What’s the Difference Between Heat Pumps and Furnaces?
There are several different options you have for heating your home over the winter in Randallstown. The two most common heating systems are heat pumps and furnaces, with each having its different benefits. Discover the differences between a heat pump and a furnace and how they stack up against each other for both your heating experience and the life of the system.
How Does It Heat Your Home?
There are specific differences in how the two systems work to heat your home. Both depend on heating the air that’s circulating through the system and then pushing it back out. However, how each heats the air is different, and that changes what you experience during a heating cycle.
There are electric furnaces and fuel-burning furnaces. Electric furnaces use an electric current to heat a resistance coil. Fuel-burning furnaces burn either natural gas or propane that heats up a heat exchanger. The exhaust fumes produced by this process are vented to the outside through a flue, and incoming fresh air passes over the hot heat exchanger and is blown into the air ducts.
Heat pumps don’t create heat in the way furnaces do. Rather, they use refrigerant to absorb heat from outside your home and transfer it inside. This is the same method an air conditioner uses, just working in reverse. Heat transfers from warm to cold. The major requirement for a heat pump to work is that the refrigerant in the outside coil must be colder than the air if it is to absorb heat.
Differences in Heating Cycles
What you’ll experience during heating cycles is vastly different between furnaces and heat pumps. Furnaces raise the temperature of the air circulating through the system by anywhere from 40 to 70 degrees. The actual air temperature coming from your vents will often be about 120 to 125 degrees. This is why the air feels so warm when you put your bare feet in front of the heat register.
With this kind of temperature rise, furnaces will typically run cycles of 10 to 15 minutes. Depending on the weather outside, it will commonly run anywhere from two or three cycles per hour, with the coldest days needing more.
Heat pumps don’t produce a specific temperature rise for the circulating air. Rather, it creates a rise compared to the heat source. This means that the average temperature your heat pump will produce is around 90 to 95 degrees. This is still warm but will feel much cooler than if you’re used to the air a furnace produces.
Heat pumps tend to run longer cycles, sometimes as much as 20 minutes or more, depending on the temperature outside. It may run up to two cycles per hour to keep your home at a consistent temperature.
Which Is More Efficient?
Efficiency is measured differently between furnaces and heat pumps. Furnaces have an annual fuel utilization efficiency (AFUE) rating. This is the ratio of how much heat it puts in your home compared to the total heat it produces. There will always be some level of heat loss in a gas or oil furnace. High-efficiency furnaces have an AFUE rating of 90% or better, with 98.5% representing the current top of the efficiency range.
Heat pumps are rated according to the heating seasonal performance factor, or HSPF. This is the ratio of heat output during the cold season compared to the electricity used. The Energy Star label is awarded to any heat pump with an HSPF of 8.2 or higher. At this rating, the heat pump will generate 2.4 times the amount of heat over the chilly season compared to the energy it uses. The highest-rated heat pumps have an HSPF of 10, which is about 2.93 times the amount of electricity it consumes.
Different Types of Heat Pumps
There are several different types of heat pumps on the market, with differences in the heat source and the compressor type used. Compressors come in either single or two-stage options. Single-stage compressors run on high all the time and use the most electricity. Two-stage compressors have two different settings, running on the first stage about 70% of the time and on the second stage when it’s exceptionally cold outside.
The heat source is the more interesting aspect to consider. The easiest and lowest cost heat pump to install is an air-source model, which has an outside unit very similar to an air conditioner. However, there are also geothermal heat pump systems. The ground-source geothermal system uses coils buried in the ground. There are also water-source geothermal systems, which use deep water as the heat source.
Maintenance and Repair Differences
When you have a furnace, you also likely have an air conditioner for cooling your home over the summer. This means that you have two different units to maintain and repair.
Maintenance for heat pumps and furnaces is very similar in terms of frequency. With either unit, you want to perform fall maintenance to ensure everything is operating optimally and that there’s no indication of wearing parts.
Heat pumps also need spring maintenance to ensure that it’s switching back over to cooling mode properly and that nothing was damaged over the winter. This is similar to the spring AC tune-up. Your entire system requires two maintenance visits a year, regardless of what kind of system you have.
With repairs, however, a separate furnace and AC system may leave you with two units needing substantial repairs in the same year. A heat pump reduces that risk because it’s a single unit. If you need repairs in the spring, chances are you won’t need that same repair again in the fall.
Heat pumps cost more than furnaces to purchase and install. For an air-source heat pump, the average cost to install usually runs $3,500 and up, depending on size and what other work your current system needs, such as replacing or installing new duct work. On the other hand, a natural gas furnace will usually start at around $4,500 and go up from there, depending on size and efficiency.
However, the key to remember as you select your heating system is that a heat pump is a single unit that does the work of both the AC and the furnace. Installing an AC may run anywhere from about $4,000 to over $7,000. This means that for a dual furnace and AC system, you’re looking at a total install price starting at around $8,500. You can see where even an expensive heat pump costs less to install and operate.
Both systems have a finite service life, with efficiency dropping and repairs increasing toward the end of it. A natural gas furnace typically has a service life of 15 to 20 years when properly maintained. A well-maintained heat pump’s service life is commonly 10 to 15 years, very similar to an air conditioner.
Again, keep in mind that you have a single unit you’re replacing rather than two units. If you’re in your home for 20 years, you may replace your heat pump twice. However, for a split furnace and AC system, you’re likely looking at two air conditioners and at least one furnace replacement.
People around Randallstown have trusted HB Home Service Team for HVAC and plumbing services for over 100 years. Our team provides heating and air conditioning installation, maintenance, and repairs, along with a whole host of plumbing services. We also provide carbon monoxide monitors, smoke detectors, surge protection, and well-pump services. Call HB Home Service Team to schedule your consultation with one of our HVAC installation technicians to discuss whether a heat pump or furnace is the best option for your home.