You have 3 DIY vs Pro mini split options – and they are fully explained here. Mini split brands in each category are discussed, so you can buy a mini split system for your installation preference.
DIY vs Pro Mini Split Installation
Fully DIY mini split systems are available. So are fully pro-installed systems. And there is an in-between option, a DIY system with refrigerant lines that must first be vacuumed but otherwise can be safely and confidently installed without hiring an HVAC technician.
Here are the options:
Full DIY Mini Splits: These come with pre-charged refrigerant lines. That is the major key to them being fully DIY. When the lines are full of refrigerant, they don’t contain air or moisture that has to be evacuated – vacuumed – out of them first.
Once the system is installed, attach the lines, open the valves, and turn on the mini split. You’ve got heat or AC, whichever you need at the moment.
Semi DIY Mini Splits: These units come with empty refrigerant lines. That is the difference. But they have enough “extra” refrigerant in the compressor to fill the lines and still have the proper charge for the entire system. Even these systems can be fully DIY if you have the tools needed to vacuum the system. We’ll explain below.
Pro Installed Mini Splits: Most mini split systems require the help of an HVAC technician that is certified to purchase and handle refrigerant. The systems usually come with a partial refrigerant charge, but the technician has to add more during installation for proper operation of the system. In short, Mitsubishi, as one example, doesn’t want homeowners buying a vacuum and a gauge and giving it a go on their own.
Why do mini split brands require pro installation?
There are probably two reasons – one technical and one for sales purposes.
Technical: Brands like Mitsubishi and LG require full professional installation on their systems to ensure that the work is done properly. Proper installation = happy customer. The opposite is true too.
These mini split manufacturers don’t want the hassle of working with homeowners who tried DIY and something went wrong. Then they deny the warranty claim. The consumer is unhappy and leaves nasty reviews about the mini split – when it wasn’t the manufacturer’s fault.
Sales: The mini split brands want HVAC contractors selling or “pushing” their brand. It doesn’t help your local HVAC company if you buy a DIY MrCool mini split. But if Midea or Carrier or whoever offers incentives to local installers to sell their equipment, it’s a win-win for the brand and the local company.
Full DIY vs Semi-DIY Mini Splits
This seems to be where the confusion lies with some consumers. The difference has been mentioned, but here’s a fuller explanation that should clarify the situation.
Full DIY mini split systems are like “plug-and-play” devices. No professional or advanced tools are required for installation. No vacuuming is needed. The line set comes fully charged with refrigerant. As long as the correct steps are taken in the proper order, the job should go smoothly.
Semi DIY systems have one major difference. The line set does not contain refrigerant, and it must be vacuumed before the valves are opened to allow refrigerant to flow out of the compressor and into the lines. You must have an HVAC vacuum pump like this one and a manifold gauge made for the refrigerant type in the system – usually R410A. Most gauges are made for several types including R410A, as this one is.
Depending on the quality of the vacuum and gauge you buy, your total cost will range from $130 to $250 for homeowner-grade options.
Why don’t these systems come with charged refrigerant lines? It would make it a lot easier!
The answer might vary a little by manufacturer, but the general idea is that:
1). The manufacturer expects a pro to install the unit, since most homeowners don’t have the vacuum and gauge and/or don’t want the headache.
2). They want the lines to be vacuumed because it is the best way to ensure that the mini split heat pump will run properly. Either air or moisture in the line will impede refrigerant flow if allowed to remain – and vacuuming removes them.
How to Install a Semi DIY Mini Split System
Follow the directions verbatim.
That’s the best answer anyone can give. Each brand is a little different, and they all come with very detailed instructions with explanations and diagrams.
And watch a tutorial. Many brands offer their own video tutorials, but this one covers the basics beautifully.
How hard is DIY and semi DIY installation? We’d say that installing a fully DIY system like the MrCool 3rd Generation heat pump is a 4 out of 10 for handy homeowners. And a semi DIY system like those from Pioneer is a 6 out of 10 due to the vacuuming part.
Mini Split DIY, Semi DIY and Pro Installed Brands
OK, here’s a quick breakdown of brands before we move on to other important related topics.
Fully DIY Brands
There are two brands that require nothing more than a few common tools to install – no gauges or a vacuum pump. They are:
MrCool, is sometimes written as Mr Cool. The brand makes true DIY systems, the 3rd Generation units, plus semi-DIY and pro-installed mini splits. Currently, MrCool makes DIY mini split heat pumps in single zone, 2 zone, 3 zone and 4 zone systems. There are no 5 zone DIY mini splits.
Klimaire is the only other manufacturer that makes fully DIY mini split units. As the info states, it comes with, “pre-charged refrigerant lines that do not require them to be vacuumed for installation.” Klimaire also makes pro-installation mini split systems, so be sure that if you plan to DIY, you get the right type.
The Best Mini Split Brands for DIY Guide gives other specific mini split systems that you can DIY with confidence. Most are fully DIY and a few require vacuuming that you can do yourself with the tools mentioned above.
Semi DIY Brands
Pioneer and Senville are the top-selling semi DIY brands. The DIY mini split heat pumps need to be vacuumed, as shown in the demo video linked to above. It isn’t a hard job if you have a vacuum and the right gauge and you pay attention to the details provided in the mini split’s installation guide.
Buyer beware: Read the fine print on any semi-DIY mini split because most of the manufacturers decline to honor a warranty if the unit isn’t installed by a licensed contractor.
Pro Installed Brands
Everything else requires pro installation…That’s the short answer.
Brands requiring installation by a certified HVAC technician include LG, Mitsubishi, Gree, Midea, Fujitsu, Daikin, Carrier/Bryant (made by Midea/Toshiba), Lennox, York/Luxaire, Bosch, Blueridge made be Gree and Midea, and a host of others.
Warranty on Ductless Mini Split DIY Install
The MrCool warranty on ductless mini split DIY install systems is 7 years on the compressor and 5 years on other parts. Klimaire offers a couple different warranties. The single zone systems are backed by 7-year compressor and 5-year parts warranties. Most, if not all, multi zone systems have a 5-year compressor warranty but just a 1-year parts warranty. Pioneer, a quality semi DIY brand backs its products with a 5-year warranty on everything.
Common BTU and Room Size For DIY Mini Split
What size room for DIY mini split systems?
- 9,000 BTU: Maximum 350 square feet
- 12,000 BTU: Maximum 500 square feet
- 18,000 BTU: Maximum 750 square feet
- 24,000 BTU: Maximum 1,000 square feet
- 36,000 BTU: Maximum 1,500 square feet
These ratings are for rooms, zones and homes with average to good insulation and windows. They do not apply to garage or outbuilding use.
Can I DIY a multi zone (2 zone, 3 zone, 4 Zone or 5 zone) Mini Split?
Yes, but only if it is a fully or semi DIY line of mini splits. Remember that even MrCool makes both DIY and pro-installed systems, so be sure you buy the right system – one specifically designed for do it yourself installation.
Is There a 115v/120v DIY Mini Split?
Yes! Many mini split heat pumps and air conditioners up to and including 12,000 BTUs are 115V/120V systems. Some 12,000 BTU mini split units are 208/230V, so be sure to check before you purchase.
How Many Zones Can A DIY Mini-Split Have?
Up to 4. MrCool 3rd Generation DIY is your best bet for a fully-DIY 2 zone, 3 zone or 4 zone system. Keep in mind that the brand does make non-DIY systems too like the Advantage Series, so be sure to choose the right type for whether you plan to install it or plan to hire a pro.