problem installing a mini split AC

J

joe seed

Member
Hi, my grow room gets to hot so i bought a mini split AC/Heatpump. I thought I could install it myself but I didn't realize that I would need to purge the pipes which I no nothing about.

Apparently the only people in my area who purge the pipes in my area are contractors and I am not fussy about letting a stranger in my room.

I was wondering if there was any way around the purging of the pipes that I could do myself?

THanks
 
C

contraptionated

New Member
You probably already know that you need a vacuum pump to do the purge. The Yellow Jacket (brand) pump ( they come in sizes rated from...hmmm...I think around 4cfm is good for you) with the psi gauge manifold would cost you around $700 new. You most probably have everything stealth and don't want to call an HVAC guy. You're best bet is to ebay a good used Yellow Jacket 4 cfm vacuum pump with the manifold. I would imagine there's a video online of how to do the purge once you have you vacuum pump rig. Heck, you probably already knew everything I just wrote so now I feel like an idiot!
 
Nizza

Nizza

Well-Known Member
you'll also need nitrogen to charge the system and check for leaks before filling with refrigerant, this prevents you from leaking out the pre-charged refrigerant in the condenser (usually good for 10ft of lineset). you use a set of gauges to test it out(follow a video or tutorial to do all this crap)
and like said above to do everything youll need a flaring block, set of gauges, nitrogen tank with regulator, 4cfm+vacuum pump, schrader tool (for the condenser), silicone (plug hole from hole saw), hole saw (for lines to go outside),pad for condenser(prevents rain from backsplashing dirt into coils of condenser ) electrical whip + tools, and a good knowledge or following of DIY tutorials. Insulate the bigger refrigerant line and be sure not to hurt yourself! outside electrical should be waterproof and rated for outdoor weather
make friends with an a/c guy
the cool ones usually smoke.
 
jrainman

jrainman

Active Member
No you can just purge the system, vacum pump not really require, on A/C its not as critical as refrigeration, and it really a big epa thing , but there is somthing called accidental refrigerant loss , dont listen to the other PM me will walk you through it.
 
jrainman

jrainman

Active Member
Chuck we used to call too fuckin lazy to walk back to the service truck .and reclamer WTF is that, proberly put thousands lbs of 12 n 22 in the ozo back in the late 70s and early 80s
 
chuck estevez

chuck estevez

Well-Known Member
usually these mini splits only have a low pressure side port. it has a shrader valve(just like a bike tire) You open the high side ( the little copper Line) valve and hold down the shrader valve for a couple seconds. the rushing refrigerant will push the air and crap out.
 
jrainman

jrainman

Active Member
then just crack open the low side but just a quater turn ,to let the refrigerant equalize slowly so the oil in the compressor does not saturate the line ,after a min or 2 just open them all the way , but dont crank on it when you feel the oring seat just go a touch more.then put your caps back on and you are ready.

This is PURGING Not evacuating (vacum pump) the system. 2 diff things.


the refrigerant lines are made very clean from the manufacturer ,they are either put in a vacum or nitrogen charged already that is why they are rubber corked at both ends ,this is what keeps them steril till ready for use .
 
C

contraptionated

New Member
So I stand corrected about the general course of action on how to purge. VERY thorough explanation! I elect Jrainman and Chuck the official HVAC gurus of RIU! Oh, wait... I'm nobody , I can't do that.
 
J

joe seed

Member
Thanks for all the info. After thinking about it for awhile I remembered I had an old friend who used to work on AC and fridges and stuff. He figures he can help me out, he has a vacuum pump and says shouldn't be any problem to clean my lines. So I will just have to wait and see how it plays out.
 
Kite High

Kite High

Well-Known Member
also keep in mind that if not professionally installed most brands void the warranty....I knew of this so purchased units that do not do this...chuck and rain hit it on the head though
 
J

joe seed

Member
I forgot to mention , I live on a hill so I was going to use the installation bracket on the side of the house to put in the outside unit. When I fasten the bracket to the house the best I can get behind the unit will be 10 1/4 to 10 1/2 inches but I see the specs call for 11 4/5 inches. Am I going to have enough clearence behind the unit? I have all kinds of clearence to the side of the unit.

Also the installation bracket I am using was sent with the system but it does not seem like the strongest set of brackets I have ever seen. The unit weighs about 110 pounds. Do brackets have to be overly strong to support these units? thanks
 
jrainman

jrainman

Active Member
yes those specs are min requirement most time its 12'' min,yes bracket will hold by design but needs to be lagged to your framing, PIA to install and set condenser in, I would just go buy some 3/4 clean size stone ,its cheep ,then level the whole area out 2x the condenser size ,and bring the stone 3 to 4 inches above your final grade then level, place condenser 18'' off house this gives good service room , snow and debre clearance ,also better air flow to condenser, no pad needed stone has good drainage so condenser wont rot out.
 
J

joe seed

Member
I have the unit in, just waiting for my friend to purge the lines. In the meantime I was going to run the wire for my electrian friend who I cant get hold of right now. Need to know the correct wire to run. the system draws 9.4 amps max in the heating mode and 8.4 amps in the cooling mode. On the plate it says "1 Phase 60Hz 230 volts". Can someone tell me the correct wire to run? thanks
 
jrainman

jrainman

Active Member
12-3 sould be fine , those are run load amp #s RLA when sizing wire you look at tag for FLA full load amps , the units starting amp (fla) is the highest draw of amparage ,that is what you go by, but I would say your FLA would be around 15 to 17 amp so 12-3 should be fine
 
jrainman

jrainman

Active Member
Oh made a mistake 12-2 wire , dont need 12-3 ,12-2 your good , you could get away with 14 wire but, I dont know how long your homerun is back to your pannal , So go with the 12-2.
 
chuck estevez

chuck estevez

Well-Known Member
jrainman said:
Oh made a mistake 12-2 wire , dont need 12-3 ,12-2 your good , you could get away with 14 wire but, I dont know how long your homerun is back to your pannal , So go with the 12-2.
Click to expand...
i do that all the time, i forget they don't count the ground in the #'s so i say 12-3 thinking the 3 is ground when it's 12-2 and the ground is just a givin.
 
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