Step-By-Step: Setting Up Your Own Mini Split Heat Pump

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By Debarghya Roy

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Are you looking for a cost-effective and energy-efficient way to heat and cool your home or business? DIY mini split heat pumps may be the perfect fit. With their ease of installation and higher efficiency ratings, DIY mini splits are becoming an increasingly popular choice when it comes to heating or cooling any space.

Keep reading our comprehensive guide to learn more about this ideal system for homes and businesses.

Key Takeaways

  • DIY mini split heat pumps are an efficient way to both cool and heat a space, with energy savings of up to 60%, when compared with traditional HVAC systems
  • Mini splits can be easily installed as a do-it-yourself project, often eligible for tax credits or financial incentives from the government or power companies
  • These units feature zoned climate control so you can adjust temperatures in individual rooms remote.
  • With their dual functionality, they’re suitable for all climates regardless of extreme heat or cold temperatures down to -13 degrees Fahrenheit.

Definition Of A DIY Mini Split Heat Pump

A DIY Mini Split Heat Pump is a fully functional, ductless heating and cooling solution for any home. 

diy mini split heat pump

Mini split systems  also known as “ductless” or “splits” are designed with two components: an outdoor compressor/condenser, connected by conduit piping to an indoor air-handling unit. 

Components Of A DIY Mini Split Heat Pump

Accurately understanding and assembling the components of a DIY mini split heat pump is essential for proper functionality.

Indoor And Outdoor Units Of A DIY Mini Split Heat Pump

A DIY mini split heat pump system contains two main components: 

An outdoor compressor/condenser and an indoor air-handling unit. Both units are essential for the installation and proper functioning of a mini-split system.

The outdoor condenser is responsible for compressing refrigerant gas into liquid, while the indoor unit cools or heats air that enters from outside through a fan. 

Refrigerant Lines

Refrigerant lines are an essential component of any DIY mini split heat pump installation.

These specialized lines serve to connect the outdoor condenser unit with the indoor air handling units, and they play a key role in facilitating the transfer of heat between these two locations, a process that is required for efficient operation of all mini split systems.

It is important to understand that while standard air conditioning systems require basic refrigerant lines, those used in mini splits must be specifically designed for this purpose and different than traditional ones.

Control Wiring

Control wiring is essential for completing the safety circuit and monitoring multiple functions among the components of a DIY mini split heat pump. 

This includes wiring between the indoor and outdoor units to control the fan speed, compressor, heating or cooling operations, temperature adjustments, power supply and shut down.

Control wires must be installed carefully according to specific instructions from each manufacturer as every mini split unit requires different alterations for installation.

It’s important to use only electrical cables of adequate type and thickness – too thin a cable can lead to conductor melting due to high current when starting up large motors such as compressors or fans – which could pose serious safety risks.

The control wiring should also be tested thoroughly after completion in order to further eliminate any fire hazard potentials caused by incorrect installations .

Other Essential Parts

A DIY mini split heat pump system is composed of several different components, all of which are necessary for proper installation and operation. 

The main parts include the indoor and outdoor units, refrigerant lines, control wiring, and other essential parts.

All these pieces work together to provide efficient heating and cooling in the home or office space.

The refrigerant lines connect the two main units the outdoor compressor/condenser unit and the indoor air-handling unit  with each other as well as any optional accessories such as an expansion valve or suction line accumulator that helps to regulate pressure in the system.

The right-sized refrigeration tubing also ensures efficiency by allowing maximum flow rate while preventing loss due to frictional resistance.

Additionally, insulated copper wires may be used to ensure a secure connection between units so that controls can pass signals back and forth from one component to another.

Other essential parts include items such as, 

  • Drainage piping for draining condensate out of your system.
  • Vibration dampening brackets for reducing noise caused by vibrations due to compressor operation.
  • Mounting supports for securely attaching pipes.
  • Exothermic insulation blankets created through chemical reaction.

How Does A DIY Mini Split Heat Pump Work?

A DIY mini split heat pump is an air conditioning system which operates on electricity. It utilizes refrigerant to transfer cool or hot air from the outside to the inside.

