Here is Why You Should Use a Heat Pump for Heating


You heard it right. I said you should use a heat pump for heating. You may or may not have heard about a heat pump. In short, a heat pump is able to replace your gas furnace and save you tons of money on a monthly basis.

Many people are switching from a gas furnace to heat pumps for heating now. A heat pump is not a new technology but it is relatively new to some people, especially those who are using a gas furnace all the while.

“Canada is considering mandating energy performance greater than an efficiency factor of 1 (equivalent to an equipment efficiency of 100%) for all heating technologies by 2030, which would effectively prohibit all conventional coal-, oil- and gas-fired boilers.”

IEA (2020), Heat Pumps, IEA, Paris https://www.iea.org/reports/heat-pumps

I’m sure you know what is an air conditioner. Well, a heat pump is exactly like an air conditioner but better. A heat pump is able to provide both cooling and heating through process reversal.

With a heat pump, you just need to press a simple cool/heat mode on the remote controller to switch between cooling and heating.

The appearance, performance, reliability and maintenance of a heat pump are exactly the same as an air conditioner.

So, why I said you should use a heat pump for heating?

You’ll Save Money with a Heat Pump

You’ll save money with a heat pump. For a single-family home, a heat pump system is 4.86 times cheaper to operate than a propane gas furnace heating system. At the same time, a heat pump system is 4.08 times cheaper to operate than an oil furnace heating system.

When compared to a natural gas furnace, a heat pump heating system is 29.13% cheaper to operate. Meanwhile, a heat pump system is 3.87 times cheaper to operate than an electric boiler heating system.

Below is a table of comparisons for the operating cost between different heating solutions for a single-family home:-

ComparisonPropane Gas
Furnace
Natural Gas
Furnace
Oil
Furnace
Electric
Boiler
Ductless
Heat Pump
Fuel Cost ($)2.86/Gal0.96/Therm3.88/Gal0.1/kWh0.1/kWh
Heater Efficiency (%)859085100380
Distribution Efficiency (%) 98989898100
Operating Cost per Year ($)2,556.14742.022,146.252,039.18525.82
Operating cost comparison between different heating solutions (source)

As you can see from the above table, by using a heat pump, every year you will:-

  • Save $2030 vs propane gas furnace
  • Save $216 vs natural gas furnace
  • Save $1620 vs oil furnace
  • Save $1513 vs electric boiler

Notice that the heat pump has a significantly higher efficiency that results in a massive amount of saving on the operating cost. Furthermore, these furnaces are Energy Star products that have exceptionally good efficiency.

Most houses are using either an old furnace or a standard furnace that couldn’t possibly have such a high-efficiency rating which pulls them even further away from the heat pump in terms of the operating cost.

In fact, a heat pump user had shared his 6 years of savings on YouTube. His heat pump system had saved him $958 per year and the return on investment is 4 years only. You can watch his video here.

Moreover, the annual savings using a full heat pump system is $459 when compared to electric resistance heaters and $948 when compared to oil systems according to the Department of Energy.

So, operating a heat pump system is cheap but why?

Heat Pump Basics

A heat pump works just like an air conditioner. It uses a refrigerant to transfer heat from outdoor to indoor. So, where is the outdoor heat come from? To explain that, I must first let you understand the working principle behind a heat pump.

Major Components

Most heat pumps have one outdoor unit and one indoor unit. At the outdoor unit, we have 4 major components; a) evaporator coil, b) expansion valve, c) compressor, and d) reverse valve.

Meanwhile, we have 2 major components at the indoor unit; a) expansion valve, and b) condenser coil.

Below are two diagrams illustrating the major components of a heat pump:

I will not go into the detail of each component. Instead, you’ll understand how these components work to extract heat from the ambient air in the following.

Refrigerant

The outdoor unit and the indoor unit are connected by refrigerant pipes to let refrigerant flows between them in order to perform heat transfer.

A refrigerant is a chemical compound. Most existing heat pumps are using the R410A refrigerant while newer heat pumps are using the R32 refrigerant.

But, why do we use a refrigerant for heat transfer?

Refrigerants are engineered products that possess the characteristics we need to make air conditioners and heat pumps work. They are just like fuels where we mix them up with some other chemicals to make them work inside a car engine.

An installed heat pump

The refrigerant is flowing inside the copper pipes that connect the outdoor unit and the indoor unit in a closed loop. See more about it in my post How Air Conditioner Works?

The refrigerant is the key that a heat pump is able to extract heat from the ambient air even though the ambient temperature drops to near freezing point.

Sometimes, it is really confusing. How come any more heat can be extracted when outside is so cold?

Well, it is the refrigerant that makes the seemingly impossible thing possible.

Now, let’s look at how a heat pump extracts heat from the ambient air.

