Mini-split DIY with dedicated circuit

[aasdfadsf]

So...my wonderful home that is wonderful happens to have really bad airflow to the top floor. Which isn't a big deal in the winter, but in the summer, our master BR gets horribly hot. This isn't helped by the fact that our bedroom faces southwest and is exposed to the sun on three sides, and there is a door out to a balcony that also doesn't help, and while the home is a relatively new build (2006) and is thus well insulated, this results in a lot of thermal inertia. Which is to say, the walls and ceiling keep radiating heat at us long into the night despite the Colorado temperatures dropping into the 60s at night. Just opening the windows and trying to move air isn't enough. It's usually not until maybe 1 AM that everything truly cools off, which would be fine if we didn't go to bed at 9.

So my solution to this is to put in a mini-split heat pump right outside on the balcony. The setup seems perfect for this, because I can put the unit right outside where it's out of sight and out of the way and has plenty of airflow but is very close to the bedroom so I can run the line right into the room by poking only a couple of holes. That part's easy. And those systems don't cost much, they are very efficient, and it can double as a heater in the winter if I want it.

The hard part, so to speak, is that the DIY systems need to be hardwired with a dedicated 20 amp circuit. I have no experience trying to wire a new circuit, but I can do basic electrical work and it doesn't intimate me. But this...I don't really know how to do. My circuit breaker is in the finished basement, two floors down. How the hell do I run the wire up to the bedroom? I've discovered the existence of a thing called a "fish tape", but this seems like I'm working blind trying to push something through walls and conduits that might not even exist and god knows if I can get the wire where it needs to be. Maybe this is much easier than I think it is, or maybe I'm an idiot for even thinking of doing this myself and I should just hire an electrician. Thoughts?

[uniwelder]

Would conduit along the exterior of the wall be an option, aesthetically, for you? 

[BudgetSlasher]

Running wire inside a finished house without punching at least small access holes is a PITA. I've done it before but there can be everything from plumbing to wiring to fire blocks in the wall and you have to get through top and bottom plates.

Your simplest answer is to find a route outside of the finished space. Already suggested is running a conduit on the outside of the house, if you can live with that solution. To hide it, its best to paint it to match and running it somewhere against the trim and/or parallel to the siding. That tends to be less noticeable from a distance. If you have unfinished spaces in your house you might be able to take advantage of them; for example I have run wiring to a second floor by running across the basement, into the garage, up inside the garage, back into the house attic space, and finally down the 2nd floor wall. (if running wiring outside of the house it needs to be rated for that). I've also commandeered existing wiring for new purposes.

On the non-wiring front, have you considered noise? Outdoor units can and do transmit vibrations into whatever they are mounted to. I've been in plenty of places with the outdoor unit was mounted to the wood framing and while near silent outside it caused a droning in the framing. I chose to install mine to the poured foundation to absorb vibration. If you are a light sleeper you might want to reconsider placing the unit so close to the bedroom.

[aasdfadsf]

Would conduit along the exterior of the wall be an option, aesthetically, for you?

It would be an option. I'm actually trying to grow ivy over where the wire would supposedly run, so it's probably not an issue aesthetically. Of course it requires punching yet another hole in the exterior of the house.

[aasdfadsf]

On the non-wiring front, have you considered noise? Outdoor units can and do transmit vibrations into whatever they are mounted to.

From what I've read, these things are remarkably quiet. Heat pumps have apparently come a long way, even from just 10 years ago. At any rate, it would have to be a jet engine before the noise made it a net negative if it really cools off the room.

[sonofsven]

The most direct route is to run plastic conduit from point to point.
Generally running solid wire (not romex cable) is the way to go in conduit, #12 in this case I believe.
You can change directions with LB type fittings, which have a removable cover plate that is used as access to pull wires (but no connections), or end at an appropriate weather box made for wire connections.
Otherwise you'd need to plan a route up into the attic and then down to your location, likely removing drywall in numerous locations (closets?).

