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

[kbeefy]

My 36k is scheduled for delivery today.
I just found out about a camping trip we're leaving for tomorrow, so I guess I'll start the install next week.

 

[Browneye]

Is it my imagination, or do the Mr. Cool’s seem to come up short on coolant/refrigerant after a few years. Makes me think there is a problem with the couplings or initial charge.

On a related note, recovering the refrigerant and weighing back in is difficult. I wonder if adding a little back in at a time until performance improved is a way to “cheat” while not taking too big a chance on destroying the compressor. Would that be a pound at a time? No idea what the right increment is.

They shouldn't be leaking freon unless there's a failure in the circuit. I could tell mine was getting low when it wouldn't cool all the time, and it kept icing up. So as the gas circulates through it will have periods where there is no gas, then a rush will come thru and ice over the coils in the air handler. Wife thought it was pretty funny when it was spitting out chunks of ice.

My AC tech brought gauges and a tank of gas, and a leak detector, added freon until the pressures were where he wanted them, the found a leak in the flex line to fixed line union. Since that is a welded piece the whole thing was replaced under warranty. I then had him out again to make sure the freon level was correct. About a hundred bucks each time.

I'm not an AC tech so I can't tell you what the values are, but a pro knows how to do this. If you think your unit needs a top up and you don't have the gauges to check, hire a pro. It's well worth the money spent. Over charging can send the pressures up too high, under and it won't cool properly. There's only about four pounds in the whole thing, so adding a pound could be 25% of it's capacity.

 

[250]

I've heard about the coolant issue a bit down the road, and the layout I've proposed to the mrs has some extensions in the line sets to reach the various rooms. Its a point of mild concern for me.

Its too bad those extensions are price as they are, we'll need a multi head unit on each end of the house as a run of Romex is significantly cheaper.

 

[Highbeam]

Hello folks, I just installed a 24k DIY Mrcool. My first. We love it. The outside unit is noisier than I expected. Lots of refrigerant/compressor type hissing sounds when it's running. Is this normal? Everything is working perfectly.

It's not loud but the fan is not the major source of noise as I expected.

 

[tarantino]

Hello folks, I just installed a 24k DIY Mrcool. My first. We love it. The outside unit is noisier than I expected. Lots of refrigerant/compressor type hissing sounds when it's running. Is this normal? Everything is working perfectly.

It's not loud but the fan is not the major source of noise as I expected.

I have installed 4 mini splits, 3 of them MrCool including a 24K one. Can't recall any hissing sounds. The only noise I hear is the fan.

 

[Highbeam]

I have installed 4 mini splits, 3 of them MrCool including a 24K one. Can't recall any hissing sounds. The only noise I hear is the fan.

Maybe hissing isn't the right word. It's the sound of refrigerant being compressed and sprayed through the orifice. Similar to when you shut off a car engine and the AC keeps on hissing for a few seconds. I can hear it when listening to the copper pipes too.

 

[tncatadjuster]

My Mr Cool 24K 2years old is very quiet with no hissing. Were the valves fully opened, if that is a possibility.

 

[3rdgendslmech]

Has anyone had the door stop closing all the way when it's powered off?
Little bit of a back story.....I put a shelf about 12-14 inches under the indoor unit. Started putting stuff on the shelf under the unit quarts of oil etc...Among those quarts of oil was a gear oil container which are taller than a regular quart of oil. As the day went on it warmed up and I turned on the unit and the door hit the gear oil container. It didn't break anything on the unit, but now when you power it down the door does shut all the way, and it seems like air door points down further.

 

[Crowbarman55]

Has anyone had the door stop closing all the way when it's powered off?
Little bit of a back story.....I put a shelf about 12-14 inches under the indoor unit. Started putting stuff on the shelf under the unit quarts of oil etc...Among those quarts of oil was a gear oil container which are taller than a regular quart of oil. As the day went on it warmed up and I turned on the unit and the door hit the gear oil container. It didn't break anything on the unit, but now when you power it down the door does shut all the way, and it seems like air door points down further.

Mine wouldn't close all the way too. To fix it I turned the unit off, gently pull down the door all the way by hand. Then push it closed all the way as far as you can. Turn the unit back on the swing mode for a few swings. Turn it back off and see if that works. You may need to repeat this whole thing a couple times. It worked for me on the 3rd try. Good luck and let me know if it works if you try it.
Todd

 

[Browneye]

Has anyone had the door stop closing all the way when it's powered off?
Little bit of a back story.....I put a shelf about 12-14 inches under the indoor unit. Started putting stuff on the shelf under the unit quarts of oil etc...Among those quarts of oil was a gear oil container which are taller than a regular quart of oil. As the day went on it warmed up and I turned on the unit and the door hit the gear oil container. It didn't break anything on the unit, but now when you power it down the door does shut all the way, and it seems like air door points down further.