DIY mini split heat pumps also offer energy savings when compared with traditional HVAC systems due to their dual functionality providing both cooling and heating capabilities from one machine running at very efficient levels depending on climate conditions outside.

The indoor and outdoor units (compressor/condenser) of a DIY mini split heat pump are connected by copper tubing, which transports refrigerant back and forth between them.

It consists of an indoor unit that delivers cooled or heated air to the indoors, and an outdoor compressor unit which pumps refrigerant through pipes connected to a pair of evaporator-coils inside the building.

This split system architecture eliminates the need for large ducts normally used in central air conditioning systems, making installation faster and easier while reducing energy loss due to greater efficiency.

The outdoor unit converts the incoming ambient temperature via its compressor, changing it into warm or cold energy in order to adjust internal temperature levels within your home as required.

A control wiring is used for monitoring and controlling purposes, allowing you to adjust the settings that will work best for your climate in any particular weather.

Mini-splits have become increasingly popular due to their high level of efficiency compared with traditional HVAC systems since they don’t lose large amounts of energy from ductwork leakage.

Benefits Of A DIY Mini Split Heat Pump

In addition to energy efficiency and cost savings, DIY mini split heat pumps offer dual-functionality, as they can cool and heat a space regardless of the climate.

Energy Efficiency Of A DIY Mini Split Heat Pump

Mini Split Heat Pumps are noted for their remarkable energy efficiency when compared to traditional heating and cooling systems. ENERGY STAR certified mini splits can be up to 60% more energy efficient than many electric radiators, according to data from 

Additionally, Mini Splits allow users to control the temperature in individual rooms or zones more precisely- thus avoiding wasted energy on overcooling or overheating certain areas of the home.

This feature makes Mini Split Heat Pumps ideal for people living in smaller living spaces with neither space nor cost resources available for installation of a comprehensive central HVAC system.

Cost Savings Of A DIY Mini Split Heat Pump

A DIY mini-split heat pump can be an investment that pays off in long-term savings. Compared to traditional HVAC systems, a DIY mini-split saves energy on heating and cooling by providing more precise temperature control, reducing the need for additional equipment such as ductwork and reducing the demand for energy through its high efficiency ratings.

This also means lower operating costs since it uses less electricity over time. In addition, do-it-yourself installations of mini splits are often eligible for income tax credits or other financial incentives from the government or power companies, making this even more cost effective.

For example, MrCool’s DIY 24k BTU Mini Split Heat Pump Air Conditioner qualifies for up to 30% Energy Star Tax Credit with some rebates reaching up to $500 depending on the state or utility company.

Dual-Functionality: Heating And Cooling Of A DIY Mini Split Heat Pump

DIY Mini Split Heat Pumps offer the added advantage of dual-functionality, providing both heating and cooling. 

This is a major cost savings to homeowners as there is no need to purchase additional HVAC equipment for climate control throughout the year.

During warmer months, DIY mini split systems can be used as an air conditioner while in cooler temperatures they work to efficiently heat the home or sections of it. 

DIY Mini Split Heat Pump Are Suitable For All Climates

DIY mini split heat pumps are designed to operate in a wide range of climates.

With their advanced technology, they can provide both heating and cooling functions for individual rooms, even in extreme temperatures as low as -13 degrees Fahrenheit.

The reason why DIY mini split heat pumps are so adaptable across different climates is due to their Refrigerant Cycle Technology which absorbs and releases energy from the air depending on whether it needs to warm up or cool down a room.

It also features dual condensers which use pressure differences inside the refrigeration lines to control how much hot and cold air is flowing through each one, thus providing zoned climate control when operational.

Installation Guidelines For A DIY Mini Split Heat Pump

offer detailed guidelines for installing a DIY mini-split heat pump system, including tools and materials needed, safety precautions, a step by step installation guide, as well as the feasibility of self-installation.

Feasibility Of Self-Installation Of A DIY Mini Split Heat Pump

Self-installation of a DIY mini split heat pump may be feasible for those with the necessary tools.

Extensive knowledge of electrical and plumbing systems, and comfort in working within city ordinances.

