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Eight Reasons Why You Should Choose Ductless Heating Cooling over Window Unit

Window AC VS Mini Split

Eight Reasons Why You Should Choose Ductless Heating Cooling over Window Unit

Although they have long been the HVAC norm in Europe and Asia, ductless mini splits are becoming more popular in homes and businesses throughout the United States. Their rise in popularity is due to their many benefits and advantages over other popular HVAC systems, such as window air conditioner units or central air systems that use ductwork. Read below to find out why you should choose ductless heating and cooling over a window unit, and then order a mini split system from ComfortUp today!


Ductless mini split air conditioning systems consist of an outdoor condenser or compressor connected to one or more indoor air conditioner units by copper wires and pipes. They are available in single or multi-zone systems

A single-zone system features one outdoor unit connected to only one indoor unit. In contrast, a multi-zone system can feature up to eight indoor units connected to the same compressor. Multi-zone systems come under different names depending on the number of indoor units. For example, a system with two units is dual-zone, three units is a tri-zone, four units is a quad-zone, and five units is a penta-zone.

Single-zone systems offer climate control over the indoor area, room, or level where that one air conditioner is physically located. Multi-zone systems allow you to adjust settings on each air conditioner independently of each other, meaning that changing the settings on one air conditioner will not impact others on the same system. 

This is especially beneficial because it allows you to create different climate zones in the same building. It lets you meet the temperature needs of all building occupants, whether of a home or a business. Window units are technically single-zone heating and cooling systems, meaning that they do not offer the advantages of multi-zone ductless mini split systems. 


woman relaxing in air conditioned room

Mini splits offer versatility in several different areas of performance and function where other HVAC systems, such as window-mounted units, cannot. 

One area is their installation location. Window air conditioners must be installed in a window, meaning they are not viable options to heat and cool windowless rooms such as basements or garages. You can install ductless mini splits in any room because they do not require windows. 

Even though they can be installed anywhere, certain areas benefit significantly from a mini split’s presence. 

For example, ductless mini split systems are ideal in basements. Basements typically suffer from temperature imbalances and inconsistencies because they are located below the ground. Additionally, basements usually do not have windows, making a ductless mini split the best way to regulate your basement’s temperature. 

Mini splits are also ideal in home offices. The environment created by a ductless mini split in a home office can stimulate focus and help preserve important paper documents. Additionally, mini splits work great in bedrooms

Sleeping in the cooler environment (ranging between 60℉ and 67℉) that a ductless mini split can create isn’t just more comfortable; it also offers numerous health advantages. You can benefit from increasing your sleep quality and melatonin levels and promoting a healthier metabolism.

Ductless mini splits also offer versatility in regards to the size. The “size” of an HVAC system refers to its ability to heat and cool a certain room or area. It is measured in tons and expressed in British Thermal Units (BTUs), which is the amount of energy required to increase the temperature of water by one degree Fahrenheit.

ductless mini splits for any room graphic

Window air conditioners usually only have the power to heat and cool small- to middle-sized rooms. On the other hand, ductless mini splits are designed for specific rooms in size, so there is certainly a model that can heat any area no matter its square footage. ComfortUp sells single-zone systems with BTUs ranging from 6,000 to 24,000 BTUs and multi-zone systems from 18,000 to 42,000 BTUs. 


Ductless air conditioners with heating capabilities are called heatpumps. They can heat and cool an indoor area, whereas most window AC units only have a cooling mode.

Mini split heatpumps cool by pulling in warm air and blowing it over a series of evaporator coils within the air conditioner. The warm air is exposed to the refrigerant, absorbing the heat and sending it to the outdoor condenser through the pipes and wires. Cold air is then dispersed throughout the indoor area. 

Reversing the refrigerant flow allows your system to bring warm air into your home through the air conditioner rather than sending it outside. Mini split heatpumps can even heat and cool an indoor area in even the most extreme outdoor climates. Some systems can heat your home when the temperatures drop as low as -22 ℉!


Ductless mini splits are much more efficient than other HVAC systems such as window units or ducted central air. Mini split cooling efficiency is measured using the Energy Efficiency Ratio (EER) and the Seasonal Energy Efficiency Ratio (SEER), whereas the heating efficiency is measured with the Heating Seasonal Performance Factor (HSPF). 

Window AC units are typically only able to cool, so they cannot receive an HSPF rating. Most mini splits in cooling mode feature higher SEER ratings across the board than window AC units. 

EER rating

The EER rating of an air conditioning system is calculated by dividing the cooling output (the total amount of BTUs removed from the interior air per hour) by the power input (the unit’s wattage when running at 100%). In other words, it is the unit’s capacity in BTUs divided by its nominal wattage.

The EER rating represents the air conditioner’s theoretical maximum cooling power. Although it is a useful figure to know, its real-world value is limited, as most mini splits do not run at 100% capacity all year long.

SEER rating

The SEER rating system was designed to reflect the unit’s performance in conditions closer to the real world by running it at partial loads at specific time intervals: 25% power (EER-25%) for 12% of the testing period, 50% power (EER-50%) 45% of the time, 75% power (EER-75%) 42% of the time, and 100% power (EER-100) 1% of the time.

The SEER rating is effectively an average of the unit’s EER-25%, EER-50%, EER-75%, and EER-100%, multiplied by the time spent at each power percentage. 

The formula is as follows: (1 x EER100% + 42 x EER-75% + 45 x EER-50% + 12 x EER-25%) / 100 = SEER rating.

HSPF rating

The HSPF rating is the heating equivalent of the EER and SEER ratings. Only air conditioning units with both cooling and heating modes, such as ductless mini split heatpumps, can receive an HSPF rating.