Heat Extraction

The sole purpose of the following explanation is for a beginner to get a grasp on how a heat pump extracts heat from the ambient air. The figures are tuned for easy understanding and they don’t represent the actual numbers.

At the outdoor unit, a refrigerant passes through the expansion valve which causing its temperature to drop to 41°F (5°C).

Let’s say the outside air temperature is 50°F (10°C). So, the outdoor unit fan draws the ambient air to provide heat energy to the cold refrigerant.

Technically, the refrigerant doesn’t change in temperature because the heat energy is used for phase change.

Now, the refrigerant had changed completely from liquid to gas to prepare itself for the compressor.

Inside the compressor, the refrigerant gas gets compressed and its temperature is raised to 104°F (40°C). Now, the refrigerant becomes hot already.

So, the hot refrigerant travels to the indoor unit where you get the warm air from. Then, the refrigerant returns back to the outdoor unit and the cycle repeats.

Honestly, the above example is an extremely simplified version but I think it’ll make you understand better.

Here is a visual diagram in addition to the above explanation:

While I used an outside temperature of 50°F (10°C), a heat pump can still work below that. See more about Do Mini Splits Work in Cold Weather?

Now, you know how does a heat pump extracts heat from the ambient air.

Let’s proceed to see why a heat pump is so efficient.

Efficiency

In layman’s terms, a heat pump amplifies the heat gained from the ambient air and transfer the amplified heat into the house.

The refrigeration cycle which I just explained above is the “amplifier” that makes a heat pump so efficient.

A gas furnace burns fuel directly to generate heat while a heat pump doesn’t generate heat but transfer the “free” heat from the ambient air into the house.

“Heat pumps don’t generate heat. They transfer heat.”

Therefore, a heat pump doesn’t need to use much external power because a portion of it is “subsidized” by “free energy” from the ambient air.

In many countries, heat pumps are considered a renewable energy solution.

Ok, heat pumps are good but, it is worth it for you?

Heat Pump Purchase Cost

A typical 9,000 BTU ductless mini split heat pump cost around $800-$1000 to purchase while some are available at around $700 but I don’t recommend the cheaper one though.

Heat pumps are sized based on per room basis. What I mean is you need to calculate the capacity needed for each room instead of the total square footage of your house.

Most of the time, you’ll be using one unit of 9,000 BTU heat pump in the bedroom, study room or other standard rooms. If you have a big living room, usually a 12,000 BTU heat pump will do the job.

You rarely need anything above 18,000 BTU for a single unit of the heat pump.

For a single-family home, you may have three normal bedrooms, one primary bedroom, one living room, one dining room and one small study room. Thus, you’ll need 7 units of the ductless mini split heat pump.

If you opt for a ducted system then yes, you’ll need one single large capacity heat pump but I suggest you still calculate the total capacity based on per room basis.

Here are a few posts that may help you in sizing the heat pump system:

Heat Pump Installation Cost

As for the installation, most people usually call for a professional to help but you can install it by yourself especially when you buy from DIY-friendly brands such as MrCool.

Nevertheless, the installation cost for a 9,000 BTU ductless heat pump can range from $300-$1500 based on location but is too wide of a price range for anyone to do a budget.

The problem is there are not many competent ductless heat pump installers in the United States, causing the installation cost of a heat pump equivalent to the purchase cost which is too high overall.

In Malaysia, for example, our installation cost for a 9,000 BTU air conditioner (we don’t need heat pumps) is only about 10% of the purchase cost.

Time Taken

If the installer is competent, it shouldn’t take more than 3 hours or even 2 hours to install one heat pump unit complete with testing.

Previously, when I moved into my new house, I call up a friend to help me install 8 units of the air conditioner. He brought another skilled worker to speed up the work. In the end, it took them a solid 9 hours from 10am to 8pm (excluding lunch hour) to complete all 8 units with testing.

However, my house was pre-installed with concealed refrigerant pipes, drain pipes and power cables. So, they are able to finish one unit in about an hour.

But, if an installer tells you that they only can finish one or two heat pumps per day. Ask them why!

Nevertheless, the electrical side sometimes may take longer than expected especially when the house was not designed for multiple heat pump units. Breakers, conduits, switches and cables are all needed to modify/install a new set and these work eat up a significant amount of time.

Hourly Rate

Now, let’s do the math:-

In the United States, a typical HVAC technician labor cost is about $75-$150 per hour.

Let’s just use $100 for an easy calculation.

Assuming that it is really difficult and a heat pump unit needs 4 hours to install, one unit will cost you $400 to install only. Even if the installation needs extra accessories, it’ll add what, like $50? The total installation cost of one unit shouldn’t be more than $450.

But, if you need the electrical modification work that I mentioned earlier, then it’s a different story. It’ll be much more expensive.

I was shocked when I saw owners share their ductless mini split installation cost on Quora and Reddit. Some of them said they paid $1500 on the installation for one unit. It is ridiculous.