Factors such as,

  • Age of building
  • Type of construction 
  • Local permitting requirements 

All need to be taken into consideration when deciding to carry out the installation yourself or hiring a licensed technician.

While self-installing your unit includes potential pitfalls like violating safety codes and electrical measurements going wrong it can save considerable costs on labor if armed with the correct information.

Tools And Materials Needed

Installing a DIY mini split heat pump requires the right tools and materials, or else the installation may not be successful. 

Perfect Aire DIY mini splits come pre-charged with 25-foot lines; however, other items will likely need to be purchased.

Tools RequiredDescription
Tape MeasureAccurate measurements of room dimensions are necessary in order to purchase the proper size system.
Volt Ohm MeterThis is used to check for shorts in wiring and make sure all electrical components work properly.
Electric Drill/Driver with BitsDrilling pilot holes will be required to install mounting brackets.Screwdrivers – Phillips head and standard both needed.
Materials RequiredDescription
Refrigerant Lines & ConnectorsThese should be compatible with the type of refrigerant your system is designed for and able to withstand temperatures up to 300°F.
Control Wiring & ConnectorsHighly conductor PVC wire should be purchased which is also UV rated for outdoor use.
Mini Split Wall Mount BracketA bracket needs to be purchased in order to secure the indoor unit on an exterior wall of your home. Make sure this bracket can hold the weight of your unit before purchasing one (MrCool 4pc Bracket System recommended for mini splits.)
Line Set Cover Kit & AccessoriesTo help protect lines running between your outdoor and indoor units. You’ll need a line set cover kit that can withstand outdoor weather conditions such as high winds and heat. (Perfect Aire recommends their own PAMBS68 Universal 72” line cover kit)

Safety Precautions

When installing a DIY mini split heat pump, it is essential to take the necessary safety precautions

This includes following the installation manual and adhering to appropriate wiring standards and regulations.

Additionally, an electrical safety check should be conducted beforehand as well. It is also important to ensure that all gas or liquid side service valves are properly opened during installation.

The number of indoor air-handling units which can be connected to each outdoor unit depends on its model.

Step-by-Step Installation Guide Of A DIY Mini Split Heat Pump

Installing a DIY mini split heat pump can be an economical and energy-efficient way to cool or heat your home, but it’s important to ensure that you perform the installation correctly. 

Here are steps for installing a DIY mini split air conditioner/heat pump:

  • Locate the indoor and outdoor units of the air conditioners in their desired positions.
  • Make sure both main power breaker boxes have been switched off before beginning wiring work for safety purposes.
  • Connect electrical wires and run wire conduit between indoor and outdoor units according to manufacturer directions.
  • All exposed wires must meet local codes as well narrow gauge copper lines connected inside encased conduits is usually sufficient for most models).
  • Ensure appropriate placement of fan coil unit near its designated wall or ceiling mount point, tight sealant connection should also be used when required.
  • Install any other components beyond the basics such as line sets, thermal expansion valves ext lolers etc with direction from manufacturer instructions & diagrams.
  • Coordinate tubing length measurements including refrigerant lineset(s), liquid tube piping & evaporator cables connecting needs dependent on climate changing requirements‎ prior calling up local HVAC technician.

Choosing The Right Size DIY Mini Split Heat Pump

Choosing the right size mini split heat pump is essential for best performance, and understanding how to estimate cooling and heating loads can help make this process easier.

Estimating The Cooling And Heating Load

When determining the size of a mini split heat pump needed for your space, it is important to accurately calculate your cooling and heating load

This takes into account factors such as climate, amount of insulation in walls and windows, sunlight exposure levels, areas needing cooled/heated, number of occupants in a space and more.

The most accurate method for calculating this load value is to consult with an HVAC professional on-site who can measure the temperature needs based on specific dimensions of the rooms that need cooling or heating.

Alternatively you can use the 30 BTU per square foot estimation method,  this figure represents what’s needed to cool and/or heat spaces according to their wall structures (effective R-Value) as well as how much energy they lose due to glass windows or other infrastructure deficiencies.

