What Mini-Split did you use, and Why?

[Nan_wpg]

All true.
I think a 40cft nitrogen tank is 200, regulator is about 150, micron gauge is around 200, vacuum pump anywhere from 150 to 900, depending on quality, 37degree flare block about 150, for correct minisplit flares...

Anybody buying a minisplit for a diy install, needs this stuff, or they can buy a diy minisplit like Mr cool that has precharged lineset... plug and play communication wiring, and requires no flaring...

Having a minisplit and installing it incorrectly leads to a system full of acid, and a failing unit needing service and refrigerant added frequently...

Did you mean 45 degree flare block? I thought 37 is for hydraulic, and 45 is hvac, plumbing, propane?

what tools would you recommend (type of tools, and “tier” of tools) given the following considerations:

1. When I retire I’ll be taking a 5 month AC tech course at a community college (going to start acquiring my tools)
2. I’ll likely be instaling at least 15 mini splits at our lake (monkey see monkey do) as everyone contributes on the lake, and I’d like to bring this skill set.
3. I’d like to do a small retirement hustle focusing on mini splits in cottage country. (No interest in traditional AC and duct work)

the only hvac tool I have right now is a ridgid (or husky) flare tool from Home Depot that I used for our propane flares.
im a buy once/cry once kinda guy.

I kinda have an idea what I need (flare tool, nitrogen, vacume pump, Nylog blue, and a manifold, vacume guage, and valve stem tool/various adaptors, etc. just not sure “what” to buy if that makes sense? I gather Yellowjacket is a good brand.

I order 2 service manuals from this website, and they have a tool list for mini splits. Just wondering your thoughts?

 

[Supervstech]

This is very handy. It’s what I carry on my truck on minisplit installs.

 

[Supervstech]

This manifold set makes short work of diagnostic, includes vacuum gauge, and has built in refrigerant charts for all refrigerants.

 

[Supervstech]

This vacuum pump is incredibly handy.
I add in a spare battery ($250) and pump downs are like clockwork.

 

[Supervstech]

These pro-fit connectors are not cheap, they require care and prep to use correctly with pipes, but they have never leaked on me.

 

[Crowz]

These pro-fit connectors are not cheap, they require care and prep to use correctly with pipes, but they have never leaked on me.

Have you ever used them replacing a compressor?

I've got to replace a compressor in one of my mini splits and I don't have the nitrogen setup and was considering trying this to keep from having to solder the new on in. Just wondering how well they would hold up with the vibration that close to the compressor.

 

[Murphyslaww]

Pioneer 21 SEER, 9k btu, from home depot for $750, for an 8x14 art studio shed, mainly for the sub 1100 watt max power usage. It has worked well for us, in a shed that only has one layer of R9 fiber board insulation. It's not perfect, but can keep it around 25 degrees below ambiant. It struggles to stay below 85 degrees when it's 105 out, though. We feed it with 1200 watts of panels on top, an 80 amp epever charge controller, and a 4000watt inverter. The inverter is only that large because we needed the headroom to keep the fans off all the time, which is working. We started with a 2000watt, and the fans would start running as soon as output reached 650watts. Now they almost never run.

 

[ChrisG]

Did you mean 45 degree flare block? I thought 37 is for hydraulic, and 45 is hvac, plumbing, propane?

what tools would you recommend (type of tools, and “tier” of tools) given the following considerations:

1. When I retire I’ll be taking a 5 month AC tech course at a community college (going to start acquiring my tools)
2. I’ll likely be instaling at least 15 mini splits at our lake (monkey see monkey do) as everyone contributes on the lake, and I’d like to bring this skill set.
3. I’d like to do a small retirement hustle focusing on mini splits in cottage country. (No interest in traditional AC and duct work)

the only hvac tool I have right now is a ridgid (or husky) flare tool from Home Depot that I used for our propane flares.
im a buy once/cry once kinda guy.

I kinda have an idea what I need (flare tool, nitrogen, vacume pump, Nylog blue, and a manifold, vacume guage, and valve stem tool/various adaptors, etc. just not sure “what” to buy if that makes sense? I gather Yellowjacket is a good brand.

I order 2 service manuals from this website, and they have a tool list for mini splits. Just wondering your thoughts?

View attachment 160456

For the Install I just did above, I bought many of the tools that AC Service Tech has listed, few substitutions. Two stage pump from harbor freight, Appion 5/16 valve core removal tool (only 1, can clean micron gauge with denatured alcohol), CPS Micron, Nylog, mastercool gauge set (only used for Nitrogen pressure test), crow foot adapters for torque wrench, wire cutters and strippers, one vacuum rated 3/8 to 1/4 hose, nitrogen tank from local air/gas place, tank regulator from Amazon, bubble leak detector.

I have to say it all worked great. The did the nitrogen pressure test for 6 hours. Vacuum held at 220 microns for 3 hours. Just double check everything and steps when re-inserting valvecore.

