Heating with a Mini-Split Unit: The Coolest Way to Stay Warm This Winter

Heating with a Mini-Split Unit: The Coolest Way to Stay Warm This Winter

As the temperatures begin to drop, our thoughts turn away from how to stay cool in sweltering summer temps to how to keep our homes and offices comfortable without paying ridiculous heating bills this winter. One of the best ways to do this is with a ductless mini-split unit.


  • Mini-split systems offer highly efficient heating during winter, making them versatile for both cooling and heating needs.
  • These systems are energy-efficient and eco-friendly, helping you save on utility bills and reduce your carbon footprint.
  • Proper sizing and the correct installation are crucial for optimizing the performance of a mini-split system as a heating solution, ensuring year-round comfort.

Ductless mini-split heating systems offer a modern and efficient way to stay warm during the winter months, even in areas where temperatures reach below freezing or when you need to heat a space that has multiple rooms or challenging layouts.

That said, many still believe that central forced air systems are the only way to heat their home or office effectively.

But this is no longer the case.

Let’s dig into what makes ductless mini-split systems so good at what they do and why this innovative and cost-effective heating and cooling system could be right for you!

What Are Mini-Split Systems?

Mini-split systems, sometimes called ductless mini-splits or ductless heat pumps, are advanced HVAC systems designed to provide precise heating and cooling capacity all year round.


Unlike traditional central heating and air conditioning systems that use ductwork to distribute air, a ductless mini-split air conditioning system operates without requiring ducts.

They consist of two primary components: the indoor unit and the outdoor unit.

Indoor Unit: The indoor unit or air handler is typically mounted on a wall or ceiling within its living space. It houses essential components, including the blower fan, evaporator coil, and air filters.

Outdoor Unit: The outdoor unit or condenser, often placed outside the building, contains crucial components such as the compressor and condenser coil.

The outdoor and indoor units connect via electrical and refrigerant lines that facilitate the exchange of vital information and heat transfer between the outdoor and indoor units. These connections are integral to the functionality of a mini-split system.

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Efficient Heating for Winter: Harnessing Heat Pump Technology

Mini-split systems excel in providing efficient heating during the colder months thanks to their innovative use of heat pump technology.

The outdoor unit for most mini-split systems is a heat pump.


Unlike traditional heating systems that generate heat by burning fossil fuels like natural gas, liquid propane, or oil, heat pumps transfer heat from one place to another.

These units provide heating and cooling functions, making them versatile and energy-efficient.

How Does the Heat Transfer Process Work?

During heating mode, the mini-split outdoor unit acts as an evaporator, extracting heat from the outside air, even in very low temperatures.

The ultra-cold refrigerant in a gaseous state absorbs heat circulating within the outdoor unit. The compressor then pumps the refrigerant to the indoor unit.

Is a Ductless Mini-Split More Energy Efficient?

Once the refrigerant is inside the indoor unit, it releases the absorbed heat, causing it to condense back into a liquid.

This heat is then circulated into the room to warm the indoor space. The key benefit here is that the system doesn’t generate heat through combustion, as traditional HVAC systems do.

Instead, it efficiently moves existing heat from the outside to the inside, which requires significantly less energy.

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Finding the Warm Air, Even in Winter!

A mini-split heat pump extracts heat from the outside air, even when temperatures are frigid.

But how is this possible? Here’s how the process works, in a nutshell:

  • Refrigerant: The key to this process is the refrigerant, a special fluid circulating within the mini-split system. The refrigerant changes from a liquid to a gas and back again at low temperatures.
  • Outdoor Unit: In heating mode, the outdoor unit of the mini-split system serves as an evaporator. Some heat energy is still present, even when the outdoor air is cold. The heat pump’s fan draws in this outdoor air.
  • Heat Absorption: The cold outdoor air passes over coils containing the refrigerant. As the air comes into contact with the coils, the refrigerant within them is significantly colder than the outdoor air. Because of this temperature difference, the refrigerant can absorb heat from the outdoor air.
  • Refrigerant State Change: As the refrigerant absorbs heat, it changes from a liquid to a gas. This phase change is possible because the refrigerant has a low boiling point, even at low temperatures. The absorbed heat energy is now stored in the form of a gas.
  • Compressor and Compression: The gaseous refrigerant is then compressed by the mini-split system’s compressor. This compression increases the temperature and pressure of the refrigerant.
  • Indoor Unit: The now hot refrigerant gas gets sent to the indoor mini-split unit (also known as the indoor air handling unit), which acts as a condenser. Within the indoor unit, a fan blows air over coils containing the hot refrigerant.
  • Heat Release: As the indoor air passes over the coils, it picks up the heat from the hot refrigerant. The refrigerant releases the stored heat energy into the indoor air, causing it to warm up.
  • Cycle Repeats: After releasing its heat energy, the refrigerant returns to the outdoor unit to start the process again. This cycle repeats continuously to maintain a warm indoor temperature.