Tips For Choosing The Right Size Of DIY Mini Split Heat Pump

Choosing the correct size unit when installing a DIY mini split heat pump is arguably the most important part of the installation process and a key factor in ensuring energy efficiency, comfort, and system performance.

It is important to calculate the local climate conditions and use proper sizing methods in order to determine the correct tonnage for your area. 

Room size in square feet is also an important factor in determining the correct BTU sizing for a MRCOOL DIY mini-split system

HVAC professionals should be hired to perform a manual J-load calculation to accurately measure cooling or heating load requirements for larger areas.

Additionally, a unit installed with too little capacity will not efficiently maintain desired temperature settings.

While a unit with too much capacity will cause an energy inefficient environment due to rapid cycling or short run times leading to higher electricity bills.

Other key factors whilst considering size include,

  • Noise level rating (dB)
  • Estimated EER rating (energy efficiency ratio)
  • Total power input (Watts)

Maintenance Of DIY Mini Split Heat Pumps

Regular maintenance and troubleshooting are important for maximizing the efficiency of DIY mini split heat pumps, such as cleaning and replacing filters.

Cleaning And Replacing Filters

Cleaning and replacing filters is an essential part of maintaining a DIY mini split heat pump, as dirty filters can affect the efficiency of the system and reduce its lifespan.

Congested air filters increase energy consumption which can skyrocket monthly energy bills, while reducing SEER rating – meaning cooling systems won’t be as effective anymore.

Furthermore, poor indoor air quality or inadequate ventilation can occur if periodic maintenance isn’t done in due course. 

Thus, it is important to clean filters regularly or replace them every 3-6 months depending on usage and environment; manufacturers typically recommend vacuuming the filters every two weeks to keep them clean.

Tips For Extending The Lifespan Of  DIY Mini Split Heat Pumps

Here are some tips to extend the life of your DIY mini split:

Replace filters regularly

Clogged or dirty filters can cause the system to suck in dirt and dust which then settles into other parts of it, preventing expelling of heat from occurring effectively. 

Therefore, as part of regular maintenance practices, making sure you replace or clean filters routinely once every 3 months is generally best practice when using a standard filter size.

Fix small issues promptly

As with any furnace component that isn’t properly working at all times small problems may occur as time passes such as strange noises coming out from inside the unit etc.

Shut down correctly

Make sure the procuring procedure is established for proper shutdown after each use within cooling/heating cycles since leaving it on “mode-idle” might damage appliances eventually.

Shutting off power supply would primarily eliminate this risk but would recommend unplugging completely since more often than not happens a human error causing units still being left connected and draining electricity unnecessarily.

Optimal usage temperature range setting

Apart from previously mentioned points, extending maximum useful lifetime requires avoiding overexposure as well so instead of running cooler/warmer once accustomed definitive ambient operating optimum temperature always remind oneself establishing certain boundaries few degrees above lowest/highest degree 

Common Issues And Troubleshooting Of DIY Mini Split Heat Pumps

The most common issue associated with DIY mini split heat pumps is improper installation

Without proper training in troubleshooting, a mini split system may not perform as expected. 

Other factors that homeowners can look out for when diagnosing an issue include:

  • Error codes installed in the indoor unit can alert them to any performance issues that arise with their DIY mini split pump system.
  • External factors such as water running from gutters into a well – placed outdoor mount or snow impeding airflow should be taken into consideration when clearing fault codes or identifying causes of malfunctioning equipment due to environment conditions.
  • Refrigerant is needed due to leaks or incorrect installation method this could lead to potential problems such build up excessive pressure stresses especially at higher evaporator temperatures which will reduce cooling capacity output compared to its design specification .
  • Blocked filters can restrict liquid flow through aftercooler leading drop coil temperature below freezing point resulting in ice formation stalling further cooling down process completely effectively stop working heating elements.
  • Mostly during longer winter days lowering total heat output eventually increasing the cost of installing a second unit .

Top Brands And Models Of DIY Mini Split Heat Pumps

Observations and reviews from customers are important when selecting the right brands and models of DIY mini split heat pumps.

