The most common mini split installed is a 12,000 BTU unit– which can heat or cool up to about 550 square feet. Depending on the size of your home, you may need to install multiple mini split AC systems — perhaps of varying sizes — to adequately heat or cool the property.
A 24,000 BTU system will generally heat and cool a space that is around 1,500 sq. ft. However, this number will vary based on a few other factors.
Realistically, a 15,000 BTU mini split can cover up to a 620 square foot room. In almost all cases, a single-zone system is engineered with more BTU power than its rated for. We have a mini split calculator you can use to get a quick size calculation.
Even though it takes a powerful system – especially in a large home – a ductless mini split is up to the task. With the right size system in place, it's capable of cooling an entire house, from the basement all the way up to the attic.
Cons Of Ductless Mini Split AC System
The downside of this type of system is that it doesn't provide as much comfort and cooling on the hotter days, which can be a problem. And since they don't have ducts, you won't get any extra heating if your home's temperature dips below 60 degrees Fahrenheit.
Compared to a traditional electric HVAC system, a ductless mini-split system generally has a longer life when maintenanced properly. A traditional electric Heat Pump average life expectancy is 15 years, with proper maintenance. A ductless split system average life expectancy is 20 years with proper maintenance.
Issues with over-sized ductless mini split systems: If the mini split system is too large for the space, this can cause “short cycling” -- a term for when the system turns on and then off very quickly because it heats or cools the space too fast.
Your Mini Split System Sizing Guide
According to the EPA, the basic rule to determine your basic BTU requirements is to add the square footage of every room covered by your system's indoor units and multiply the result by 20. This principle is the 20 BTU per square foot rule.
They are some of the most energy-efficient systems on the market. They save space, they improve the indoor air quality, and they provide even heating and cooling throughout your home. If you are considering investing in a ductless mini-split system for your home, contact Energy Monster today to learn more.
Usually, we use a 20 BTU per sq ft rule of thumb. Example: For a 1,500 sq ft home, you would need 1,500×20 = 30,000 BTU output. You can use one 30,000 BTU mini splits, two 15,000 BTU mini splits, or three 10,000 BTU mini splits. Be aware of the airflow and access to different rooms (secondary factor).
This system has a cooling and heating capacity of 48,000 BTUs, ideal for 5 rooms up to 2,250 square feet (300 square feet each).
1,500 – 2,000 sq. feet: 30,000 BTUs. 2,000– 2,500 sq. feet: 34,000 BTUs.
Realistically, a 30,000 BTU mini split can cover up to a 1,240 square foot room. In almost all cases, a single-zone system is engineered with more BTU power than its rated for. We have mini split sizing calculators you can use to get a quick size calculation.
Mid-level mini splits run at 100 percent efficiency down to 20°F and typically require a base pan heater. These work well for heating moderate to cold climates. Economy-level mini splits run at 100 percent efficiency down to 30°F and may shut off at temperatures below 20°F. These are best for moderate to warm climates.
Let your system run continuously.
Set it and forget it. A mini-split system uses less energy and keeps temperatures most consistent when it runs continuously, as in, 24/7.
And, this is why ductless heating and cooling seems to run all the time while still using far less electricity than conventional HVAC. Now, the heat pump doesn't switch off once you reach the temperature you want. Instead, it continues running to keep that temperature steady.
Mini splits on average last about 20 years. If you consider how much money you can save on electricity and maintenance you will see that going with a mini split system can be a great decision. Adding a mini split system will also increase the value of your home should you ever decide to sell it.
A multi-zone mini split system consists of two or more indoor mini split units which are all connected to a single outdoor unit or compressor. Typically, a multi-zone mini-split condenser or compressor can be connected to a total of eight indoor units.
One of the few drawbacks to mini splits is that mold can build up inside the units. Because of how they operate, this problem is much more common than with conventional forced-air heat and AC. But, mold prevention or cleaning is easy if you catch it early.
A mini-split system is energy efficient, among many other things. In fact, the United States Department of Energy says that a mini-split with a zoning system can save you as much as 30 percent on your energy bill. The primary reason for the efficiency of a mini-split is its ability to operate without ductwork.
Ductless Mini Splits Are High Maintenance
However, this preconception is entirely false. Ductless mini split systems don't require any more maintenance than a traditional HVAC system.
Roughly speaking, the 'off-season' for the HVAC industry runs from March to May and hits again from September to November. These two periods avoid extreme seasonal temperatures, so the average HVAC company is less busy. This is a great time to get a great deal on a new HVAC unit.