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Old 10-04-09, 08:06 PM   #10
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Originally Posted by Xringer View Post
I won't be doing the whole install, but I want to do most of it.

I would also like to install and test the line-set tubing. Which does not look
very hard to do. I just wonder if I buy the tools (vac pump & R410A gauge set) will I ever use those tools more than once..
Well, only you can answer that one...

On the other hand, you might get inspired, even empowered, and hack all kinds of stuff.

... 'course, you could sell the stuff on ebay.

BTW, if you're going to test your line set, I think you'd be better with a micron gauge than an R-410a gauge.

What you'd do is to pump a good deep vacuum, like maybe sub-100 microns and see how well it holds over night. If, the next day your vacuum is maybe 90 to 120 microns, you're OK. If it's in the range of 700-2000 microns, you got some 'splaining to do.

Originally Posted by Xringer View Post
But, since I plan to call in a certified AC guy to release the R410A,
for the warranty sign-off. I'm wondering if I should skip testing the line-set
and just let him do it.?.
Your call...

Originally Posted by Xringer View Post
YES, I am very interested in every step of your install..
Did you take any pics?
No pics... I didn't realize the power of blogs at the time, so I didn't document it... and it's really so easy to do.

So first, while at the freight pick-up place, I visually checked the shipping cartons to see if there was significant damage. There was not any, so I accepted the shipment and signed for it. (It's much easier to reject the shipment at the freight depot)

Second, I got the beast home, and opened the boxed to check for internal damage. Everything checked out ok with the minor exception that there was a very minor crack in the plastic fan cover which I decided I could live with. I also went over the manifest to see that I had received everything I was supposed to receive.

I read all the instructions several times until I was satisfied that I understood everything I needed to do.

You'll need to drill a hole in the wall about 3" in diameter, and some forethought is called for. The indoor unit can have the lines dress in several different directions. I decided that coming straight out the back right side seemed to be the most logical. I had a site planned above a window that would have been quite unobtrusive, but there was a wall stud that prevented the desired placement of the unit. My house is small and old and after much consideration, I found a location that wasn't my first choice, but works well.

There's a metal plate that needs to be mounted it will carry the indoor unit. For condensed water to flow out through the drain tube, the metal plate, and thus the whole indoor unit needs to be leveled properly. I aginize over the mounting, not wanting any rattles when the unit operated, but there is virtually no vibration when the indoor unit is running, so my agonizing was misplaced.

There is a plastic tube through which the refrigerant tubes, the wire which communicates with the outdoor unit and the drain tube run. There's a jumbo plastic nut thingie that cinches it all down. Pretty neat, really.

So you hook up the wires, as per the instruction book, and run the copper lines, the wire and the drain tube out through the wall, and 'hang' the inside unit on the hooks that are part of the sheet metal. I think I got a bit worked up trying to make all this happen as it should, and it wasn't working and I was lifting and trying, and sweat was running out of my arm pits and down my sides, when the whole thing just 'thunked' right into place exactly as it was supposed to. Everything lined up perfectly.

I installed my little electric box outside, near the spot where the electric lines from the unit would most easily dress. My power was 120V because my unit was only 9,000 BTU. I verified my work at the master breaker box and at the box at the heat pump, then powered up just the box and assured that live,neutral and ground were where they belonged. All good.

There is a LRA rating of the compressor. LRA is an abbreviation of Locked Rotor Amps. It refers to the worst case of the compressor when the rotor is frozen and there is power to the the compressor. In this case, the breaker MUST NOT be rated higher than the LRA. The breaker also needs to be high enough to allow normal operation and start-up current peaks. Your instructions will make this simple for you by specifying the proper breaker rating. Don't use this breaker for anything other than you heat pump.

I located the outdoor unit where I wanted it, connected the wires from the heat pump electric box to the heat pump (breaker in "OFF" position, of course). I also hooked up the wires from the indoor unit as per the manual. I used di-electric grease on the terminals and connectors, since it's gonna be outside.

With regards to ester oil on flare fittings, I used some stuff recommended by a local HVAC supply store, for HVAC assembly, they all refer to as 'snot'. I verified that it was compatible with R-410a. I think that ester oil (verify compatibility) would be just fine.

My manual had torque specs for the flare fittings. The manual I downloaded did not have torque specs. I went with the torque specs.

I used flare wrenches where possible but needed to make a special wrench head to use with my torque wrench.

Here's a photo:

It's ugly, but worked very well.

I made sure that I hit the torque specs given in the manual that came with the unit. The amount of force required to hit the specs was more than I had anticipated.

I even let it rest for a few hours and went back to verify I had enough torque, everything was good.

The next stage is the pump down. You should have the proper gauges, including a micron gauge, and do a test pump with your equipment before you start to make sure everything is working well.

Make sure you put NEW VACUUM PUMP OIL in your vacuum pump right before you use it, as it is purposely hygroscopic and can quickly absorb atmospheric water.

So then I hooked up my manifold gauge set (with Bourdon type gauges as you pictured) and my vacuum pump and pumped it down. I didn't have my micron gauge yet so I was flying blind. I let it run for two hours to assure the best vacuum I could get.

At this point, I didn't know how much vacuum I really had because the Bourdon gauges do not read down to the low vacuum levels where you need them to indicate small changes.

Several weeks later, after I got my micron gauge, I did a mock-up of my pump-down setup, using the same equipment (except fo the heat pump) and NEW OIL and ran it again for the same time. I am happy to say that the vacuum I pulled was in the neighborhood of 80 microns, and quite good enough. But that was the first time I really knew that I had done it right. Not a good way to go.

But you really need to know your real vacuum when you are doing the real pump-down.

This should not be a faith-based situation!

So, after I did the pump down, I followed the instructions per the manual, admitted a small amount of R-410a and checked with soap bubbles. Then admitted the full R-410a load, used 'snot' in the valve covers, and tightened them down and tested.

Everything good.

On hindsight, there were procedures where I agonized too much, like the indoor unit wall mounting bracket.

There were also other areas where I should have agonized a bit more, like the pump down.

On the pump-down, I was lucky. If I had the micron gauge when I was doing the pump-down I would have been certain.

Certain is better than lucky.

Best Regards,

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Last edited by AC_Hacker; 10-05-09 at 03:00 AM..
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