[aasdfadsf]

Thanks to everyone who's pitched in. My thinking on this is that I've got a receptacle that's perfectly placed outside simply to plug the unit into without needing to create a dedicated circuit. After doing some testing, that receptacle is on a circuit that only serves the jack-and-jill bathroom that connects the kiddos bedrooms. I mean, there are only two light fixtures and a fan that might put a load on that circuit. Those lights are of course now LEDs, which draw nothing. I should research the fan, but we never run it. The heat-pump units I'm looking at would be 9000 BTUs and draw about 7-10 amps when running and are acceptable for a 15 amp circuit. But no one wants to tell you that it would be okay to run it off of an already existing circuit, because CYA.

I'm thinking that I should just plug it in and go with that, but maybe I'm a fool. Someone set me straight if this is a bad idea.

[nereo]

Thanks to everyone who's pitched in. My thinking on this is that I've got a receptacle that's perfectly placed outside simply to plug the unit into without needing to create a dedicated circuit. After doing some testing, that receptacle is on a circuit that only serves the jack-and-jill bathroom that connects the kiddos bedrooms. I mean, there are only two light fixtures and a fan that might put a load on that circuit. Those lights are of course now LEDs, which draw nothing. I should research the fan, but we never run it. The heat-pump units I'm looking at would be 9000 BTUs and draw about 7-10 amps when running and are acceptable for a 15 amp circuit. But no one wants to tell you that it would be okay to run it off of an already existing circuit, because CYA.

I'm thinking that I should just plug it in and go with that, but maybe I'm a fool. Someone set me straight if this is a bad idea.

Hair dryers pull a lot of amps (often up to 13), which is why most bathrooms have their own dedicated circuit(s). Maybe your kiddos don’t use a hair dryer (yet), but will that space ever be used by guests who might?

[aasdfadsf]

Hair dryers pull a lot of amps (often up to 13), which is why most bathrooms have their own dedicated circuit(s). Maybe your kiddos don’t use a hair dryer (yet), but will that space ever be used by guests who might?

Weirdly enough, the receptacle in that bathroom (which is not GFIC) is on a different circuit. There are three different circuits in the master bath, and yet the one that the balcony outlet is on, which is just a few feet from the master bath, is on a circuit from way down the hall. I spent a lot of time flipping breaker switches and going all over the house to test things because none of it makes any sense.

[zolotiyeruki]

Is your current electrical run with Romex, or solid wire in EMT?  If the latter, you might be able to fish a circuit up through the existing conduit.

[Abe]

I'm looking into doing this for my kid's bedroom. What models are you looking at?

I think an external conduit is the easiest bet. You can caulk it reasonably well to avoid drafts and water infiltration.

[aasdfadsf]

I'm looking into doing this for my kid's bedroom. What models are you looking at?

I think an external conduit is the easiest bet. You can caulk it reasonably well to avoid drafts and water infiltration.

After massive deliberation, I bought the ROVSUN 9000 BTU unit: https://www.amazon.com/gp/product/B09T6Y6ZLW/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Haven't tried to install it yet, but I'll post about it, including whatever my failures, when it happens. This unit is supposedly good enough for 450 sq. ft. I need to cool off about 200, so there is no need for a 20 amp unit or one that needs 220 volts.

I really do think that these things are the wave of the future, so it's probably useful for everyone to think about what these machines can do. There may come a time very soon in which new housing builds don't even bother with central AC or heat and all the stupid duct-work anymore, you just plunk two or three of these in the right place, even for a very large home.

I very much appreciate everyone who provided very good knowledge about how to tape a new circuit, and I likely could have pulled it off, but I just don't think it's necessary. I'm going to use the receptacle I already have that is on a 15 amp circuit, for the reasons I mentioned upthread.

[BudgetSlasher]

I'm looking into doing this for my kid's bedroom. What models are you looking at?

I think an external conduit is the easiest bet. You can caulk it reasonably well to avoid drafts and water infiltration.

