MRCOOL DIY Mini Split, Seriously, I Think...

[abgiles]

So, the unit arrived today. I was extremely happy to see Averitt show up, as it's been insanely hot and humid here, and even with the insulation the shop temperatures have been in the high 80's, with humidity in the high 70's.

Unfortunately, the outside unit was damaged in shipping, and I refused it (I was on the phone with Ingrams as the driver was on the phone with Averitt). I will say, that the driver was the one to first notice the damage, and also insisted that we open the package to inspect the unit (I would have anyway, but he was extremely professional about it). We both documented the damage, and he was great to let me know that they would cover it.
I called Ingrams and they had a new unit in shipment before the end of the day. I did install the interior unit, and it was super easy.

 

[Browneye]

-----------

This set of behaviors now strikes me as associated with the app itself (possibly how the app behaves on your ios version).

When I close out the app on android, I get a message that says "click twice to exit". I exit by clicking twice, and the app closes. Whatever state the AC unit is in (i.e. powered up in heat mode) remains when the app is closed out. In other words, when I re-open the app and log into the mr. cool unit, the state is whatever I left it in.

In your case, the app appears to not be closing out completely, but possibly losing communications with the mr. cool cloud server.

Maybe there is a different method for closing the app that will ensure it shuts down, I don't know. I can't afford apple products

It closes out fine, leaves the unit where you left it, and when you logon it shows you it's state. I just think the interface is what to expect - I'm used to buggy software working with MS programs. LOL Apple always seems to work well. I'm amazed software works as well as it does. And I'm a network guy, that's my profession these days.

So far we love the unit. Enough to almost want to buy another one for the master bedroom. That end of the house has a window unit in the back office - a fourth bedroom, and it cools it all off back there. It's just a 6400btu unit. I can get a state of the art Frigidaire 10K btu for $300 that would do an even better job. It's hard to justify the $1200 for another mini split. I do have to say they are much nicer to live with than a window air unit though. They are so quiet and move a lot of air if you need them to. The window air cools pretty well, but much noisier. Wife complained about trying to talk on the phone with the window air on high. A bigger unit could run at a lower speed though, and would be quieter. They are all about as quiet as the mini split outdoor unit - high 50's decibels. Whereas the inside split unit is almost silent.

 

[Acuratechva]

Has anyone opened their MR COOL to see what compressor it has?

I picked up an ebay generic system that claims Toshiba. Yet no local havac store could look up the part numbers.

And GNCC does not appear to be part of Toshiba from what i was able to find.

I made a move as its one of few 110v heat pumps for 500$ i am ready to risk.It of course got smashed and seller turned out to be a douche so its going back.

So back to the question has anyone researched MRCOOL's compressors and availability of major components?

 

[8mpg]

I got my MrCool installed last night. Didnt take but an hour or so. I works well but it ran all night long trying to cool down my garage. I shut it off this morning to see how well the garage would hold its temp. I'll get better numbers later. So far so good!

 

[Browneye]

AUX isn't really a 'generic brand', it's just not that common in the US. Huge manufacturer in China. There are few sellers around these parts that sell them, one is our local hydroponics supply house. Seem like good product.

I read somewhere recently that GMCC or GNCC or whomever they are, had made their millionth compressor unit. I guess they make a ton of them. From what I can gather there are only a handful of companies around the world that make these compressors - everybody buys them as a component to build their AC units.

The biggest issue with AUX, like any other non DIY brand is you need to connect a properly flared line set, vacuum it, test it in vac at least if you don't charge with nitrogen and pressure test, then open the freon valves and start the unit. It's a helluva lot more complicated than simply connect and go like the MRCool DIY units. But it can be done, or you can have a pro do it.

In any case, if it starts and runs properly you're likely to like it a lot. It's as good as any of them out there.

My personal opinion is that parts for any of them could be nip and tuck. I'm starting to think they are one-time-use throw away units. If they fail you put a new one in. Time will tell I guess. Keep in mind the importers are bringing container loads in by ship from China. I can't see them having individual component parts on hand for them, but perhaps I'm wrong. It would be nice if someone would tell the truth about this - all we get are platitudes from the manufacturers, importers, and distributors.

