How to charge a mini split?

[Milton Shaw]

What I cannot understand is why the EPA and other groups are not targeting the copper thieves that steal A/C outside units for the copper and always let all the refigerant out of the system. These are always fully charged working systems that are stolen. That refigerant loss is always a lot more than any technician would ever let out of a system. The copper the thief steals is just a minor crime to police but freon release should be a major felony for the EPA. Refigerant release is a $10,000 fine why aren't the police or EPA trying to prosecute them for releases.

 

[JackDiddly]

http://www.achrnews.com/articles/127297-man-gets-prison-time-for-venting-r-22

 

[404]

What I cannot understand is why the EPA and other groups are not targeting the copper thieves that steal A/C outside units for the copper and always let all the refigerant out of the system. These are always fully charged working systems that are stolen. That refigerant loss is always a lot more than any technician would ever let out of a system. The copper the thief steals is just a minor crime to police but freon release should be a major felony for the EPA. Refigerant release is a $10,000 fine why aren't the police or EPA trying to prosecute them for releases.

Copper crooks don't have 10K in an account. People in the trade do.

 

[dowmace]

Copper crooks don't have 10K in an account. People in the trade do.

Exactly, and it's not about being enviromental it's about revenue.

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[sixty4]

One hour service call and some refrigerant? It was just not worth it for me to buy the gauge setup and refrigerant for a one or two time event.

 

[Trey T]

...That's for much more than just Daikin. Just about anything. For R134a, I have a luggage scale, and hang the cylinder from it. It easily reads to the closest ounce is more than acccurate enough, and is super cheap.
...

charging by weight is only done when you know the initial charge and the void space (length of lineset), which is determined by the manufacturers. If for some reason you lose refrigerant and have to charge again, you can not use the weighing method and you have to rely on the thermodynamic criteria for that type of system; meaning that you have to look at equipment specs, refrigerant chart, and your HVAC guage to adjust the charge properly.

 

[bzinsky]

charging by weight is only done when you know the initial charge and the void space (length of lineset), which is determined by the manufacturers. If for some reason you lose refrigerant and have to charge again, you can not use the weighing method and you have to rely on the thermodynamic criteria for that type of system; meaning that you have to look at equipment specs, refrigerant chart, and your HVAC guage to adjust the charge properly.

shucks...too much to learn.

Just bought a cool LG diagnostic tool, $99 bucks, plug it into the outdoor unit, it connects to your phone, and you get all the data you need. Going to let hvac tech use it.

 

[Trey T]

Can you take some picture? I didn't even know there's such thing as on-board diagnostic sytem or related.

 

[bzinsky]

Can you take some picture? I didn't even know there's such thing as on-board diagnostic sytem or related.

Don't have it yet, its being shipped.

LG sims 2.0, you don't need wifi at the location, it just uses wifi to connect to your phone. There's an app in the app store for android and iphone you use with it.

 

[bzinsky]

What would be badass is if I could stream this data to one of you guys and I could hire you from across the country, or wherever you may be.

Tried to get a car tuning app off the ground like that several years ago, someone smarter and more ambitious beat me to it.

 

[SALIV8]

since you just purchased and installed 20 units, dont they have warranties? I would think LG will not warranty anything that a diy installed.

No offense, but hopefully you thought of this? For stuff like this you need a local pro that is authorized by LG. Or you will be up the creek on the warranty if something happens..

either way good luck. sometimes spending a little more for the piece of mind and warranty is worth it.

hopefully Im wrong and LG will warranty your work.

I would get on the horn with LG and ask them who they recommend in your area.

 

[walrus]

charging by weight is only done when you know the initial charge and the void space (length of lineset), which is determined by the manufacturers. If for some reason you lose refrigerant and have to charge again, you can not use the weighing method and you have to rely on the thermodynamic criteria for that type of system; meaning that you have to look at equipment specs, refrigerant chart, and your HVAC guage to adjust the charge properly.

Can't do that with these mini splits. Recover, calculate what you need to add for line sets, add original charge and then weigh in total.

 

[patrickoneal]

What is it with HVAC tradesmen that makes them so hostile to DIY work?

I installed two mini splits myself pretty much from reading the manual and getting information online. I bought a nice JB vacuum pump, a BluVac micron gauge, flaring tool, got my EPA certificate(just to avoid supply house hassle, you don't need certification to buy R410a or equipment). I still came out way ahead of what a contractor would have charged me, they all seem to rip people off on mini-splits. In fact, for the prices I've seen quoted here for installation, I could replace my "no warranty" systems if I screwed them up and still come out ahead money wise.

This isn't rocket surgery, and LOL at the dude that made a big deal out of the systems running at 450 PSI. Pretty sure my brakes and clutch run at a higher pressure than that and nobody gets up in arms about DIY auto work. Seems like you can ask about framing, electrical work, plumbing, concrete, masonry, installing lifts, anything but HVAC and advice comes easy without tradesmen jumping up and down screaming.

 

[LS6 Tommy]

What is it with HVAC tradesmen that makes them so hostile to DIY work?

I installed two mini splits myself pretty much from reading the manual and getting information online. I bought a nice JB vacuum pump, a BluVac micron gauge, flaring tool, got my EPA certificate(just to avoid supply house hassle, you don't need certification to buy R410a or equipment). I still came out way ahead of what a contractor would have charged me, they all seem to rip people off on mini-splits

This isn't rocket surgery, and LOL at the dude that made a big deal out of the systems running at 450 PSI. Pretty sure my brakes and clutch run at a higher pressure than that and nobody gets up in arms about DIY auto work. Seems like you can ask about framing, electrical work, plumbing, concrete, masonry, installing lifts, anything but HVAC and advice comes easy without tradesmen jumping up and down screaming.

i'm not hostile to DIY, iIdon't jump up and down, I freely give info and advice, specifically to help peolple like you who don't "know" the trade, but are obviuosly capable of doing their own work. People with no clue, that may cause themselves harm or a major problem are different. I politely tell them they should call a contractor.

BTW, you say you don't need a 410a cert to purchase refrigerant or equipment. That's true. You need the certification to WORK with the refrigerant and equipment.

It's interesting that the HVAC trade is the lowest paying trade, but everybody whines about how they get ripped off by HVAC contractors.

A vapor, even at "only" 450 Psig is a LOT more dangerous than a liquid at 1200 Psig, like your brake system.

Tommy

 

[LS6 Tommy]

shucks...too much to learn.

Just bought a cool LG diagnostic tool, $99 bucks, plug it into the outdoor unit, it connects to your phone, and you get all the data you need.

Except pressures, which is what you meed MOST...

Tommy

 

[raceman17]

I recently had to replace the a coil in my house unit. I bought the replacement coil online, bought a 30 lb cylinder of 410a off of eBay and a set of gauges to go with it. Had the vacuum pump already so that wasn't needed. I used argon instead of nitrogen to purge the system while brazing the lines and for pressure testing since I didn't have the nitrogen. Was actually quite simple to do. I followed the manufactures recommendations on how to charge the system and was up and running in a few hrs.

No certification required... Just do some research and buy your stuff online.

It ***** that you can't support the local shops because of all the regulations but they have their reasons. I have mine too..

Doing things myself instead of paying people to do it is always a more satisfying feeling then just handing over the cash.

 

[magicrat]

Yea its all overhead....Im a one man show....All the AC companies around hate me cuz i dont charge what they do...As to the OP....410 a is cheap....get some gauges for like a hundred bucks and charge to specs....probably will still be cheaper than calling a company.

 

[magicrat]

As for that gadget i saw in a n earlier post.....interesting tool for an AC tech.....but for a DIY guy.....even if it told you what was wrong you would still have to know how to fix the problem....

 

[brewchief]

Yea its all overhead....Im a one man show....All the AC companies around hate me cuz i dont charge what they do...As to the OP....410 a is cheap....get some gauges for like a hundred bucks and charge to specs....probably will still be cheaper than calling a company.

What specs are you going to charge it to? Can't use superheat since it's a txv system and can't use supcooling since the txv is in the outdoor unit so no access to liquid line for temp or pressure. Only way to do it properly is to evac the charge and weigh in the proper factory charge plus whats needed for linset length.

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[magicrat]

Usually there is a chart with the ambient temp and pressures either in the paperwork or on the unit from the manufacturer. Assumming unit was installed correctly in the 1st place.

 

[Trey T]

Can't do that with these mini splits. Recover, calculate what you need to add for line sets, add original charge and then weigh in total.

