Quote:
Originally Posted by
MrGreeno 
Funny that this thread popped up..
I just got an estimate for a mini-split for my 19'x15' HT... $3400!!!
I politely said "no thank you" and am looking at units on Amazon.
$560 shipped and all I need is a vacuum pump for a final connection, they seem to have some good reviews.
And that pump will cost you $300 minimum for a one time use tool. And do you know HVAC theory at a technician level? Do you WHY and HOW the vacumm pump is used? You should have a gauge set to check the charge and of course know how to read and interpret the results. Depending on the distance from the condenser to the room unit you may be short on Freon. The factory charge is based on a certain line set length.
Also, do you have a brazing touch as well as the skills to use it. Refrigerant tubing is silver soldered or brazed.
PLUMBING SOLDER IS NOT ACCEPTABLE.AND
Doing what you propose is
ILLEGAL. In order to work with CFC refrigerants you must have an EPA 608 license. And then you have to document any use of additional Freon or disposal of such. No vendor will sell you Freon without that license. They can't. Yes, you can buy parts, tools, even pre-charged condensers due to loopholes in the law. Selling, buying, owning an uninstalled precharged HVAC condenser is quite legal. Just don't open the valves, that's where the law is broken. Silly, isn't it. But that's the federal government at work.
Now all that aside I do my own HVAC work too. I have the pump and gauge sets as well as a drum of Freon R22. I justified it by having three HVAC systems and having to moved them twice during the HT build. It would have cost me over $5K to move these units twice. I am also an EE and have been around commercial units for years and did buy a HVAC technician training book and study it first. And I did not vent any Freon into the air. I did the "pump down" procedure properly.
Anybody can learn to do anything. I can't stand the attitude that some contractors have where they think their trade skills were given at birth. But HVAC is a lot more complicated than replacing a water heater. Just make sure you study and understand the technology first so you don't damage the new unit. Because if DIY installed, the manufacture most likely will void the warranty - especially the compressor which is what will fail with improper charging.
Also
ANYONE can get an EPA 608 license by taking a course and passing the test. It's no different than a driver's license. You don't have to be an experienced HVAC contractor to get an EPA license. Just pass the test. Some HVAC techs don't like it but that's the law.
Edited by Glimmie - 3/15/13 at 11:02am