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Author Topic: who does HVAC ?  (Read 1624 times)

7808

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who does HVAC ?
« on: August 12, 2009, 07:29:15 PM »
i got a central air unit related question -  friend of a friend remodled a home couple years ago from ground up and now getting forclosed, selling all there recently bought appliances, made a deal with me for the central air unit and high effciency furnace.   and i already bought all there other appliances.  ive installed a furnace before and have a little hvac expeience from work but not much, i DO have access to gauge manifolds and  some probly empty" propane grill sized" tanks that i think used to have refridgernt in them.. obviously were not going to call someone out to help un-installin it properly because were cheap and unsafe

so i im going to cut the power  at both breakers, disconnect/cut the wires,  but as for letting the pressure out i was considering putting on my full face mask and some gloves and axe'ing the copper lines and running   O0 but seeing as how i have access to shit i could probly use to do it safer can anyone explain?  i belive the smaller line is the high pressure line and the bigger one is low pressure.  rather then cutting i could probly hook the gauges up and just open them up and run off for a few minutes (how long would this take to empty?)  i also kinda remember somthing about traping all the pressure in the compressor or somthing so the lines shouldnt have much in them but im not sure if i can do this on residential shit or not? 
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patsmx5

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Re: who does HVAC ?
« Reply #1 on: August 12, 2009, 07:49:42 PM »
You just shut the king valve on the high side and let the compressor run and it will vacuum the system into the outside unit.
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Quote: Originally Posted by Adam Hopkins
There is no such thing as too much boost. You could have too little rod, piston, or sleeve. But never too much boost.

7808

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Re: who does HVAC ?
« Reply #2 on: August 12, 2009, 08:06:18 PM »
i figured that had to be some easy way thats good enough.  wheres the king valve?  by the a coil ? on the unit outside?
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patsmx5

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Re: who does HVAC ?
« Reply #3 on: August 12, 2009, 08:29:26 PM »
The king valves are on the outside unit, on the outside of it where the lines go out of the unit. They'll usually have a big hex cap ontop of them. Take the caps off and inside are the king valve, just use a allen wrench to turn them.
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Quote: Originally Posted by Adam Hopkins
There is no such thing as too much boost. You could have too little rod, piston, or sleeve. But never too much boost.

Adam Hopkins

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Re: who does HVAC ?
« Reply #4 on: August 12, 2009, 09:55:40 PM »
Your getting good advice from pat, just make sure thast you have the gauges on the big line and watch for when the pressure either reaches vacuum, or has stopped droping, or you hear a god awful sound coming from the compressor and then crank like hell to close the king valve. Already have the small line closed off and the big line halfway down with the tool already in the valve before you ever start to hold down the contactor.

Also another tip is that those copper lines do not use a standard plumbing solder. You have to get silver solder and a hot ass torch. You usually have to go to a HVAC supply store to get the solder.
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snarf

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Re: who does HVAC ?
« Reply #5 on: August 13, 2009, 01:23:38 AM »
Da problem is you need sooo many specialty tools to do this even half wright.  You need to cut the line with a tubing cutter so that it stays round, so you can braze it in later.  Also are you reusing the same line set?  Your going to need to put a vacum on it to get all the air and moisture out wen your done reinstalling it.  If the unit is not going to be installed properly than all that high eficency stuf is going to go out da window.  If any non-condensables are left inside than you could end up with a unit that run's all day and dosn't cool your house down.  Also if you have left over jugs of refigerant they have a one way valve in then and can't be reused.

I have a degree in hvac and have been doing it for years and I still run into headaches every now and then.  There is a good reason peaple are willing to pay me a TON of mony to do this for then.  Your better off paying some one to do the job right.
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7808

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Re: who does HVAC ?
« Reply #6 on: August 13, 2009, 02:53:45 PM »
  i dont see what fucking up da a/c would have to do with dat high effciently furnace,  they high because they dont waste heat out da roof in winter.. if i remember right. furnace will probly go in my garage anyways..  ac might too  O0

also you can always re cut dat copper 1" away from where it was hacked with a $5 tubing cutter.

i just need to get the a/c unit out of there, i will worry about installing it later, my house already has a/c but the one is older and possibly going out but i have a home warranty that covers all that shit i just want it cause its methhead cheap and newer
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