BTW, I bought another DIY unit today. Ingrams has some 'scratch and dent' units at a huge discount. I could care less about a scratch on the face of the air handler in my bedroom, or a dented housing on the outside unit. Guess we'll see when it gets there. I was tickled with the value proposition.

 

[8mpg]

Anyone have any input?

My MrCool unit doesnt seem to want to shut off when reaching the programmed temp in auto. I have a indoor temp gauge saying 75*F and 35% humidity but have the a/c set to 78*f. I have yet to see the unit shut off. The unit itself doesnt seem to have a way to see its reading of the ambient temp. Any thoughts?

 

[Browneye]

I would think there's a pretty good swing from high to low in 'auto'. Personally I have not used it yet - the other modes yes, but not auto.

When we get to temp we shut it down. It always cools off at night here, so we don't need it to run for a lot of hours or a lot of months. Heating is about 3 months a year, so is cooling. The rest of the time it's temperate.

My understanding is the reading for ambient temp is in the indoor unit. So you have to adjust it up or down to suit.

 

[PoorOwner]

Anyone have any input?

My MrCool unit doesnt seem to want to shut off when reaching the programmed temp in auto. I have a indoor temp gauge saying 75*F and 35% humidity but have the a/c set to 78*f. I have yet to see the unit shut off. The unit itself doesnt seem to have a way to see its reading of the ambient temp. Any thoughts?

The indoor fan won’t shut off if that’s what you are asking.
You would see the outdoor fan stop if it reaches the temp and a little lower.
It will have a different temperature than your thermometer because it is reading the air from the intake closer to the ceiling.

 

[8mpg]

Thanks guys. I went out this morning and the fan on the head was still running and the thermometer in the garage said 77*f and the unit was set to 78*f. The compressor outside and fan was not running so I guess its technically "off". Just surprised on how it operates.

I think Im going to have to look into a dehumidifier. It jumped from 35% to 65% overnight.

 

[big_bake]

Thanks guys. I went out this morning and the fan on the head was still running and the thermometer in the garage said 77*f and the unit was set to 78*f. The compressor outside and fan was not running so I guess its technically "off". Just surprised on how it operates.

I think Im going to have to look into a dehumidifier. It jumped from 35% to 65% overnight.

maybe try running the unit in dry mode.

also google air sealing a house. you'll get some tips on places to look and seal. that warm moist air is getting inside the space somehow.

 

[8mpg]

maybe try running the unit in dry mode.

also google air sealing a house. you'll get some tips on places to look and seal. that warm moist air is getting inside the space somehow.

The big leak is the garage doors (4 of them). The rest of the building is sealed pretty tight with spray foam, a double sill plate seal, caulked wood joints, etc. I'll try the dry mode.

 

[Browneye]

Okay, got another Mrcool installed - this time a 12K btu unit for the master bedroom and east wing of the house. Since this is appears to be the defacto thread on MrCool mini splits on the internet I thought I would chronicle this installation - it was a doozy. LOL

First, here is a comparo of the outside condenser part of the unit - my original 24K unit, and the new 12K to the left. It weighs half of the other one! The inside unit is 11" less in width. Like a 'mini-me'.



I had been contemplating on upgrading the 6K window air in the back office to a 10K unit - would have cost about $300. The smaller unit actually does a pretty good job keeping things cool back there, but on really hot days our bedroom just never quite cools off. So a bigger unit made sense, but gee, a mini split is just so much nicer - it works better, heats AND cools, and is soooo quiet. So I have been shopping 9-12K btu mini's that could be connected to 110-120v since I have power at the outdoor location where I would install one.

Ingrams sells a LOT of units - I don't think anyone doubts that. So they have a lot of damaged and returned goods. They have a 'scratch and dent' section and I was perusing recently and saw a dented DIY condenser for really cheap, and a refurb air handler for also a really good deal - the combo about $500 under regular price. They said full warranty - guaranteed to work, just some cosmetic flaws so they couldn't sell them as brand new items. So I pulled the trigger on a 12K 115v unit. It was too good of a deal to pass up.

