blankets to keep warm. The heating system can also run throughout the day but still fails to achieve the set temperature. Think about how an overworked furnace will impact your energy costs too!

On the other hand, oversized furnaces create their own issue. It will warm some areas too fast, making the thermostat think the whole house has reached the desired temperature. This will trigger the furnace to shut off even though other rooms are still cold. Occupants may complain about these uneven temperatures. The furnace will short-cycle, which causes a spike in energy costs.

Call To Make An Appointment: (732) 349-5059

Related Article: An Overheating Furnace Is A Major Concern

Furnace Efficiency

image of a poor efficiency rating depicting furnace efficiency

The activity level of a furnace dictates the fluctuations in its energy consumption. For instance, the start-up and shut-down phases tend to consume more energy. As a result, these phases should be minimized. It is during the steady state or the furnace’s middle phase that it reaches maximum efficiency. 

Oversized furnaces tend to switch on and off quickly. As mentioned above, this is a problem known as short cycling. It occurs repeatedly throughout the day, using more energy than a correctly-sized furnace. The unit will never achieve a steady rhythm. On the other hand, undersized furnaces are likely to work harder to heat your home. This can cause significant wear and tear. Heating systems account for most of the energy needs of US homes. Incorrect sizing only makes it worse for families and the environment.

Call Point Bay Fuel Today Explore Our Case Studies

HVAC Lifespan

Short cycling hinders comfort and efficiency while also causing lifespan issues on the furnace and its components. Quickly turning on and off results in faster wear and tear in components. This may cause your heating system to only work for a decade or less instead of getting 20 years of more service life. This may also happen when you have an undersized furnace.

You will need a premature furnace replacement if this occurs. This means spending thousands on a new installation. Remember that heating systems aren’t trivial investments. Therefore, you should spend money wisely and have an HVAC professional accurately assess the right furnace size for your home. Smart selection means having an experienced HVAC tech to assist you in finding the ideal furnace for your home.

Related Article: The Importance Of Home Air Sealing Your Home On Energy Costs 

Energy Costs

image of  a couple calculating bills and home heating

Everything comes at a cost. Consuming more energy means you will pay higher monthly bills. This is true whether you have a furnace powered by heating oil, propane, or natural gas. An undersized or oversized furnace will make you spend more on fuel than necessary. The difference can be thousands of dollars annually. You have to pay for this much in excess but not get anything good in return. You will experience uneven heating instead of home comfort. Ensure that you get an accurately-sized furnace to prevent wasteful spending. Ask an HVAC professional to compute the right size.

Learn More About Our Home Heating Services Call To Make An Appointment

How Proper Furnace Size Is Calculated

Here are several ways a furnace size is calculated properly:

Load Calculation

Every home has unique heating needs. Many factors can influence the load, such as orientation, layout, floor area, window type, siding material, and insulation level. Manual load calculation is a long and complex process, so HVAC professionals usually utilize advanced software to help them. They will input the values, and the software will generate immediate results.

Old-fashioned technicians may depend on rules of thumb to arrive at their numbers. However, this usually yields inaccurate results. Ensure you hire a reputable HVAC contractor who uses modern techniques to get the exact figures you can rely on. Do this when you need a heating system replacement. 

Related Article: 7 Must-Have Accessories to Improve HVAC Performance


fujitsu gas furnace upgrade toms river new jersey

Are you unsure about replacing your furnace? Do you want to study all your options before getting professional assistance? To get a quick estimate, two variables are available for you to use. The first is your home’s square footage, and the second is your area’s heating factor. Multiply these two, and you will get a rough estimate. 

Indoor heating needs to respond to outdoor temperatures. Expect mostly high temperatures year-round if you live near the equator. Moving up in latitude means the place gets colder, and the heating system load becomes heavier. For instance, California’s heating factor is 30 to 35 BTUs, while Minnesota’s is 50 to 60 BTUs.

Learn More About Our Furnace Installation Services Call To Schedule A Consultation


The regional climate is out of your control, but you can insulate your home. High insulation levels lower the influence of external factors on your home’s temperature. Place your material of choice across vulnerable spaces like floors, exterior walls, attics, and ceilings. You may also place insulation on crawl spaces or the basement. You should also seal the gaps along windows and doors. Having proper insulation can mean you can get a furnace that operates below the expected load and still works fine. For instance, you own a 1000-square-foot home in Minnesota that typically requires a 60,000 BTU furnace. The proper insulation can mean that this load may be reduced significantly.

Related Article: How HVAC Comfort Zones Cut Energy Costs


Compatibility is what is crucial when purchasing a furnace for your home. Ensure you get the furnace size that best fits your home instead of the biggest one available on the market. Have an HVAC professional conduct advanced load calculations to get accurate results. Your diligence will reward you with a longer furnace lifespan, efficient energy usage, considerable energy savings, and a comfortable home.

Get Started - Call Point Bay Fuel Today

Related Article: Key Differences Between HEPA & MERV Filters

Call Point Bay Fuel For All Of Your HVAC Requirements


For your HVAC service needs in Ocean County and Monmouth County, New Jersey, call Point Bay Fuel. Our professionally certified technicians specialize in exceptional heating and cooling installations, replacements, repairs, and maintenance. Our knowledgeable and experienced technicians can always conduct accurate and safe HVAC services.

Point Bay Fuel guarantees quality services at the most competitive prices in the area. Our tune-up services can ensure better comfort, energy efficiency, and reduced home heating costs. We can also suggest the best HVAC repair or replacement system that is within your budget. All our work comes with a guarantee. Give Point Bay Fuel a call today to schedule a service appointment. We offer free, in-home estimates.

Call Now: (732) 349-5059 Read Our Testimonials

Contact us now by calling (732) 349-5059 to speak to one of our home comfort specialists! Click the link to view our service area.