Contractor

However, I understand that the problem is due to the lack of ductless mini split installers. Central air conditioning contractors sure will charge you more.

The United States is huge. Different areas have different installation costs but the purchase price remains the same.

You can seek advice from the manufacturer. They should be able to lead you to a good installer that can protect both your installation quality and their reputation. For example, Fujitsu’s contractor search.

Most ductless mini split heat pumps come with all the brackets, refrigerant pipes and accessories that are sufficient for a full installation. But, keep in mind that they don’t provide tools.

Brands like MrCool are doing a very good job in designing their mini splits for DIY-ers. They even have a very detailed installation video.

Return on Investment

Now, let’s do a calculation on the ROI that you’ve been waiting for:-

Given that a house with 1500 square feet is replacing an old centralized propane gas system. Typically, two to three units of the ductless mini split heat pump should be sufficient to heat the entire house.

Using an average cost of $900 per unit, the total purchase cost for three heat pumps is $2700.

Now, let’s expect a high installation cost of about $800 per unit and thus, the total installation cost is $2400.

So, the overall cost of the new heat pump system is $5100.

Taking an annual savings of $948, the new heat pump system will break even in just a little more than 5 years.

As for the service and maintenance, one heat pump may cost about $85 to service depending on your location but you can always service by yourself.

The most expensive part of a heat pump is the compressor but companies like Daikin offer 10 years warranty on the compressor while most companies offer a standard 5 years warranty (at least).

All and all, we are looking at a return on investment within 6 years. If you ask me, I think it is a pretty decent return considering that a heat pump lasts about 10-15 years.

Furthermore, if you are a hands-on person, you can save on the installation cost which will give you an even greater ROI in just 3 years.

Environmental Contribution

Let’s talk about the environmental issue. It is a hot topic nowadays and it will continue to be a major topic to be discussed globally.

IPCC just released the most comprehensive report on climate change here.

Cooling and heating are producing a lot of carbon dioxide. Particularly, electricity generation and heating emit the most carbon dioxide.

The burning of coal, oil and natural gas are the top three carbon dioxide emitters which many people in the United States and other regions (especially in the Western) are contributing for a straight 90 days during the winter with their gas furnace.

Meanwhile, ductless mini splits that don’t burn are used by 77% of the people around the world as of 2016. Now, it is even more.

As of 2016, 77% of the world’s air conditioning system is the ductless mini split air conditioning system.

International Energy Agency

By switching from a gas furnace or electric system to a heat pump system, you not only save money but also saving the environment.

IPCC had stated that it is inevitable that global warming is going to raise the average temperature by 1.5°C but if carbon emissions are heavily reduced, we might have a chance to stay below it. Otherwise, if nobody takes action now, we could end up with more than 4°C of temperature increase globally which the consequences are unimaginable.

I think this is my ultimate reason for why you should use a heat pump instead of a gas furnace now. I don’t mean that you should switch to heat pumps immediately but when the times come, use heat pumps or perhaps, some other new systems with high energy efficiency if available.

Original: IEA (2020), Is cooling the future of heating?, IEA, Paris https://www.iea.org/commentaries/is-cooling-the-future-of-heating

From the above worldmap, you can see that by switching from gas to heat pumps, how much carbon dioxide emissions can be reduced. For example, in Canada, switching from gas to heat pumps can reduce CO2 emissions by 86%. It has a higher percentage because the electricity there is cleaner.

Yes, we can argue that air conditioners and heat pumps still consume a lot of electricity and indirectly produce carbon dioxide at the power generation level. However, as a normal person, we can’t do much because we need air conditioners and heat pumps.

But, we can help to contribute to the environment by obsoleting old gas furnaces that are directly producing carbon dioxide and switch to high-efficiency heat pumps.

If you are concern about the environmental impact of the refrigerant used in heat pumps, check out my post Best Refrigerant Gas for the Air Conditioner.

Conclusion

Overall, the heat pump system is a great heating solution. Whether you are currently using a ducted system, a boiler system, have a small room or a big house, the heat pump system fits really well.

However, do pay attention to the limitation of the heat pump system which I’d covered in my post Do Mini Splits Work in Cold Weather?

Nowadays, heat pumps had advanced to a point that makes a lot of sense to use them. The return on investment is pretty decent. If the installation cost can be lowered, it is a no-brainer to use a heat pump.

Gas furnaces and boilers are directly contributing to carbon dioxide emissions. When the time comes, we should obsolete the old systems and use the new high-efficient heat pump system that saves money and reduce the impact on the environment.

If you are ready to switch to a heat pump system, check out my mini split guide A Beginner Guide on Ductless Mini Split Air Conditioners and my recommended heat pumps in my post Do Mini Splits Work in Cold Weather?


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Yu Chang Zhen

I enjoy working on air conditioners and ventilation fans because Malaysia is a very hot country.

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