After massive deliberation, I bought the ROVSUN 9000 BTU unit: https://www.amazon.com/gp/product/B09T6Y6ZLW/ref=ppx_od_dt_b_asin_title_s00?ie=UTF8&psc=1

Haven't tried to install it yet, but I'll post about it, including whatever my failures, when it happens. This unit is supposedly good enough for 450 sq. ft. I need to cool off about 200, so there is no need for a 20 amp unit or one that needs 220 volts.

I really do think that these things are the wave of the future, so it's probably useful for everyone to think about what these machines can do. There may come a time very soon in which new housing builds don't even bother with central AC or heat and all the stupid duct-work anymore, you just plunk two or three of these in the right place, even for a very large home.

I very much appreciate everyone who provided very good knowledge about how to tape a new circuit, and I likely could have pulled it off, but I just don't think it's necessary. I'm going to use the receptacle I already have that is on a 15 amp circuit, for the reasons I mentioned upthread.

A couple things to consider.

That model does not have a pre-charged lineset, like some brands. That means you will likely need additional tools, such as a vacuum pump, micron gauge, and probably a torque wrench to name a few. I am unclear if pre-charged linesets would get around point 2.

Also, legally (presuming you are in the USA) you need EPA 608 certification to handle r410a or charge systems; it looks like type 2 for mini splits. It seems that includes releasing the pre-charge from an outdoor unit into the lines and head.

[aasdfadsf]

That model does not have a pre-charged lineset, like some brands. That means you will likely need additional tools, such as a vacuum pump, micron gauge, and probably a torque wrench to name a few. I am unclear if pre-charged linesets would get around point 2.

It is pre-charged, but you do have to vacuum the line. There are some models that come pre-vacuumed, but none that were the size I wanted. You can buy or rent a vacuum pump, but I decided to buy one of these: https://www.amazon.com/gp/product/B08HNGXWKP/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

I might be taking a chance on this, but I find it really hard to justify buying a $100 vacuum pump that I'll only use once.

As for the second point, neither the seller nor anyone else I've seen has said that you need an EPA certification to do this. I have literally not seen that for a single unit I've looked at. It might be the case that you need the certification if you are going to add refrigerant, but again, it is pre-charged and you don't need to add any.

[BudgetSlasher]

That model does not have a pre-charged lineset, like some brands. That means you will likely need additional tools, such as a vacuum pump, micron gauge, and probably a torque wrench to name a few. I am unclear if pre-charged linesets would get around point 2.

It is pre-charged, but you do have to vacuum the line. There are some models that come pre-vacuumed, but none that were the size I wanted. You can buy or rent a vacuum pump, but I decided to buy one of these: https://www.amazon.com/gp/product/B08HNGXWKP/ref=ppx_yo_dt_b_asin_title_o02_s00?ie=UTF8&psc=1

I might be taking a chance on this, but I find it really hard to justify buying a $100 vacuum pump that I'll only use once.

As for the second point, neither the seller nor anyone else I've seen has said that you need an EPA certification to do this. I have literally not seen that for a single unit I've looked at. It might be the case that you need the certification if you are going to add refrigerant, but again, it is pre-charged and you don't need to add any.

To the first point, It is a gamble. Unvacuumed (and depending on the manufacturer) nitrogen purged lines can cause issues.

As for the second point, here it is straight from EPA:

https://www.epa.gov/section608/epas-refrigerant-management-program-questions-and-answers-section-608-certified

Is technician certification required to install an R-410A mini-split?

Yes. Adding or removing refrigerant from a mini-split as part of installation, and/or connecting or disconnecting hoses or pre-charged lines requires a section 608 technician certification. Activities reasonably expected to violate the integrity of the refrigerant circuit include but are not limited to: Attaching or detaching hoses and gauges to and from the appliance; adding or removing refrigerant; adding or removing components; and cutting the refrigerant line.

My understanding they also interpret releasing the pre-charge in the outside unit as adding it to the lines and inside unit.

[index]

It sounds like you may be under the 12 or 15 ft minimum lineset length so it will be over charged. It sounds like a lot of shortcuts are being taken. No vac, no micron gauge, no dedicated circuit. It will probably work but you're cutting the life short by not getting water vapor out of the lines. Make sure you use a torque wrench to attach the flares and nylog especially if you aren't checking for leaks. The flare nuts on the commercial linsets and flared ends ate usually trash. You should invest in a flaring tool and use the nuts that come with the unit.

Really just buy the $500 worth of tools you need to do the job right and sell it afterwards for $250. These aren't hard to install but you are gambling wasting $600 to save $250 and ate going to end up with a 5yr unit instead of a 10yr if everything works out due to not evacuating the lines.

[joenorm]

Thanks to everyone who's pitched in. My thinking on this is that I've got a receptacle that's perfectly placed outside simply to plug the unit into without needing to create a dedicated circuit. After doing some testing, that receptacle is on a circuit that only serves the jack-and-jill bathroom that connects the kiddos bedrooms. I mean, there are only two light fixtures and a fan that might put a load on that circuit. Those lights are of course now LEDs, which draw nothing. I should research the fan, but we never run it. The heat-pump units I'm looking at would be 9000 BTUs and draw about 7-10 amps when running and are acceptable for a 15 amp circuit. But no one wants to tell you that it would be okay to run it off of an already existing circuit, because CYA.

I'm thinking that I should just plug it in and go with that, but maybe I'm a fool. Someone set me straight if this is a bad idea.

Every Mini-Split I have ever seen has been 240volt. You cannot simply plug them into a receptacle.

[index]

Thanks to everyone who's pitched in. My thinking on this is that I've got a receptacle that's perfectly placed outside simply to plug the unit into without needing to create a dedicated circuit. After doing some testing, that receptacle is on a circuit that only serves the jack-and-jill bathroom that connects the kiddos bedrooms. I mean, there are only two light fixtures and a fan that might put a load on that circuit. Those lights are of course now LEDs, which draw nothing. I should research the fan, but we never run it. The heat-pump units I'm looking at would be 9000 BTUs and draw about 7-10 amps when running and are acceptable for a 15 amp circuit. But no one wants to tell you that it would be okay to run it off of an already existing circuit, because CYA.

I'm thinking that I should just plug it in and go with that, but maybe I'm a fool. Someone set me straight if this is a bad idea.

Every Mini-Split I have ever seen has been 240volt. You cannot simply plug them into a receptacle.

There are some 6k an vs 9k btu units that are 120v. You give up some efficiency though.

[aasdfadsf]

Well, I installed it and it works great, at least so far. It pumps very cold air and quickly cools off the room no matter how hot it is outside, which is exactly what I wanted. Of course we've just reached the end of the present heatwave, which is slightly annoying (heatwave, please strike after I have installed your bane), but there will be many more. I can post further explanations of the install and pictures if anyone cares.

To respond to "index's" very good points:

It sounds like you may be under the 12 or 15 ft minimum lineset length so it will be over charged.

It's 16.4 ft (5 m), and I didn't cut it short. I had leeway as to where to place both the indoor and outdoor units, so I put them to where the entire length was used without any slack.

It sounds like a lot of shortcuts are being taken. No vac, no micron gauge, no dedicated circuit. It will probably work but you're cutting the life short by not getting water vapor out of the lines. Make sure you use a torque wrench to attach the flares and nylog especially if you aren't checking for leaks. The flare nuts on the commercial linsets and flared ends ate usually trash. You should invest in a flaring tool and use the nuts that come with the unit.

Guilty as charged with regard to shortcuts. I did take some.

I did vac the lines using the Kwik-E-Vac system. Assuming it works as it's supposed to, then there should be no water vapor or air in the lines. I do think that if I were to do it again, I would try to get a vacuum pump. I'm not sure if the money saved is worth it given the uncertainty involved. However, I didn't find any cost-effective way to rent one or even buy one. The cheapest I saw was $100, and I don't know if that included the manifold and gauges. I might not have researched this enough, but when I saw the Kwik-E-Vac, I just thought that was the solution I needed. Maybe so, maybe not.   

I did use Nylog. Everyone loves Nylog and it seems to serve as an idiot-proofer. I also checked for leaks using the old soap and water, and of course there were none, but I could only do it on the outside unit. It just wasn't possible on the inside unit given the space it was in. I did not use a torque wrench. Open-ended ones are really expensive and most Youtubers I watched felt comfortable enough not using one (they all used Nylog).

Didn't try to re-flare anything. Did not seem smart. The units these days are supposedly manufactured extremely well, but I guess we'll see. 

Really just buy the $500 worth of tools you need to do the job right and sell it afterwards for $250. These aren't hard to install but you are gambling wasting $600 to save $250 and ate going to end up with a 5yr unit instead of a 10yr if everything works out due to not evacuating the lines.

Could be, but $500 worth of tools is getting very close to the actual cost of the unit itself. Reselling them is a major pain in the ass, even if I can get 50% back. Even assuming the lifespan is reduced somewhat, that is likely an acceptable tradeoff.

[index]

Well, I installed it and it works great, at least so far. It pumps very cold air and quickly cools off the room no matter how hot it is outside, which is exactly what I wanted. Of course we've just reached the end of the present heatwave, which is slightly annoying (heatwave, please strike after I have installed your bane), but there will be many more. I can post further explanations of the install and pictures if anyone cares.

To respond to "index's" very good points:

It sounds like you may be under the 12 or 15 ft minimum lineset length so it will be over charged.

It's 16.4 ft (5 m), and I didn't cut it short. I had leeway as to where to place both the indoor and outdoor units, so I put them to where the entire length was used without any slack.

It sounds like a lot of shortcuts are being taken. No vac, no micron gauge, no dedicated circuit. It will probably work but you're cutting the life short by not getting water vapor out of the lines. Make sure you use a torque wrench to attach the flares and nylog especially if you aren't checking for leaks. The flare nuts on the commercial linsets and flared ends ate usually trash. You should invest in a flaring tool and use the nuts that come with the unit.

Guilty as charged with regard to shortcuts. I did take some.

I did vac the lines using the Kwik-E-Vac system. Assuming it works as it's supposed to, then there should be no water vapor or air in the lines. I do think that if I were to do it again, I would try to get a vacuum pump. I'm not sure if the money saved is worth it given the uncertainty involved. However, I didn't find any cost-effective way to rent one or even buy one. The cheapest I saw was $100, and I don't know if that included the manifold and gauges. I might not have researched this enough, but when I saw the Kwik-E-Vac, I just thought that was the solution I needed. Maybe so, maybe not.   

I did use Nylog. Everyone loves Nylog and it seems to serve as an idiot-proofer. I also checked for leaks using the old soap and water, and of course there were none, but I could only do it on the outside unit. It just wasn't possible on the inside unit given the space it was in. I did not use a torque wrench. Open-ended ones are really expensive and most Youtubers I watched felt comfortable enough not using one (they all used Nylog).

Didn't try to re-flare anything. Did not seem smart. The units these days are supposedly manufactured extremely well, but I guess we'll see. 

Really just buy the $500 worth of tools you need to do the job right and sell it afterwards for $250. These aren't hard to install but you are gambling wasting $600 to save $250 and ate going to end up with a 5yr unit instead of a 10yr if everything works out due to not evacuating the lines.

Could be, but $500 worth of tools is getting very close to the actual cost of the unit itself. Reselling them is a major pain in the ass, even if I can get 50% back. Even assuming the lifespan is reduced somewhat, that is likely an acceptable tradeoff.

Fair enough. I'm hopeful everything works out. My unit was $1600 so I spent the extra money for the right tools. I've ended up installing four now between friends and a vacation home. Minisplits save a bundle and are great at dehumifying a space. 

Between $2.5k of spray foam in my attic and the ($2.5k all in with tools and duct work) ducted minisplit, my gas and electric bill is down $70 per month. That's almost a 17% roi.

[aasdfadsf]

Thanks for the support. The machine works awesomely at present, but if for some reason it starts faltering, whenever it may happen, I'll post about it as a potential warning.

I learned one very important thing: Mini-splits and GFCI breakers don't like each other. After an initial great run, the next day it kept cutting off, and this scared the shit out of me, because I was convinced that I probably fried the thing and how I am going to explain this to my wife and even worse you guys who are going to say I told you so and what a fucking fool aasdfadsf is.

After googling, it turns out that the voltage harmonics of mini-splits will trip GFCI breakers always and everywhere even if there is zero ground leakage. I felt much better after learning that. It also turns out that the code has had exceptions put in to try to deal with this, but the code is abstruse. My solution was don't use GFCI, and that totally solved the problem! Great, but I think that means it not to code. I will put further work into this, but negligible safety problems aside, it's working very well.

[BudgetSlasher]

Thanks for the support. The machine works awesomely at present, but if for some reason it starts faltering, whenever it may happen, I'll post about it as a potential warning.

I learned one very important thing: Mini-splits and GFCI breakers don't like each other. After an initial great run, the next day it kept cutting off, and this scared the shit out of me, because I was convinced that I probably fried the thing and how I am going to explain this to my wife and even worse you guys who are going to say I told you so and what a fucking fool aasdfadsf is.

After googling, it turns out that the voltage harmonics of mini-splits will trip GFCI breakers always and everywhere even if there is zero ground leakage. I felt much better after learning that. It also turns out that the code has had exceptions put in to try to deal with this, but the code is abstruse. My solution was don't use GFCI, and that totally solved the problem! Great, but I think that means it not to code. I will put further work into this, but negligible safety problems aside, it's working very well.

Earlier you mentioned this circuit also serves a jack-and-jill bathroom (wet room). Since you are talking about breakers, I assume the bathroom is no longer GFCI protected; in my mind that is more than a negligible safety problem.

The simplest way that I know to address this is to put a GFCI outlet in and rather than attaching the downstream outlets (or mini-split) to the load side of the outlet you tie in into the line side. Of course if there are multiple outlets in the bathroom/other location needing GFCI upstream of the mini-split you will have to do this for each outlet.

[aasdfadsf]

Earlier you mentioned this circuit also serves a jack-and-jill bathroom (wet room). Since you are talking about breakers, I assume the bathroom is no longer GFCI protected; in my mind that is more than a negligible safety problem.

Yes, but weirdly it's only the lights and an exhaust fan in that bathroom that are on that circuit. Don't ask me why. The receptacle in that bathroom is on a different circuit and is not itself a CFCI receptacle, but it might be down-line from another GFCI on whatever the heck circuit it's on. I haven't yet figured out what circuit that's on, but you are totally right that you don't want a bathroom receptacle not to be on GFCI. But taking the GFCI off the circuit I'm running the mini-split on can't affect that.

Now, we also have spiral staircase that reaches our flat roof, and up there there is a switch that runs an exhaust fan and also another receptacle that we never use except for LED Christmas lights cascading down the stairs when the season strikes. Those are on the circuit that I'm using for the mini-split, but there is no worry about load on that, and definitely not water. To make things even more fun, there is a light switch for the top of the stairs in the same box as the exhaust fan switch, but it is on a different circuit. Who the fuck wired this place? 

[index]

Who the fuck wired this place?

The next guy will be wondering the same thing about the a/c that shares a circuit with the bathroom!

[BudgetSlasher]

Who the fuck wired this place?

In my family they're called "Bud the electrician", I can drop that in any conversation and they'll know the wiring is dickered.

Strangely there is a guy named Bud who works in almost every trade and they seem to have been involved in all of houses at some point.

[Dancin'Dog]

I'm thinking about installing some mini splits at our mountain place.  We've never had A/C there, so that will be a nice bonus for the rare occasions that we need it.  We've always heated with propane and a wood stove, but it would be nice to have a heat pump too.


I'm not in a big hurry to get it done, so I'll have plenty of time to read up and watch YouTubes.  I'll probably try an off brand, just because I enjoy trying cheap things out. 


It looks like some models are able to run multiple interior units from one exterior unit.  I wonder if all of the interior units need to be on the same floor?  The HVAC system at on primary home has separate systems for each floor.  If each interior mini split unit has its own thermostat perhaps they can be used on different floors.  I'll have to confirm that.