Unfortunately the picture they showed of the condenser didn't convey the entire damage. My guess is this one fell off a truck or pallet, the whole end was caved in:




And the air handler was scratched on the front face, and the copper lines were exposed behind the unit. I thought I was getting a new unit that had been refurbed, but it was actually a 'return'. I was highly suspect. But some GEL-GLOSS plastic polish restored it to like-new, and I wrapped the lineset with closed cell neoprene and commercial grade duct tape - good to go.

Next I removed the end panel off the condenser and straightened the whole thing out, and the lip of the bottom pan of the unit. Even the insulation around the compressor had been jogged out of place - it was sitting up too high, not down around it like it was designed. Rearranged everything, inspected the piping from the valves, everything looked good inside, reassembled - good to go.










Now time for installation. Since my location puts the condenser right below the air handler on each side of the outside wall, I ended up with about 15 extra feet of lineset. I inquired with MrCool.com on this, and also did a lot of research about coiling or looping AC linesets. Everybody said no, if you're going to coil them make the loops horizontal.

So I had been racking my brain for a solution, and finally came up with a shelf to hold the excess lineset in combination with a weather shield over the condenser. To the big-box home improvement store I went, plans in mind and a materials list for what I needed. Half inch exterior plywood, a 2x8, some trim, roofing, flashing, and a host of stuff to put it together. This is what I came up with:





I also fished up romex from the adjacent 110 receptacle and installed a cut-off switch and waterproof box for the connection pigtail. 20a outlet circuit for this part of the house with nothing else on it - will carry the 9amps for the mini split just fine.

The stucco on this old house is about an inch thick. Drilled through and installed the wall sleeve, fed the line set through, and hung the inside unit. Coiled up the excess line set and fed it out through the bottom of my storage box and down to the condenser.

All told this took about 20 hours to complete, from fixing the damage to installing with the lineset storage box. Finally finished up the paint trim last night. Sorry, no interior pics - it is uneventful.

 

[softailtom]

Nice install and a good idea for the line set

 

[abgiles]

I just completed my installation yesterday of my MrCool DIY 36K unit, and couldn't be happier. I have a 30'x60' metal shop with 2" of closed cell spray foam insulation on the walls, 3" on the ceilings, and two insulated garage doors (R-19).

I had to make a custom mounting plate to go between the risers. Drilling a hole in the shop was a bit nerve wracking, but well worth it.





I ran my lineset on these metal bases I found at Lowes for about $4 each. I have 22' of lineset on the back wall of the shop, and will cover them today with vinyl gutter as some have used. I drilled holes for zip ties and wrapped the lines in the lineset tape.







Outside unit was pretty straightforward, and once all checks were complete, the unit works well and cooled off the shop from 90F and 75% humidity to 79F and 55% humidity in about 5 hours.



I'll test it out during the heat of the day here in NE Florida. Supposed to be a heat index of 103F today.


Complete shop build thread here: https://www.garagejournal.com/forum/showthread.php?t=393258

 

[Browneye]

Nice.
The romex coming out should have come directly in behind the outdoor box. Otherwise should be shielded, conduit, etc.

I can't believe we got by without AC for the past six years since our central unit quit.

 

[abgiles]

Nice.
The romex coming out should have come directly in behind the outdoor box. Otherwise should be shielded, conduit, etc.

I can't believe we got by without AC for the past six years since our central unit quit.

Thanks, but it's not Romex. Picture is hard to see, but it is MC cable.

I'll fill the hole when I put on the vinyl covers on the lineset.

 

[Browneye]

 

[jjtrou2072]

I have been following this thread for a while now and I think I'm almost ready to pull the trigger.

I have a 30X40 space in a pre-engineered metal building with the typical insulation. The problem is that the eve height is 16' which puts the center of the roof somewhere just north of 20'. I have been contemplating the 36K Mr. Cool DIY system but I am worried that it is going to have a hard time with the tall ceiling. Any thoughts?

 

[Browneye]

Cool air sinks - you shoot for stratification.
I find it happening with my 15’ cielings - 75 at the floor and 80 at the ceiling. It’s very comfortable.

 

[abgiles]

Cool air sinks - you shoot for stratification.
I find it happening with my 15’ cielings - 75 at the floor and 80 at the ceiling. It’s very comfortable.

