Ductless AC self installation?

bstrussAugust 28, 2014

We have a 900 sq ft 3 bedroom cabin and the central has gone out, so were considering a couple of window units. However, I am attracted to the new ductless systems because of the energy savings and zone features etc (would need probably two zones). However, from what I have read, the installation costs hit the pocket book hard via an AC contractor and then you are back to central unit costs.

Ironically, the manufacturers claim that installation is not difficult, and many youtube videos seem to illustrate that. Therefore, my question; Does anyone know of any manufacturers which have truly DIY install friendly models by someone fairly skilled but not requiring an AC person? It is not the actual installation, but the finishing stages with the gas lines from which I understand an AC person is usually needed. But yet, some manufacturers claim 'its a snap' because the refrigerant is already contained in the system and just needs to be actuated.

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None of the REPUTABLE (big four) mini split manufacturers offer fully DIY units. Those would include Mitsubishi, Sanyo/Panasonic, Daikin, Fujitsu. I have seen one of these cheap off-brand Chinese "DIY" units in the field. I can confirm it was complete junk, and a leaker. I would never have something like it in my own house or recommend it in good faith to anyone.

"Ironically, the manufacturers claim that installation is not difficult, and many youtube videos seem to illustrate that"

Yes, the primary market for these units is older homes without ductwork. In these cases, ductwork is often extremely cost prohibitive to install and mini splits come out cheaper. However, if you had central A/C already, it would be much cheaper to replace that and I've never heard anyone claim otherwise. Also: because they are more technologically advanced, the actual equipment usually costs more than a conventional central system.

My advice: do it right, or don't do it at all. Have you had it looked at yet? It might be a cheap, simple repair. If you have had it looked at and it doesn't make financial sense to repair, I would get your existing system replaced unless your ductwork is beyond saving. If you can't afford to have the system replaced, get window units like you were originally. I would only recommend mini splits in your case if the ductwork is in bad shape and uneconomical to repair. Have you gotten quotes for system replacement yet?

    Bookmark   August 28, 2014 at 1:04PM
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Hi Hvtech and thanks for your response!. Actually the structure is an older double wide mobile home which was cinder blocked all around and new pitched roof with heavy insulation placed on top of the existing mobile roof etc. The walls appear to have R-11 (1984) and are 3.5" studs.

The ductwork existing now seems okay (in crawl space underneath), but one thing I don't like is how the vents are placed rather intrusively into the floors - especially in the bedrooms. The existing AC unit was found to be completely out of freon, and it is also has a heat unit operated from propane - which I plan to do away with.

Because of the age of the unit and the other factors, it was deemed not a good idea to try to repair it. I was quoted a price of $3900 for a new 2.9 ton heat pump. I am beginning to think that window units might be the way to go - though I will obviously loose efficiency with cooling in hot humid Florida.

This post was edited by bstruss on Thu, Aug 28, 14 at 14:05

    Bookmark   August 28, 2014 at 1:53PM
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One other question; How many AC people might be will to just handle the final stages of a ductless install (gas lines etc), if everything else was hooked up and ready to go? This might save money, but I am not sure how many would do that. Also, I have read that many current contractors don't have much experience with these newer units, so that is a concern.

    Bookmark   August 28, 2014 at 2:08PM
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With a DIY - I don't know what kind of warranty you can get - since you are the installer.

No matter what, you will need the system evacuated by a tech with a vacuum pump.

Also consider the energy efficentcy of the central air, or ductless, or window units.

Consider the cost of elecricity.

IMO, window units are the worst: look tacky, don't circulate the air well, noisy, most moving parts * 3 to replace.

    Bookmark   August 28, 2014 at 2:43PM
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^What you say about warranty/installation is true for GOOD mini splits, but they do sell these crappy Chinese "quick connect" units online that are deigned to be DIY installed. I'm not even sure if they come in heat pump versions though. As for the GOOD brands, they will certainly void the warranty if you don't get them installed by an authorized person. The online retailers that sell these units often apply warranties of their own - but unlike the manufacturers, they often try to skate out of honoring them.

As for how many contractors are willing to do that... it really varies. All you can do is call and ask. I would tend to say that the better ones would refuse such a job. The blame game is always an issue with any DIY installed HVAC system. Say the homeowner buys a system online, starts the install, and a tech finishes the install. A few days later, the system fails. Whose fault is it? The homeowner? The contractor? The manufacturer? The online retailer? These installs have the tendency to turn into big messes and everyone points the finger at someone else, leaving the homeowner to fend for themselves with their newly installed useless hunk of metal. Talented contractors generally don't want to put their name on those installs or get involved with those situations. There are plenty of hacks out there, though, who will do anything to make a buck, including finishing DIY installs. That's not to say ALL CONTRACTORS who get involved with DIY are hacks, but in my experience is just seems to be that way a lot of the time.

Running a business is expensive, especially a service business with gas guzzling trucks and pricy insurance. Thus, contractors are expensive, especially good ones. Sadly there isn't much that can be done about that. Most would love to offer far lower prices than they do and still make decent money, but it just isn't feasible.

    Bookmark   August 28, 2014 at 3:03PM
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I would add, having watched two multi-zone mini-splits installed in my house, with some expander units installed to interior walls, that just installation alone would be very demanding for one person. Two or more persons may be best for complicated routing. Significant strength is needed for holding the wall units in various positions while hooking them up. Also, significant study of installation requirements and wiring requirements would be needed. Last, the DIY-er needs a suitable (expensive I bet) vacuum pump, suitable (expensive) gauge set, and working knowledge of NFPA 70.

I would not do that project myself, although I did support the electrical hookup as it had to interface with the existing complex wiring.


    Bookmark   August 29, 2014 at 2:59PM
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Thanks everyone. I think my approach is going to be window units in this case, being that it is basically an older mobile home, and I don't want to sink too much money into it. The extra $100 or so monthly in cooling during the hot months will easily be offset by the $3200 less I would be paying.

    Bookmark   August 29, 2014 at 5:23PM
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I've done a lot of research on mini-split heat pumps (I'm more interested in heat than AC) and considered DIY but will likely get a Fujitsu or Mitsubishi, installed by a trained HVAC contractor for reasons noted above by others. However, you may want to take a look at the Friedrich Residential Breeze, made specifically for DIY. It looks easy to install and would be covered by warranty.

Here is a link that might be useful: Friedrich DIY mini split AC

    Bookmark   August 29, 2014 at 9:30PM
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^Thanks for pointing that out, it is the first DIY mini split I've seen that is actually from a reputable manufacturer. I have never worked with one though. I wonder if it is any better than the other DIY crap out there.

    Bookmark   August 29, 2014 at 10:02PM
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I did a Daikin mini split as a DIY install and it was very easy, and it has been problem free ever since.

Why did I DIY? Because the HVAC guys around (I got five quotes) all wanted $4500-5000 for a mini split system that costs $1400 from United Refrigeration (with line set).

My install is not difficult. As a DIY, I actually ran a longer line set, to a more aesthetically pleasing location than where I told the HVAC guys they could place it (which was merely straight through the wall and down in a line hide run 8 feet vertical to the condenser).

I know the standard line of that someone has to pay for the required training, the van, the time to go pick up the AC unit, etc. But many of those types of costs are also borne by plumbers, electricians, mechanics, and other tradespeople, who don't try to charge anywhere near the same rate for labor (and I live in a large metro area so there is plenty of competition). Some value added is there IF a proper manual J is run and calculated, but that isn't thousands of dollars for the job I requested.

Also interestingly, after being shocked by the HVAC guys on what they were asking for splits, I got a few quotes for central system for my upstairs (after being told by the mini split guys that a three way mini split for up there would be $15k). The central air guys came back cheaper, with duct installs, than the split vendors!!

I get it that line set runs CAN be difficult, even if "easier" than running a big duct system. But that really is the only place the difficulty lies.

I bought a Daikin unit with line set from United Refrigeration, and all US-made equipment to do the job (so my tools were pricier). I bought Yellow Jacket off Amazon, but cheaper Chinesium tools can be found elsewhere, and used stuff can also be found.

You'll need a good flaring tool, a deburring tool, a set of gauges, a GOOD vacuum pump, and some pressurized gas (e.g. Nitrogen) to help with leak checking. A refrigerant sniffer is also valuable to use to check for leakage issues.

A few other things you'll need are a hole saw, drill, screwdriver, UV resistant line set tape, some rubber tubing and fittings (if you're extending it a long way), appropriate breakers, wire, a suitable disconnect, some flex conduit, and probably a few other things I don't recall.

The biggest challenge is running the line set. Many HVAC guys use line hide stuff and run the lines on the exterior of the home. We chose to run ours inside the wall and through the basement, since the line run would be suitable to ensure proper oil return to the compressor and it allowed us to make an invisible, aesthetically pleasing install. Running control wires isn't an issue, but line sets plus drain hoses need to go down a hole that needs to be right where you want the evaporator, and be bundled tight enough that you can flush mount the evaporator on the wall. Its a bit tougher than going straight out the back.

Fortunately these systems are not braze-on. I know how to solder for plumbing, and Id still hire a pro for critical stuff like behind walls. If it were brazing, Id have hired a pro for certain. But this is all 45 degree flare. I used a $100-ish, US made tool to do it. Lube the tool, set it, flare it per instructions, deburr it, add some nylog, and torque it properly with appropriate wrenches/sockets to a specified value with a torque wrench.

After flaring all of them, take your gauges, and your vacuum pump, and pull a long, hard vacuum. It wasn't a hard job, and because of the flaring, there isn't a ton of skill, assuming you can pull wire. Why the prices for installed systems are so high I still cannot get my head around... I get it if pulling line set is very complicated and indirect, because that can be a killer. Otherwise, not much to it. Good luck.

    Bookmark   August 29, 2014 at 11:40PM
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^How much did you spend on tools?

About how much time did you spend on this project, including research?

What kind of a warranty do you have should it break?

The average handy household DIYer would consider that job exactly the opposite of "easy." In fact I would venture to say the average DIYer would not understand a good portion of your post. Of course, the original poster could be as skilled as you and getting ready to order the tools right now after reading your post, but I would guess if that were the case, he would have just jumped in and not started this thread.

    Bookmark   August 30, 2014 at 12:23AM
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And for any DIY project, personal time value and lost opportunity value need to be considered as costs, depending on how one is otherwise employed. A factor in favor of DIY is the perceived negative value of any faults that might be projected to result from disinterest in the perfection of the result by the commercial installer.


    Bookmark   August 30, 2014 at 2:38AM
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I spent right around $900 for tools. I could have gone to Harbor Freight and gotten everything for half that or less, but I wanted the US-made stuff where I could.

The split system with line set was $1400 to my door. A permit was $75. I did buy two crowfoot sockets suitable for this type of torquing and they were around $75 total since I bought S-K. I also paid my landscaping guy $100 to make a concrete pad.

So I was in it for around $2500. It took me around eight hours working VERY slow. The lowest quote I got to do this install (again, with a much simplified routing compared to what I did, which was where the time commitment was) was $4400.

Maybe y'all make $250/hr, but even with a professional position, I don't. And the $2000 or so savings can buy a LOT of personal time and accommodation for the "opportunity cost".

I get it that businesses have different overhead costs than I do personally, but the pricing on these things is excessive. And it's evidenced not only by my DIY job, but the fact that when I got quotes for doing a tri-split AND quotes for doing a ducted system for my upstairs, the ducted system was cheaper, even with high SEER Carrier equipment being specified.

    Bookmark   August 30, 2014 at 9:47AM
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Then, a (possibly rhetorical) question that comes to mind is: Beyond the general desire of many small business owners to become wealthy enough to retire early (not that this is unique to small business owners), is there a lack of split-mini competition that allows them to operate with excessively high margins, or are taxes and regulation costs of doing business driving overhead rates to high multiples of labor and parts costs? If the latter is true, why is the ratio apparently lower for ducted systems?

I am glad your project worked out. I congratulate anyone who accumulates more tools in trade for sweat equity. And thanks for the process description; it may help someone else.

One other question that comes to mind is: Was the Daikin (Big Gold?) unit materially less expensive than web store prices for equivalent BTU/hr Mitsu units?


    Bookmark   August 30, 2014 at 10:42AM
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Don't think I'm attacking you in any way JHZR2, what you accomplished is impressive, and there are many contractors who probably would not have done as good a job as you. There are hacks out there who don't even pull vacuums. But I just want to be careful that you don't convince someone not as skilled as you that it's an easy job and inadvertently cause them to get in over their head.

