There are typically two types of heating systems to choose from: furnaces or heat pumps. Whether you live in Santa Clarita, California or the colder climates of Montana, figuring out what type of heating system to use in your house can be a difficult decision, and we are often asked the pros and cons of these two systems. So which should you choose, heat pump or furnace? The biggest factor in answering the heat pump vs furnace question is to first ask yourself what part of the country you live in. Heat pumps, for instance, will only work in places with mild winters, whereas furnaces can brave the harshest winter climates. But before we discuss a heat pump vs furnace debate in more detail, we first need to take a more in-depth look at each of these systems, and what they are designed for. Those of you who read our articles regularly, know that we are a small, U.S. Veteran-Owned HVAC company in Southern California, and pride ourselves in giving people honest, straight answers to their questions. In this article, we will discuss heat pumps, furnaces, and then show you how to figure out which is best for you and your climate.
First, How are Heat Pumps and Furnaces Measured?
Annual Fuel Utilization Efficiency (AFUE)
Before you tackle the heat pump vs furnace question, you first need to know how to compare the two. Any type of heater, whether it is a gas furnace or an oil furnace, is measured using a rating called Annual Fuel Utilization Efficiency (AFUE). The AFUE is an objective means of comparing two different types of heaters, and is shown as a percentage. It can be thought of as kind of like a SEER rating for heaters. For instance, an AFUE of 60% would mean that 60% of the fuel burned by this heater can be used as useful heat to warm your house, and the other 40% is wasted through your exhaust vent. The higher the AFUE percentage, the more efficient the furnace or heat pump is. Below is a chart that directly compares different types of fuel – as you can see, some fuels are far more efficient than others:
More can be found on AFUE from Wikipedia: Wikipedia – AFUE Heat Pump vs Furnace Fuels.
Heat Pumps and SEER
But Tim, why are you talking about SEER values in an article about heaters? Because, a heat pump, which will be discussed in more detail later, is basically an air conditioner that has the ability to run in reverse, heating your house instead of cooling it. A heat pump is 100% electrical…it doesn’t burn fuel like a furnace does, so it can’t be rated with AFUE! Instead, it is measured the exact same way as your air conditioner – using a SEER value.
SEER stands for Seasonal Energy Efficiency Ratio, and it is a means of (poorly) measuring the efficiency of your air conditioner or furnace throughout the season. I say poorly because it is based on laboratory measurements, in a controlled environment – we have not seen any of the high SEER units truly decrease electricity bills to the degree that they claim (although they will decrease your bill some). It is ranked on a scale between SEER 7 (no units less than SEER 7 still exist), and SEER 21 (or whatever the highest SEER on the market is at the time), with higher SEER values being more efficient. On average, most heat pumps on the market are SEER 14 0r SEER 16.
For more on SEER, and what it means, see:
Before we directly compare a heat pump vs a furnace, we will have to know the difference between them and how they work. A heat pump is a machine that transfers heat from an area of cool air (called a “heat sink”) to an area that is warmer. The most obvious application for this is to remove heat from the air outside of your house and transfer it into your home as a means of heating. If you are familiar with how an air conditioner or refrigerator works, a heat pump is essentially the same thing only run in reverse.
In fact, the term “heat pump” itself can be a bit misleading, as people often assume that it is only a means of heating a home, but the name actually refers to the fact that it transfers heat, not the direction it directs the heat to. In actuality, any heat pump can also theoretically be run in reverse in which case it is referred to as an “air conditioner.” Are all heat pumps air conditioners and vice versa? In theory yes, but in practice, no they are not – this is just a matter of manufacturer’s preference and the intended use of the HVAC unit. Simply put, all air conditioners are heat pumps, but not all heat pumps are air conditioners. An air conditioner is a heat pump that is specialized for hot weather operation. If an air conditioner can be reversed and used as a heater too, then the unit is referred to as a “heat pump.”
Check out how air conditioning works.
Heat Pump vs Furnace – Heat Pump Pros as a Source of Heating.