 

[Nan_wpg]

For the Install I just did above, I bought many of the tools that AC Service Tech has listed, few substitutions. Two stage pump from harbor freight, Appion 5/16 valve core removal tool (only 1, can clean micron gauge with denatured alcohol), CPS Micron, Nylog, mastercool gauge set (only used for Nitrogen pressure test), crow foot adapters for torque wrench, wire cutters and strippers, one vacuum rated 3/8 to 1/4 hose, nitrogen tank from local air/gas place, tank regulator from Amazon, bubble leak detector.

I have to say it all worked great. The did the nitrogen pressure test for 6 hours. Vacuum held at 220 microns for 3 hours. Just double check everything and steps when re-inserting valvecore.

Did you use an existing torque wrench with the crow foots? I was thinking of buying the digital crescent torque wrench.

I like the ac service,tech books. Great resource

 

[ChrisG]

Did you use an existing torque wrench with the crow foots? I was thinking of buying the digital crescent torque wrench.

I like the ac service,tech books. Great resource

I have an existing torque wrench. Would like to buy a digital crescent but costs were adding up to install it correctly. The CPS micron gauge and Nitrogen tank was quite the budget hit.

Good thing is I’m installing a floor mount Senville 18k Aura in a few weeks in a different level and have all the tools.

 

[Nan_wpg]

This vacuum pump is incredibly handy.
I add in a spare battery ($250) and pump downs are like clockwork.

1 Amazon reviewer claims only one VacUme operation per battery charge. Is that true? Is that why you bought the extra battery?

 

[Supervstech]

1 Amazon reviewer claims only one VacUme operation per battery charge. Is that true? Is that why you bought the extra battery?

It depends on how big a system I'm recovering, and if it was well purged or if old oil is present... but yes, I always recharge my battery after use, so the spare battery keeps me going on a busy day.
Before I got the spare, the one battery easily handled a second unit without recharging.
Sometimes I would give the battery a 10 minute charge to be sure it would make the pump down.
I've never run a battery dry, but I have been pumping and had the alarm beeping as it was finishing a pump down.

 

[Supervstech]

Also if the system isn't pu.ping down quickly into the sub 1000microns I know there is moisture present, or there is a micro leak, and I need additional pressure o find the leak.

 

[boxvan]

Pioneer 21 SEER, 9k btu, from home depot for $750, for an 8x14 art studio shed, mainly for the sub 1100 watt max power usage. It has worked well for us, in a shed that only has one layer of R9 fiber board insulation. It's not perfect, but can keep it around 25 degrees below ambiant. It struggles to stay below 85 degrees when it's 105 out, though. We feed it with 1200 watts of panels on top, an 80 amp epever charge controller, and a 4000watt inverter. The inverter is only that large because we needed the headroom to keep the fans off all the time, which is working. We started with a 2000watt, and the fans would start running as soon as output reached 650watts. Now they almost never run.

I've been testing out a similar 9K Pioneer model in an 8x16 box truck, R-10 on the walls/floor and a bit higher on the ceiling/roof, and it's been holding a relieving 74, with an outside highs of 90+ and about 75% humidity (only one day over 100 in the past month). I've been really surprised and happy with how quiet both units are.

 

[RCinFLA]

Have you ever used them replacing a compressor?

I've got to replace a compressor in one of my mini splits and I don't have the nitrogen setup and was considering trying this to keep from having to solder the new on in. Just wondering how well they would hold up with the vibration that close to the compressor.

When a compressor is replaced, the A/C system already run, has distributed POE oil throughout the system. POE oil if very hygroscopic, meaning it likes to suck up humidity. The absorbed humidity has to be removed and it can take a while under vacuum to drag it back out of the POE oil.

Tape or cap the ends of piping as soon as you cut the compressor out to minimize the humid air intrusion.

Nitrogen flushing can help get the free humid air out, reducing the time to achieve deep vacuum. When having trouble achieving below 500 microns of vacuum after replacing compressor, multiple nitrogen flushes (2-5 nitrogen flush then vacuum cycles) can help to get the moisture out quicker.

If system left open for half to full hour with POE oil in tubing and evaporator it can take two-three hours on vacuum pump to get POE oil to give up the absorbed humidity. As POE slowly gives up the humidity it keeps you from getting a good timely vacuum.

Without a nitrogen flush and very low nitrogen flow, you should not do a normal copper pipe brazing job since it causes oxide ash inside tubing. Use Staybright 8 silver solder which does a good job at lower torch temperature avoiding the internal ash/acids build up.

Normal compressed air could be used on a new virgin mini-split that has original refrigerant sealed in compressor to pressure test lines as long as inside unit does not have a filter-dryer. Compressed air will have much of its humidity squeezed out during compression and left in bottom of air compressor tank.

Still better to use nitrogen. Using only vacuum for leak test is not a great leak test. First the pressure is only 14.7 psi at near perfect vacuum so not very stressful to potential leak locations, and if you do have a leak, the vacuum will pull humidity from outside air into system. Better to find a leak with couple hundred psi pressurized system with soapy solution on all flare joints.