Features And Benefits  Of DIY Mini Split Heat Pumps

Ductless mini-split heat pumps offer an energy-saving, cost-effective alternative to traditional HVAC systems. 

The small size and flexibility of these units make them ideal for cooling or heating individual rooms, rather than an entire house or building.

Installing a DIY mini split heat pump is easy and relatively inexpensive, making it an attractive solution for many homeowners looking to keep their houses comfortable all year round while saving on their energy bill.

Mini split heat pumps can provide a variety of benefits over traditional HVAC systems such as enhanced energy efficiency, cost savings due to reduced demand on central air conditioning systems, dual-functionality in both heating and cooling with maximum temperature control accuracy at any time of the day or night, and suitability in climates from dry deserts to humid tropical areas.

Comparison Of Different Brands And Model Of DIY Mini Split Heat Pumps

As you evaluate the options, consider the top brands such as Daikin, Mitsubishi, Fujitsu, MrCool, Senville, and Energy Star

Here is a comprehensive table comparing different brands and models of DIY mini split heat pumps:

Brand and ModelKey FeaturesSpecificationsPrice Range
DaikinSmart inverter technology Energy efficientWhisper quiet operationBuilt-in air purifierSEER Rating: 19-23.5BTU: 9,000-24,000$1,500-$3,000
MitsubishiAdvanced inverter technology Energy efficientQuiet operationSmart controlsFiltration systemSEER Rating: 16-26BTU: 9,000-36,000$1,500-$3,500
FujitsuEnergy efficient, Compact design, Smart controls, Wireless remote control, Inverter technologySEER Rating: 16-33 BTU: 9,000-36,000$1,500-$3,500
MrCoolPre-charged refrigerant lines and quick connectionSmartphone app controlEnergy efficient AffordableSEER Rating: 16-22BTU: 12,000-24,000$1,000-$2,000
SenvilleInverter technologyEnergy efficientWhisper quiet operationBuilt-in air purifier Smart controlsSEER Rating: 19-25BTU: 9,000-36,000$1,200-$2,500
Energy Star FPHW121AHighly efficient cooling and heating22.0 SEER ratingInverter technologyWi-Fi controlSEER Rating: 22BTU: 12,000$1,600-$2,300

Reviews From Customers

Customers often leave ratings and reviews about DIY mini split heat pumps, allowing potential buyers to get an insight into each product from the perspective of someone who has already used it.

Reviews from customers on various brands provide useful information that can be used in making a purchase decision. 

Daikin, Mitsubishi and Fujitsu are the top three mini-split brands with many satisfied consumers leaving positive feedback about their installation experience as well as durability over time.

Common themes include ease of installation, energy efficiency, cost savings compared to traditional HVAC systems and dual-functionality for both heating and cooling.

Newer brands such as MrCool have also gained popularity due to its advanced features like voice control capability through Alexa or Google Home devices.

DIY Mini Split Heat Pumps Vs. Traditional HVAC Systems

The table below highlights the main differences between these two types of heating and cooling systems:

CriteriaDIY Mini Split Heat PumpsTraditional HVAC Systems
Energy EfficiencyHigher energy efficiency due to the absence of ducts, which can lose up to 30% of conditioned air.Lower energy efficiency, as ducts can leak conditioned air, resulting in wasted energy.
Size & FlexibilitySmaller size and greater flexibility for zoning or heating and cooling individual rooms.Larger size and less zoning flexibility, as they require ducts to distribute conditioned air.
InstallationCan be installed as a DIY project, reducing installation costs.Requires professional installation, resulting in higher installation costs.
Initial CostGenerally higher initial cost compared to traditional HVAC systems.Lower initial cost in comparison to ductless mini split systems.
Long-term SavingsPotential for long-term cost savings due to energy efficiency and lower maintenance expenses.Less potential for long-term cost savings, as energy efficiency is lower and maintenance costs can be higher.
Government Incentives & Tax CreditsEligible for various incentives and tax credits, depending on the model and location.May also be eligible for incentives and tax credits, but availability may vary depending on the system and location.

Government Incentives And Tax Credits Of A DIY Mini Split Heat Pump

The following are the different government incentives and tax credits issued to the people to buy a mini split heat pump.