Heat pumps have quite a few advantages, the most notable of which is their energy efficiency with modern heat pumps ranging from an AFUE of around 80% to over 95%. A heat pump uses electricity to transfer heat from one area to another, which means that it never has to generate heat itself. It simply moves the heat that already exists from one area to another like from the outside of your home to the inside. A heat pump is also more environmentally friendly because it requires no fossil fuels to heat your home.
Cons of a Heat Pump.
So why aren’t heat pumps the standard for cold weather? They seem almost too good to be true? Well, there’s a catch. Because heat pumps are transferring heat from one area to another, what happens if it is -20 degrees outside in the middle of a North Dakota winter? Is there any heat to transfer into your house? That’s the catch. A heat pump only works well if the temperature is above freezing, and is almost useless in the middle of a harsh northern winter. Ideally a heat pump is used when the temperature outside is over 50 degrees fahrenheit, so heat pumps are out if you live in Montana unless you also have a supplemental means of heating your house. So what do people in Bozeman, Montana do? They use a furnace.
Heat pumps can also suffer from Dirty Sock Syndrome, so make sure you learn proper sanitization for your heat pump before you even turn it on: Dirty Sock Syndrome.
Here is where the heat pump vs furnace discussion really becomes clear. A furnace uses a fuel to generate its own source of heat and then circulates this heat throughout your house. There are many types of furnaces, including gas furnaces, oil furnaces and electric furnaces, all of which have their pros and cons but essentially accomplish the same thing – they utilize a fuel to burn as a means of heating the air inside of your home.
Heat Pump vs Furnace – The Pros of a Furnace as a Means of Heating.
The biggest pro that a furnace has is that it will heat your home in any condition, regardless of outside temperature. If it is 50 degrees out or -10, a furnace will burn it’s fuel and heat your home. This reliability is priceless if you live in colder regions like Bozeman. Another pro in the furnace category is the initial investment price. A furnace is generally around $500 to $1000 cheaper than a heat pump when installed, not including any duct work. That’s not chump-change.
Cons of a Furnace.
The biggest argument against the use of a furnace is the cost of fuel. Depending on the type of furnace that you purchase, you can be spending thousands of dollars a year on fueling your furnace. I’d recommend you take a look at the most common types of fuel for your area because even though you might plan on buying a gas furnace there might not be gas available in your area. Don’t just assume that the fuel you use to heat your home is your choice. A lot of it depends on the infrastructure of your area.
As you can see, propane is twice as expensive as some of the other fuels, so do some research on your area. Furnaces also have a large range of efficiency, ranging from AFUEs of 55% to over 90% depending on what type of fuel and furnace you use, as well as how much insulation you have. Again, this is as much of an art as it is a science, but don’t just assume that whatever your neighbor uses is the best type for your region.
For more information on proper insulation: What type of insulation should I use in my attic and how much?
Heat Pump vs Furnace – Which Should You Choose?
The biggest factor that should be used to examine the heat pump vs furnace debate is the region you live in. In general, if you live in Bozeman, Montana or any northern states that endure harsh winters, then a furnace will be your best option. If you live in Santa Clarita, California or some of the southern states that only rarely dip below freezing, then I’d recommend a heat pump option for your home. Here is a rule-of-thumb temperature range that you can use:
Heat Pump – Average Winter Temperature > 50 Degrees Fahrenheit.
Furnace – Average Winter Temperature < 50 Degrees Fahrenheit.
It is important to note that although a heat pump itself does not work well below 50 degrees, you can purchase heat pumps that have a hybridized approach by incorporating an electric heat source into them for use if the temperature drops below the ideal range for your heat pump. This is useful to know if your winter climate is somewhere in between the furnace and heat pump ranges or if you are on the fence with your decision.
Final Thoughts on the Heat Pump vs. Furnace Debate
The heat pump vs furnace debate is a difficult decision to make, but hopefully you now know some of the pros and cons of each. In general, the bigger factor that should be used in your decision is the region you live in. If you have cold, snowy winters, go with a furnace. If you have mild winters like in California and Florida, stick with a heat pump. For more information on related topics, visit the ASM Air Conditioning Blog. ASM is based in Santa Clarita, Los Angeles and San Diego – if you live in our area, don’t hesitate to give us a call with any questions you might have – we’d be happy to help you: