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Bridging the gap Hydronics to AC

Good afternoon folks,

I run my own plumbing and hydronic contractor business which specializes in hydronic heat. Im looking to bridge the gap and keep business booming during the summer time when the no heat calls come to a hault and when the new construction jobs get completed.

Primarily I will start installing minisplit units, but would like to do repair and diagnostic work too. I already did much research on minisplits, but need some guidance where to look for educational reading, which websites to frequent (manufactures or exceptional installers), what gauges are necessary, and what brands are quality and which are second best or best not to be installed.

Better understanding AC will also open my services into the geothermal world.

Thanks in advance!


  • Techman
    Techman Member Posts: 2,144
    A bridge

    Welcome brother ! Read a lot of the past threads here to get the jist  of things, the language and stuff.
  • Jack
    Jack Member Posts: 1,046
    Contact the manufacturers

    And their local reps. Of the majors, Fujitsu, Mitsubishi and Daikin, Fujitsu is in N NJ and have regularly scheduled trainings. As well, the local reps, Wales Darby have a training facility and also provide training.

    I think this an excellent move on your part. Become really good at these mini-split systems and specialize in them and it is, in my opinion, all up-side for you. Good luck!
  • NYplumber
    NYplumber Member Posts: 503

    Thanks guys. I will contact a few reps locally to start the process.
  • AFred
    AFred Member Posts: 81
    2 cents

    Go for it NY.

    Try to stick with 1 brand. We use Fujitsu, great product, Mitsubishi is another good one. I will tell you almost all of the problems I have are 'Installer error', I do most of the mini-splits at my shop so its usually me that screwed up. What I mean is the better you get at installing them the more trouble free they are. If you do have an issue, do not hesitate to call tech support!

    Must have tools:

    -A good 410a flareing tool.(I use a yellow jacket 60278 and love it) A dab of oil on the cone helps. This will do most of the reaming of the pipe for you.(don't over ream the pipe before you flare)

    -Nitogen. Since I started using nitro about 3-4 years ago call backs for leaks have ended! The nitro is cheap, leaks are not. I usually test to 300-350psi.

    -Decent gauges.

    -Decent vaccum pump. I don't use a micron gauge(some people will shame me for that). But if I can't find a leak with nitro I'm not gonna find it with a vacuum. Just make sure you pump it down long enough. Keep your pump maintained.

    Eventually you will need a recovery unit, the appion g5 twin is the best bang for your buck, its fast.

    Like anything you install, the more you install, the better/faster you get. I have yet to have a customer regret buying mini-splits. Good training is worth every penny.

    Good luck!

  • Techman
    Techman Member Posts: 2,144
    edited June 2013
    Shame! Shame!

    Oh AFred, you have sinned! The deepest vacuum is only negative 15lbs of pressure. So that's not all that deep. Look at it this way. KindaSorta,You are starting out with  25,000 microns per in. of vac and there is 30" in a vac so 25,000 x 30 = 750,000 microns and you have to pull down to 500-350 microns, that's a lot of pulling to do . The first part of the evacuation gets rid of air which is non-condensibles . That first part takes you down around 10,000 micons then the 2nd part kicks in . This is where the moisture/water part does it thing. The water/moisture boils off into a vapor and get sucked out by the vac pump , and IF it is an actual drop of liquid water ( maybe it rained a little during the install ) ,the micron level will not drop any further until that one and only drop of rain is boiled away. So a micron gauge will show that process.. So down around 350 there is no, none, any, water/moisture to turn into acid and kill the compressor.  What say you now ,sinner!
  • AFred
    AFred Member Posts: 81
    Shame shame

    Forgive me father Techman for I have sinned.

    I had a micron gauge on my last set of gauges. I (doubting thomas/andrew) never trusted it. My new set of gauges are a yellow jacket 4-valve analog set, and I can only get away with spending so much of my bosses money. Maybe I don't have the coconuts to demand a good micron gauge. I don't want to get stuck with the crappiest $70 gauge that I won't trust, that's probably what I'll end up with if I demand one. I know this is kinda a cop-out, but untill I get that magic gauge I think I'll be letting my vacuum pump run for a long time everytime.


    PS: Any recommendations on micron gauges?
  • Techman
    Techman Member Posts: 2,144
    That depends!

    For a sinner use your gauges!!  For a convert, I have good results with the J-B digital micron gauge. So , whats it going to be???Do you feel lucky? Well do ya !? Its the ONLY way to go, its NORMAL!!!!!!!!!!!!!!!
  • TonyS
    TonyS Member Posts: 849
    Ductless is perfect for

    your hydronic customers since they dont have any duct in the house.

    It keeps me busy all summer long.

    I use to handle Fujitsu but what I have found is that after several years the Fujitsu plastic really yellows.

    So as of the last few years I have been installing Comfort star and Samsung.

    The Comfort stars work really well and internally are identical to Samsung but they only come in white.

    The Samsung Vivace is mirror black just like the TV.

    I find you don't need gauges since the txv is inside the condenser unit. That is why you insulate both lines. What you do need is a good automatic scale and a small reclaimer.