[BudgetSlasher]

I'm thinking about installing some mini splits at our mountain place.  We've never had A/C there, so that will be a nice bonus for the rare occasions that we need it.  We've always heated with propane and a wood stove, but it would be nice to have a heat pump too.


I'm not in a big hurry to get it done, so I'll have plenty of time to read up and watch YouTubes.  I'll probably try an off brand, just because I enjoy trying cheap things out. 


It looks like some models are able to run multiple interior units from one exterior unit.  I wonder if all of the interior units need to be on the same floor?  The HVAC system at on primary home has separate systems for each floor.  If each interior mini split unit has its own thermostat perhaps they can be used on different floors.  I'll have to confirm that.

Generally they do not need to be on the same floor. A good manual will tell you how much height difference can be between the outdoor units and the highest head and also between the indoor heads. I've seen multiple large to medium brands with heads on multiple levels.

[index]

This is the best YouTube video I've seen for the vacuuming down and charging the system.

https://www.youtube.com/watch?v=k9uohbYDuRs

To do the job right (and use any unit you want) you'll need some special tools:
-appion core removal tool - $50 ebay
-straight yellow jacket ball valve - $25 ebay
-vacuum rated hose - $20 amazon
-micron gauge - $50 to $150 ebay (get a name brand, you can buy one for $75 and resell for the same minus fees and shipping)
-vacuum pump - $100 - $200 (either cheap one you keep of amazon or name brand and resell it on ebay)
-flaring tool (don't use the flare nuts on the linset) - $25 new on amazon (black and silver - they are knockoffs of a expensive one and work great)
-tubing bender - if you are going to be trying to do 90 degree turns - $30ish
-torque wrench - $60 ebay
-Nylog - $5

That is $500 worth of tools on the high side and you can probably shave that down to about $400 by going lower end and resell everything if you are never going to use them again for $250.

You can always skip the vacuum phase, but you will cut the life of your unit down as water vapor mixes with the 410A and rusts out the compressor. You could skip the micron gauge, torque wrench, and flaring tool - but you risk loosing your charge and a $400+ service call to fix the system and charge it (IF you can find an HVAC tech to work on it).

The quick way to install these is how they do it in Central America. You cut and reflare with good nuts, nylog then tighten the flare connections. Hook up a cheap vacuum pump and let it run for an hour then release the refrigerant. The guys who do this have a good sense of the proper amount to tighten the flares and are confident they can flare correctly. The micron gauge and torque wrench are really only there to check your work.

[aasdfadsf]

I'm not in a big hurry to get it done, so I'll have plenty of time to read up and watch YouTubes.  I'll probably try an off brand, just because I enjoy trying cheap things out. 

That's what I did. Rovsun is an off-brand, or at least a new one, but I'm pretty convinced that they make every single one of these things in the same factory and just put different brand names on them. Anyway, I am thus far very happy with it. I spent less than $1000 in total and got exactly what I wanted.

And yeah, the YouTubes are good. Being someone who remembers a time from before the internets, there are readings and stuff you can do, but videos are very useful.

[bacchi]

Who the fuck wired this place?

In my family they're called "Bud the electrician", I can drop that in any conversation and they'll know the wiring is dickered.

Strangely there is a guy named Bud who works in almost every trade and they seem to have been involved in all of houses at some point.

My partner's dad is/was a carpenter and he worked with a Bud. Bud's favorite carpentry tools were a sledge hammer and duct tape.

