Everything you need to know about the wild world of heat pumps

Let our writers guide you through the perplexing, complex world of technology to better prepare you for what lies ahead, as explained by Tech Review. Click this link to learn more.

The era of heat pumps is beginning to take shape.

Heat pumps are easy to manufacture and move heat to cool or heat buildings. Electricity is used to power them. The idea behind them was first developed in the 1850s, but they weren’t actually produced until the 1960s. However, all of a sudden, they have become the most in-demand household appliance, thanks to recent government incentives, the potential for financial savings, environmental advantages, or even both.

The specifics of how heat pumps operate are fascinating, despite the fact that the basic concept may be straightforward. This gadget appears to defy physics almost in the name of regulating the temperature in your home. New kinds of heat pumps are more effective and have improved cold weather performance.

The way a heat pump functions.

In its most basic form, a heat pump transfers heat from one location to another. Though they are mostly used for heating, heat pumps can also be used for cooling by drawing heat from inside and dispersing it outside, much like an air conditioner. Depending on the situation, many heat pumps can even be operated in reverse to provide cooling or warmth.

The refrigerant, a fluid that circulates in a circuit while absorbing and discharging heat, is the protagonist in a heat pump. The system is driven by electricity, which rotates the cycle with the refrigerant.

At different times in the cycle, the refrigerant is compressed and inflated as it moves through the heat pump, switching between liquid and gas forms. This allows it to absorb and release heat. (If you determine that this level of precision is sufficient, feel free to continue on to the following question. If not, I’ll show you how it all works by taking you on a tour of a heat pump).

Certain heat pumps aren’t designed to warm a room when the temperature is below zero, but there are versions that perform well at lower temperatures, according to Meyer. Tiny space heaters can be used as a backup during cold spells, but if you choose a system that is the right size, you shouldn’t require them, he adds.

What has changed recently in heat pump technology?

Meyer argues that the efficiency and performance of heat pumps have increased, particularly in the cold, thanks to improvements in a number of their key components.

Refrigerants are one significant advancement. Prior to its phase-out in the US and other major markets due to its ozone-depleting properties, freon, also known as R-22, dominated the market.

In today’s market, one of the refrigerants most frequently utilized in heat pumps is a chemical mixture known as R-410A. R-410A has a lower boiling point than R-22 and is also somewhat less hazardous to the ozone layer. This allows it to absorb more heat at lower temperatures, increasing efficiency in the cold.

Moreover, other aspects have improved. Modern heat pumps pressurize refrigerants to higher pressures using modern compressors that utilize less energy. New “variable-speed” compressors also allow heat pumps to change their power output. Finally, more effective heat transmission is made possible by upgraded and larger heat exchangers that transmit heat from the air to the refrigerant.

Heat pumps come in a variety of forms and are already available. Almost 85% of installed heat pumps are air-source models, like the one I just described. They come in a range of shapes and sizes. Other models, referred to as ground-source or geothermal heat pumps, however, draw their energy from the earth rather than the atmosphere.

In what ways do heat pumps combat climate change?

Natural gas or heating oil is often used in the heating of buildings, which is why the sector currently accounts for 10% of worldwide emissions. Yannick Monschauer, an energy expert at the International Energy Agency, believes that heat pumps will be the main technology utilized to reduce the impact of heating on the environment.

According to Sam Calisch, head of special projects at the nonprofit organization Rewiring America, which focuses on electrification, heat pumps “function everywhere,” even though they may not operate at their best efficiency in colder locations.

From Alaska to Maine, heat pumps are operational nationwide in the US. Moreover, heat pumps are used to heat roughly 60% of buildings in Norway, along with 40% of structures in Sweden, and Finland.

Even in the coldest locations, heat pumps may operate effectively. Nevertheless, according to Andy Meyer, senior program manager at Efficiency Maine, a company that oversees energy efficiency initiatives in the state, picking the correct heat pump is essential to ensuring that it performs well as temperatures drop.

Certain heat pumps aren’t designed to warm a room when the temperature is below zero, but there are versions that perform well at lower temperatures, according to Meyer. Tiny space heaters can be used as a backup during cold spells, but if you choose a system that is the right size, you shouldn’t require them, he adds.

How has heat pump technology changed recently?

The effectiveness and performance of heat pumps have increased, particularly in the cold, Meyer claims, thanks to improvements in a number of their key components.

The refrigerants are one notable advancement. The industry used to be dominated by freon, commonly known as R-22, but due to its effects on the ozone, it has been phased out in the US and other key markets.

One of the refrigerants most frequently utilized in heat pumps nowadays is a blend of molecules known as R-410A. In addition to having a somewhat lesser impact on the ozone layer than R-22, R-410A can absorb more heat at lower temperatures, increasing efficiency in the cold.