I'm going to test that out today, and turn off my 3 ceiling fans on my building. It's 30x60, and I have the 36K unit. I have 12' sides, and my roof is about 16' at the max height.

 

[abgiles]

Cool air sinks - you shoot for stratification.
I find it happening with my 15’ cielings - 75 at the floor and 80 at the ceiling. It’s very comfortable.

And of course, again you were correct!! I was able to maintain 78F yesterday without the fans on at all, letting the air stratify. I wasn't able to do that on Thursday with them on. I had 78F and 33% humidity, which was very nice to work in. I did play around and turned on the fans to see how much it would change things, and it jumped to 82 and 45% in about 3 minutes. Left them off after that.

 

[Browneye]

Nice!

 

[Browneye]

Okay, an update here on my two installed units. Readers digest version is...they're doing great, work as expected, pump out 3 tons of ice cold air!

Yesterday it was 95 outside and the two units had no trouble keeping this old house at a comfortable 74-75. I had them set about there, then lowered them down a couple of degrees for the high ceilings - they sense room temp at the head unit so you have to take that into account. It's supposed to be 113 today - virtually unheard of in southern California! We're extremely thankful to have air conditioning this week!

The other good news is that the outside condenser unit does shut down when the room reaches temp. So left on overnight, when everything cools off, if you leave the fan on 'auto', it goes virtually silent and the condenser shuts off.

Some upgrades and notes to go along with the MrCool units...

Our west facing window wall has been a heat source for the past two decades. These are old aluminum framed single pane windows and slider, about 12' of width, 6' high. I ordered out GILA Platinum window film and applied it to the inside. Not too tough, need a helper to pull the liner off the film, and get it hung on the glass. Sqeegee it out and let it setup.

The pane to the very far right is what is left that does not have film. It cuts about 70% of the heat gain without reducing too much light. We could not be happier with this upgrade.



Along that same wall the prevous owners had scabbed onto the copper water line there that goes out to the pool area, and put a cold-only wet bar and sink. Problem is it has leaked for who knows how long, and they built it right over the old 40yo carpet. Once we started closing up the house with the new AC we could smell mold. I suspected a problem there so decided to tear it all out. Sure enough, it was really disgusting, removed all the old bar and plumbing, repaired the leak, de-molded it, and insulated the west-facing wall - new sheetrock going on. Yes, this old house does not have insulation in the walls - why that was okay in the early 70's is beyond me. The good news is the stucco is over an inch thick, so it does keep the weather out and it's durable. That's about all it has going for it.



Bedroom air not only cools the master but the bathroom and extra bedroom/office in that end of the house - about 400 square feet. I am now able to do away with the window air unit in the office, replace the window pane there.



In the main part of the house the bigger 2-ton unit has no problem keeping up with the heat gain with very little insulation, maybe R15 in the peaked ceiling, and cools the living room, dining room, and kitchen - about 800 square feet.



This is the outside unit, just on the other side of the wall in our atrium, next to the master bedroom. One thing any new installers need to be aware of is that these make a considerable about of condensate water. We collect it from the other one for potted plants on the patio, but this one drains to a surface drain. Also worth noting is the 12K unit is 110/120v which is a lot easier to configure power to it. I know they are supposed to have a dedicated circuit, but with a 100a panel I don't have any more open slots, so I connected to the nearby outlet circuit on a 20a breaker. There isn't anything else running on this line so it works fine for the MrCool - it's about 9ah at full tilt. I did install a waterproof shut-off switch for it on the outside wall.





In summary, we are more than delighted with these mini split units. They are quiet, easy to operate, pump out tons of cool air, and cost a quarter of what they HVAC guys wanted for a new central air system. Best thing we've ever done for this old house!

 

[Mosby]

For those of you have installed a Mr.Cool system...

I am looking at the 36k unit for my shop. It is an "L" shaped shop in a rectangular building, The other part of the rectangle is interior space that is already climate controlled. I want to put the air handler in the crook of the "L" and run the tubing down the short wall of the "L" to the exterior wall. Since the air handler will be on an interior wall, I need the lines to go in from the side, top or bottom, but not directly into the back of the unit. And preferably on the right side of the unit as you are facing it mounted on the wall.

Is this possible?

