What Size Gas Furnace Do I Need

Ownership a new furnace is a major decision these days since at that place is and then much choice on the market, including different brands, models and variants, technical capabilities, furnace types, and efficiency ratings. But one of the most essential factors to consider before purchasing a new furnace is the size that is platonic for your home.

Installing a correctly sized furnace is more than just estimating the square footage of your home. When sizing a furnace, at that place are several factors you need to consider. Now, we'll review what those aspects are, why it'south essential to properly size a furnace, and how you lot tin can purchase a furnace that'southward the perfect size for your location, environment, and comfort goals.

The goal of this article is to guide you in choosing the required size of furnace for your heating needs. It is calculated by taking the required heating BTU per square foot for virtually homes and your climate zone. Our heating BTU calculator takes these critical things into consideration, assuasive y'all to give an answer for mutual questions as "how many BTUs to heat a home?" or "What size furnace do I need?"

The BTU per square pes heating rule of thumb varies greatly depending on your climate and the surface area of your firm or room yous wish to estrus up.

Why choosing the best Furnace Size Is So Important?

Although information technology may be tempting to cull a smaller furnace to save money on the purchase price or a larger furnace to boost space-heating, but with furnaces just equally with so many things in our lives nosotros should follow the rule of Golden hateful: you demand one that is just perfect, for your home.

A furnace which is far likewise powerful volition cycle irregularly. This is problematic because it will generate hot and common cold zones around the home, decrease efficiency, crave additional maintenance, and shorten the furnace's lifespan.

A furnace which is undersized volition operate continuously and won't be able to maintain a comfortable temperature in your home. The boosted workload volition also increase your energy costs, cause maintenance bug, and shorten the life of your furnace.

Some other drawback of having a furnace that is the incorrect size is that it will reduce your heating system'southward overall efficiency.
The AFUE (Annual Fuel Utilization Efficiency) is the thermal efficiency measurement of a furnace based on normal operation. The AFUE tries to represent the equipment's actual, season-long average efficiency, taking into business relationship all operating factors.

You won't be able to get the efficiency rating you paid for if your furnace runs continuously or irregularly because information technology is the wrong size. That means more than energy utilisation and higher heating expenses.

Your furnace must be correctly sized for your home in order to perform at the efficiency level information technology is rated for.

How many BTU practise I need for my firm?

That is a crucial question that must be answered correctly. On the coldest winter days, a furnace that is way too undersized will not heat your domicile properly. Areas farther abroad from the furnace may become uncomfortably cold in your habitation.

An oversized furnace will waste big amounts of free energy, and create hot patches around vents close to the furnace before the heating wheel stops.

When you talk about furnace size, you are non talking virtually the actual physical dimensions of the unit of measurement. Rather, the size of a furnace is adamant by its heating output and the amount of heat information technology tin provide.

The output of a furnace is often measured in British thermal units (BTU) per 60 minutes. A BTU is a unit for energy, particularly the corporeality of energy necessary to raise the temperature of one pound of h2o by one degree Fahrenheit. Heat is now understood to be the same as energy. The joule (J) is the electric current SI unit for rut and energy; one BTU equals virtually 1055 J.

Furnace BTU

You lot need to remember, that "BTU/h" is sometimes abbreviated to merely "BTU". The mod unit of power for heating and cooling systems is the watt. grand BTU/h is approximately 293.one W.

Some manufacturers take started to calculate furnace size in MBHs rather than BTUs. Ane MBH is 1000 BTU per hour, then you're yet using the same unit: 60 MBH is equal to 60000 BTU.

The general BTU per square foot heating rule of pollex varies from 30 BTU per square foot to sixty BTU per foursquare pes based on your climate zone. That is a significant variation, with ane furnace being twice every bit powerful as the other, so the size factors are explained hither to help you in how to size a new furnace for a business firm.

A bigger furnace, such as one with an output of 120000 BTU per hour, volition provide enough estrus for a larger space. A smaller furnace will have a smaller BTU capacity, such equally 40000 BTU per hour, and would be suitable for only a smaller stride.

Computing BTU requirements for a firm

Permit's get-go with this very useful map. The climate becomes progressively colder from zone 1 to 3.

Observe your location on the map. If you lot're on or close the edge between two zones, choose the higher number, the cooler zone.

Canada climate zones

Have the square footage of your dwelling. If you don't know it, you can await upwardly the blueprint of the business firm, or measure rectangles inside your home. Multiply the width by length for each rectangle and add them together.

Information technology is not quite authentic, just still very useful for our purposes. While you lot shouldn't use this calculation to make a final decision about furnace size, yous can use it to get an idea of the size range to wait at when you lot buy a new furnace. You can go a basic estimate using the foursquare footage of your firm.

The general dominion of thumb is that you need between thirty and 60 BTU per square foot. Depending on your climate zone, yous can determine how many BTU per square pes you need.

Furnace BTU sizing chart

Square footage	Furnace BTU for Zone one	Furnace BTU for Zone 2	Furnace BTU for Zone three
1000	30000 BTU	45000 BTU	60000 BTU
1250	37500 BTU	56250 BTU	75000 BTU
1500	45000 BTU	67500 BTU	90000 BTU
2000	60000 BTU	90000 BTU	120000 BTU
2500	75000 BTU	112500 BTU	150000 BTU
3000	90000 BTU	135000 BTU	180000 BTU

Allow's say you live in the Greater Toronto Surface area (Zone ii), in a domicile which is 2000 foursquare anxiety. The nautical chart would tell that yous demand approximately a 90000 BTU furnace.

These are only examples with approximated values to show how these factors would affect the furnace size you need to purchase, how many BTUs needed to heat a house.

Professional furnace sizing

The best style to ensure your furnace is the right size for your habitation is to get an evaluation from a professional HVAC expert at Furnace Pro.

Furnace Pro Inc. has been proudly providing professional Furnace Installation services to accurately calculate the square footage of your home, factor in all the other elements that can impact furnace size, and requite you a precise BTU chapters for your furnace.