Please assist in last step for my Mini split install

[diyerforlife]

So I just found this site and looks awesome. As the name suggest i always opt to do the work myself. If its on my house or on my cars, I love getting my hands dirty and learning new things.

I've done many a/c's on cars before so I thought i would attempt a mini split install in my garage. Same concept right, LOL. (im sure some would disagree) Well i bought a Freidrich 12.5k btu for my garage and i vacuumed it down and the pressure held for 3 days so i figured there are no leaks. Now i'm stumped on how to take the gauges back off the port on the outside unit. The instructions say


1
2
3
4
5
6.Fully open high/low pressure valves.
7.Remove charging hose from charging end of low pressure valve
8.Tighten bonnet of low pressure valve.


Well every time i try to unscrew the hose i loose freon. So i thought okay maybe tighten the low pressure valve on the unit, then take off hose and re open it, right? makes sense? no, it still loose freon.

And the bonnet, that's a cap right? is that the piece that converts the valve to the gauge that i had to buy in order to fit my gauges on the port? Is there some type of blow off valve that will release just enough freon that's built up in the hoses only? Like a valve stem for a tire? I'm too scared to keep unscrewing the hose in fear once its completely off i will loose all freon in the system

I need to drop a trans in and its 100 degrees where I'm at, please help guys.

Thanks

 

[Jackfre]

When all else fails...follow the instructions. Yes, you will loose a bit of refrigerant. Just commit to it and screw it off as quickly as you can. Your unit is pre charged for a specific length of line set. Check your manual for that info and compare it to your line-set length. Do it and put the trans in.

 

[JakeKohl]

there is a schraeder valve in unit where the gauge line connects. You just need to unscrew the gauge line as quickly as possible. It may help to physically hold inward pressure on the line with one hand (engaging the seal) while you turn the threaded collar with the other. Once the threads push the hose far enough to start leaking, reverse your pressure by pulling on the hose and unthread like heck. Depending on the design of the manifold, you might be able to get almost no release this way.

I can tell your automotive refrigeration background is with 134A systems and not with the older R12 systems! (but now I'm dating myself) ;-)

One tip: disconnect the low-side hose while the unit is running (it will see lower pressure at the connection). Disconnect the high side with the unit off and after allowing the high and low sides equalize for several minutes (it will see lower the pressure on the liquid connection).

Another tip: the design of the connection point is one of the differences between a budget manifold set and a more professional unit. It's easier to remove the better gauge with less refrigerant loss.

One last tip: you can also use one of these devices between the unit and your hose next time - they're made to allow these hoses to be attached and removed with as little loss as possible (check the thread type vs your system type...I didn't look at this one closely).
http://www.grainger.com/Grainger/Quick-Coupler-10U326?cm_sp=IO-_-IDP-_-BTM_BTB05209020&cm_vc=IDPBBZ2

 

[rlitman]

there is a schraeder valve in unit where the gauge line connects. You just need to unscrew the gauge line as quickly as possible.

This. Oh, and the schraeder valve is not designed to permanently contain the refrigerant (just like in your car's A/C). You must complete the job by putting the caps back on the fitting, with the proper torque.

 

[diyerforlife]

Thanks guys. I will unhook them when i get off work. One last question. Is there a torque wrench specifically for these type of lines? I have my good old craftsman 1/2 drive one with crows feet (3/8's FML) and a converter, but it felt way too tight when i was torquing the inside lines so i went off feel on the outside lines.

Thanks again. I'll post back when she's up and running.

 

[JakeKohl]

You would need a torque wrench with interchangeable heads (expensive)
http://www.belknaptools.com/adjusta...rchangeable-adjustable-drive-torque-wrenches/

You could get close with a crows foot adapter on a standard torque wrench but it would alter the torque reading (it would torque the fitting a little more than the wrench setting - but would be calculable with some dimensions on the crows foot adapter).

 

[diyerforlife]

Alright guys i unplugged her while she was running and all is good. She's blowing snow. I cant wait to use her on Sat while i install my transmission. Is it normal for the lines to condense up so bad? I mean, i know cars a/cs do, but i'm wondering if she's dripping in the walls? I mocked it up on the wall with the lines still exposed and she sweats pretty bad. She also sweats out by the port on the outdoor unit as well.

 

[JakeKohl]

Alright guys i unplugged her while she was running and all is good. She's blowing snow. I cant wait to use her on Sat while i install my transmission. Is it normal for the lines to condense up so bad? I mean, i know cars a/cs do, but i'm wondering if she's dripping in the walls? I mocked it up on the wall with the lines still exposed and she sweats pretty bad. She also sweats out by the port on the outdoor unit as well.

That's normal...but...you should have insulated the linesets before you ran them to reduce the heat loss/gain and prevent the circulation of air around the copper (from which the coolness extracts the moisture leading to condensation).

The outdoor unit / exposed lines will condensate - unless you want to go nutz with the insulation (not really worth it there).


DSC_3014 by Team Seacats, on Flickr


DSC_2774 by Team Seacats, on Flickr