I sent an email to Mr. Cool asking this question, but it has been 5 days and no response. Hopefully this isn't a representation of their after sales service.

Hope I described the situation clearly enough. Thanks in advance for any help

 

[Browneye]

Where the lines exit from the air handler is completely configurable - right or left, surface or behind wall. There are even knock-outs on each side for surface exit of the lines.
Lineset is 25 feet.

 

[Mosby]

Thanks Browneye!!

 

[Jinks]

For those of you have installed a Mr.Cool system...

I am looking at the 36k unit for my shop. It is an "L" shaped shop in a rectangular building, The other part of the rectangle is interior space that is already climate controlled. I want to put the air handler in the crook of the "L" and run the tubing down the short wall of the "L" to the exterior wall. Since the air handler will be on an interior wall, I need the lines to go in from the side, top or bottom, but not directly into the back of the unit. And preferably on the right side of the unit as you are facing it mounted on the wall.

Is this possible?

I sent an email to Mr. Cool asking this question, but it has been 5 days and no response. Hopefully this isn't a representation of their after sales service.

Hope I described the situation clearly enough. Thanks in advance for any help

That is an exact description of my system. I have a Mitsu. installed by the "professionals" Larry, Moe, & Curly... Mr. Cool DIY wasn't around when I got mine, so I used the "professionals" to get a warranty. Had to loan them tools, & they made a minor mess of the line run, but the system has been working fine for 3 to 4 years.

I'd recommend using pvc for the drain line to keep a down slope, but other than that it's an easy install. If mine ever dies I'll replace it with a DIY.

 

[Browneye]

Record high yesterday here - 116. Main part of the house maintained at about 82-84, we're satisfied with that. The old central air system was good for about a 25deg drop, so MrCool way out performs that. 35deg or so drop is not too shabby. If we had some decent insulation I'm sure it could maintain under 80. As soon as the sun went down it dropped right down under 80.

Bedroom stayed a balmy 74. Insulation has been upgraded in walls

It was 108 at 9pm last night - in 25 years here this is a record. Thank dog for MrCool!!

 

[yeldogt]

Thanks, but it's not Romex. Picture is hard to see, but it is MC cable.

I'll fill the hole when I put on the vinyl covers on the lineset.

Is that outside ? because that cable does not look rated for exterior.

I'm not sure how the 2" foam is in FL .. but with 3" the 36k would be way oversized to maintain the temp. I'm not sure what the minimum output is not he mr cools .. some of the mini S are 1/3

 

[yeldogt]

I'm not sure why people are acting surprised that these things work .... the sizing is no different because it's a mini. A proper sized unit will cool a space.

Also -- large high spaces are always cooled without air movement unless the cool air is coming from the ceiling. Turning on a ceiling fan w/ AC in a high space will increase load

 

[Browneye]

My primary argument with sizing methods is the assumed ambient tempuratures. Every one I worked on use an average daily or seasonal temp figure that was way below our really hot days when we really DO need AC. So sizing tends to get rounded up to the next tonnage to compensate.

The stratifying temp levels within a room or building with high ceilings is a new concept for me. It really works, but just used to seeing so many ceiling fans in rooms and homes in the southern regions, it's just assumed you need to move the air around. NOT! I've even started shutting off box fans and room fans - don't need them with airconditioned environ.

The reason I exclaim about performance is due to the fact there are so many claims of failures with equipment - the industry makes it sound like if you don't utilize a HVAC pro you're a complete *****. Like a surgeon cutting out his own appendices. LOL

 

[NUTTSGT]

For those of you have installed a Mr.Cool system...

I am looking at the 36k unit for my shop. It is an "L" shaped shop in a rectangular building, The other part of the rectangle is interior space that is already climate controlled. I want to put the air handler in the crook of the "L" and run the tubing down the short wall of the "L" to the exterior wall. Since the air handler will be on an interior wall, I need the lines to go in from the side, top or bottom, but not directly into the back of the unit. And preferably on the right side of the unit as you are facing it mounted on the wall.

Is this possible?

I sent an email to Mr. Cool asking this question, but it has been 5 days and no response. Hopefully this isn't a representation of their after sales service.