Some other elements have also improved. Modern heat pumps employ new compressors that can raise refrigerant pressures while consuming less power. Furthermore, new “variable-speed” compressors enable heat pumps to ramp up and down in power. The heat exchangers that transport heat from the air to the refrigerant are also getting bigger and better, which allows them to move heat more efficiently.

Heat pumps come in a variety of styles that are already available. Like the one I’ve described, about 85% of those that have been installed are air-source heat pumps. There are numerous sizes and forms available for them. Some designs, referred to as ground-source or geothermal heat pumps, on the other hand, absorb heat from the earth instead of the atmosphere.

How do heat pumps aid in combating global warming?

Because natural gas or heating oil are widely used to heat buildings, the sector is currently responsible for 10% of all emissions in the world. According to Yannick Monschauer, an energy analyst at the International Energy Agency, heat pumps will be the main technology utilized to reduce the climatic impact of heating.

Grid-supplied electricity powers heat pumps. While fossil fuel facilities continue to support global power systems, renewable and low-carbon energy sources also play a role. Heat pumps are therefore more environmentally friendly than directly fueled by fossil fuels when it comes to the existing energy balance in all major markets, according to Monschauer.

Efficiency is the true climatic superpower of heat pumps. The efficiency of modern heat pumps can reach 300% to 400% or even higher, which means they produce three to four times as much heat as they consume in the form of electricity. Theoretically, a space heater could operate at 100% efficiency, but the greatest ones available today only manage about 95%.

The varied degrees of efficiency of heat pumps and heaters are due to how they operate. Electricity-based energy must be transformed into heat for space heaters to work.

Heat pumps do not turn power into heat; instead, they use electricity to collect and distribute heat. Although it’s a little distinction, it essentially means that a heat pump may be able to provide far more heat for the same amount of electricity.

The amount of refrigerant used, how the installation is done, the temperature difference between the space the heat pump is heating and the outside, as well as other parameters, all affect the heat pump’s maximum efficiency.

What else should I know if a heat pump is something I’m thinking about?

The initial expense of heat pumps is a significant deterrent to adoption; nowadays, a single unit can cost between $3,000 and $6,000 to buy and install, and bigger homes sometimes need numerous units.

But, for certain users, over the course of their approximately 15-year lifespan, heat pumps are already less expensive to purchase and run than alternative systems, particularly if they are used to simultaneously heat and cool a home at various times of the year, according to Monschauer.

Also, there are incentive programs for heat pumps in over 30 nations worldwide, many of which offer prizes to low-income households or those who buy high-efficiency appliances. With consumers receiving up to 110% of the purchase price back as a tax credit, Italy has particularly substantial subsidies for heat pumps that are installed when buildings are retrofitted for energy efficiency.

With additional refunds for low- and moderate-income households, the US’s Inflation Reduction Act provides a 30% tax credit on the cost of a heat pump. For some households, the funding may cover the entire expense. To help consumers figure out the IRA subsidies they are eligible for, Rewiring America offers a calculator.

What comes next for heat pumps?

Despite the fact that heat pumps now are a lot more advanced than they were ten years ago, the technology still has a lot of room for improvement.

Costs associated with installation might be reduced by new designs like the self-contained window units offered by the startup Gradient. Small, portable units are now being offered by other businesses, like Midea and LG. These new alternatives might make heat pumps usable in places where they would normally be prohibitively expensive or impossible to install, like older apartment complexes.

Advancement is feasible in the refrigerant industry. Modern refrigerants are still powerful even though they emit fewer greenhouse gases than more traditional ones. With cautious handling and precise production, leaks can be avoided. Although the threat of global warming posed by refrigerant leaks is outweighed by the benefits of heat pumps for the climate, further methods might further lower this threat.

For instance, Gradient uses R-32, a refrigerant that is less likely than R-410A to contribute to global warming. Other kinds of refrigerants, such as the hydrocarbons propane and butane, represent much less of a risk to the environment. Due to the significant flammability of some of these more environmentally friendly refrigerants, safety systems are required.

The already enormous variety of heat pumps on the market will be expanded with the aid of new technological developments. And if the technology becomes more widespread, prices should decrease over time.

Sales of heat pumps increased 15% globally in 2021. A 35% increase in sales in 2021 made Europe one of the regions with the fastest growth, and the energy crisis will probably keep this trend going. The majority of homes with heat pumps installed today are still in North America, although China leads in terms of new purchases.

Wherever you turn, the heat pump era is now in full swing.

Update: Further details about the price of installing a whole-home heat pump have been added to this article.