    I also just purchased a UNIWELD 2 stage vac pump that weighs 9 pounds. I also keep a 300 ft tank of nitrogen in the shop and refill my 10 ft tank after each job. No sense in dragging around a 35 lb vac pump and a large tank of nitrogen for a mini split.

    You will be drilling a lot of 3 inch holes through a lot of different materials, so be prepared with an assortment of bits.

    I have also found in homes with pets and some without that the squirrel cage blower will have to be cleaned after a couple of years. After watching guys struggle with a bottle brush or making a mess on the wall I have found it is best to remove the blower wheel and use a garden hose to clean it. It is not that complicated but I would recommend taking your first one apart on a bench in your shop until you become familiar with it. Long magnetic screwdrivers really help as does a small magnetic dish.

    Also after taking them apart you will find they all roll off the same Chinese assembly line using the same parts.

    You will also need a few adapters( 5/16 OR 1/2x20 UNF)  core remover and a 5/16 low loss x 1/4 flare adp. Also because there is no low and high side you will need a dye injector and you will need another 5/16 low loss x 1/4 adapter for that.

    I love installing ductless and my customers  love it even more.
  • NYplumber
    NYplumber Member Posts: 503

    Thanks for the replies. After much research I have decided that Daikin, Mitsubishi, & Fujitsu will be my brands of choice.

    I am still looking for online training (Taco style - webinars), a good forum to read, as well as quality installers on youtube showcasing their work.
  • TonyS
    TonyS Member Posts: 849

    Who ever is selling you Daiken should be setting you up with training. Join the Daiken University for a few hundred bucks and it gives you access to all their courses.


    Daiken cost a little more but some of their units have some unique features such as being able to dehumidify without changing room temperature.

    The Aussie on youtube ia always ripping them apart, His videos are entertaining and you will learn alot. Here is a link to one of his videos, you can subscribe from there.


  • Keith W.
    Keith W. Member Posts: 29
    Fujitsu & hydronic cooling

    So I have been installing Fujitsu mini-splits for years, I find them a good product and a good company to work with. I've done all their trainings, they are decent, though my complaint about all mini-splits that I've worked with is that there are some tricks to getting the wall units properly installed (there's VERY little space for refrigerant/electric/drain lines the smallest Fujitsus), and if you don't do it JUST RIGHT you will regret it. They really didn't cover any of that kind of detail in their training. I keep thinking of making a youtube video on it...

    I also started using Nitrogen for leak testing years ago, I follow their procedure for some of their bigger units which specifies 600 psi (had to buy a special regulator -- I suspect the 500 or so that most all regulators can reach would have been fine). As someone pointed out, the best vacuum testing is only 15 psi, so with 600 psi I never have problems. The max operating pressure of these units is over 400 psi, so there's good reason to crank it up. When you are testing the evacuation, use a micron gauge, but the 600 psi is the reat test.

    Another trick I only picked up a few years ago: Nylog. I'm about to piss off most everyone reading this, but Nylog is an oily gooey stretchy stuff made of refrigerant oil (hence it comes in two flavors, for mineral oil vs. synthetic/HFC systems). You USE IT ON FLARE FITTINGS! It's completely dissolvable in refrigerant, so you don't contaminate you system if you get some inside the line (this is VERY IMPORTANT for R410a mini-splits: it's why, I suspect, we use flares and not brazing). It makes the fittings really bomb-proof, IMO. I bought a bottle for like $10 years ago, I think it's still 80% full: you use almost none. I hope they don't go out of business because of me.

    Finally: I am gearing up to do my first (small, residential) hydronic air-source heat pump install: Daikin makes one (the Altherma), as does Aermec (the ANK: ships from Canada). I'm leaning towards the Aermec right now, but the Daikin has more traction in the US right now, as a company. Both are big companies elsewhere (Japan & Italy/Europe, respectively). Anyway, you can link things like radiant floor and "hi-wall fan coils" (very much like mini-splits, but you don't run refrigerant lines, you run very well-insulated water lines to each of the units). In any case, you might want to look into them too. Both of the units are available in a mono-bloc design, wherein the refrigerant is entirely sealed in the exterior unit, no refrigerant lines at all, but the trade-off is that your water lines have to then go outside, and in a freezing climate that means anti-freeze in the entire system.

    Better stop there! Good luck! I think it's a very smart move, though I'd encourage you to get smart about building science too: the more you are installing new units or helping with major rehabs, the more commonly you have opportunities to convince the clients to tighten up or increase insulation on their houses, which is generally a better idea than a larger system. I think it's really unfortunate that building envelope issues are typically completely divorced from comfort system design -- that is, they are taken as a given, even when there is opportunity to improve them. The 3000 sf house I'm designing a system for right now requires less than 20 kBtu heating and cooling in the DC area, whereas I just visited another house very recently built with minimal thermal considerations, a good bit larger granted (near 5000sf) but with over 120 kBtu heating and cooling demand. Design failure, IMO. Check out buildingscience.com


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