# mini split unit comes precharged?



## chillypilgrim (Sep 2, 2015)

stupid question...I usually work on refrigerators. I am doing a Fujitsu Mini split. 12k 115v. It says it comes pre charged with R410A for use with line sets up to 35feet.

Since my line set is only around 12 feet, Am I required to "evacuate" refrigerant from the system first? (in order to achieve proper low side pressure)


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## CompleteW&D (May 28, 2011)

I would think that would be covered in the instructions. Or have your HVAC professional check your system out after install to ensure it is set up and going to work properly.


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## flashheatingand (May 3, 2008)

I would just evacuate the lineset


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## chillypilgrim (Sep 2, 2015)

I called fujitsu and they informed me it was a varying speed compressor. You don't need to touch the refrigerant level if your line set is anywhere from 9-25 feet long ! Simply amazing technology !


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## Tom M (Jan 3, 2007)

If you cut the charged length why won't you have to evacuate the 410 in order to not lose it? Are they suggesting coiling up the extra line to reduce the length? 
Just asking, I never install them.


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## beenthere (Mar 5, 2009)

The condenser comes precharged for up to 35 foot of line set. The line set itself is not precharged.


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## marbledust (Jun 20, 2014)

chillypilgrim said:


> stupid question...I usually work on refrigerators. I am doing a Fujitsu Mini split. 12k 115v. It says it comes pre charged with R410A for use with line sets up to 35feet.
> 
> Since my line set is only around 12 feet, Am I required to "evacuate" refrigerant from the system first? (in order to achieve proper low side pressure)


First thing is to tighten your flare nuts down...than fill the lines and coil with a nitrogen charge(300psi)there abouts...some folks wait 24 hours and check pressure than.
If she holds your charge..hook up the vacuum pump and run her until you get 500microns,there abouts.
now she is ready to open up the valves(5mm allen):clap:


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## ShepherdHVAC (Jan 7, 2016)

*Help*

I agree with using the pressure test then holding to 500 microns


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## AustinAirCo (Aug 21, 2015)

The mini split will probably have a leak in a few years. These are more or less disposable air conditioners, similar to window units in that the manufacturer's spew out new models so frequently it's a mind numbing thing to keep any of it straight. 

I think most have a compressor warranty of 5 years / 7 if you're lucky. But most other parts are only 1 year. If you install it yourself then forget about the warranty because it will be void.

Every manufacturer makes model specific parts. Which means if you need a part you may not find it in stock have to wait for weeks to get it because most are made in Japan / China and elsewhere. Because models of these units change so frequently you may not find the part you need anyway. 

When the units are new, they work great. Very quiet and super efficient. BUT hooked to a bad power source (brown outs, power surges etc.) Trouble will follow fairly quick... in most cases within a couple years or less. 

Other than all these serious flaws... They're GREAT! :clap:


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