Author Topic: Is Installing a Mini-Split a DIY job?  (Read 1671 times)

m8547

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Is Installing a Mini-Split a DIY job?
« on: February 13, 2018, 12:03:57 PM »
The top floor of my house doesn't have air conditioning, so I'm considering putting in a mini-split. I have two other mini-splits in the house, but this room at the top that doesn't have one is the only room that really needs it, since it gets the majority of the heat gain. Is this something I could do myself? I watched a few Youtube videos, and it doesn't look too bad. Basically:

  • Install a bracket for the indoor unit
  • Cut a hole in the wall, install indoor unit
  • Run refrigerant lines, drain, electrical from indoor to outdoor unit
  • Install a circuit for it, and a disconnect box
  • Cut and flare refrigerant lines, torque connections
  • Purge lines with nitrogen and/or vacuum pump (is nitrogen necessary) and check for leaks
  • Open valves to release pre-charged refrigerant into lines

So I'd need to but a vacuum pump, refrigerant manifold, a tubing flare tool, and maybe some nitrogen (how does one buy nitrogen?). That's a few hundred dollars, but much less than the cost of paying someone to install one of these, and I can use the tools again if the other units which are 15+ years old stop working and need to be replaced.

Has anyone here installed one of these? Is there anything difficult I'm missing? Running all the lines will be labor intensive to make it look good, but probably not particularly difficult. Purging the lines and making sure it doesn't leak is important, but also tdoesn't sound too difficult.

This is on the third floor, and I'll probably want the compressor at ground level, so I'll need a system that can pump refrigerant up at least 30 feet.

Would it be worthwhile to take out the other two mini-splits and put in a single compressor that can supply three indoor units? I think that would be more expensive, and if a measured amount of refrigerant needs to be added, that might be beyond my DIY skill level. The old units are only about 10 SEER, but the first two floors have so little cooling load that it probably doesn't even matter.

Any chance I might be able to find someone to come out and just do the refrigerant work if I do everything else? I know a lot of companies don't like anything to do with DIY work.

GuitarBrian

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Re: Is Installing a Mini-Split a DIY job?
« Reply #1 on: February 14, 2018, 03:02:20 PM »
I have never installed a mini split. I did install a central unit. I ran the lines, got the duct work set. Air handler and compressor set. I hired a guy to braze the lines and charge the system. It was much cheaper than hiring a company to do the whole thing.

I have watched several mini splits go in at the neighbors... And it looked down right easy.  The hardest part was running the lines up the wall. So if you are handy... It sure looked straight forward.

You can buy a vacuum pump at harbor freight. I bought my gauges online for $30. They work just fine.

Topping off a system is also straight forwards. You can watch videos on how it's done. You will need a Pressure Temp chart. Just like on a car... It is sometimes listed on the gauge. Or you can look it up online. 410a is non ozone depleting. Originally no license was going to be required, but the AC techs lobbied and got it included in the licensing. You can buy cans of 410a on Amazon easily.

Or you can do all the work (lines/hanging etc) and find an AC tech to flare the lines  and pump down the system. Check craigslist, or post a gig ad to find someone.

I don't have an opinion on single compressor vs multiple... Your choice. Installing a single new unit would be easier I think.

BudgetSlasher

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Re: Is Installing a Mini-Split a DIY job?
« Reply #2 on: February 14, 2018, 03:46:34 PM »
maybe some nitrogen (how does one buy nitrogen?).

I've always gotten my nitrogen from welding supply shops of the AirGas chain.

Quote
I know a lot of companies don't like anything to do with DIY work.

I have read that some manufactures take a keener interest in if a product was DIY'ed to void warranty.

kork

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Re: Is Installing a Mini-Split a DIY job?
« Reply #3 on: February 14, 2018, 03:50:35 PM »
I have multiple mini splits in my home.  Having watched them get installed and troubleshooting issues afterwards, I wouldnít try to do it myself.  Iíll do a lot of home maintenance , minor electrical, plumbing, etc...  mini split, nope...

kudy

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Re: Is Installing a Mini-Split a DIY job?
« Reply #4 on: February 14, 2018, 05:05:11 PM »
I did part of a mini-split myself - mounted the air handlers inside, ran the lines and electrical, mounted the compressor outside. I then found a local HVAC company to come out and do the final hose connections and vacuum/opening of refrigerant lines; they charged me their hourly rate ($120/hour), and it took two hours.

FiftyIsTheNewTwenty

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Re: Is Installing a Mini-Split a DIY job?
« Reply #5 on: February 15, 2018, 08:40:54 PM »
I get the impression that while the top brands (Mitsubishi, Daikan, LG, etc.) can be bought online, this is sort of a gray market.  They want you to buy from their dealers who can guarantee the installation.  If you don't, you may have a hard time with a warranty claim (besides being on your own for troubleshooting and repair).

The lesser brands, or ones advertised for DIY, are often less efficient. As "off brands" they may be harder to get service and parts for.

Please tell me how I'm wrong -- I'd love to have a go at this myself!  But I want a top-notch system.  In my case, I want to replace two conventional systems, one of which is dead, with a single outdoor heat pump and 2-4  heads.

kudy

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Re: Is Installing a Mini-Split a DIY job?
« Reply #6 on: February 16, 2018, 10:34:10 AM »
I actually bought mine on Amazon. It is an "off brand," Pioneer brand, 2 head, 17 SEER rating. Not the top of the line efficiency, but it was more affordable than the top SEER rated and is still quite efficient when heating and cooling.

FiftyIsTheNewTwenty

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Re: Is Installing a Mini-Split a DIY job?
« Reply #7 on: February 20, 2018, 06:18:35 PM »
I actually bought mine on Amazon. It is an "off brand," Pioneer brand, 2 head, 17 SEER rating. Not the top of the line efficiency, but it was more affordable than the top SEER rated and is still quite efficient when heating and cooling.

How much is it saving vs. your previous system?  Also, how well is it serving your whole house, with respect to the layout and where the heads are located?

Livethedream

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Re: Is Installing a Mini-Split a DIY job?
« Reply #8 on: February 25, 2018, 04:38:06 PM »
Iím getting ready to install a DIY specific mini split this next month. The main thing that defines this system as DIY is you donít need to vacuum test the lines. It comes pre-charged and you simply loop the extra line. Comes with flare fittings for easy hookup.

Iím going to pay someone to install the breaker and thatís it.

kudy

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Re: Is Installing a Mini-Split a DIY job?
« Reply #9 on: March 05, 2018, 03:54:52 PM »
How much is it saving vs. your previous system?  Also, how well is it serving your whole house, with respect to the layout and where the heads are located?

Sorry, I missed these questions. My previous system was baseboard heat and no A/C. Running the mini-split now to cool in the summer (new feature) and heat in the winter (for two bedrooms only), my overall electricity use has dropped about $10-15/month. This definitely isn't serving my whole house, as the two head units are on the far wall in two bedrooms upstairs, so very little of the heat/coolness reaches other parts of the house.

dummy

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Re: Is Installing a Mini-Split a DIY job?
« Reply #10 on: March 07, 2018, 12:26:41 AM »
Yes I think installing a mini split is a diy job, and then hire out a pro to make the final connections, pump down, nitrogen purge etc.  Well worth it to have  a pro look over your work.  Some minisplits even come pre charged and only need to have the ends screwed together.  Now thats easy peasy.