Heat Pump vs Gas Furnace Calculator: Essential Factors Explained

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Heat Pump vs Gas Furnace

When it comes to heating solutions, one of the time-tested appliances is a gas furnace. But now, many property owners favor heat pumps. The choice comes down to energy efficiency – and you can find the answer with a heat pump vs gas furnace calculator. 

Heat pumps run on electricity, while gas furnaces utilize natural gas or propane. The two tools also differ in terms of the technologies they use. The long-term cost of using either depends on the fuel price in a location and the device’s efficiency.   

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Today, we will help you understand whether you should go for a heat pump or a gas furnace. So keep reading!

What is a Heat Pump?

A heat pump is a temperature control device that performs heating and cooling. The appliance works by using the method of heat transference. That means it draws warmth from the outdoor atmosphere and pushes it indoors to make the inside air warm and cozy. 

During the summer, the appliance can reverse this process and transfer heat from the indoor air to the outdoors. Thus, it is an excellent replacement for an air conditioner and a heater. Because of such versatility, heat pumps’ popularity is on the rise. 

This machine works on electricity and doesn’t produce heat. So it is an eco-friendly option. But because it needs outdoor air to have a certain level of heat that it can draw and transfer, its efficiency decreases when the outside air temperature goes below 30 F.  

What is a Gas Furnace?

A gas furnace is a heating solution that uses natural gas or propane to raise indoor temperatures. The appliance generates heat through the process of fuel conversion. The heat it delivers gets distributed in the building to raise the indoor temperature during winter. 

A gas furnace burns a lot of fuel to produce its own warmth and dissipates it into the atmosphere. So, people looking to decrease their carbon footprint do not consider a gas furnace an eco-friendly heating solution – even though it is a popular appliance. 

You must remember that a gas furnace cannot cool indoors. Buildings with furnaces usually also have an AC. However, because they have burners and heat exchangers, they work efficiently even when the temperature outside is low.

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Gas Furnace vs Heat Pump: Points of Distinction

Let’s take a quick look at the differences between a gas furnace and a heat pump to help you understand which is the right device for your property – 

Gas Furnace vs Heat Pump Comparison Table

Features Gas Furnace Heat Pump
Mechanism Heat production Heat transference
Initial Cost Lower unit price Lower installation cost
Outdoor Weather Works at any temperature Low efficiency below 30 F 
Lifespan 15-40 years, depending on maintenance 20-25 years due to year-round use
Maintenance Low maintenance throughout the lifespan Low maintenance; but needs part replacement in some models
Eco-Friendliness Converts gas to heat and by-products Runs of electricity with no heat or by-product
Noise Level Soft whooshing noise unless there’s a mechanical issue Noisy starting and turning off of compressor and noisy operations
Space Required More clearance space, but only an indoor unit is needed Less clearance space, but indoor and outdoor units needed
Heating/Cooling It only acts as a heater, with no cooling abilities It can act both as a heater and cooler
Running Cost It depends on various factors It depends on various factors
Heating Capacity 24,000-120,000 BTUs, covering 500-3,000 sq. ft. 9,000-60,000 BTUs, covering 200-1,400 sq.ft.

 Now let’s analyze the differences between the two. Take a look:

a) Mechanism

A gas furnace converts fuel, i.e., propane or natural gas, and turns it into heat to raise the indoor temperature. On the other hand, a heat pump performs its heating action through heat transference – i.e., absorbing heat from the outside to push it inside. 

b) Initial Cost

The unit price of a gas furnace is less than that of a heat pump. If your property has direct gas access, installing a furnace costs less. But if you have ductwork, installing heat pumps costs less. Furnace installation usually costs more.  

c) Outdoor Weather

Since a gas furnace can produce heat to raise the indoor temperature, it can operate in any climate, no matter how cold it is outside. But a heat pump needs heat in the outside air, which it can transfer. So its efficiency reduces below 30 degrees. 

d) Maintenance

Both need only preventive checks and filter changes. But some heat pump models need refrigerant lines and fittings changed frequently. They may also require part replacement after working for the first 10 years. Furnaces are low-maintenance throughout their lives. 

e) Lifespan

The average lifespan of a gas furnace is about 30 years. Proper maintenance can last up to 35 years, while a lack of it can reduce its life to 15 years. Heat pumps last for 20-25 years. The difference is mainly because heat pumps run throughout the year.

f) Eco-Friendliness

Gas furnaces produce heat that’s dissipated into the environment. They burn fuel, and the conversion leads to gaseous by-products. But heat pumps are known for being eco-friendly. They don’t produce heat or combustion by-products and run on electricity. 

g) Noise Level

Both appliances can be noisy when they have mechanical issues. But the heat pumps are usually noisier than gas furnaces under normal circumstances. They create a racket when the compressor starts or turns off. Gas furnaces make a whooshing sound.   

h) Space Required

Gas furnaces are installed indoors. They need 30″ clearance on all sides. However, a heat pump occupies less space because it demands only 24″ clearance on its sides. However, though it is installed outside, it needs an air handler inside.   

i) Heating/Cooling 

A gas furnace can turn fuel to heat and is a temperature control solution for cold months to keep the indoors warm. But a heat pump can transfer heat from the inside to the outdoors in summer, like ACs – and in the opposite direction during winter, like heaters. 

j) Running Cost

It’s tricky to say which heater costs higher to run. That’s because the cost depends on their energy efficiency, i.e., how efficiently they use the fuel. Costs also depend on the price of the fuel, i.e., gas used by furnaces and electricity used by heat pumps. 

k) Heating Capacity

A gas furnace can supply 24,000-120,000 BTUs – covering between 500 sq. ft. and 3,000 sq. ft. But their heating is often uneven in individual zones. A heat pump can generate 9,000-60,000 BTUs, warming between 200 sq. ft. and 1,400 sq. ft. evenly.