I was an HVAC tech for many years. I loved the work but never made anywhere close to $250 an hour! A serious injury when I got old forced me to get a less physically demanding job. The place I'm at now does HVAC work and repairs/sells used kitchen and laundry appliances, so I"m happy that I can still stay in touch with both industries despite having an office job now and not being able to run service calls.

    Bookmark   August 30, 2014 at 10:49AM
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kas, I was looking at the Mitsubishi Mr Slim units, and that was what I originally wanted. However, we have a United Refrigeration store not five miles away, and they have started selling Daikin vs Mitsubishi for whatever reason. Reading online it seems that both are top manufacturers and so I wasn't concerned. Id use either/or, and whatever the best shipped price is.

Warranty support is an issue, especially if a DIY install. However, I figured that (1) with the savings I had, I could buy an entire new system, (2) my money is green and repair folks will come to do repairs if I make a call, regardless of install.

If you know that there are more companies selling Mitsu than Daikin (or some other brand) in your area, you might make a choice related to that. MANY folks online are doing the DIY install and hiring an HVAC company to do the final connections and startup.

You also have a great question WRT why the pricing is higher. No idea. Some say the systems are higher cost. But yet anyone can go online and see pricing for these units. Its all in the install.


Im not taking anything you say as an attack, and appreciate your insight in all these threads! And yes, people have to have some concept of what they are doing to do it DIY (as well as an investment in tools). It isn't just a hack job, and though it is easy, its not easy like tiring your shoe or only pulling wire. Thanks again!

    Bookmark   August 30, 2014 at 11:12AM
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That Friedrich unit looks interesting BB. There is not much installation or DIY language on the website. However I found a local distributor so I might call them and get their input. I used to do AC work decades ago. It probably wouldn't take me long to get up to speed - with the right tools etc.

    Bookmark   August 30, 2014 at 12:21PM
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That friedrich is all about the lineset. No mini splits that I'm aware of use brazed joints, all flares. But the friedrich uses a quick connect so you don't have to do that either... Just mount the units, make holes and connect. I suspect that the lineset was vacuumed and filled with a slight refrigerant overpressure to keep air and moisture out, and then the hints must be set up with the appropriate pressure.

    Bookmark   August 30, 2014 at 12:53PM
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There’s a thread on the Heating and AC forum that’s been running for two years debating the issue of high installation costs. It’s a great read; the link is below. Mini splits have been used throughout the world for decades, but are new in this country and there’s very little competition to bring installation costs down. Most homeowners and many contractors have never heard of them. With increased efficiencies and units that can now heat a space when the outside temperature is as low as -15 degrees, they’re starting to become better known and more available in the northeast and Canada as an alternative to oil heat in locations where natural gas is not available. (This is not a sales pitch, lol; I've become obsessed with the subject.) This year, for the first time, I’ve seen a few local HVAC companies running ads for mini-splits (I live near Albany, NY). Installation of the wall unit is probably easier than the ceiling cassette or ducted style, which is one reason I’ll likely go with a pro. To the OP (sorry to hijack your thread), please let us know what you decide to do.
@bstruss -- From what I've read, the Friedrich mini is manufactured by one of the big Japanese companies. Though Mitsubishi, Fujitsu and Daiken are the top tier leaders in the field, there are many lesser known units for much less $. Some of them get great reviews. But I haven't seen any other specifically marketed to DIY homeowners. Let us know what you find out about the Friedrich.

Here is a link that might be useful: Why is split ductless so expensive when installed

    Bookmark   August 30, 2014 at 9:14PM
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Lol, that was my thread. Nthe HVAC guys tried to tell me that it's none of my business why they charge what they do, or how dare I ask.

But the reality came out that it is a predatory business, at least some businesses. We can be sure there are great and reasonable folks, but it seems that most aren't good at reasonably quoting a job.

If you have some diy skill, and the lineset run is reasonable, it's a good chance to learn something. Even if you pay the absurd $1000-ish startup prices that some state.

Another point of interest, we spend a lot of time in the caribbean. All concrete construction, US territory with the same taxes, licensing, etc. Only there vehicles have an ex cost tax, training always requires travel off island, and fuel is $4.50+ with electricity over 50c/kWh. And startup costs from the local guy are $250-350.

    Bookmark   August 31, 2014 at 12:05AM
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In the particular installation I am considering, it is a very rural area and code will not be an issue. I am learning a lot of good information here!

    Bookmark   August 31, 2014 at 12:10AM
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