What Size Furnace For 1500 Square Foot House

gettyimages-769718545 — Johner Images/Getty Images

Choosing the right size furnace is an important part of owning a home. Non just will a suitably sized furnace efficiently oestrus your firm, information technology will too keep your family comfortable and help regulate the energy bills.

Only with so many unlike sizes and models on the marketplace, how practise you lot know which furnace is best for your needs? Luckily, calculating the correct furnace size for your house is easier than yous may realize.

In short, the size of your house and your local climate volition play the largest roles in determining the right furnace for you. Withal, there are also a few other factors to consider, including furnace efficiency ratings, sun exposure and the condition and construction of your domicile.

Below, we'll walk you through everything you should know nigh shopping for a new furnace, including how they're rated and which size to consider for your home.

How furnaces are measured

Before discussing furnace size recommendations, it'south essential to sympathize the basics behind furnace ratings.

Furnace capacity is measured in British Thermal Units, which limited how much heat is required to increase the temperature of one pound of water by i degree Fahrenheit. BTUs are also used to measure out heat pumps, air conditioners and similar devices.

Residential furnaces come in diverse sizes, simply most homes should be fine with a furnace in the range of 30,000 to 100,000 BTUs. We'll explain how to cull your size beneath.

Factors to consider when choosing a furnace size

For the most accurate furnace size interpretation, you should consider a few factors, including your local climate and the square footage of your dwelling house. Here'south how these factors (and others) impact which size furnace you should cull.

Home size

Every bit you might expect, bigger houses will require larger-capacity furnaces than smaller houses. To determine an appropriate furnace size, you'll need to know the approximate square footage of all heated areas in your home.

There's a good chance y'all already know the square footage of your home, simply if you don't, try looking up your online home listing or blueprints. If you tin't find either of those, you tin can get a rough guess by multiplying the length and width of each heated room in your house and then adding it all together.

Climate

When you're ownership a new furnace in the Us, you lot likewise need to consider your climate. Depending on where yous live, your heating needs could be drastically different than someone in another part of the country. Conveniently, the US is split into several different climate zones, and so it's easy to discover yours.

If you live in a warmer part of the state, like Texas or Florida, y'all won't need equally much power from your furnace. In these zones, 30 to 40 BTUs per square human foot should get the task washed. You might even observe that a furnace isn't necessary and get a heat pump instead.

It'south a dissimilar story in the colder regions. In places similar Wisconsin and Wyoming, your furnace needs to work harder to provide heat, and so yous may need around 50-60 BTUs per square foot.

Furnace efficiency

New furnaces are rated on their annual fuel utilization efficiency (AFUE), expressed equally a per centum and mandated by the federal government. Furnaces with higher AFUE ratings volition transfer a larger percentage of rut into your home, resulting in less energy wastage and fewer emissions.

In the by, furnaces were only about 55 to 70% efficient. Today, you lot tin notice furnaces with AFUE ratings as high equally 98.5%. Although these loftier-efficiency furnaces are more than expensive, they don't demand to be as large as less-efficient models. Plus, they tin can help you salve money on energy bills since more fuel is converted into heat.

Other factors

Outside of these factors, the atmospheric condition at your domicile can also influence what size furnace you need. For example, if your house receives a good amount of sun exposure each twenty-four hours, yous could purchase a smaller furnace than someone whose house is in the shade. Similarly, if you take a newly-congenital business firm with solid insulation, your furnace won't demand to be as powerful as it would in an former or drafty house.

gettyimages-1344298893 — Marvin Samuel Tolentino Pineda

Calculating the right furnace size for your dwelling house

With all of this in mind, let'south walk through some examples to make up one's mind which size furnace yous need to keep your dwelling house warm.

Permit's say that you lot accept a brand-new 2,000-square-foot home in Houston (which is in Zone 1). In that case, you lot'd multiply your square footage by the estimated BTUs in your zone. To put it together:

2,000 square feet Ten 30 to 35 BTUs = 60,000 to 70,000 BTUs

On the other terminate of the spectrum, allow's say that you live in an older one,500-foursquare-foot habitation in Minneapolis (Zone 5). In that scenario, you'd need:

1,500 square feet X fifty to sixty BTUs = 75,000 to 90,000 BTUs

In these examples, yous'll finish up with a range of furnace sizes – which is where factors like insulation and sun exposure come into play.

Every bit a rule of thumb, you can stay in the lower end of the range if you have a newer home, good insulation and receive quite a chip of sunshine. If not, expect toward the higher end.

For the new domicile in Houston, that means about 60,000 BTUs, whereas the older home in Minneapolis would need closer to 90,000 BTUs.

The bottom line

Finding a furnace that fits your home is beneficial for many reasons, including your condolement and safety, your wallet and the environment. The examples above will requite you a good idea of what type of furnace to look for, but you lot should consult an HVAC professional person for a precise furnace size recommendation based on your domicile size, climate and other factors.

Explore more CNET coverage about this topic:

Furnace buying guide: Find the best furnace for your home
This one simple thing can help your furnace concluding years longer
Heat pump buying guide: Everything you need to know virtually this furnace and Air conditioning alternative