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Heat Pump vs Gas Furnace Calculator 

The cost of running a heating machine on a property is essential. You need to determine the cost efficiency of heat pumps and gas furnaces to determine the right heating solution for your home. The calculation requires you to look at several factors. 

Energy Cost

Gas furnaces run on natural gas or propane, while electricity fuels heat pumps. The energy source prices don’t just differ from each. The price of each fuel differs in different states. So natural gas, propane, and electricity have varied charges in each state. 

Depending on where you live, the expenditure on the fuel used by your heating appliance will change. Let’s consider Alaska, where the price of electricity is $0.228/kWh, and natural gas is $1.15/therm (price per 1000 cubic feet/10.37)

If you want a heat capacity of 60,000 BTUs, a heat pump with the highest energy efficiency rating will lead to a per-hour cost of $1.01. On the other hand, a gas furnace of the highest efficiency level will set you back by $1.16 for every hour of the same heat. 

Device Efficiency 

Every device you’ll use comes with an efficiency rating. It indicates how well the device can use the energy. Heat pumps come with an HSPF rating of 8.2 and 13. Gas furnaces come with an AFUE rating ranging from 80 to 98.5. 

For a heat pump, a rating of around 10 is considered impressive. But a gas furnace rated 95 is considered a high-efficiency heating device. But what do these ratings mean? Before buying the device, it will help if you understand the ratings. 

If a heat pump has a 10 HSPF rating, the device can produce 10,000 BTUs of heat every kilowatt hour (kWh). Assuming that we need 60,000 BTUs, it is safe to say that the 10 HSPF heat pump will take 6 kWh to yield this heat.

A gas furnace with an AFUE rating of 95% means that it can utilize 95% of the energy of 1 therm of natural gas, i.e., 95% of 100,000 BTUs or 95,000 BTUs. So it needs (60,000 BTUs / 95,000 BTUs) = 0.63 therms of fuel to supply 60,000 BTUs of heat.  

So, in Alaska, the cost of delivering 60,000 BTUs with an electricity-powered heat pump will be $0.228*6=$1.36800. At the same time, producing 60,000 BTUs with a gas furnace in Alaska will cost $1.15*0.63=$0.72 when you use a 95 AFUE-rated furnace.  

Other Factors 

These are the two most important aspects that affect the output, efficiency, and cost of operating a heat pump or a furnace. However, that’s not all. Other elements come into play, as well. The size of the property matters – and so does the external temperature. 

So if you reside in an almost frigid zone, the effectiveness of heat pumps will drop, and they’ll continue to use more energy. They are most efficient when the temperature is above 40 degrees. Here’s a calculator to help you estimate the fuel price above 60 F. 

Here’s another calculator by Maine.gov to help you compute the possible fuel prices. You can use any heat pump vs gas furnace calculator to estimate your heater’s fuel cost and energy efficiency. There are many calculators available online. 

Gas Furnace vs Heat Pump: Which One Should You Choose?

The most prominent factor for any property owner while choosing the ideal heater is the cost of operating the device in the long run. But as you must have understood by now, finding this information requires careful computations and considerations. 

But besides the estimations and numbers, there are other things you must think about. Before investing in a furnace or a heat pump, you must ask yourself if the appliance will cater to your needs.

  1. If the winters in your region remain mildly cold with an average temperature of 30-40 degrees, a heat pump is a splendid choice for your property
  2. A furnace will be more effective if you live in a region where winters get intensely chilled. It will provide better heating and keep the indoors cozy. 
  3. For a small/medium building, a heat pump is appropriate. A mini split heat pump will enable you with zonal control, while other variants will allow uniform heating.
  4. A furnace is a good choice for a large property above 1,400 sq. ft. It is engineered to heat properties as large as 3,000 sq. ft. 

Final Words

A heat pump vs gas furnace calculator can be a great tool to offer an overview of the possible energy cost you are looking at for the foreseeable future. Such calculations can help decide the ideal heating solution for your building. 

But you must have all the data about local fuel prices, product efficiency ratings, etc., readily accessible. We suggest consulting an expert to support you with the number crunching. And don’t forget to consider other aspects like climate and property area, too!


Should you have a heat pump if you already have a furnace?

The job of a heat pump is to act as a heater in the winter and a cooler in the summer months. So, if you already have an actively used furnace, switching to a heat pump is not required, especially if you live in an intensely cold region. An AC for the summer will suffice.  

Does a furnace last longer than a heat pump?

A furnace usually lasts a few years longer than a heat pump. That’s because a heat pump is usually used yearly as a heater and a cooler. But a furnace is only used in winter. Both require regular maintenance and checks for an extended lifespan.

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