Yes, you can reset the stop limits in the door motor. It likely has some kind of hall sensor. Generally cycling it full up and full down should do it.

 

[Highbeam]

My Mr Cool 24K 2years old is very quiet with no hissing. Were the valves fully opened, if that is a possibility.

Yes sir, all the way against their stops. I reversed the system yesterday to make heat and maybe blow some bubbles through the system and as required by the manual's test.

Still audible compressor sounds other than the low thump of the fan.

 

[Browneye]

Yeah, mine is near silent - all you hear is a very faint noise from the fan blowing air.
But then I'm near deaf. LOL

 

[Highbeam]

I'm thinking the buzz/hiss sounds are just normal AC sounds. There is a compressor working in there and the expansion valve is in the compressor.

Everybody loves pics. Here's my contribution to the thread. 24kbtu MR cool DIY. Note the horizontal coil behind the unit. ALso elevated so there is no low point in the line for oil to trap. Would have been MUCH easier to just coil it up vertically like all the videos, including the MRCOOL videos, show. I ended up with 15" behind the unit to allow room for the coil. 4" minimum bend radius was honored or exceeded. The larger lines of the 24 and 36 models were very hard to bend right without kinking and honestly it's hard to tell if you kinked them since they're inside the insulation. It feels good though. Because of that I might be inclined to recommend the 18k units.

Oh and I am glad this thing isn't in my living room. The inside unit is also pretty loud with blowing and not something I would want right by my head when I'm watching TV.

Excellent performance so far. Single story home and the whole house is within about 2 degrees when it's 97 outside.

 

[Crowbarman55]

Here's mine I did about a month ago. 18K MRCOOL.
Todd

 

[Browneye]

I like the car WAY more than the AC.

 

[jcarapet]

Finally found a 4 ton 4th gen DIY in stock. Ordered Monday, delivered Friday. It sits and waits for a couple months.

Premium home source had it and free shipping over Ingrams. Saved me a couple hundred

 

[kbeefy]

Guess it's time to do something with this....




36k + 3x 12k handlers

 

[Paycheck]

Guess it's time to do something with this....




36k + 3x 12k handlers

Cook lunch?

 

[Browneye]

Holy smokes - 4 ton!?!

 

[kbeefy]

Looking for suggestions on replacing the 'MC' line with a longer set (lineset extension). I have all the parts but I'm not sure how to remove the original. It seems I should probably remove the entire air handler shroud/cover to gain access, but this seems excessive.

I haven't found any mention of it in the manual aside from 'replace lineset'.

 

[kbeefy]

This is as close as I can get without removing the cover.

 

[Browneye]

The cover/housing is pretty easy to remove, locate the assembly screws, it all comes apart. You may be able to gain access to the connections, under the assumption is is a later version with a union at the coil - you can see here mine does not - the coil and line are all one piece. The flex part of the lines are welded to the rigid section attached to the coil.

Anyway, why not just extend it from the other end?

 

[kbeefy]

I've had most of my 36k system running for about a week.

I'm disappointed that it doesent shut off when the desired temp is met.
I assume I'm doing something wrong, but with my previous heat pump reached the set point (honeywell controller, I believe) the system shut off.

My MrCool sometimes just keeps cooling (set to 72, shut it off at 69) or just keeps running fan after temp set point is reached (4-8 hours).

Does anyone have any experience with this?

 

[Browneye]

The outside compressor/condenser will shut down. The inside air handler will slow to a whisper, but does remain powered on for when there is a temperature change and demand.

There's also the timer settings to turn on or off on the remote.

I just turn mine off when we open the windows and doors. Early in the day I'll close everything up and setup the on-timer for when I want the unit to start cooling. In the evening, if it is left on, I'll setup an off-timer to shut it down when we no longer need cooling.

 

[kbeefy]

The cover/housing is pretty easy to remove, locate the assembly screws, it all comes apart. You may be able to gain access to the connections, under the assumption is is a later version with a union at the coil - you can see here mine does not - the coil and line are all one piece. The flex part of the lines are welded to the rigid section attached to the coil.

Anyway, why not just extend it from the other end?

Mine is the 4th gen, it's a bit different inside.

After opening the front cover it was obvious how to get everything apart.



The extension that came with the coupler had the wrong ends on it, had to replace them with the correct ones.
Not a big deal, maybe designed for the older units.

 

[kbeefy]

The outside compressor/condenser will shut down. The inside air handler will slow to a whisper, but does remain powered on for when there is a temperature change and demand.