Hope I described the situation clearly enough. Thanks in advance for any help

I can't help with the information you desire but do keep in mind that this past week has been a Holiday week during the Summer when many people take their vacation or have a short work week trying to cram several things in small time.

I'd give them a few extra days.

 

[budco]

Ordered a 36K last week and it will be here Monday. Putting it in a 40x30 shop. Try to remember to take some pics and post them.

 

[clymer]

nuttsgt, I always had luck with them responding right away, both before and after sale, a ticket number should have been generated. try forwarding the e-mail to [email protected]

 

[sleek98]

Ordered a 36K last week and it will be here Monday. Putting it in a 40x30 shop. Try to remember to take some pics and post them.

Where did you order it through?

Also what is the minimum temp in heat mode?

 

[eddieK]

My primary argument with sizing methods is the assumed ambient tempuratures. Every one I worked on use an average daily or seasonal temp figure that was way below our really hot days when we really DO need AC. So sizing tends to get rounded up to the next tonnage to compensate.

The stratifying temp levels within a room or building with high ceilings is a new concept for me. It really works, but just used to seeing so many ceiling fans in rooms and homes in the southern regions, it's just assumed you need to move the air around. NOT! I've even started shutting off box fans and room fans - don't need them with airconditioned environ.

The reason I exclaim about performance is due to the fact there are so many claims of failures with equipment - the industry makes it sound like if you don't utilize a HVAC pro you're a complete *****. Like a surgeon cutting out his own appendices. LOL

Great deal. At least they are disposable. The worst installation works good for the first few years...best of luck to you when you have the first failure.

 

[Browneye]

Great deal. At least they are disposable. The worst installation works good for the first few years...best of luck to you when you have the first failure.

Thanks. We'll need it.
Not sure why you think we have 'the worst installation', but whateve's, just cuz we didn't spend four times as much for a 'pro'.

I'm on the 3-5 year plan to bail out of so-Cal. I only need a few years. I don't need a thousand dollar AC unit to last me the rest of my life.

 

[eddieK]

Thanks. We'll need it.
Not sure why you think we have 'the worst installation', but whateve's, just cuz we didn't spend four times as much for a 'pro'.

I'm on the 3-5 year plan to bail out of so-Cal. I only need a few years. I don't need a thousand dollar AC unit to last me the rest of my life.

I'm not saying anyone here has the worst...I am saying that these do it yourself set ups have not been around long enough to know how they will perform long term.

AND I am saying many systems have been installed over the years without the proper installation and they work fine at first... Compressor replacements happen most often because of poor install procedures, as in installs without removing ALL non condensables. It takes a few years before that minute amount of moisture creates havoc with the refrigerant oil.

You cannot purge a system and achieve zero non condensables, the only way is with a proper triple vacuum procedure.

 

[Browneye]

I'm not saying anyone here has the worst...I am saying that these do it yourself set ups have not been around long enough to know how they will perform long term.

AND I am saying many systems have been installed over the years without the proper installation and they work fine at first... Compressor replacements happen most often because of poor install procedures, as in installs without removing ALL non condensables. It takes a few years before that minute amount of moisture creates havoc with the refrigerant oil.

You cannot purge a system and achieve zero non condensables, the only way is with a proper triple vacuum procedure.

I'm sure you mean well, but this just doesn't make sense. The lineset for the DIY series comes pre-charged and has shrader type valves and oring seals where they attach to the condenser valves. Connect them, open freon valves and go. There is no place for any moisture to get in.

They carry a 5/7 year warranty. Not sure how difficult a claim may be, but Ingrams has been very responsive and provide coverage and service.

I got quotes for right around $5k per unit for contractor installed like units - I have about $2500 all in for the two DIY units. I could replace them 3 more times and still be even. The old sales and service model for this type of product is no longer reasonable or applicable in my opinion. Anywhere in the world it costs about $50 to install a minisplit, but at least a couple of grand here in the US.

But you're right, time will tell the whole story. In the meantime we're enjoying our comfy home and my $$ are still in my bank.

 

[yeldogt]

The next move should be purged line sets with both head and condenser sealed -- that way you can order up what you need. The larger lines sets could be topped up w/ refrigerant to account for the extra length. I'm sure the industry wants none of it.