One of the most noteworthy aspects of a ductless mini-split system is its ability to effectively capture heat from the outdoor air, even when it’s cold outside.

This efficient heat transfer process allows mini-split systems to provide impressive climate control during winter. Because of this, ductless systems make a versatile and energy-efficient solution for year-round comfort.

Commonly Asked Questions About Using A Mini-Split as a Winter Heating Source

Ductless mini-split units are fantastic heating and cooling systems that can save businesses and homeowners a substantial amount of money each year while making their space more comfortable.

That said, for most Americans, this type of HVAC system is lesser known than the heating and cooling systems we are used to.

Knowing the answers to some of the most common questions about ductless mini splits will help you make the best choice for your comfort, budget, and the environment.

What are the advantages of using a mini-split for heating in cold climates?

Mini-splits are highly efficient in extracting heat from cold outdoor air, making them suitable for cold climates. Advantages include:


Energy Efficiency: Mini-splits use heat pump technology, which is more energy-efficient than resistance heating methods like baseboard heaters or electric furnaces.

Zoned Heating: Mini-splits allow for zoned heating. Zoning means you can control the temperature in individual rooms or zones, optimizing comfort and energy use.

Quick Warm-Up: Mini-splits can provide rapid heating compared to some traditional systems, ensuring you stay comfortable.

Are there any limitations when using a mini-split as a primary heating source?

While mini-splits are efficient and effective, there are some limitations to consider:

Extremely Low Temperatures: In cold conditions, the efficiency of a mini-split decreases, which can affect its heating capacity.

Consider a mini-split model designed for extreme temperatures if you live in an area with severe winters. Sometimes labeled “hyper heat or “ultra heat,” these systems perform better than standard mini-splits when outdoor temperatures fall below 0℉. A backup heating source may be helpful during frigid spells.

Initial Cost: Mini-split systems cost less than a central heating and cooling system with ductwork. However, a mini-split system can cost more than upgrading or retrofitting an existing central system. Remember that a mini-split’s energy savings over time will offset its initial cost.

How does the efficiency of a mini-split system compare to other heating options?

Mini-split systems are generally more efficient than traditional resistance heating methods, such as electric baseboard heaters.

They can achieve a high Heating Seasonal Performance Factor (HSPF) rating, indicating their efficiency. Compared to central heating systems like furnaces, mini-splits often offer better efficiency due to zoned heating and the ability to avoid energy losses through ductwork.

What factors should I consider when sizing a mini-split for heating purposes?

Sizing is crucial for efficient heating. Factors to consider include:

Room Size: The square footage of the area you want to heat is a primary factor. An HVAC professional can perform a load calculation to determine the correct size.

Insulation: Well-insulated spaces require smaller units, while poorly insulated areas may need larger units.

Climate: Consider the lowest outdoor temperatures in your area to ensure the mini-split can meet your heating needs.

By addressing these questions and tips, you can make the most of your mini-split system for heating in cold climates while ensuring its long-term efficiency and effectiveness.

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When You’re Ready to Turn on the Heat, Turn to Alpine Home Air for Help

When the temperatures begin to dip and it’s time to turn on the heat, turn to Alpine Home Air Products for help.


With over 20 years of experience in the HVAC world, Alpine has proven to be an industry leader and well-versed in the most innovative products on the market today.

Whether you’re facing the chill of winter or the heat of summer, our extensive range of mini-split systems provides the perfect HVAC solution for your needs.

With Alpine Home Air’s expertise and commitment to customer satisfaction, you can trust us to deliver top-notch products and support.
Don’t wait to take control of your indoor comfort, and contact us today!

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