There's also the timer settings to turn on or off on the remote.

I just turn mine off when we open the windows and doors. Early in the day I'll close everything up and setup the on-timer for when I want the unit to start cooling. In the evening, if it is left on, I'll setup an off-timer to shut it down when we no longer need cooling.

I've been doing the same, I set a timer to shut it off at 10pm and another to turn it on at 6am.
I manually turn them on or off otherwise, at least that prevents me from forgetting one and it running all night.
Seems odd for something touted as this efficient would leave the fans running 24/7.

I'm going to try out 'comfy mode' via the app, it might do what I'm looking for.

I've also discovered that the remotes and the app do not play well together. I haven't determined the exact behavior, but sometimes the app won't do anything and the remote will.

 

[Browneye]

I gave up on the app. [shrug]

 

[kbeefy]

I gave up on the app. [shrug]

FWIW, 'Comfy mode' via the App does completely shut the unit off.
Not sure why that can't be normal behavior, but it is what it is.

 

[v10climber]

I use comfy mode to keep the garage between two temperature set points. Works great. Never have to touch it and the garage is always cool when I walk out there. Took some experimenting with temperature set points to get to where it wasn't running all the time.

 

[Browneye]

It's been over a hundred every day for over a week here in so-Cal - breaking all records. At least night time temps drop to 75 or so. Finally supposed to drop back to 80's this weekend.

My two units haven't been shut off for a week - just set the temp up to 80 overnight - and 77 during the day for very comfortable inside temps. Since they're near the ceiling and thus the ambient temp taken there on its thermostat, it keeps the room temps a comfy 75-78.
The 'follow-me' setting also works pretty well if you want it to maintain a temperature setting at the remote.

They've been working overtime and just brilliant. Although our powerbills were $375 for July and $400 for August. Ouch. I guess it could be worse.
Twenty thousand homes in the bay area were blacked out on Monday with temps at 115. Double OUCH.

 

[Browneye]

Wow...this thread is asleep for quite a time here...

I just bought another 9K BTU unit for the back bedrooms. It's almost in...my cement drill bit wouldn't drill, so waiting for the rain to stop now so I can finish hooking it up. Air handler is hung, wiring is done - had a spare 20A breaker in the panel, and the unit sits right in front of the electrical panel, so running wire was a matter of pulling thru and elbow into the main panel. Super easy install on this one.

I want it to cool both back bedrooms - they are small 10x11 bedrooms - so I got one of these room-to-room fans from AC Infinity - it's way cool, super quiet, will push 160cfm on high at 20db, and has a thermostat for heating or cooling. 6x12 inches - $80.

 

[threewood]

I installed a MrCool 18k DIY mini split 2 weeks ago and it has been wonderful. It's in the enclosed and insulated portion of our new shop (30'x14' insulated).

I have a newer 100a service to the shop so I added a 20a 2 pole breaker and 12-2 wire for the unit. I welded a stand for the outside unit. When it was 26 degrees out for several days it held 70 degrees inside. I can't wait to try it out in the heat. The conduit has since been moved closer to the units it has more dip.

 

[Browneye]

I returned the AC Infinity register fan I posted above, as the one I really wanted came back in stock.

This one is 120VAC instead of 24VDC, it pushes up to 303cfm at 48db. It's a lot nicer more powerful unit that can easily be hardwired, for $10 more. And it's double sided so I don't have to mcgyver a vent on the other side of the wall.

I just love these guys - they make really great products...no affiliation:

Room to Room Fan 8" with Temperature Controller, Two-Way Reversible Airflow

Balance home temperatures utilizing this 8-inch room-to-room fan. It features a smart controller and reversible airflow to move air between living spaces easily.

acinfinity.com

 

[296GTB]

Can anyone with experience with the 4th gen Mr Cool 12k BTU unit confirm that for sure I can have the drain and lines exit the right side of the unit instead of directly behind it? I have to install it on an interior wall due to a huge window taking up most of the exterior wall for a room.

 

[Browneye]

The condensate drain can be attached to either side of the air handler, and completely separated from the lineset and power cable.
IIRC it comes attached to the right side with a plug in the left side - easily reversed.

 

[296GTB]

The condensate drain can be attached to either side of the air handler, and completely separated from the lineset and power cable.
IIRC it comes attached to the right side with a plug in the left side - easily reversed.

Thanks for verifying. I just need it going out either side, but not directly out the back since that leads into another room.

 

[Browneye]

They make a LOT of water. On our 2-ton one I routed it over to a watering pail near the patio, and it fills that 2gl pail up a two or three times on a hot day. I don't know if I would drink it, just from old drain lines and any pollutants coming off the cooling coils, but the plants love it!
If it over fills then the water just drains across to a surface water drain.