[aasdfadsf]

To do the job right (and use any unit you want) you'll need some special tools:
-appion core removal tool - $50 ebay
-straight yellow jacket ball valve - $25 ebay
-vacuum rated hose - $20 amazon
-micron gauge - $50 to $150 ebay (get a name brand, you can buy one for $75 and resell for the same minus fees and shipping)
-vacuum pump - $100 - $200 (either cheap one you keep of amazon or name brand and resell it on ebay)
-flaring tool (don't use the flare nuts on the linset) - $25 new on amazon (black and silver - they are knockoffs of a expensive one and work great)
-tubing bender - if you are going to be trying to do 90 degree turns - $30ish
-torque wrench - $60 ebay
-Nylog - $5

I agree with the vacuuming, and if I had to do it over again, I don't think I'd use the Kwik-E-Vac shortcut that I used (though I have no reason to think it didn't work). I also like the idea of a tubing bender -- would have totally been worth the $30. But I don't get the reflaring. Why would you want to do that? This seems based on the assumption that 1) the manufacturer could not have done it right, and 2) you're going to do it better and not mess it up. Seems unlikely to me, but maybe I'm missing something. Also...Nylog is your idiot-proofer.

[index]

To do the job right (and use any unit you want) you'll need some special tools:
-appion core removal tool - $50 ebay
-straight yellow jacket ball valve - $25 ebay
-vacuum rated hose - $20 amazon
-micron gauge - $50 to $150 ebay (get a name brand, you can buy one for $75 and resell for the same minus fees and shipping)
-vacuum pump - $100 - $200 (either cheap one you keep of amazon or name brand and resell it on ebay)
-flaring tool (don't use the flare nuts on the linset) - $25 new on amazon (black and silver - they are knockoffs of a expensive one and work great)
-tubing bender - if you are going to be trying to do 90 degree turns - $30ish
-torque wrench - $60 ebay
-Nylog - $5

I agree with the vacuuming, and if I had to do it over again, I don't think I'd use the Kwik-E-Vac shortcut that I used (though I have no reason to think it didn't work). I also like the idea of a tubing bender -- would have totally been worth the $30. But I don't get the reflaring. Why would you want to do that? This seems based on the assumption that 1) the manufacturer could not have done it right, and 2) you're going to do it better and not mess it up. Seems unlikely to me, but maybe I'm missing something. Also...Nylog is your idiot-proofer.

The flare nuts that come on the preflared linesets are not forged. The flare nuts on the units are. No idea why the lineset suppliers save $8 total and use cast flare nuts. You can feel the difference if you hold both types, the forged nuts are twice as heavy. The cast nuts on the linset can crack over time, especially if they were over tightened.

You will probably be fine. They probably only fail 1-2% of the time, but it's a big deal if you install a lot of them. The install instructions usually recommend to reflare as well.

[index]

I'm not in a big hurry to get it done, so I'll have plenty of time to read up and watch YouTubes.  I'll probably try an off brand, just because I enjoy trying cheap things out. 

That's what I did. Rovsun is an off-brand, or at least a new one, but I'm pretty convinced that they make every single one of these things in the same factory and just put different brand names on them. Anyway, I am thus far very happy with it. I spent less than $1000 in total and got exactly what I wanted.

And yeah, the YouTubes are good. Being someone who remembers a time from before the internets, there are readings and stuff you can do, but videos are very useful.

The big advantage of the higher tech units comes into play for heating. Heat pumps loose efficiency at cooler outdoor temps. A cheap 12k btu minisplit will put out 2k btu at 0F but a more expensive one can still operate at the rated 12k btu. The advertising is misleading, some say heats to -5F but they have no capacity below 20F if you look at the curves.

For cooling or heating above 30F, I'd go cheap!

There are a few factories in China that make all of them. Midea and Gree are the two big ones and most of the units are rebadges of the two. Poke around on minisplit warehouse and you can get a feel for what's offered.

[uniwelder]

I also like the idea of a tubing bender -- would have totally been worth the $30. But I don't get the reflaring. Why would you want to do that? This seems based on the assumption that 1) the manufacturer could not have done it right, and 2) you're going to do it better and not mess it up. Seems unlikely to me, but maybe I'm missing something.

When I put in my mini-splits, I used a 1/2" conduit bender for the copper lines.  It gives a bigger radius than needed, which might be an issue for tight spaces, but it happened to be laying around.  I've been able to use it for 3/8" to 3/4" copper lines without kinking.

The big reason for reflaring is to cut the copper lines to exactly the length needed for a nicer looking installation.  Otherwise, you'll need to coil the extra tubing around and stuff it behind the outdoor unit.