Mini-splits can only be properly refrigerant charged by weighing in specified amount of refrigerant so you will need a refrigerant scale. A poor man's solution is a $25 digital postal scale capable of at least 30 lbs with a platen big enough for refrigerant tank.

 

[Supervstech]

I was trained that POE oil NEVER releases moisture under vacuum, a desiccant core filter dryer is required to remove moisture from POE.

 

[wildhorsesracing]

I installed two Senville AURA 18k units to replace our twin 25 yr old 3 ton heat pumps and have been happy with the results. I have been running them off of my twin 6500EX-48 with no issues. In fact my wife turns them down to 60* on sunny days to chill down the house.

 

[ChrisG]

I installed two Senville AURA 18k units to replace our twin 25 yr old 3 ton heat pumps and have been happy with the results. I have been running them off of my twin 6500EX-48 with no issues. In fact my wife turns them down to 60* on sunny days to chill down the house.

We love the 24k Aura just put in. Sips power and is working perfectly. Ordering an 18k Aura floor mount for another level in our cabin. Can’t wait to see how these heat in the winter.

 

[RCinFLA]

I was trained that POE oil NEVER releases moisture under vacuum, a desiccant core filter dryer is required to remove moisture from POE.

POE oil will release moisture under vacuum but it increases required holding vacuum time.

A system can be pressure tested with nitrogen to ensure there is no leaks but when vacuum pull is done it takes a long time to achieve lower than 500 microns of vacuum. With some moisture in POE oil it can take 2-3 hours to pull vacuum down.

POE oil is very hygroscopic (absorbs moisture) and should be exposed to atmosphere as short of time as possible.

If a system is worked on below about 40-45 degs F, when vacuum begins to be pulled, the moisture can quickly freeze before it has a chance to evaporate. This will prevent getting moisture out of system by vacuum.

 

[Supervstech]

POE oil will release moisture under vacuum but it increases required holding vacuum time.

A system can be pressure tested with nitrogen to ensure there is no leaks but when vacuum pull is done it takes a long time to achieve lower than 500 microns of vacuum. With some moisture in POE oil it can take 2-3 hours to pull vacuum down.

POE oil is very hygroscopic (absorbs moisture) and should be exposed to atmosphere as short of time as possible.

If a system is worked on below about 40-45 degs F, when vacuum begins to be pulled, the moisture can quickly freeze before it has a chance to evaporate. This will prevent getting moisture out of system by vacuum.

Ahh, 2-3 hours of vacuum is equal to NEVER on a component change… pull a good vacuum below 500microns, do a nitrogen purge, pull it again, and ensure a good fresh filter dryer is in the liquid line of the system and good to go…

 

[Nan_wpg]

Ahh, 2-3 hours of vacuum is equal to NEVER on a component change… pull a good vacuum below 500microns, do a nitrogen purge, pull it again, and ensure a good fresh filter dryer is in the liquid line of the system and good to go…

When you say purge, is that the same as a nitrogen sweep?

 

[Supervstech]

When you say purge, is that the same as a nitrogen sweep?

Yes

 

[Bluedog225]

I thought the actual liquid lines were not accessible on splits. No? Where do you put it? Thanks

 

[Supervstech]

I thought the actual liquid lines were not accessible on splits. No? Where do you put it? Thank

It would need to be inside the unit in the liquid line passage exiting the condenser coil, very difficult to find on a minisplit.

 

[RCinFLA]

Ahh, 2-3 hours of vacuum is equal to NEVER on a component change… pull a good vacuum below 500microns, do a nitrogen purge, pull it again, and ensure a good fresh filter dryer is in the liquid line of the system and good to go…

Attached is a good video on A/C oil air/moisture absorption. It comes out but can take a very long time to accomplish.

A/C techs cannot afford to sit around for several hours waiting to achieve proper microns of vacuum. Time vs. money says use it once (from a metal oil container) and throw the rest away. Avoid buying oil sold in plastic bottles. Avoid gallon jugs. Plastic does not provide a good hermetic seal.

When a compressor is changed you have to analyze how the old compressor failed.

A compressor motor burn out will cook the oil causing contaminates in oil with acids that will harm system. Need to flush and/or acid neutralize system. Common practice, short of full system flush, is to place an acid neutralizing suction line filter prior to new compressor suction line input, then come back in 7-10 days and replace the filter with a new one that is left in system. Copeland recommends replacing acid filter after 72 hours.

A compressor that fails for poor compression can leave excess oil in evaporator. When new compressor is installed the oil comes back to new compressor resulting in too much oil. Can cause hard starts on compressor and reduced system efficiency due to excessive oil coating in tubing walls of condenser and evaporator.

Should also change high pressure liquid line filter. It may be hidden between outside grill and condenser within outside unit.

On a normal run system. The original factory compressor oil sump load of oil will distribute 8-10% into system (mostly in evaporator), and 1-3% gets wicked into motor stator wire winding. Some of the oil wicked in motor windings dips back to oil sump during off rest period of compressor.