True but I believe it has to do with the R410a than the heat pump system, which has been around for long time. Recover and add is the simplest way.

 

[monkeyspanners]

True but I believe it has to do with the R410a than the heat pump system, which has been around for long time. Recover and add is the simplest way.

Its all minisplit systems no matter what refrigerant they use, be it R22, R407C or R410A. In fact even the bigger VRF VRV systems need to be charged by weight.

 

[monkeyspanners]

Usually there is a chart with the ambient temp and pressures either in the paperwork or on the unit from the manufacturer. Assumming unit was installed correctly in the 1st place.

I've never seen such a chart on a minisplit nor seen one referenced on a manufacturers training course, they need to be charged by weight only dependent on line set length.

 

[Trey T]

Its all minisplit systems no matter what refrigerant they use, be it R22, R407C or R410A. In fact even the bigger VRF VRV systems need to be charged by weight.

Wait... you're saying charging by weight is the only method? Engineers and scientist don't simply add them to see if they work or not, there are parameters they need to evaluate.

 

[brewchief]

Wait... you're saying charging by weight is the only method? Engineers and scientist don't simply add them to see if they work or not, there are parameters they need to evaluate.

Only method to field charge, no way to charge by subcooling due to design.

Have you installed or serviced any mini splits?

 

[Trey T]

I've serviced and installed R22 at my other home. Installed one mini-split (daikin 9K BTU, IRRC) about a year ago. never diagnose a heat pump though (split or mini-split).

I took two thermodynamic courses in college that deals with variety of refrigerants... dont know if that's the right answer.

 

[walrus]

I've never seen such a chart on a minisplit nor seen one referenced on a manufacturers training course, they need to be charged by weight only dependent on line set length.

There is no chart, compressor, fans varies depending on temps at sensors, indoors outdoors, condenser, load etc Its an algorithm known to the manufacturer and I doubt they want others to know. Fill by weight only

 

[magicrat]

maybe not on the brands ur dealing with but i have seen charts on 90 percent of the stuff i work on Texas(check website for minisplits).....Yea u could charge by weight but u could just look at pressures and get real close to where u need to be(yes i know its not fundamentally correct). Maybe im just a hick from the south but we do it all the time down here and its 95 to 105 all summer... Residential is mostly close enough....Commercial is usually by the book and refridgeration done to the T.

 

[walrus]

maybe not on the brands ur dealing with but i have seen charts on 90 percent of the stuff i work on Texas(check website for minisplits).....Yea u could charge by weight but u could just look at pressures and get real close to where u need to be(yes i know its not fundamentally correct). Maybe im just a hick from the south but we do it all the time down here and its 95 to 105 all summer... Residential is mostly close enough....Commercial is usually by the book and refridgeration done to the T.

Mini splits are used more for heat than cooling where I am. if you want efficiency which folks using them for heat do, you have to charge by weight. I'd like to see a chart for a Fujitsu wall hung ductless split
http://www.fujitsugeneral.com/wallmountedRLS3.htm

 

[magicrat]

I guess we're talking two different things.....I turned my heater on once in winter for 5 minutes just 2 make sure it worked......and 90% of minisplits we have here are for cooling only......as u can imagine our heating needs are very slim down here and I am far from a heating expert

 

[magicrat]

Actually I don't think I've ever installed a minisplit that had a heating option on it.

 

[Ohmthis]

Magicrat, please don't take offense, but the others are giving advise to the "proper" way of adding refrigerant. I've installed Mitsubishi, fugitsu, and daikin mini splits and they ALL use the weigh in procedure. These are totally different animals than a standard split system. You can't "beer can cold" the charge. Have you actually worked on them?

 

[magicrat]

Yea at least once a week in the summer......but I'm assuming the OP isn't a hvac tech and may or may not have all the proper tools and knowledge at his disposal....if he did he wouldn't be asking.....so as I said he can get close enough with gauges.....however as walrus is stating that yall in the north have to be more precise for heating.....which Im really notvsure about bcuz the minisplits here are mostly cooling only.

 

[Ohmthis]

Magicrat, what are you checking to "get it close", just pressure?

 

[SALIV8]

How did this all turn out? OP got me thinking of mini splits now..

Would the OP recommend mini splits for larger apartments also? Did you get a warranty with your installs?