Overview Of Incentives For Installing A DIY Mini Split Heat Pump

Installing a DIY mini split heat pump can be an efficient way to keep your home comfortable all year round, while also reducing energy expenses. 

Fortunately, there are government incentives that may help you recoup some of those costs.

The Inflation Reduction Act offers a 30% tax credit, up to $2,000 in total, for homeowners who install new heat pumps as part of a comprehensive approach to improving their homes’ energy efficiency.

Additionally, if the unit has an HSPF (Heating Seasonal Performance Factor) rating of over 8.5 then it may qualify for a federal tax credit worth up to $300 from the Nonbusiness Energy Property Credit program.

Information About Tax Credits For Mini Split Heat Pumps

Mini split heat pumps are an energy-efficient option for providing efficient heating and cooling in the home. 

At the federal level, mini split heat pumps qualify for both the HVAC tax credit and the Inflation Reduction Act (IRA) tax credit. 

HVAC tax credit

  • The HVAC tax credit covers any qualifying air conditioners, heat pumps, or furnaces purchased after January 1st, 2020 with an efficiency rating of at least 16 SEER/13 EER. 
  • For central air conditioners or 11.2 EER/8 HSPF for fossil fuel-powered furnaces or 12.5 Energy Factor (EF) for electric resistance water heaters designed solely to supply hot water to a dwelling unit’s plumbing system.
  • Non-ducted mini splits not larger than 24k BTU’s also qualify if manufactured on or after November 2021 For solar water heater systems that meet certain requirements, there is a 30% federal energy tax credit off of their cost up to $500 per 0 .5 kilowatt (KW).

Inflation Reduction Act (IRA)

IRA offers additional incentives through a separate rule set – up to 10% off your purchase price up to $300 as long as it is serviced by a certified contractor –reimbursed via check by April 15th when filing taxes in 2021 OR upcoming years.

In other words, by purchasing a high efficiency ductless mini split system you could be eligible for thousands of dollars back upon installation.

This alone should make DIY mini splits appealing whether your budget is tight or healthy given their approximate 40-45% greater saving potential over traditional HVAC systems.

Case Study: MrCool DIY 24k BTU Mini Split Heat Pump Air Conditioner Versus Traditional HVAC System

A DIY Mini Split Heat Pump is an easier and more economical solution than a traditional HVAC system. 

It comes with two-24k MrCool units that provide combined cooling of 48000 BTU, which are considered sufficient to cool most rooms.

These split units are great for energy efficiency as they don’t require any additional ducting or complex wiring, while their design allows them to be mounted wherever convenient in the home.

The installation process is much simpler compared to traditional HVAC systems since there’s no requirement for modification or significant worksite preparation. 

Once installed, the DIY mini split provides cost savings thanks to a better fit between unit capacity and conditioned space needs without wasting excessive heating/cooling power on excess space beyond requirements.


The conclusion summarizes the benefits and considerations of DIY mini-split heat pumps, detailing how proper sizing and installation are essential for optimal performance.


What is a mini split heat pump?

A mini split heat pump is an air-source, ductless system that heats and cools the interior of a home or building through multiple individually operated indoor units connected to one compact outdoor unit.

What are the benefits of installing a diy mini split heat pump?

Do-it-yourself (DIY) installation from start to finish for this type of system offers significant advantages including cost savings on labor, as well as convenience and flexibility when it comes to determining where each indoor component will be installed.

How much does DIY installation typically cost?

The total costs associated with DIY installations vary greatly depending upon both the model of equipment & level effort required however typical components can range anywhere between $500-$2000 all inclusive ,with materials accounting for only 50–70%.

Making them significantly more affordable than contractor based solutions which commonly involve upwards $1400 in extra labor expenses alone.

Do I need any special knowledge or tools before attempting DIY installation? 

Prior experience coupled with appropriate tools (screwdrivers, wiring clamps etc.) is required and safety measures such as gloves/eyewear should always be utilized while attempting these types work & prior research into understanding how everything fits together is also essential ensure success in end results

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