The HSPF rating is calculated using a process similar to that used for the EER rating: divide the total heating output (the amount of BTUs added to the interior air per hour) by the total watt-hours consumed in heating mode.

Energy Star certification

Many mini split units sold by ComfortUp are Energy Star certified by the United States Environmental Protection Agency (EPA). Energy Star certifications are given to products that operate at high levels of efficiency with a reduced environmental impact in mind. This heightened efficiency means less wasted energy, which leads to lower energy bills and a reduced carbon footprint. 

Mini split air conditioners and heatpumps must meet the following federal minimums to receive an Energy Star certification:

  • EER: 12.5 or more
  • SEER: 15 or more
  • HSPF: 8.5 or more

Even though some mini splits may have higher upfront costs than other systems, they are offset by the short- and long-term energy bill savings. 

ductless mini split unit mounted


Window air conditioners often clash with the room’s aesthetic, as they can look clunky and out of place while awkwardly protruding into the room. They can also detract from any exterior aesthetic, as an air conditioner jutting out of the window can be an eyesore to passersby. Fortunately, ductless mini splits do not have to clash with any room’s aesthetic. 

Traditional ductless mini split air conditioners are wall-mounted units. These air conditioners sit somewhere on the wall and disperse air throughout the area, and their sleek discreet look does not take away any attention from the room’s other decorations but melds in with the decor. However, there are many other mini split options available for those who want an even more inconspicuous air conditioner. 

Slim-duct mini splits look similar to traditional units but are slightly smaller and lighter, whereas ceiling cassettes are named for their resemblance to cassette tapes. 

A typical ceiling cassette is inconspicuous and sits virtually flat against your ceiling. Concealed mount mini splits are also inconspicuous, as they can be hidden from view. 

Finally, universal floor/ceiling mount options are perfect in homes or businesses with limited wall space availability. Regardless of your design needs or space restrictions, there is a ductless mini split for you!


Noise is one of the main complaints regarding window units, but ductless mini splits are the quietest air conditioner system available on the market today. Air conditioner sound is measured in decibels and window units hover around 43 dB. Mini splits can go as low as 19 dB, which is roughly the same volume as rustling leaves. 

This difference is very noticeable, as some window units can be noisy enough to impact your comfort level, and it may be hard to hear casual conversation, music, or sound from the television with a loud window air conditioner.

quiet ductless mini splits graphic

Silence is another reason why mini splits are excellent heating and cooling options for bedrooms, as they do not disturb your sleep when running. 


According to the Environmental Protection Agency (EPA), the concentration of certain air pollutants is two to five times higher than outdoors. This is especially problematic because Americans spend roughly 90% of their time indoors. 

Poor indoor air quality can be directly linked to short- and long-term health problems. It can cause eye irritation, skin breakouts, headaches, nausea, and sinus congestion while also contributing to serious diseases such as cancer, cardiovascular disease, and respiratory illness. Several factors contribute to poor indoor air quality, such as dust, mold, mildew, dirt, debris, pet hair, and various other allergens or airborne particles.

Ductless mini splits have been shown to improve your indoor air quality. Inside of each air conditioner is a filter that removes any harmful airborne particles while the system heats and cools the area. 

The filter also removes airborne moisture to deter mold and mildew growth. This leads to significantly improved indoor air quality and the accompanying benefits of increased health, safety, and comfort. 

Mini split filters require periodic maintenance to continue purifying the air at a high level. Filter maintenance varies, depending on the filter type and model, but it generally involves removing it from the air conditioner and wiping it clean with a cloth. Filters will also need replacing periodically, but this depends on factors such as the specific filter model and your system’s usage level. 

change air conditioner filter

Maintaining and replacing your filter when necessary not only keeps your air quality safe and healthy, but increases your system’s efficiency. A dirty or old filter does not allow your system to operate at maximum capacity, which leads to wasted energy and increased energy costs. Consult your filter’s accompanying instruction manual or manufacturer’s website for specific maintenance and replacement instructions. 


Through smart technologies, ductless mini splits provide home and business owners with advanced climate control that window air conditions cannot offer. Most mini splits can connect to a Wi-Fi network and be controlled via a smartphone application. This app lets you adjust your system’s settings even if you are out of range of your unit’s traditional remote or outside your own home, such as at work or on the road.

This connectivity also allows you to control more than the temperature. You can adjust airflow, humidity, and more. Mini splits can also be paired with smart thermostats such as the Honeywell D6 for enhanced control and information. 

Through the app and/or smart thermostat, you can program your system to run in specific “cycles.” Temperature cycles usually involve increasing and decreasing temperature and airflow in timed intervals to increase efficiency. 

For example, many systems have programmable “sleep cycles” that decrease volume and temperature to create the ideal sleeping environment. Another common cycle involves decreasing power during the day when nobody is at home, whether for work or school, and increasing power to ensure that your home is cool upon your arrival. Many mini splits can run self-diagnostics tests in the event of a malfunction. They can also detect any temperature or airflow imbalances in the room and correct them accordingly. 

find an installer graphic


ComfortUp proudly sells mini split systems and accessories from the industry’s most trusted brands such as Panasonic, LG, Boreal, GREE, Mitsubishi, and more. We also offer advanced warranty coverage through our extended product warranties, which cover maintenance and service costs in addition to part replacement. 

If you are unsure of your heating and cooling needs, don’t worry. We have a team of trained product specialists ready to help you find the best ductless system for your specific situation. Give us a call at 1-855-337-0001 or contact us online today!

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