On hot days, most people don't realize the water running across the parking lot at a lot of stores and commercial sites are condensate drains. They generally just route them to a convenient outlet/drain and it runs across to a storm water drain.

I may have posted this up-thread but here it is again...

 

[cwheat]

Hello all, new member here. I just ordered a DIY 3 ton 4th gen. heat pump from Ingrams for a 30x50 red metal building that is insulated with the white roll insulation material between the frame and outer metal. Looking forward to trying it out in this South Mississippi heat. I am trying to get ahead and be ready when it gets here and want to install the electrical and mounting pad ahead of time. I am going to set a couple of treated 4x6's in concrete in the ground and cut them off about 30 inches high and then bolt some galvanized angle to them for the base to bolt the condenser to so the unit will not be on the ground. Does anyone know for sure if the lineset and drain can exit straight out the left side looking at the air handler with no bending until out from under the unit cover. I don't want to bend the lines any more than necessary and I have a good place outside in close proximity to the breaker box that I can install the outer unit that will need the lines coming from that way. I plan to bring the lines straight out the left side of the plastic cover(just like they were shipped), then bend them slightly towards the back of the unit after they exit the front cover then down by the frame of the building and out through the siding to the condenser. I am planning on fabricating a 2x6 frame with a plywood front to mount the air handler to and bolt it to the the Z channel so the unit will be moved that 6 inches into the building space and that will give me room to feed the line set and drain straight down next to the building framework. Then I can fabricate a shelf about 24 inch square and bolt it to the left of the unit to the Z channel and store the extra coiled lineset horizontally and right on top of the Z channel in that shelf. The line set showing coming out of the plastic front cover for a short distance in the cooled area and the excess coiled next to that won't matter like it would if it was in a finished living space. I have looked at many you tube installations and most of them show the lines going out the back which I don't want to do because of having to store the excess lineset outside and also having to twist and bend the lines. If the installation manual on the Ingrams site shows it I have missed it. I am pretty sure I have seen what looks like cut out indentions in that left bottom front corner on the you tube video's but thought someone that had installed one may could tell me for sure.
Thanks,
Charles

 

[Browneye]

They come with the line set exiting the left side. If you want it coming out the right side you just bend them out. There are also punch-outs in the housing if you want the lineset to exit on the air handler side of your wall.

From what I can picture in my mind from your description of your air handler mount you should be fine. The tubing is easy to bend, and the actual lineset is very flexible. The newest ones come with the schraeder valves on both end of the line set, rather than permanently attached to the air handler. More convenient for installing as well as any need to replace it/change it out. And yes, any excess lineset should be loosely coiled in a horizontal manner. Doesn't matter if it's inside or out.

The junction on my older unit from lineset to air handler piping is welded and it developed a leak. Ingrams sent me a new air handler unit under warranty - didn't even want the old one back. It was kind of a hassle to have to remove the whole line set to change it. I think we're on season five with that one now and it's been fantastic.

I have three of them now - this summer they drove our electric bill to $500. Ouch! Oh well, the place is cool - not much insulation in these old houses and it's been mid-90's for over a month. They make a LOT of condensate water.

 

[clymer]

Question for the folks here - anyone come across an F5 error code? The problem is with the outside unit: Outdoor System Model Numbers: Outdoor Model DIY-MULTI-36HP230 (installed 4 years ago)

Noticed none of the 3 inside air handlers blowing cold when I had AC running.

Went outside and noticed the fan was not spinning in the outside unit.

1.) Powered everything off, shutoff main breaker to unit. Turned on the main breaker. Turned on the air handler and set for cold and went outside to wait for the outside unit to start to observe. Blower fan on outside unit begins to start, appears to be performing some kind of self-check, spinning slowly both directions, but never starts, but while attempting to spin at faster speeds I am hearing noise which may be coming from the fan motor (but difficult to tell).

2.) Again shut off the unit and main breaker. Removed top cover and cover to board. Powered the unit back up and held the red board button (press and hold until CE on the LED display). returned cover and top. Turned on the air handler and set it for cold and went outside to wait for the outside unit to start to observe. Blower fan on outside unit begins to start, appears to be performing some kind of self-check, spinning slowly both directions, but never starts, but while attempting to spin at faster speeds I am hearing noise which may be coming from the fan motor ((but difficult to tell - same symptoms, appears to be faulty part). The error is specific to the fan if I am not mistaken, but the question is - is it the blower motor, or the board. The wiring from the blower motor traverses parts of the chassis that I am not comfortable taking apart so I have an HVAC tech coming out to look at this..

Is this a bad board? The fan spins (manually) fine